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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?

Acknowledged by the Telegraph as a leading cycling journalist, John Stevenson 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 editor Tony Farelly, 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 and these days he lives in Cambridge where the lack of hills is more than made up for by the headwinds.

106 comments

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CXR94Di2 [2737 posts] 3 months ago
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whizwith wrote:

I had my LBS put on an XT M8000 11-40 on my Lynskey R260 R8050 Di2 setup . I was hoping to use an FSA 48/32 up front, but the frame can't do it with the Di2 wires in the BB. But the LBS said they could replace the 50 with a 46. So I have 46/34 up front, and 11-40 in the back. I need to go for more than a spin and shall report back but was looking for help - How should I adjust the synchro shifting? Is there a logic to the defaults Shimano uses for the 50/34 11-34 setup I had on there before? If someone can point me to a chart or something that explains the framework, I'd be grateful! Thank you

Its probably because the frame has a threaded English BB so the FSA BB not compatible

  If its a case of the bottom bracket compatibility with your frame you can use the latest Shimano groupset which is 48/32 46/30 GRX which is hollowtech.    

look here for guidance https://www.google.com/search?q=shimano+synchro+shift&oq=shimano+sy&aqs=...

I use bike calc https://www.bikecalc.com/gear_ratios to show me the gear inches or ratios, just depends which you prefer.  I use these ratios to decide when to allow synchro to jump up or down the  front derailleur.  Method is when changing to easier gearing you want the shift on the rear to drop down so many cogs, so its in the next easy ratio.  You dont want to cross chain if you can help it so change a cog early.

The 11-40 has gears : 11-13-15-17-19-21-24-27-31-35-40t

Whilst on the 46t chain ring when you get to gear 2 (35t cog) the next change will result in the syncro dropping down to the 34t chainring and setting the cassette gear to gear 4(27t)

If you look at the chart below Ive hightlighted in red and yellow the next gear points with ratios. 

Red is for changing to next easy gear    Yellow for changing up to next harder gear.  these are the points in which the front derailleur moves and the rear jumps up or down several teeth simultaneously.

hope that helps

Btw I have triple setup 48/36/26 with an 11-40 cass on Di2 with syncro

 

 

 

Avatar
whizwith [2 posts] 3 months ago
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CXR94Di2    Thank you!

I did have a follow up. So when I went into E-Tube the default settings for my old setup (34/50, 11-34) is listed in "A". The crossover points are color coded where blue is when shifting down, and the green is when shifting up. The red blocks are the combinations that are locked out (not sure if that is the right term).

If I understand the chart you provided and applied it to the new setup (34/46, 11-40), the shifting up setting would start in one of the locked-out settings. This is illustrated in "B".

If I were to apply the logic of when shifting to a harder gearing to shift it such that it is in the next hardest ratio, I come up with the scenario in "C".

Is this right or am I not going about this the right way? The combination I'm using is not available in E-tube, so I am using the old setup but applying crossover points using the gear ratio tables you recommended. Where would you set the crossover points when shifting up from the 34 ring if cogs 11 and 13 were not available.

Should I instead try to find a combination in E-tube that does not lockout the 11 and 13 cogs while in the 34 chainring?

Thank you so much for your help!

 

Avatar
CXR94Di2 [2737 posts] 3 months ago
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B table looks correct as mine.  The actual numbers arent available within E tube look up tables, so you have to find the ratios from the likes of Bikecalc and use gear positions instead, the method works fine.

You will see that you can only jump so far with rear derailleur settings as the E tube setting block wide cass jumps-have a play, folk have different gearing preferences.  Using 34t chainring with 11t cog is cross chaining and not recommended for increased chain wear and potentially more likely to jam up chain or snag derailleur- same for 46t with 40t cog.  

I use syncro shift to primarily keep my chain more inline, but its a nice little feature to use-you can toggle back to manual mode if you dont like it or particular style of riding is interferred with syncro-I mean certain gear selection for a section of road finds you jumping up and down the front derailleur too often.  I find this on steep climbs where the ratios im using sometimes have me spinning or grinding with front derailleur moving between granny chainring and middle ring

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pancake [1 post] 3 months ago
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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

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KoenM [136 posts] 2 months ago
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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.

Avatar
pockstone [309 posts] 2 months 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
iandon [23 posts] 2 months ago
2 likes

I manged to get a Sram 11 - 36 working on my  50 - 34 chainset with ultegra rear mech by swapping the top jockey wheel to 10 tooth instead of the 11 tooth standard.  I have now got the clearence for it to shift across the full range.

Avatar
kil0ran [1695 posts] 2 months 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 [1695 posts] 2 months ago
1 like

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. 

Avatar
kil0ran [1695 posts] 2 months ago
1 like

Question for the experts in this thread, why do the Shimano rear mechs have a minimum big cog size?

For example, the new RX810 list min/max big cog size as 30/34. The RX400 is 32/36. And the RX-812 is 40/42.

Is it because they're clutched mechs?

Avatar
zero_trooper [373 posts] 1 month 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
kil0ran [1695 posts] 1 month ago
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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.

 

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John Stevenson [450 posts] 1 month ago
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kil0ran wrote:

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.

I can't find a definitive reference to Shimano (or indeed anyone) ever making a 12-34 10-speed cassette — are you sure that's what you've got?

If it is, then you could just replace the 12-tooth sprocket with a 11, and it should work fine. You may need a new lockring too, they're different for 11-tooth sprockets.

What I'd do is try an SLX 11-36 cassette. Your Tiagra rear mech is rated to 34 teeth, so will almost certainly handle a 36 sprocket.

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arrhythmiarules [3 posts] 1 month ago
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Was given my son's old Scott CXrc 10 speed Ultegra cyclo cross bike.   But I wanted proper low gears to usse it as a gravel bike with 37mm tyres.   I'm getting older, slower plus have a heart arrhythmia so cant climb the hills I enjoy.  So I want and need lower gears, much lower gears.  Proper low gears.  Changed the front chainset to an XTR and put on 22 and 44.  Which Ultegra coped with - sort of.  So not good enough and jump on front chainset far too wide.  So a second hand triple XTR  with 22 32 42 using the 11 34 cassette I already had.  Fitted a bar end shifter for the triple front and a cheap 105 triple front derailleur.  All OK.  Next step was an 11 42, 10 speed cassette and use an old 9 spead XT rear changer with a gear extender from Merlin cycles.  Works fine with the Ultegra 10 speed brake leaver controlling the rear.  So now a top of 42x11 which could work better with 44 and a bottom 22x42.  Acceptable jumps mostly and I just avoid front 22 with anything to small on the rear.  I can now pedal at a good cadence up 17% grades and reasonable effort.  Works for me.  Have considered that a 13 or even 15 top would be interesting with 42 bottom for 10 spead or 48, 50 for 11 spead.   So 15 to 48 or 50 cassette with 48 32 22 front and 11 speed should work nicely.  Especially for touring with kit.  Should be possible splitting a couple of cheapish chinese cassettes to give much closer gear spacing on the top to 32 tooth section of the cassette.  Eg:  15 17 19 21 23 25 28 32 37 42 48 or 50 or just ending at 42 for 10 spead.  Using larger tyres, mine are 37mm and 48x15 still gives an acceptable top speed at 110 rpm: 29mph or 46k.  However suspect that would need a Di set up to have the computer manage gear selection to accomodate the chain tension, avoiding big front to big 2 at rear to give a shorter chain.  The electric shifting should help the whole set up ot be smooth.  Has anyone done this:  Di with triple and wide range cassette, using electronics to block big big to ensure shorter chain, smooth changes and best chain line?  Maybe trying to buy a composite chinese cassette is the first step.  With current set up a 42x15 top still gives 40k at 110 rpm.   And I rarely cruise at 36+kph anyway even with a tail wind.  Comments welcome.

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arrhythmiarules [3 posts] 1 month 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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arrhythmiarules [3 posts] 1 month ago
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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. 

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