- Indexing woes – any ideas?
I’m having a bit of trouble with my rear mech.
I can index the bottom 4 or 5 cogs, but then it starts skipping/autoshifting when I get to the top 4 or 5. However, if I work the other way and index the top 4 or 5, it starts skipping/autoshifting on the bottom 4 or 5!
Seems I can only get use out of half the cassette.
Groupset is used, but all used together. 1×9 speed/XT/LX. Chainline is centred on the middle cogs on the cassette.
Any ideas?Posted 4 years agoplyphonMember
I had a similar sounding issue (tho only over the top 2/3 sprokets)
turned out the bearings in the hub were shot, and introduced a bit of play into the cassette which was just enough to let the chain slip down a sprocket when pedalling.
Give your wheel a tug back and forth in the direction of the axle, if there’s any more movement than almost none at all, then that might be something worth looking at.Posted 4 years agoRayMazeyMember
Probably Mech Hanger.
I know this sounds a bit dodgy. However, I have sorted this in the past without any alignment tools. Just taken the hanger off the bike, placed on solid flat surface, and hammer till flat. Sorted 🙂
Is this not the done thing?and if not why not?
CheersPosted 4 years ago
take the hollow axle from an old wheel, this will thread into the mech hanger bolt hole
this then gives you…
a. something to align by eye (front/back, up/down)
b. something to grab hold of to aid realignment
c. something in the threads of the hold to prevent and mis-shaping
or buy a proper tool, one available from madison for £250Posted 4 years agopenguinniSubscriber
Im having a similar fight.
Running an SLX double I just replaced my cassette and chain.
On the workstand everything works perfectly and all gears are selected smoothly. But when I actually rde the bike there is a lot of chain slipping in the larger chainring and the smaller 3-4 cassette cogs. When using the smaller chainring everything works perfectly.
Any suggestions as to where to start?
PPosted 4 years agosomafunkSubscriber
Park Tool DAG2 mech hanger alignment tool here £50 , prob one of the most used tools we have in the workshop, every bike that comes in for a service usually needs a hanger “tweak” of some sort.Posted 4 years ago
Changed a mates cassette on Friday. He’d also been having shifting problems the same as you are describing OP.
Turns out that the mech was bent, the spring in the cage was over stretched and floppy, and the mech hanger looked to be slightly out. I borrowed a Park DAG1 from my LBS. The hanger turned out to be properly bent. Put a new one in but that was still out. Ended up with the wheel out, a g-clamp on the hanger bolt so I didn’t strip the threads, and an BIG Bahco adjustable spanner on the frame to get it somewhere near straight. Minor adjustment with the DAG, a new rear mech, and it all shifts sweetly now.
So yes, probably a bent hanger. Only needs to be a bit out for it to have an effect.Posted 4 years agosparkyspiceSubscriber
If it’s not the mech hanger, (or you fancy some garage / shed / man-cave time), check that the freehub is ok. I’ve had it before where the bearings inside have imploded and this was causing the free hub and therefore the cassette to ‘wobble’. Depending on which side of the cassette was loaded, depended upon whether or not it indexed correctly…Posted 4 years agoNorthwindSubscriber
I use an old axle, and I stick a bit of threaded bar into the dropouts to give the best point of reference… Maybe the proper tool is slightly more exact but it won’t be by much. Depends how good your eye is I guess.
Really useful thing to be able to sort out at home, you’re lucky to have such a good LBS but I like to check mine from time to time and they’re always a little bit out just from everyday crashing.Posted 4 years ago
That’s the advantage of building a relationship with your LBS.
It’s one of the tools I don’t have, along with BB & headset facing tools and headset fitting tools, but something that last Friday would have saved about an hour of faffing to get knowhere fast. Something to put on the Xmas list.Posted 4 years ago
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