SRAM X7 Troubles...

richie131

Anyone have a fully working SRAM X7 rear mech which can cover the full 27 gear range? (not advisable I know but should be possible)

mine is giving me all kinds of grief...

ta

nicklouse

yes.

is yours a long cage.

richie131

er, no - medium. commencal in their wisdom fitted it as standard.

we have had words...

compo

I would have if I could be bothered/ knew how to properly index it up

richie131

3 mechanics and SRAM technical have all tried and failed. I even had a go, as it rocket science. its impossible to set as as spec suggests.

they couldn't even agree on whether the chain was the right length.

its ridiculous. i have a brand spanker sitting there waiting to ride and i'm stuck on my old faithful cheapo bike with bog standard shimano alveo which hasn't missed a beat in 3000miles.

any guidance appreciated...

r

nicklouse

so what is the problem?

you should not be using those gear combos anyway.

richie131

i don't but SRAM assured me the X7 can in case of a bad shift by error.

mine doesn't even behave from a straight chain from middle front/middle cassette - especially downshifts.

SRAM set it up:

the upper limit screw was wrong as the chain jumped into spokes on first ride, the bottom limit doesn't hit its mark so is useless and the B screw is redundant too as it won't get anywhere near the SRAM recommended 6mm clearance.

commencal have been useless. they just keep referring me to SRAM refusing to deal with it.

the retailer have been pretty sloppy too, as they missed 'factory' mistakes with both brakes/wheels and set the gears initially - badly.

shambles..

nicklouse

Err why are you talking to sram and comencial.

you should be dealing with the point of purchase.

sram did not set it up. the shop did. (should have after assemble by the factory).

but i still dont see your problem.

richie131

problem is - i will not shift - skips gears, runs very noisy. the usual gremlins

i did deal with shop, but they are miles away, so couldn't simply "take it back." they claimed the bike was perfect.

so: went to local independant shop for second opinion. they fixed some of the 'build' mistakes but not the X7.

lost faith with them, so went to second shop (big national company) - waste of time. came back same.

THEN contacted commencal, asking for guidance. they palmed me off to SRAM, who offered to sort it for free so i accepted - why not?

bike went to SRAM Technical UK who "set it up" in their workshop. was personally handled by centre manager.

came back with a shorter chain. and no better shifts.

now, going back to shop as fed up with being passed around. it is their responsibility, i understand that.

i just hoped for some guidance on here.

eg can't understand why medium and not long derailleur fitted. commencal won't answer?

"A Yorkshire man in Sweden" - you have a long mech fitted, yes? and the derailleur runs clear of itself and cable, and all adjusting screws set as spec suggests??

if so what is the full drivetrain - what bike??? i could do with a comparison.

hopefully...

r

supersonic

What gear combos does it skip in?

Anonymous

Surely if you've had a bike long enough to rack up 3000 miles, then you would have grasped the subtleties of setting up your gears by now?

richie131

currently:

from middle of cassette shifting (physically) up to larger next 2 gears are the worst. skips through most of the time and makes a right racket in doing so. easing off on pedals makes no difference.

but, when i first got it it was fine here, it just wouldn't shift the other way and refused to drop down cassette and onto smallest gear at all.

thanks for any ideas...


[/b]

richie131

i've maintained the shimano derailled bike for all 3000miles. no issues at all. minor tweaks where needed, cable changes. its been plain sailing.

go figure?

supersonic

richie131 wrote:

currently:

from middle of cassette shifting (physically) up to larger next 2 gears are the worst. skips through most of the time and makes a right racket in doing so. easing off on pedals makes no difference.

but, when i first got it it was fine here, it just wouldn't shift the other way and refused to drop down cassette and onto smallest gear at all.

thanks for any ideas...


[/b]

Is this on all the 3 front chainrings? Or just the large one?

Have they looked at your cables? I would strip them off, ensure the ends are cut flush, the ferrules are smooth and they are cleaned and oiled. Also make sure the mech hanger is not bent.

Chain length: it should be measured around the largest chainring, and largest rear sprocket, bypassing the rear mech. Then add two links where the chain overlaps when pulled tight. The reason they measure this way is if you accidently change into this combo then it won't destroy your drivetrain and mech hanger.

But... if the derailer does not have enough capacity, then the small/small combo and combos near it may cause the chain to go slack. But hitting this gear will not cause catastrophic damage.

So why do some spec medium mechs tjhat are below the drivetrain capacity? Well they offer better shifting, and less chain slap in many cases. The manufacturers don't think anybody will use the small/small combo (or big/big - but the saftey margin is there, as above).

richie131

Is this on all the 3 front chainrings? Or just the large one?

all 3

Have they looked at your cables? I would strip them off, ensure the ends are cut flush, the ferrules are smooth and they are cleaned and oiled. Also make sure the mech hanger is not bent.

bike is brand new, hardly any miles on it. nevertheless i checked them all and all good. can't say myself whether hanger is bent but it looks ok and SRAM passed it.

Chain length: it should be measured around the largest chainring, and largest rear sprocket, bypassing the rear mech. Then add two links where the chain overlaps when pulled tight. The reason they measure this way is if you accidently change into this combo then it won't destroy your drivetrain and mech hanger.

i did this using this method and it was fine. also checked by both mechanics i took it o and they agreed. plus the shop who 'built it sent it to me as so. SRAM then shortened chain to help the medium length mech. now chain will not go big/big. it did before.

But... if the derailer does not have enough capacity, then the small/small combo and combos near it may cause the chain to go slack. But hitting this gear will not cause catastrophic damage.

this was true, but the chain was very very slack. too slack for SRAM anyway.

So why do some spec medium mechs tjhat are below the drivetrain capacity? Well they offer better shifting, and less chain slap in many cases. The manufacturers don't think anybody will use the small/small combo (or big/big - but the saftey margin is there, as above).

very good question and one i have been asking myself - and commencal. i just got a email from their warranty manager - he has refused any further contact. i wouldn't mind but i have been very polite so far.

in my experience the medium mech has only hindered the shifting.

many thanks for your help

supersonic

A long cage mech will not solve the shifting issues you describe (but will sort some chain slack). But the mech may be faulty if the chain is excessively slack, ie the spring taking up the slack maybe slack itself.

Commencal don't have to deal with you I am afraid, as you did not buy the bike from them. The shop, however, does. They should try a new derailer to see if this solves the issues, and should certainly put a longer chain back on. All this is assuming there is no other obvious cause or damage. I would push for them to try a new derailer and chain.

richie131

i agree, i think the mech itself may be at fault aswell. however i would have hoped that someone who has inspected it would have noted this by now.

i also agree that it is the shop's call to deal with it, but initially the distance involved led me down the other avenues. i hoped for a quick easy fix.

only after these failed did i contact commencal for assistance only, not finger pointing. their replies were less than helpful which just frustrated the hell out of me.

i was most suprised when it came back from SRAM and still was not right. the SRAM chap was great offering to look at it, and arranging all the shipping.

to be fair the shop have now made encoraging noises when i contacted them last week. fingers crossed they will do the right thing and i can finally get riding the damn thing!

many thanks for all your help...

cooldad

Have you tried just adjusting the thing yourself? Sounds like a lot of faffing around with the whole world when it could just be a few minutes stripping down, reinstalling and adjusting..

richie131

your telling me, the faffing about is ridiculous.

yes, i have tried doing it myself. thats the first thing i did. aside from taking the whole thing off and re-assembling i have done everything. and i mean everything.

i have no experience of a strip down and do fancy learning how in this instance.

Drysuitdiver

the long cage X7 on my decathlon B twin rockrider 8.1 works fine. only times it didn't work fine was when the chain was crudded up, the drailleur was gunked up and the rear hanger was very very very slightly bent. which decathlons guys picked up and changed in seconds on the 3 month free service check thingy.


I strtipped the rear Mech down last week and cleaned all the jockey wheels of some sticky gunge that had accrued over a few weeks of abuse. it shifted goosd befgore but its even smoother now

richie131

the bike is as good as new, less than 30 miles clock - all on road. it hasn't been near any mud yet, not even got wet considering good weather. its as clean as a whistle.

thanks for input tho..

RupertCommunicator

I had an X9 mech which I cleaned meticulously, lubed and adjusted including the cables it till I was blue in the face, yet it still wouldn't shift down properly. Spoke to the shop, they replaced it with a new one, and guess what? It was still turboshit.

Replaced with Shimano SLX and now I am thrilled with my awesome shifting.

Lesson here is - SRAM = Dogshit, Shimano = FTW.

Drysuitdiver

RupertCommunicator wrote:

I had an X9 mech which I cleaned meticulously, lubed and adjusted including the cables it till I was blue in the face, yet it still wouldn't shift down properly. Spoke to the shop, they replaced it with a new one, and guess what? It was still turboshit.

Replaced with Shimano SLX and now I am thrilled with my awesome shifting.

Lesson here is - SRAM = Dogshit, Shimano = FTW.

hmmm now on the road bike i have shimano and it is truly dogshit compared to the SRAM kit on the MTB.

horses for courses i suppose

Anonymous

RupertCommunicator wrote:

Lesson here is - SRAM = Dogshit, Shimano = FTW.

Whilst I fundamentally agree with that statement, there's no reason why you shouldn't be able to get a SRAM mech to index.

richie131

well, thanks to the shop i bought the bike from i now have a fully working drivetrain. i should add that it is shimano front to back. both the shop and i came to the same conclusion independently - ditch the SRAM derailleur and shifters.

bike already had shimano chainset and front mech anyway - don't know why commencal didn't just do that in the first place, the retail price looks very similar when i compared the two.

am well chuffed and can finally get riding and forget all this nonsense.

thanks for all comments and help..