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?