gear adjust/re-index

[craig kennedy]

ok, so I noticed last week a couple of the gears on the rear cog would be jumped over for no apparent reason, and the front one slipped off at one point.
A little reading tells me they need adjusting and a services (not been done since I got the bike so makes some sense. I have it booked into Evans for this to be done, but today thought I would have a wee go myself, figuring I cant make it worse.
Had a video tutorial that talked about turning this and that all the way clockwise, then releasing the cable
Placed on large rear, made adjustments to screw one, let it go to small rear cog, again adjustments to screw two and it all seems ok.
Started the front, similar approach, however I have noticed that the adjustment on the cable (inline) for one seems to do nothing at all, and indeed looks to be not actually connected to anything.
And on the first screw to make adjustments with the chain on the smaller front cog all was fine, but the second screw presumably for the larger cog looks to me to be too short, and actually has no impact on either small or larger front cog.
Needless to say now I am stuck on the smaller front cog, and the rear gears are about 95% ok.

So, my tinkering has made the bike no longer useable until after Evans can fix my screw ups..

Still, Chain is nice and clean now.

 

[DaveReading]

And on the first screw to make adjustments with the chain on the smaller front cog all was fine, but the second screw presumably for the larger cog looks to me to be too short, and actually has no impact on either small or larger front cog.

If you can't get the chain onto the larger chainwheel, and it's not the adjuster screw that's preventing the derailleur moving far enough, then you need more tension in the shifter cable. That's done either via the barrel adjuster (if it's only a small amount of adjustment that's required), otherwise by loosening the cable clamp bolt on the FD and pulling more cable through.

 

[13 rider]

Can you not remember where the screws were when you started how many turns etc. Normally adjust quarter turn at a time then you can always go back the screws I beleive your talking about just set the limits of the movement of the derailleurs one screw for each high ,low .can you not retention the cable back to nearer to were you started . Good luck

 

[craig kennedy]

lol, your arguments seem sound, and being an IT/Web tech person I thought, hey this should be a piece of cake, NOT.
The small adjuster thing thats inline with the cable just by the gear change thing on the handlebars no longer does anything, seems something is wrong there.
And yes I was trying to get the de-railer into the right place to stop the awful rattle when on the smaller rear cog, If you could see how I had the bike setup you would laugh. 2 logs, either side of the rear wheel, small thin piece of weed screwed to the top of the log and the rear part of the bike balanced on it, worked, ish

 

[roadrash]

dont know which online video you followed but i find this to be the best one for rear indexing..

View: https://www.youtube.com/watch?v=SkzvfCaIbyQ

 

[DEFENDER01]

Very nice video well explained.

 

[craig kennedy]

Im fairly sure I got it right.

Here is what I did (excuse the non correct terms

1. turned the adjuster at the rear fully clockwise then one part turn back again
2. released the cable from the holder on the rear
3. Put the chain onto the largest cog on the rear
4. Adjusted the screw to ensure it cannot go beyond this gear into spokes
5. released and left the chain to flow into the smallest rear cog
6. again adjusted the alternate screw to ensure it sits correctly on the small cog and not beyond
7. re-connected cable taught to rear fixings.
8. Checked and it seemed to be good, all gears appeared to work with reasonable smoothness.
9. Same process for the front, chain onto front smaller cog
10. released cable
11. noted there is no adjustment at this point (only on handlebars)
12. adjusted screw one so chain was in the middle of the rail
13. Put chain into larger cog, and again adjusted screw 2 so it could not go beyond (I figured out the screws) this point (off the cog entirely)
14. Put cable back in connector tight

Now, it seems its now working much better than before, however there appears to still be skipping gears on the rear cog. When starting out on the smaller front cog and larger rear cog its fine, and as I press the black button to move towards the smallest rear cog, it skips down without any noticeable issue (could be cleaner and crisper), but if I then go back up towards the larger rear cog, a small push of the brake lever switches the gear up one cog, but I am able to push it harder and skip up 2 gears (not sure why) and all the time the front cogs are ok.

Also, I am confident I need to do some Truing on the wheels, but don't have a spoke tool, so will have to get one, there is a very clear wobble as I put the bike into a fast speed (bike is upside down at this point).

One more thing I noticed, when the wheel (Rear) is in the frame socket, but not locked in yet, there is a very slight bit of movement, if I push it all the way in, and lock it into place, I am able to see that the wheel is 2-3mm towards one side of the frame, is that normal?

I may not be explaining it very well, so tomorow night I will try and take some pics to illustrate what I mean, but I think Evans should be able to help (hope)

I have had a few falls on the bike (shoes locked into pedals and the van thing) but I don't see that it looks bent.

 

[RichardB]

but if I then go back up towards the larger rear cog, a small push of the brake lever switches the gear up one cog, but I am able to push it harder and skip up 2 gears (not sure why)

I don't know what system you are using, but I have Shimano Rapidfire shifters on my early 90s MTB and they do this. Single click takes you from large to small, single or double click to go from small to large in steps of one or two gears. It's for quick downchanges. A feature, not a bug.

 

[sackville d]

dont know which online video you followed but i find this to be the best one for rear indexing..

View: https://www.youtube.com/watch?v=SkzvfCaIbyQ

My fave tutorial out there.It totally demystifies rear mech adjustment.

 

[blimpnoddle]

Hi Craig

I don't think you specify how long you've had the bike. Is it possible some of the gear jumping at the back is caused by a worn cassette/chain? I had similar problems and no amount of adjusting cured the problem. Only had the bike about 7 months and didn't think wear would be an issue. Then I bought a chain wear indicator (essential item imo) which showed wear was beyond the point (1mm) that required both chain and cassette to be replaced. Now everything runs perfectly.

 

[craig kennedy]

ha, yes, It turned out I needed a new chain and rear cassette. My question is this.

For years I had a bike that would be classified now as a hybrid, but with only 3 gears, using the old style lever.

I never looked after it, and eventually it got stuck in 3rd gear so I removed the gearing parts, leaving the rest of it.
I never oiled it, never did anything and used the bike for long (15 miles) and short hops daily for about 8 years until it eventually fell appart.
Never did I have to replace the chain or rear cassette, nor did the chain ever come off?

I have had this new bike for about 2 years, but only actually cycled about 200 miles in it at most?

Its a bit like the old washing machine and TV thing, if you have a washing machine thats older than ten years old then it could last forever, but if you got it 2 years ago then its likely to have 1 more year before it will need replacing.

 

[craig kennedy]

I would say I don't cycle hard, or terribly fast, I do change gear regularly but aren't we meant to?

So, what do I do about not wearing them down again? or what dont I do?

 

[blimpnoddle]

I would get one of these:http://www.chainreactioncycles.com/x-tools-chain-wear-indicator/rp-prod10219

When the chain is worn to .75mm I would replace it fairly soon afterwards. That way the cassette and chainset will last much longer and work out cheaper and less hassle in the long run. If the chain is already worn beyond 1mm then it and the cassette need replacing immediately.

And avoid cross chaining.

 

[craig kennedy]

Cross chaining, thats where Im using the small cog on the big cog and vice versa right, yes Im now more aware of that than before

 

[T.M.H.N.E.T]

Cross chaining, thats where Im using the small cog on the big cog and vice versa right, yes Im now more aware of that than before

Yes. Depends on the groupset though, some (any SRAM groupset with YAW derailleur) lets you do it.