Two Gearing Issues with 90s Marins

MahatmaAndhi

I've only recently started cycling this year and, being broke, went for the first decent looking bike I saw at a reasonable price - a 1995 Marin Pine Mountain for £70.

On the way to work one day, I cracked the rear grip shift housing, so I was down to three gears. As I eventually wanted to change to triggers, I ended up buying a Shimano STX RC 8-speed shifter as its replacement.
I've changed the shifters over and replaced the cable and housing, but I can't seem to get the rear gearing sorted properly.
The closest I got to being right before I ended up messing it up further and moving on to my other bike (more about that in a sec) was:

1st Gear, jump to 3rd, 4th, 5th, 6th, 7th, 8th

Then on the way back up:

8th, jump to 6th, 5th, 4th, 3rd, 2nd, 1st

I just can't get that final bit right. Anyone have any ideas please? It's a Deore XT rear mech. I think it's original with the bike.

Whilst the Pine Mountain was out of commission, a Marin Palisades Trail came available for £15. Happy days. The guy I bought it from said that the front gears don't work, but I thought I'd have a crack at it. I changed the cable and housing over on that one too, and got it working a treat. However, in 8th gear the rear cage is so far back that it's parallel to the floor, so the chain is rubbing against itself where it passes the jockey pulley.
It's not a huge deal as it's not a gear that I use often, but I'd rather not have the issue and would prefer to know if I am doing something fundamentally wrong.

Sorry for gassing. Thanks for any help received!

02gf74

Really 2nd bike and chain rubbing.
By 8th gear you mean smallest Sprocket on the cassette. If so on which chainring is it? If smallest chainring then that is probably OK but you should not be using that combination.

But that usually is because the rear mech cage is too short and/or chain is too long.

JBA

You need to start from scratch and methodically set up the gearing.

Have a look on the Park Tools website for plenty of ‘how to’ videos.

The problem with the Palisades Trail sounds like the chain is too long. You need to size the chain correctly and remove the extra links.

veronese68

As above, the second bike sounds like the chain is a touch too long if that happens when on the small ring at the front. If you're on the big ring it's far too long. Park Tools website for gear set up and setting chain length.
On the first bike XT is better than original for that. You could have a bent hanger making gear set up difficult. Assuming everything is 8speed that lot should work.

MahatmaAndhi

Thanks for the quick replies.

Regarding the chain length, I have a motorbike chain breaker. Would this be suitable, or is it too heavy duty? I haven't looked in to setting it yet, but for removing the extra links I'm assuming that I'll need a tool.

I'll keep doing minor tweaks on the Pine Mountain and see if I can get it right. Otherwise, it's a trip to the LBS when the pennies come in.

veronese68

Motorbike chain breaker will be too big, the pin pushing bit and the width of the chain. If it only happens on small front small back the easiest short term solution is not to do that. Best to avoid extremes either end anyway. Big front with smaller rear, middle front around middle rear and small front with larger rear. Assuming you have a triple up front you don't really have 24 useable gears, more like 15. Hope that makes sense.

MahatmaAndhi

Yeah, it does. I'll leave it be for now then. I generally stay on the middle up front and only change out of it for steeper hills (up or down) which are few and far between around Peterborough anyway.
Thanks very much.