Slipping gears

[ClichéGuevara]

I'm in the throws of tweaking an old mountain bike for commuter/camping use. (Raleigh Glide) It had twist grip shifters, which had lost the ability to index, so as I was replacing them, I thought I'd improve the gear range, so changed the freewheel from 14-28 to 13 - 32 with Acera shifters and a HG 40 chain. I checked and oiled, but didn't replace the outer cables.

Because of the order they came in, the shifters went on first, but I only set the gears roughly as I thought they'd only need resetting later.

Next on was the freehub, with the old chain. This seemed to work well, indexed across the range, but if I pedal backwards, the chain dropped from the large rear cog towards the middle gears and jammed (not toward the wheel). It was fine going forwards and freewheeling. I assumed this was the chain.

It didn't make sense, but the machinehead chain length calculator, gave the same length for the new as the existing chain, but as it worked, that's what I did. It has the same issue when back pedaling. (from memory, 42.5 hub to hub centres, 42t - 32t, but don't quote me)

I run out of time to look too long, but thinking about it, could it be the jockey wheels? They seemed free enough, but that's only from threading the chain on, I've not specifically checked them.

Any suggestions?

 

[Mile195]

I've had jockey wheels, stretched chains and stretched cables all cause problems with shifting. Jockey wheels are easy to check. A little play is ok (in fact one of them HAS to have a bit of play in order for the indexing to work), but not too much. For the price of a set of jockey wheels (£12 upwards), it might be worth throwing some new ones on it anyway since it's so quick and easy.
I appreciate you've changed the inner cables. However, might be worth throwing some lube down them if you didn't do that when you changed them.

 

[Globalti]

There's no point in doing all that without changing the cables, especially the outers and especially where the cable curves round to the rear derailleur. The cable will be manky and crudded up with rust and nothing will work. Why spoil the ship for a hap'orth of tar?

 

[raleighnut]

Get the gear hanger checked for alignment as well, an old bike could have taken a knock here and its probably a steel one on an older Raleigh so it can be tweaked OK.

 

[ClichéGuevara]

Cheers folks.

It'll be tomorrow at the earliest before I get the chance to look, but there's plenty of food for thought. I'll invest in some outer cable while I'm at it. As pointed out, it seems a shame not to.