Home

In July I'll be doing the Maratona dles Dolomites and in the week leading up I'm going to be ticking off a few other climbs in the area including an attempt on the mighty Zoncolan.  Having seen the trouble the Pros had, mostly with 34/32 gearing, I'm fairly certain I'll need a bit of extra help and may not be successful in my endeavours.

With that in mind I thought I'd have a go at getting some easier gearing on my bike (Cannondale Super Six) which has a SRAM groupset and share my experiences here for future generations and also to get some feedback or guidance if anyone else has tried the same.

My initial thoughts were to go for a Praxis chainset with 48/32 rings but I wasn't sure that my front mech would go down far enough (the mount is riveted to the frame) - so a stupid big cassette looked like the way forward - 11-36T. It's like a dinner plate.

I already had a Red WiFli rear mech on the bike but after a bit of experimentation I came to the conclusion that even with the B screw fully extended it really couldn't safely cope with 36 teeth. 10 Speed SRAM MTB mechs are the same cable pull ration as 10/11 speed road (top tip - 10 speed SRAM road mechs work fine with 11 speed shifters). I haven't got money to burn on an X0 rear mech to save 100g so a £40 X5 rear mech will have to do. No need for a clutch mech.

I bought both long and medium cage versions with the thought to return one after experimenting - I don't really want to go long-cage if I can help it  although the maths (50-34+36-11=41) indicate I'd need it to cope with the extra chain length. Having fitted the medium cage and a new chain at the correct length I've found that everything shifts and works fine with two exceptions: 

1. In small-small the chain is not quite tensioned enough and rubs on itself under the mech but it's kind of OK - not flapping around.

2. In big-big the chain rattles a bit on the upper part of the front mech which I could move up a bit but I don't want to compromise front-shifting and risk a dropped chain

I think I can be disciplined enough to not go for both of these extremes and the worse that will happen is a nasty noise. I'm pretty certain that the long-cage would deal with point 1 but I think I'll stick with medium for looks.

The only other thing to bear in mind is that the MTB mechs don't have a barrel adjuster so I needed to fit an in-line one and the cable 'loop' where it enters the mech is much tighter than for a road mech so this might lead to less reliable shifting.

That's it... anyone else tried this? 

 

13 comments

Avatar
BehindTheBikesheds [2025 posts] 1 month ago
1 like

Could you have not bought a 33T chainring for your 110mm BCD chainset? It wouldn't buy you much (about 3% lower ratio) but it might have meant a 34T at the rear could have worked out and thus save you from buying a different rear mech.

I've just fitted a 11-32T Shimano 'dustbin lid' to my gravel bike, with an Ultegra 6800 short cage it works just fine on the big big, not that I would do that tbh and neither should you, you're not in a race.

Some frames/setups just don't allow you to work much beyond their specified capacities, Shimano seems to go beyond by quite a bit o almost all frames. The older 6700 short cage had a 30T big limit and though I never tried it I reckon it would have coped with a 34T.

Have fun.

Avatar
bondirob [5 posts] 1 month ago
4 likes

Here's what I did.
Compact chainset up front with 11 speed 11/40 cassette.
Used standard Shimano medium cage derailleur and a Lindarets road link from 18bikes (£22) which basically extends the derailleur. Put a longer chain on (obviously).
Worked fine, took it for a spin up Pea Royd lane which they use for national hill climb championships and knocked a over a minute off my fastest time.
This is the easiest and cheapest way to get appropriate gearing
Alternatively my winter bike has an 11/36 mtb cassette with compact up front. I did this by simply fitting a longer 'b' screw to a medium cage.

Avatar
dave atkinson [6379 posts] 1 month ago
1 like

yeah, the first issue is because the mech doesn't quite have enough capacity, but it's unlikely to be much of an issue. i'd experiment with the front mech position, it may be that it only needs a slight tweak that won't affect shifting. gluing a bit of old inner tube to that section of the cage will cut down the noise considerably if it's bare metal right now

Avatar
CXR94Di2 [2114 posts] 1 month ago
1 like

Bondirob has the cheapest effective way to get low gearing. 

If you need more, you could go mtb/cyclocross crank and 11-40 cass. 

My bike is setup with a 44/28 crank, and a 11-40 cass for mountains.  I can spin up the likes of Ventoux and I dare say the Zoncolan no problem.

The other end of the spectrum I did the Tour of Cambridge last weekend and averaged over 21mph with the same bike, different wheels, 11-25 cassestte

Avatar
VecchioJo [413 posts] 1 month ago
1 like

have you seen the Wolf Tooth Roadlink, it might be a cheap and simple answer to your situation as it allows your existing road mech to work with large cassettes 

Avatar
Pauldmorgan [236 posts] 1 month ago
0 likes

Thanks for all of your replies on this...

I looked at the roadlink but was put off by it saying "Shimano only" (I'm on SRAM) - anyone tried it with SRAM? I guess at £20 it's worth a punt to save a bit of weight and money.

As far as chainset changes - I don't think I can get a 33T that will work on my SRAM chainset and I wasn't convinced enough that my front mech would go 4mm lower to go to a 48T and the cost of a new chainset and BB would be the most expensive way of doing things.

With a little tweaking of the B screw I managed to get it to not rub in small-small *just*.

Will be giving it a proper road test up a hill later today.

Avatar
PRSboy [285 posts] 1 month ago
0 likes

Nothing useful to add other than to say when I grovelled up the Zoncolan on a 34/32 I saw quite a few others spinning away on MTBs or triple chainsets and felt very jealous!

Nothing else on the Maratona route is anything like as bad.  The only Dolomites climb that comes close is the later sections of the Fedaia.

Avatar
VecchioJo [413 posts] 1 month ago
1 like

Pauldmorgan wrote:

I looked at the roadlink but was put off by it saying "Shimano only" (I'm on SRAM) - anyone tried it with SRAM? I guess at £20 it's worth a punt to save a bit of weight and money.

 

"The RoadLink™ RD adaper installs in minutes, is optimized around Shimano ten- or eleven-speed road derailleurs and shifters, but works well with SRAM and Campy too"

Avatar
LastBoyScout [448 posts] 1 month ago
0 likes

I got up the Col du Tourmalet on my old road bike by slapping an 11-32 MTB rear cassette on it.

Standard chainset and no change to the rear mech apart from fiddling with the B-screw.

Avatar
VeloUSA [259 posts] 1 month ago
1 like

"My initial thoughts were to go for a Praxis chainset with 48/32 rings but I wasn't sure that my front mech would go down far enough (the mount is riveted to the frame)".

Take a look at this adapter.

https://wickwerks.com/products/fit-link-adapter/

Avatar
PRSboy [285 posts] 1 month ago
1 like
LastBoyScout wrote:

I got up the Col du Tourmalet on my old road bike by slapping an 11-32 MTB rear cassette on it.

Standard chainset and no change to the rear mech apart from fiddling with the B-screw.

I don't think Zoncolan would be a lot of fun on a standard chainset and a 32.

Avatar
Pauldmorgan [236 posts] 1 month ago
2 likes

Quick update: Wolf Tooth Roadlink fitted and working great with Sram Red 22 Wifli mech - thanks for the advice  1

Avatar
2old2mould [78 posts] 4 weeks ago
0 likes

I'm not that great a climber but I did Zoncolan on 34/29 and while it was horrendous it was doable... Just. I'd say a 32 would make it manageable if you're taking your time. Agree with earlier comments about Fedaia, that shouldn't have been that hard, and yet it was one of the worst rides I did in the Dolomites.