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How to get ultra-low gearing for gravel bike adventures

Out of the box, gravel bike gears are too high. Here's how to sort them out

Want lower gears on your gravel bike? We do, so we set about combining some parts that aren’t supposed to work together to get a massive gear range. Ssshh, don’t tell Shimano.

Gravel bikes are over-geared.

Typical gravel gearing

Out of the box, your typical gravel bike has a 50/34 chainset and an 11-32 cassette, giving a range of gears that’s fine on roads unless you’re riding somewhere very hilly, but with limitations you very quickly bang up against when you venture off road.

That bottom gear is far too high. When I head out of Cambridgeshire to the gentle slopes of Suffolk I find myself wanting something lower for longer climbs. When he tested Trek’s new Checkpoint David Arthur — who is much, much fitter than me — found he had to get off and walk when riding the Cotswolds. "Compact chainsets have no place on gravel bikes," he said in a road.cc office discussion of the issue.

In gear inches that typical 50/34 & 11-32 set up has a low of 29in and a high of 123in — a 428% difference between smallest and largest.

Not only is 29in too high, but so is 123in. You’re never going to use that top gear off-road and you’re not going to get much use from it on the road either. (I could digress into a rant here about component makers supplying almost nothing but pro-class top gears on bikes that will never see a sprint for the line, but that's a topic for another time.)

Let’s try and cook up a better gear selection.

Sprockets

gravel gearing 4.JPG

The arithmetic of gearing makes a change of sprockets the most effective way to get lower gears, and in the last few years Shimano and others have made available 11-speed cassettes with ranges of 11-36, 11-40, 11-42 and even 11-46, all with the same sprocket spacing as our gravel bike’s 11-32.

But there’s a problem: no Shimano road derailleur is rated to work with a sprocket larger than 34-tooth. How about a mountain bike derailleur? Nope. For some reason known only to Shimano, their 11-speed road and mountain bike shifting systems aren’t compatible. Back in the nine-speed days you could use a Deore XT rear derailleur on a road bike if you wanted to, but that’s not the case for 11-speed. What to do?

Well, Shimano’s assessments of derailleur capacity have always been conservative. When Shimano say something won’t work, that often means it won’t work to the high standards Shimano sets, not that it won’t work at all.

And this is what we find with Shimano’s latest GS line of 11-speed 'Shadow' road bike rear derailleurs. The £58 Ultegra R8000 medium cage derailleur (RD-R8000-GS for fans of part numbers) is not supposed to be able to shift to a sprocket bigger than 34-tooth, but YouTube is full of backroom tinkerers demonstrating that it works just fine with an 11-speed 11-40 cassette.

gravel gearing 5.JPG

The 105 GS rear derailleur looks geometrically identical to the Ultegra, but is typically £20-£30 cheaper. Could this be a cheap way of getting really low gears on a gravel bike?

To find out, I bought a 105 RD-7000-GS rear derailleur (£36.95), an SLX CS-M7000 11-40 cassette (£40.77) and an 11-speed Shimano chain (£19.01). I thought about pushing my luck and going for 11-42, but I wussed out. Maybe another time.

The cassette is a big beast of a thing. I don’t think I’ll ever quite get used to just how huge a 40-tooth sprocket is, never mind the 50-tooth and bigger sprockets now available for mountain bikes. Rotor’s 13-speed system includes a 52-tooth sprocket. When Ah were a lad, that were a chainring!

The 11-40 cassette fits straight on the hub of my Prime RR-28 wheels in place of the 11-32, and the 105 R7000 GS rear derailleur substitutes perfectly for the 105 5800 GS unit. To give the derailleur the best chance of handling the big sprocket I dial the B-tension ‘angle of dangle’ screw all the way in, pulling the body of the derailleur as far back as it will go. I tweak limit screws and cable tension and run carefully up and down the gears.

Success! It shifts just fine to that huge sprocket, clicking into place as if it were designed to.

I’m still running the original chain, so I try shifting the front mech into the big ring. Bad idea. It’s immediately obvious that things are going to go seriously wrong if I try to use the big/big combination.

I ditch the original chain and fit the new one I’ve bought. At this stage I don’t have the chainset I want to use, but I want to ride this weekend. The existing chain would probably work fine with the 46/30 chainset I’m waiting for.

Out on the road and the trail, the difference is soon obvious. I keep glancing down, thinking I must be getting close to the lowest gear, and finding I’m actually in the middle of the cassette.

This isn’t very surprising. The 34/25 combination on the old set-up, 37 gear inches, was two gears from the lowest. In the new set-up’s 34/24 (38.3 inches) I still have four lower gears.

My proving ride takes riding buddy Al and me down a narrow, wet bridleway into the village of Linton, home of the excellent Linton Kitchen cafe. We’re in the middle of a drought, but the leaky water tower at the top of the hill means there’s always a stream here to flick mud up at you.

Fuelled by coffee and carrot cake, we tackle the bridleway in reverse. My state of fitness could be accurately described as woeful, but nevertheless, it’s a doddle. The average gradient of the top section is about 10 percent, which by Cambridgeshire standards makes this a Proper Hill™, and climbs on trails never have perfectly even gradients. I pootle up it easily. Al zooms on ahead. Not having a 34/40 low gear he doesn’t have any choice, I tell myself. It’s nothing to do with him being a lot fitter than me. Ahem.

For fans of gear charts, this is where we started:

  11 12 13 14 16 18 20 22 25 28 32
50 122.7 112.5 103.8 96.4 84.4 75.0 67.5 61.4 54.0 48.2 42.2
34 83.5 76.5 70.6 65.6 57.4 51.0 45.9 41.7 36.7 32.8 28.7

 

And this is where we are now:

  11 13 15 17 19 21 24 27 31 35 40
50 122.7 103.8 90.0 79.4 71.1 64.3 56.3 50.0 43.5 38.6 33.8
34 83.5 70.6 61.2 54.0 48.3 43.7 38.3 34.0 29.6 26.2 23.0

 

In short, we’ve stretched the range from 428% to 538% with no downside except for a bit of extra weight. I think the gaps between gears are still reasonable; more on that later.

To go even lower (and wider) we’re going to need a change of chainset.

Chainset

One thing I wanted to avoid in this project was trying to persuade road and mountain bike components to work together. There was a time when you could cross the streams easily, but Shimano’s road and off-road derailleurs now have different geometries, so you can’t use mountain bike mechs with road shifters without some sort of cable pull converter. That’s a level of bodging I wanted to avoid.

gravel gearing 6.JPG

That means the chainset can’t be too small or a road front mech won’t work well with it because the curves of the cage won’t follow the shape of the chainring. I therefore settled on one of FSA’s Adventure chainsets in a 46/30 'sub-compact' configuration. That’s enough of a difference to be worth the hassle, but not so much that the shifting will be balky.

FSA makes several 46/30 cranksets, from the high-zoot K-Force and SL-K Modular units with carbon fibre arms to the inexpensive Tempo CK Adventure cranks that fit old-school square taper bottom brackets. In the middle, at a sensible price and weight, there’s the new Energy Modular BB386 Evo crankset (£200), with hollow forged aluminium arms, so I went for one of those.

gravel gearing 3

Fitting was straighforward, with just one caveat: the position of its mount stopped the front derailleur going quite as low as I’d have liked. The front derailleur cage ended up a couple of millimetres higher than Shimano recommends.

That’s another reason not to use a mountain bike chainset. If you have a braze-on front derailleur it’s unlikely you’d be able to get it low enough for the 38-tooth outer of a typical mountain bike double — and of course you probably want a higher top gear than the 38 ring would provide.

The gear range

With the FSA 46/30 chainset, the resulting gear range is massive. Here’s what it looks like:

  11 13 15 17 19 21 24 27 31 35 40
46 112.9 95.5 82.8 73.1 65.4 59.1 51.8 46.0 40.1 35.5 31.1
30 73.6 62.3 54.0 47.6 42.6 38.6 33.8 30.0 26.1 23.1 20.3

 

That’s a 558% range, much bigger than the 428% we started with and most of the extension is at the bottom of the range where it’s most needed. But we’ve also preserved a decent high gear for those zoomy road descents.

Only mountain bikes have lower gears. While single-chainring gearing has all but taken over on mountain bikes, some double-chainring bikes are still available, with gearing down to a positively wall-climbing 22/42 (around 15 inches, depending on wheel and tyre size).

Those systems sacrifice the high end though. With a 36/11 or 38/11 top gear (around 90 inches) you’re going to be doing quite a bit of coasting on descents.

Riding

Out back, the 105 rear derailleur clicks effortlessly and without fuss from one sprocket to another, even when it gets to the final 35 and 40-toothers that it's not supposed to be able to handle. Up front, the old 5800 front mech flips easily between the 46 and 30 chainrings.

This set-up is noticeably gappier than the one it replaced. There are a couple of 15 percent jumps between gears, and the gap between the two highest, provided by the 11 and 13 sprockets, is a whopping 18 percent. I can live with that, but if you're a finely-tuned pedalling machine who struggles to change cadence more than a few percent, you're going to find it a bit jarring.

The big advantage of a gear set-up like this is that it reduces the need to hit the redline every time you go uphill. Back when I was doing a lot of mountain biking, I was always the guy pootling along at the back while everyone raced up the first couple of hills. And I was the one with plenty in the tank at the end of the ride, sitting on the front towing everyone for the last 10 miles home.

Tweaks and alternatives

If Shimano's 11-40 cassette is just too gappy for you, SRAM makes an 11-36 11-speed cassette (£63.05) that shrinks the biggest gap by dropping a 12 between the 11 and 13. With a sub-compact chainset like the FSA that still yields some usefully low gears. SRAM says the 11-36 is only compatible with single-chainring gear systems, but that's almost certainly a matter of marketing rather than engineering.

If you wanted to go electronic, you could assemble a Di2 version of this transmission without breaking any of Shimano's rules. The XTR and Deore XT electronic rear derailleurs work with Ultegra and Dura-Ace Di2 drop-bar shifters. The Di2 rear derailleurs are rated for a 42-tooth sprocket in a 2 x 11 system, so you could go slightly lower than I have. I'd love to hear from anyone who's tried this.

WolfTooth RoadLink

If you wanted to save money, you could use a £22.95 Wolf Tooth Roadlink to extend the capacity of your existing rear derailleur. According to the manufacturer, the Roadlink will extend any non-Shadow GS rear derailleur to work with an 11-40 cassette.

That'll work if you're still running 10-speed too. SunRace makes a couple of 11-40 10-speed cassettes, the £30.59 MS3 and lighter MX3 (£40).

Conclusion

I think the system I’ve put together provides the best wide-range gravel bike gearing currently available, at a sensible price. It's very handy that it can be put together in two stages and the most effective one — changing the sprockets — is the cheaper.

There are plenty of arguments for alternatives, though. People fitter than me like the simplicity of 1 X 11 systems and are prepared to sacrifice a bit of range to get an easy life, and more power to them.

It's a pity Shimano doesn't make it easier to put together a wide-range system like this. They could offer SGS versions of the Ultegra and 105 Shadow rear derailleurs, for example, with the capability to handle 11-40, 11-42 or even 11-46 cassettes. And they need to offer chainsets with smaller rings and front derailleurs that work with them. Maybe next year, eh?

John has been writing about bikes and cycling for over 30 years since discovering that people were mug enough to pay him for it rather than expecting him to do an honest day's work.

He was heavily involved in the mountain bike boom of the late 1980s as a racer, team manager and race promoter, and that led to writing for Mountain Biking UK magazine shortly after its inception. He got the gig by phoning up the editor and telling him the magazine was rubbish and he could do better. Rather than telling him to get lost, MBUK editor Tym Manley called John’s bluff and the rest is history.

Since then he has worked on MTB Pro magazine and was editor of Maximum Mountain Bike and Australian Mountain Bike magazines, before switching to the web in 2000 to work for CyclingNews.com. Along with road.cc founder Tony Farrelly, John was on the launch team for BikeRadar.com and subsequently became editor in chief of Future Publishing’s group of cycling magazines and websites, including Cycling Plus, MBUK, What Mountain Bike and Procycling.

John has also written for Cyclist magazine, edited the BikeMagic website and was founding editor of TotalWomensCycling.com before handing over to someone far more representative of the site's main audience.

He joined road.cc in 2013. He lives in Cambridge where the lack of hills is more than made up for by the headwinds.

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90 comments

Avatar
pockstone replied to KoenM | 4 years ago
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KoenM wrote:

I just bought a Gravelbike from Ribble, but as I use it 80% of the time as a winter roadbike therefor I have 2 sets of wheels 1 with 11-32 and 30mm tires and one with 11-34 and 38mm tires so I can easly change it without having to adjust it. If I ever will use it more for gravel I probably buy a new Shimano GRX RX810 48/31 crankset so I would still have enough of a high gear and alot lower than the 50/34 I now have, but as I said before that will only be if I go gravelriding more.

I've just bought and fitted (just waiting for the chain...and weather... to dry so not ridden yet,) an FSA 46 -30 chainset for my Pinnacle Arkose. Hopefully the last act in a long saga of incremental increases to cassette size and swopping the road derailleur for a DeoreXT MTB mech.

If you plan on swopping your chainset, take a look at the Miche Graff chainset reviewed here this week. It appears to be a straight swop into a Shimano BB . I wish I'd known about it a few weeks ago.

 It might not have been cheaper than the FSA, but I could have swopped my expensive to replace and fairly short lived FSA BB for a Shimano one and saved about 200g in the process. Not a lot of weight, but it would have only cost me about a tenner extra, if that. Not a bad Hairsine ratio, and interchangeable with the 105 chainset on my road bike too.

Beware the Shimano GRX, I think it may need a matching GRX front derailleur. (Although I can't see why any front mech wouldn't be adjustable to suit.)

Avatar
zero_trooper replied to kil0ran | 4 years ago
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kil0ran wrote:

Inspired by this article and the recent review of the Miche Graf chainset I've just upgraded my Fairlight Faran. This has been set up for a while with 40mm WTB Nanos, 50/34-11/28 on Tiagra shifters, 105 chainset, and R7000 front mech. So a proper frankenbike.

I've now shifted this to an FSA Tempo Adventure 46/30 with the Tiagra 12-34 cassette (already had the Tiagra long-cage mech). I really like the look of the Tempo Adventure and have made peace with installing a square taper BB - this bike isn't about getting the weight down.

Despite the drop from 50 to 46 I haven't needed to drop the front mech. It's way out of Shimano's tolerances but shifting is absolutely fine - I'm amazed that I didn't even have to tweak the cable tension. FWIW the Tempo with a 118mm axle maintains the same chainline as the 105 with a Hollowtech BB.

Very noticeable difference on the couple of rides I've done so far. I'm spending a lot more time in the big ring on the roads but being able to stay seated on offroad climbs is fantastic. Need to get fitter because I find I can't spin a granny gear at a high cadence for long enough for some of my climbs - long, deep-rutted chalky/flinty stuff on Cranborne Chase/Salisbury Plain. Also need to get better at bike handling! Riding slow in ruts surrounded by nettles and thistles is tricky!

Has really re-energised my cycling though. I've also swapped to a Brooks Flyer saddle which I find really suits me and I've started riding in plain clothes as it were (i.e. no padded shorts)

Wondering if I can swap the 12 ring for an 11? Not really necessary on the WTB Nanos as they're so draggy on the road and I'm not doing long distances but I do find I spin out the 46/12 if I'm feeling like smashing it. Doesn't help that my run back home from my usual haunts is pretty much downhill. 

That’s a great effort Kil0ran! As you’ve said, re-energised your riding. And don’t forget, having a square taper BB is so ‘on trend’ as my fashionista daughters would say.

Please give us a further update in a few months. I’ll expect you in plaid shirts by then 

Avatar
dmartel replied to Sparkyspice | 2 years ago
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Thank you so much for this. I have the same configuration (AbsoluteBlack sub compact, long cage derailler) and it gave me the confidence to go to a 42 tooth cassette. Used 116 links ou of 118 links on a new chain (!).
Works flawlessly.

Avatar
Tones0000 replied to CXR94Di2 | 4 years ago
0 likes

CXR94Di2 wrote:

Just use XT/XTR derailleurs and the new GRX crankset job donewink

 

Do you use synchro shift on your install? I did some calculations and it looked like you need to be careful when running cranksets with 16 (or 17) teeth when the MTB etube software assumes you are using 10 tooth differences. It appeared that users would be limited to only a few FD shift points that weren’t all that optimal to ensure that the di2 system didn’t shift “down” into higher gear or shift “up” into a lower gear.

Avatar
kil0ran replied to pockstone | 4 years ago
1 like

pockstone wrote:

KoenM wrote:

I just bought a Gravelbike from Ribble, but as I use it 80% of the time as a winter roadbike therefor I have 2 sets of wheels 1 with 11-32 and 30mm tires and one with 11-34 and 38mm tires so I can easly change it without having to adjust it. If I ever will use it more for gravel I probably buy a new Shimano GRX RX810 48/31 crankset so I would still have enough of a high gear and alot lower than the 50/34 I now have, but as I said before that will only be if I go gravelriding more.

Beware the Shimano GRX, I think it may need a matching GRX front derailleur. (Although I can't see why any front mech wouldn't be adjustable to suit.)

You need to be able to set the front mech up with +2.5mm extra throw, so I'd imagine it depends on limit screws and how accurately you can set up your front mech in the first place. Might be a challenge with an 11-speed setup due to finer tolerances. The latest Shimano front mechs (R7000/8000 and probably Dura-Ace) are already designed for a wider chainline. In my experience 2.5mm shift is easily achieved through accurate cable tension/limit screws/barrel adjusters so you might be OK with your existing mech. The new GRX mechs aren't particularly expensive so it's easy enough to experiment with your existing setup and get one if required.

Avatar
kil0ran replied to zero_trooper | 4 years ago
0 likes

zero_trooper wrote:

kil0ran wrote:

Inspired by this article and the recent review of the Miche Graf chainset I've just upgraded my Fairlight Faran. This has been set up for a while with 40mm WTB Nanos, 50/34-11/28 on Tiagra shifters, 105 chainset, and R7000 front mech. So a proper frankenbike.

I've now shifted this to an FSA Tempo Adventure 46/30 with the Tiagra 12-34 cassette (already had the Tiagra long-cage mech). I really like the look of the Tempo Adventure and have made peace with installing a square taper BB - this bike isn't about getting the weight down.

Despite the drop from 50 to 46 I haven't needed to drop the front mech. It's way out of Shimano's tolerances but shifting is absolutely fine - I'm amazed that I didn't even have to tweak the cable tension. FWIW the Tempo with a 118mm axle maintains the same chainline as the 105 with a Hollowtech BB.

Very noticeable difference on the couple of rides I've done so far. I'm spending a lot more time in the big ring on the roads but being able to stay seated on offroad climbs is fantastic. Need to get fitter because I find I can't spin a granny gear at a high cadence for long enough for some of my climbs - long, deep-rutted chalky/flinty stuff on Cranborne Chase/Salisbury Plain. Also need to get better at bike handling! Riding slow in ruts surrounded by nettles and thistles is tricky!

Has really re-energised my cycling though. I've also swapped to a Brooks Flyer saddle which I find really suits me and I've started riding in plain clothes as it were (i.e. no padded shorts)

Wondering if I can swap the 12 ring for an 11? Not really necessary on the WTB Nanos as they're so draggy on the road and I'm not doing long distances but I do find I spin out the 46/12 if I'm feeling like smashing it. Doesn't help that my run back home from my usual haunts is pretty much downhill. 

That’s a great effort Kil0ran! As you’ve said, re-energised your riding. And don’t forget, having a square taper BB is so ‘on trend’ as my fashionista daughters would say.

Please give us a further update in a few months. I’ll expect you in plaid shirts by then 

Proper shiny metal cups on the square taper BB, looks great! Also removed the need for a spacer - my Faran is a prototype frame and the BB shell measured 67mm in my calipers, so always needed a 1mm spacer for hollowtech.

Thing is, now I'm thinking about switching to 650B wheels and back to Gravelking SKs for non-muddy stuff. Probably pointless as I'll only get a handful of rides before autumn turns everything to slosh and the Nanos come into their own.

Out again this morning, middle of nowhere (by south-east standards), big climb, birds of prey circling overhead, view across at least three counties at the top of the climb. Bliss. Also had a gerrofmylaaaand moment with a gamekeeper, oops (he was right, I'd missed the bridleway)

I'm going to ride (gulp) my road bike tomorrow. Time I tried my Cambium C17 in standard clobber.

Best of all, freeing up the 105 chainset gave me enough bits to build my old Triban 3 as a Zwift bike so I got to do some spannering today too.

 

Avatar
CXR94Di2 replied to Tones0000 | 4 years ago
0 likes

Tones0000 wrote:

CXR94Di2 wrote:

Just use XT/XTR derailleurs and the new GRX crankset job donewink

 

Do you use synchro shift on your install? I did some calculations and it looked like you need to be careful when running cranksets with 16 (or 17) teeth when the MTB etube software assumes you are using 10 tooth differences. It appeared that users would be limited to only a few FD shift points that weren’t all that optimal to ensure that the di2 system didn’t shift “down” into higher gear or shift “up” into a lower gear.

 

Yes I use Synchro 

On twin chainrings I use it to stop the extremes of cross chaining and on my triple setup to keep the chain straight as possible.  I understand the shift points can be misplaced especially when using non standard gearing.  You can with a little experiment tweak the shift points to match your own preferred style of riding

Avatar
arrhythmiarules replied to kil0ran | 4 years ago
2 likes

kil0ran wrote:

 had a gerrofmylaaaand moment with a gamekeeper, oops (he was right, I'd missed the bridleway)
 

Of topic but.........  In Scotland gamekeeper would not be grumpy and would likely have welcomed you and been chatty.  We have a right to roam responsibly whereever.  It should be a right all over. 

Avatar
morlbo | 5 years ago
0 likes

Ok. first of all sorry for my english language. and sorry for late commenting.

Now, first problem I want to bring is not the rear mech itself SM105GS and chain climb over a 40t end position, but the overall capacity of the drivetrain, which is supposed to be 37t.

Now a 46/30 can be surely called a low gearing and 20.8 Gear inches is a good MTB wall climbing gear indeed, if we want to put a 19 Gear inches limit from the triple era: granny 24t front vs 36t last position cassette, what I call super-low.

558% too is a great achievement but not in a 45t drivetrain. I'm Asking me how you can manage it, with a 37t RD, and a Wolftooth even if want to expect a +5t from it.

It seems to me your chain is quite short, and a MTB RD must come in.

A more "standard" 36/20 11-36 has 536% ratio in "just" a 39t drivetrain easyer RD climb and more manageable +2t over the RD capacity.

Personally I can't live without 11-12-13-14-15 in flat lands riding slick wheeled. I my opininion a compromise can be found in a bigger jump in the FD, 17t or 18t even in low gearing. Most can feel it uncomfortable, when swapping chain rings and have to adjust +-6 gears to compensate.
But in this way I can keep my precious narrow speeds, and get a respectable 506% to 509% respectively 20.0-101 38t and 20.8-106 39t managed by a 39t road RD capacity, instead triyng to build a MTB from gravel road bike.

http://goo.gl/FwYRhL

Avatar
Dominic Schulz | 5 years ago
0 likes

I use that mentioned SRAM PG 1170 11-36 cassette on my ultegra 8000 equipped gravel bike (with a compact) and it works absolutely fine. Thats plenty of a low-down gear already, however i just never ever used the top gear, so a  less-than-compact front chainset would probably be a good idea as soon as i start touring with a big of extra wheight in the bike. i wouldnt lile bigger jumps between gears on the cassette btw. Keeping an eye on that FSA crankset. there is also the option of using absolute black 30/46 chainrings if you already use a recent shimano road crank. they have a special design to fit the small ring to the 110mm cranks. 

Avatar
littlemig replied to Dominic Schulz | 5 years ago
0 likes
Dominic Schulz wrote:

I use that mentioned SRAM PG 1170 11-36 cassette on my ultegra 8000 equipped gravel bike (with a compact) and it works absolutely fine. Thats plenty of a low-down gear already, however i just never ever used the top gear, so a  less-than-compact front chainset would probably be a good idea as soon as i start touring with a big of extra wheight in the bike. i wouldnt lile bigger jumps between gears on the cassette btw. Keeping an eye on that FSA crankset. there is also the option of using absolute black 30/46 chainrings if you already use a recent shimano road crank. they have a special design to fit the small ring to the 110mm cranks. 

I have a similar setup with a compact but r7000 mechs and 5800 shifters. All good. I found lowest gear of 34-34 was not quite low enough for a few sections of where I ride off road. The 11-36 helps. I didn't use road link. Just had to be careful with chain length and then adjust the b screw. All seems to function very well.

Avatar
bdr | 5 years ago
0 likes

I tried the very same setup on my Kinesis Tripster AT and was not able to get satisfactory shifting. Setup: SpaCycles triple TD-2 crank with 46-30T chainrings, Ultegra RX-800 RD, 11-40T SLX cassette. Shifting does work fine with a Wolftooth Roadlink DM, although there's no chain tension in the small-small combination. Chain length was determined by the big-big measuring method. I cannot remove any more links.

Running an 11-40T casette with the stock R7000, R8000, RX-800 derailleur will be highly dependant on your particular derailleur hanger. 

Avatar
x7zise | 5 years ago
0 likes

Great article, thank you, very inspiring, especially for my arhtrosis knee!

Here's what I did: I installed on my Ridley X-Trail Alloy 2018 a  FSA Energy Modular BB386 Evo crankset 46/30, a SRAM PG 1170 11-36 cassette linked with a Wolf Tooth Roadlink to the pre-installed Shimano 105 RD-5800-GS medium cage rear derailleur. That was quite exciting since I had not done interventions of such a scale on my bikes before (thanks to youtube). Beside minor problems (shifting vom13 to 12 to 11 teeth is a bit on the slow side) it works. [Edit: I removed the Roadlink and now the system works just fine.] The difference between the single cogs is at some points quite big (I espescially do not like the 19 to 22 jump) but I suppose that is the trade off in such a set up.

Avatar
pancake replied to x7zise | 4 years ago
0 likes

x7zise wrote:

Great article, thank you, very inspiring, especially for my arhtrosis knee!

Here's what I did: I installed on my Ridley X-Trail Alloy 2018 a  FSA Energy Modular BB386 Evo crankset 46/30, a SRAM PG 1170 11-36 cassette linked with a Wolf Tooth Roadlink to the pre-installed Shimano 105 RD-5800-GS medium cage rear derailleur. That was quite exciting since I had not done interventions of such a scale on my bikes before (thanks to youtube). Beside minor problems (shifting vom13 to 12 to 11 teeth is a bit on the slow side) it works. [Edit: I removed the Roadlink and now the system works just fine.] The difference between the single cogs is at some points quite big (I espescially do not like the 19 to 22 jump) but I suppose that is the trade off in such a set up.

Again, wonderful read, and practical!  Thank you!

I too have a 2018 Ridley XTrail C50 with 105 deraileurs and Shamino crank.

I want to confirm if I'll need to change out my BB and if so which one would you suggest.

Will I also need any special adaptors to do this job?

I noted above the member used his existing 105 RD-5800-GS medium cage rear derailleur...is this pushing it and should I get the recommended deraileur as noted in the article if I want to go to the 11-40 deraileur.

Thanks,

P

Avatar
deepakvrao | 5 years ago
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My wife and I live in India, but frequently travel to the Alps, Jura and the Pyrenees. We usually carry luggage on our bikes. These are regular titanium road bikes with regular road gearing. We also do some rides off road, and that with luggage means we 'need' a lower gearing.

When we travel, I swap out our regular cassettes, and put on a 11-36 cassette on mine, and a 11-40 on my wife's. 

The setup is Rival shifters, SRAM Via GT [an odd SRAM RD which can take a 36 cog cassette], and on my wifes bike, I put on a Roadlink for the 40 cassette.

Was wondering if I can put on a 11-46 with the same set up. Any ideas?

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pratn0 | 5 years ago
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I'm currently running a DI2 XT derailleur on an sram 11 - 42 cassette(left over from the old setup)  on a 1x 42 front chain ring (soon to be absolute black oval).  no chain catcher the clutch seems enough as not had any chain drops yet.

I'm running the R785 STI's and have to sprinter blips soldered into the cabling of the R785s that sit under the top for stealth shifting changes while climbing . i've configured them to change down on the left buttons and up on the right.

I've kept the MT800 display on the bars so i have connectivity from the system though Bluetooth to my head unit and phone.

Had no issues with the shifting and the system has been solid.  love it and now looking how i can get Di2 on the road bike on the cheap.

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vanderlay | 5 years ago
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Hi John

Great article. I’m running 46/30 FSA modular front and 11-34 Ultegra 11 speed rear at the mo. I’d like to go to 36 or 40 at the rear but isn’t derailleur capacity an issue for chain length? Do you need to avoid small/small or big/big completely? I worry that I’ll forget and end up with a mangled rear mech and wheel!

Cheers

Chris

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twelvestocks | 5 years ago
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I usually refer to what the article refers to as capacity as the max tooth of the derailleur. What I normally consider capacity relates to the amount of chain that the derailluer can wrap, given the difference in distance around the smallest ring and sprocket combination compared to the biggest.

I've found that while Shimano are conservative in their quoting of max tooth (as correctly stated in the article), the capacity they quote is accurate. This can mean that if you put a bigger cassette on and then set your chain length to be able to access the big-big combination, you can then be unable to get to some of the smaller sprockets when on the small chainring. The chain may be slack running the risk of coming off and/or slapping on the chainstays. 

I've found this using an RX9000 derailleur on a Specialized Roubaix with a 50-34 compact chainset. I fitted an 11-36 cassette (only 2 teeth bigger than recommended). Quoted capacity for this derailleur is 39 teeth. My setup needs 50-34 + 36-11 = 41 teeth. I find that I can't use the small-small combination. This is a cross chained combination to be avoided anyway and so I just live with it. 

I'd quite like to find a way to create or buy a 48-34 or 46-32 chainset and not have this small problem, but I've yet to work out how to do it. 

 

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Argos74 | 5 years ago
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Y'all are doing the work of Satan.  Carry on.

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Turaco | 5 years ago
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Nice piece. Sadly it only arrived just after I went down the XT derailleur, 11-42 cassette, tanpan shifter pull converter route….
Given the chance again, I’d go the route you have described, though I’d be tempted to opt for the Ultegra RD-RX805-GS derailleur with the mtb style clutch. The XT derailleur route works fine, but it isn’t really practical if you want to keep converting between mountain bike and road cassettes. 
One issue I found that will apply to the 11-40 cassette with a 105 derailleur is that Shimano 11speed mountain bike cassettes have a slightly smaller pitch than their 11speed road cassettes. The whole cassette is 1.85 mm narrower. This meant I needed to put in a spacer in to hold the cassette tight its hub.
 

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D-Squared | 5 years ago
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My gravel bike has a 40 chain ring and 10-42 cassette. That covers everything I encounter on the roads it is intended for. 40x42 gives me 25 gear inches that will take me up most hills - it takes me up a couple of regular 18% climbs seated (which I need to be to keep weight on the back wheel in the loose stuff). And the 40x10 is all I need for a fast ride on the tarmac on the way to my dirt destinations. Only drawback (and it applies to the setup described in this article too) is that my gravel bike inevitably tempts me to push the boundaries into places where I really should be on the MTB

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rogermerriman replied to D-Squared | 5 years ago
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D-Squared wrote:

My gravel bike has a 40 chain ring and 10-42 cassette. That covers everything I encounter on the roads it is intended for. 40x42 gives me 25 gear inches that will take me up most hills - it takes me up a couple of regular 18% climbs seated (which I need to be to keep weight on the back wheel in the loose stuff). And the 40x10 is all I need for a fast ride on the tarmac on the way to my dirt destinations. Only drawback (and it applies to the setup described in this article too) is that my gravel bike inevitably tempts me to push the boundaries into places where I really should be on the MTB

 

Ah not the only one, my gravel bike and the CX before it remind me of the MTB's I grew up on, oddly I find its the tyres that fail, nomally sidewall rips! I have been trying not to push so hard!

 

with that in mind the 32-32 has been fine in this dry weather! be a touch over geared come winter!

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Shades | 5 years ago
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My hybrid/tourer MTB triple chainset (Deore I think) needed replacing.  I wanted to simplify things and the mechanic came up with a Shimano SLX set-up; 38/28 with 11-42 cassette.  Good low gears for hills and enough to cruise along the flat.  Not a set-up that I've seen on a bike in an LBS.

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CXR94Di2 replied to Shades | 5 years ago
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Shades wrote:

My hybrid/tourer MTB triple chainset (Deore I think) needed replacing.  I wanted to simplify things and the mechanic came up with a Shimano SLX set-up; 38/28 with 11-42 cassette.  Good low gears for hills and enough to cruise along the flat.  Not a set-up that I've seen on a bike in an LBS.

I was running a 40/28 XT crankset but found I had too high a cadence on the flats or slight decline to keep up with guys on compact crankset, so I upgraded the outer ring to 44t which was much better, almost perfect setup for me. But I then wanted even more speed and reduced cadence, so I upgraded my setup to triple with 48t outer chainring. (see above)

I now have a bike (Kinesis Tripster V2) which I can use for fast flat riding 22+mph and with even lower gearing than my MTB double crankset for alpine climbs, the chain line is much improved with less chain deflection, being Di2 I can program the shift sequence to chain alignment optimal.

My range in gear inches. is 17" to 115"

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CXR94Di2 replied to CXR94Di2 | 5 years ago
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CXR94Di2 wrote:
Shades wrote:

My hybrid/tourer MTB triple chainset (Deore I think) needed replacing.  I wanted to simplify things and the mechanic came up with a Shimano SLX set-up; 38/28 with 11-42 cassette.  Good low gears for hills and enough to cruise along the flat.  Not a set-up that I've seen on a bike in an LBS.

I was running a 40/28 XT crankset but found I had too high a cadence on the flats or slight decline to keep up with guys on compact crankset, so I upgraded the outer ring to 44t which was much better, almost perfect setup for me. But I then wanted even more speed and reduced cadence, so I upgraded my setup to triple with 48t outer chainring. (see above)

I now have a bike (Kinesis Tripster V2) which I can use for fast flat riding 22+mph and with even lower gearing than my MTB double crankset for alpine climbs, the chain line is much improved with less chain deflection, being Di2 I can program the shift sequence to chain alignment optimal.

My range in gear inches. is 17" to 115"

Ive gone onto a triple now 48/36/26 with Di2 XTR derailleur, for even better climbing and higher top speed

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CXR94Di2 | 5 years ago
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I run XT Di2 on my bike, but now upgraded the front derailleur to Triple XTR. I have a crankset of 48/36/26. and either run 11-32 for general riding or 11-40 Cass for alpine climbs

All setup with 'Syncro Shift' so there is no cross chaining. In fact the drive line is superior to a double crankset

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arrhythmiarules replied to CXR94Di2 | 4 years ago
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CXR94Di2 wrote:

I run XT Di2 on my bike, but now upgraded the front derailleur to Triple XTR. I have a crankset of 48/36/26. and either run 11-32 for general riding or 11-40 Cass for alpine climbs All setup with 'Syncro Shift' so there is no cross chaining. In fact the drive line is superior to a double crankset

 

Now I like that set up.  Thanks.  You have answered some of my questions about Di2.
 

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Bmblbzzz | 5 years ago
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Yean, ^^ riding "unsuitable bikes" in unsuitable places should be done. Occasionally! A bit of "comedy off-roading". But maybe not as a regular thing. 

Triples, yes. But they're becoming rare as OME, which means that if you're altering a stock bike – as opposed to building up from scratch – you're almost certainly going to have to get hold of a triple shifter, which ain't cheap. 

Oh, and mudguards are good too!

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alexb | 5 years ago
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I spent a happy few hours on Sunday riding NCN21 from around Crystal Palace down to Eridge, on my audax bike running full-length mudguards and road tyres (700x28c) with a 30 speed Campag triple set up.

Despite what Sustrans will have you believe, this route involves quite a lot of off-road trails, some quite narrow and loose. I was amazed at what I could clear with 30x29t as my lowest gear on essentialy slick (Vittoria Randonneur at the rear Michelin Dynamic at the front) tyres.

I'd thoroughly recommend taking your unsuitable bikes off road from time to time. I had a blast haging the back end out on loose descents, but the whole 1x, massive rear sprockets, enouromous derailleur cages fad at the moment drives me mad. Most of the time the answer is a triple chainset and shifters. Yes, it's a bit of extra weight, but I'd guess that my extra chainring weighs a lot less than the massive steel sprockets used to replace it and it allows me to use pretty cheap components elsewhere.

 

 

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michophull | 5 years ago
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Hmm. I'd personally be inclined to try an old school MTB triple chainset, say 24-34-44.

If your front shifter won't cope with three rings then I'd dump the 44. 

You can keep your existing cassette, rear mech, and shifters that way.

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