Discussion in 'Bicycle Mechanics and Repairs' started by maroon, 25 Sep 2017.
Any mtb's out there reading this that can help please?????
I'd suggest changing your crankset may be the way to go. Depending on how your front derailleur is attached to your frame and how much it can be moved up or down, it may be the better option.
A 26-36-46 chainset would lower your gears around the same as a 34t cassette and wouldn't require a whole new drivetrain.
Have you tried it with an 11-32? As assuming your granny ring is a 30t, 30-32 is pretty damn low anyway, are you sure you need to go to 30-34? Your current rear D will cope fine with the 32.
Take a look at this post from @jowwy where he talks about a Wolf Tooth adaptor.
I was actually considering that I'll pop back to the shop and find out whether this is possible , I'll also ask about the wolfstooth.
Thank you wasn't aware this existed
We need to know what the OP's triple is but this is a good bet.
Partly because you haven't specified the problem (but jumped to a solution (thread title). On a commuter bike, if you are struggling on 30-30 (ie a 27" gear) and your commute forces you to ride over some serious hills, how much lower - percentage - gear do you need? Going from 30 to 34 largest sprocket will give you an extra 13%.
My recommendation is to swap the 30t small chainring for a 28t (6.7% gain) and swap your cassette for one with a 32t largest sprocket (another 6.7% gain). You will end up with a drivetrain which gives you the advantage you seek on the hills at with relatively low expense. The downside is that, since your are asking the RD to perform outside its envelope, the chain will not wrap enough to avoid chain/cage/jockey wheel interference when on small/small. And careful adjustment of the B screw will be needed to avoid the guide wheel fouling the 32t large sprocket. But on a commuter you can ride to avoid the former - and you'll quickly hear the RD/chain telling you to change up to the middle ring. The FD chainring shift from the (new) 28t to the 39t may not be quite as smooth, but will work well enough. I effectively did just this for the Mille Pennines audax (included Hardknott (@200k), Wrynose and Rosedale Chimney (@750k)): I swapped my inner 30t for a 28t and my cassette from 12-27 to 12-30.
Do we know what actual components the bike has yet?
It will depend on the capacity of the front and rear mechs to take up the slack in the chain: in order for the chain to fit around a 34t it will need to be longer, so the mech needs to be able to take up the extra slack.
As has been said, you must have a pretty hilly commute, or take a lot of stuff to work! (says he who had a 22/32 on his commuter for a while)
If you are using a Shimano Ultegra 6700 10 speed shifter you can use some MTB rear mech's allowing larger rear sprockets to be used. Note it only works with certain model years.
With the Shimano Ultegra 6700 10 speed shifter the 9 speed rear mech' that worked was a Deore M591, at that time both were current. The subsequent 9 speed rear mech' generations with different product codes I believe didn't; at least they didn't when I tried later editions, which I discovered as the 6700 STI was still current when the Deore rear mech' was updated. To make sure it was not a one off we tried several of the new Deore 9 speed mechs', we even upgraded to an XT, different cassettes and chains, none worked; sourcing the older Deore M591 sorted the issue perfectly.
Although now an old model I dare say if you look hard enough you will find it, new old stock on ebay for example. I've just Googled Shimano Deore M591 rear mech's and often the replacements are actually listed; you will need to make sure it's the M591.
@maroon Why not share how you've addressed your 'problem'. A fair bit of advice was given (on 26 September) but no feedback from you. @Paul_Smith SRCC has just resurrected this thread with more advice.
Frankly the idea of needing to fit a MTB rear mech to help with the mega hills you have to climb for commuting seems extreme (both the hills and the idea).
You've got a triple already so your gearing is already better than the vast majority with a compact (50-34).
What big hills are you climbing on a London commute?
Actually it was your review of the yukon I read a lifetime ago that got me started on the path of owning a titanium bike.
Do you still have yours??
Not big hills I think at this stage just general unfitness but hoping to correct that this year
Apologises for the lack of update, I actually ended up with an 11-32 on the back and more than happy with the results
Thank you all for your advice and guidance very much appriciated
I have just changed my Ultegra 11 speed RM to the med cage to accommodate date a 32 large cog .Chain wheel 50 34 no problems. I did try this combination with the Ultegra small and could have about got away with running the small R D Did change R M to a 105 long mech.Cant really say I can notice a lot of difference.
Separate names with a comma.