[Closed] Dropping gearing on a CX bike

The chainring option will work fine, but the thing that might suffer is front shifting as the mech will likely not be happy with the 24t, the cage may be too high. Dropping the mech will help but still might not be great. Got any old rings you could run to give it a try?

I run a 28-42 MTB double on my CX bike with campy front mech, it works fine now but to do so I had to move the mech out a bit as the chainline was further out. I achieved this by using an eccentric shim to offset the mech.

Why not stick with the current gearing first and see how you get on?
It's surprising what you can do if you try, it's pretty steep round here and I manage with 36 front 32 rear.

I did the same as STATO but didn't particularly fuss with the mech. Deore C/S with the outer ring moved to the middle and a 28 inner.
Currently the same but with a SRAM road set up. Works fine. 28 inner means that I can run a nice close 12-25 10 speed cassette.

I've got 46/36 - 11/32 on my CX. I'm a big, fat, unfit biffer. I never think I need anything easier.

Ride it and see. The worst that will happen is you will be walking for a few sections.

i've got 30:42 on a triple with no outer. cx70 derailer shifts great on the stand but i've not really ridden the bike this year!

I've been using my CdF as a commuter for year or so with 11-32 cassette and 34/46 rings. All 9sp Sora
I'll not be commuting any more and I feel like doing something daft with it like turning up on a local evening MTB ride and seeing how it goes, but I fancy dropping the gearing a bit

I'd have thought you'd be fine with that gearing - I'm running a Dirty Disco in the Peak on and off road with a pretty similar set-up and it manages okay. I guess you could always bang on an 11-34 or even one of the 11-36 things - yes, there is a nine speed one, it's just heavy, aimed at tourers I think - but I'd try it with what you have first and see how it goes.

Yah I might just try it. I used to single speed round here, so I might live!
I think I do have some old chain rings too.

BWD - the cassette is a 12-36. It needs a specific mech (as I mentioned above) I've fitted this exact combination on my wife's touring bike. 🙂

If you go down the XT chain set route, how about swapping the front mech for a a Sora triple? My tourer came with one as stock with Sora 9sp triple shifters and (I think.....) an Alivio triple with a 26t inner. Worked a treat.

[quote="PeterPoddy"]There's not much I can't get up with sheer powerHmmmmm, just leave it like it is then.

😉

If you go down the XT chain set route, how about swapping the front mech for a a Sora triple?

Could you simply replace the 36T inner chainring with say a 30T? I'm treading water out of my depth here, I've yet to do this sort of thing, but I'm presuming that a 16T difference between large and small rings is pretty close to the limit (going on compact 50/34 road chainsets).

This would give a lower bail out gear of ~26 gear inches, instead of the current ~29.

http://sheldonbrown.com/gear-calc.html

Could you simply replace the 36T inner chainring with say a 30T?

If it's a standard compact double, I think the smallest you can go is 34.

BWD - the cassette is a 12-36. It needs a specific mech (as I mentioned above) I've fitted this exact combination on my wife's touring bike.

I didn't know you needed a special mech for the 12-36 cassette btw, no chance of fitting a longer b-screw or just banging on a spare mountain bike mech?

why no more commuting?

I have a 22/38 front ring set up and that shifts fine with 105 front road shifter.

MTB cranks and 32/44 chainrings up front, fine for most things rough or smooth.

If it's a standard compact double, I think the smallest you can go is 34.

You can get a 33 chain ring which will fit. Is 33/32 low enough?

I think you might need a triple shifter to make that work properly. Not sure you can match road double shifters with triple mechs?

Possibly, I'm using the shifters now with a double front mech and compact chainset, I think there's room for some experimentation. Sora mechs are very cheap too.

My CX runs a 50/34 and 11-32 and I've not yet run out of gears off road. I find the front pops up before the ground is too steep for that gearing.
Definitely give it a go before bothering to change anything.

PeterPoddy - Member
I've been using my CdF as a commuter for year or so with 11-32 cassette and 34/46 rings

Just got around to reading this thread..

The gearing you are using is pretty high anyway, is there a reason you need higher?

I'm using 34/46 and 11/30, the only real issue I have is the 25% gravelly or loose climbs when the rear spins out, best just get off an walk up it which is often quicker.
But I do ride with a guy who has an 11/36 on the back and 34/46 and he uses a med cage on the rear to cope, looks fine and works fine in practice and didn't cost that much for a new cassette & cage (about £80 IIRC) Often he's spinning out whilst climbing but when you get to the steep and rutted/gravelly stuff I climb with the bike on my back quicker than he spin up it..

But I get your point, so perhaps a 11/36 and med cage would help..

I'm on 38 front 11-36 rear on my CX so a similar gear to your 34/32 and it's fine

I run a triple and 36 cassette with slx rear mech (9spd)
Rarely use the granny ring but nice to have on really steep climbs.

Peter I'm with you, low gears are an asset

Incase you've not seen it this site might help

http://www.cyclingabout.com/wider-gear-range-road-shifters-gears-for-easier-hill-climbing/