Indexing on '91 Kona driving me mad...

[bertberr]

I recently replaced the chain again on my '91 Cinder Cone, but cassette was still fine so left it alone.

But, the indexing is proving a real nightmare. On the few rides I've done with the new chain I'm getting a metallic sounding noise from the cassette / RD / jockey area when in the fourth sprocket. When looking at the chain / sprocket relationship while up on the workstand, the chain is definately making contact off centre of the sprocket. However, when I adjust the noise away via three or four anti clockwise turns of the barrel adj', I then get the same noise on the first & second sprocket... :evil:

And vica versa, everytime I adjust one away, the other starts making a noise... just don't know what to look at next? I'm only doing one turn at a time on the barrel adjuster, so its not as if I'm overdoing it the other way.

Buy a new cassette (7spd Shimano HG) even though the other looks fine? Or hit with large hammer out of frustation and hope for the best? Or any other ideas?

 

[terryhfs]

Check the cable is clamped right and you haven't taken it the wrong route (easily done). Always set indexing with the smallest two sprockets - if they're right and it doesn't work further up the block there's a cable problem.

 

[jonnyboy666]

sounds like the rear mech hanger is very slightly bent

 

[bertberr]

I'll check cable routing tomorrow, though it doesn't have a separate hangar - RD bolts straight to frame. I did think it might be a RD alignment problem, but just looking at the mech from the back, it looks OK, at least to the naked eye...

Is there any way an LBS can check a frame for 'trueness', bearing in mind that if there is an issue we must be talking microns...???

 

[rc200ti]

Other suggestions:
Jockey wheel pins secure?
How old is the rear mech? Check that the pivot pins aren't worn allowing the arm to move out of alignment under load.

 

[Steve Kish]

At least 75% of my shifting problems have been cable orientated.

Clean cable and check for any kinks. Buy a new cable inner wire if you're flush .... a good quality 1.12mm one!

 

[pete_mcc]

Is there any way an LBS can check a frame for 'trueness', bearing in mind that if there is an issue we must be talking microns...???

All decent shops will have a hanger aligner that will get it to within microns.

Other things to check along with the above - is the chain correct for the number of speeds (ie it's not a 6 speed chain on an 8 speed block or a 9 speed on a 7 speed block)? When you say the cassette is fine, have you checked it under pressure?

 

[Andy R]

Is there any way an LBS can check a frame for 'trueness', bearing in mind that if there is an issue we must be talking microns...???

All decent shops will have a hanger aligner that will get it to within microns.

Well, near enough anyway, but certainly not to within microns
Just eyeball it or hold a steel straight-edge on it and see if that looks square/parallel to the frame. If it does, it's not the hanger that's the problem. If it seems slightly out then tweak it back with an adjustable.

I personally think your problem will lie with the mech. but check your cables are ok first - in fact it's probably just as easy to fit new outers and inners anyway for the few minutes that it takes.

 

[Jason802]

Get one of these: http://www.cyclebasket.com/products.php ... 0s276p2333

I bought one between myself and a few friends and was amazed that out of 13 bikes only one was actually correct. As a lifetime cyclist this is absolutely essential, until they replace the rear mech of course. One frame I had with a brand-new replaceable hanger was one of the worst!

PS. This is one of my favourite shops with some great bargains that often undercut the big boys. They do have a universal £6 delivery fee (except on frames I think), but even with that you can normally save cash if you're buying a couple of things. Again I do batch purchases with friends to share the delivery cost.

 

[bertberr]

I've checked the following:

1. Cable - no kinks and routing seems OK at the back i.e. no sharp angle as it enters RD, though maybe there is a little too much outer between shifter and 1st cable guide (see pics).

2. Jockey wheels spinning OK and pins/bolts tight.

3. Chain is a 7/8spd (SRAM PC850)

4. RD (Deore LX M581 marketed as 9spd mech but apparently fine on a 7spd cassette once limits adjusted, as they have been) is less than a year old with next to no wear.

Pete_mcc - what do you mean by checking cassette under pressure?

Andy R - what aspect of the mech do you suspect may be the cause?

Jason802 - that alignment tool looks interesting, can't figure out by looking at it how it actually works...