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Manual gear changing; the ad hoc approach.

Posted: 8 Apr 2012, 1:06pm
by Barrenfluffit
The front mech can't push the chain far enough inboard to shift on to the smallest ring; its the original 1980's double mech and otherwise does a sterling job. Its been adjusted but just can't come any further inboard.

The bike is a galaxy double to triple conversion and in normal (middle ring) use the chainline is ideal. So the inner ring is just for granny gear use. The current BB has lots of life in it so I'm wondering about an ad hoc approach.

Currently I use my foot to push the chain over but one day I'm going to put my foot properly in the spokes. Also it requires foot eye co-ordination which gets a bit challenging at the end of a long ride.

Does anyone have a suggestions or pictures of an alternative arrangement which would be easier to operate!

Re: Manual gear changing; the ad hoc approach.

Posted: 8 Apr 2012, 1:21pm
by CREPELLO
Fit a triple front mech perhaps?

Re: Manual gear changing; the ad hoc approach.

Posted: 8 Apr 2012, 1:32pm
by james01
After many years of bike fettling I can offer the following little bits of advice which have helped to make an old double mech shift a triple :
1. Set the mech absolutely as low as possible so that it almost touches the big ring. This gives it the best position for shifting to the small ring.
2. Inspect the mech to see what is physically stopping it moving further inwards - filing a tiny bit of metal off an end-stop can make a world of difference.
3. Misalign the mech so that the tail end is swivelled slightly inboard (ie to the left). This can sometimes work well, but sometimes you end up with messy changes onto the big ring.
4. With pliers or a Mole wrench bend the outside of the cage inwards at the point where it contacts the chain when shifting onto the small ring.
5. ...or on a similar vein glue a short strip of metal inside the outside edge of the cage where it contacts the chain.
6. Remove bottom bracket and add a spacer washer on the r/h side thus shifting the whole chainset a couple of mm to the right.
If this lot doesn't work, a cheap new triple mech isn't that expensive, so why bother ! :D

Re: Manual gear changing; the ad hoc approach.

Posted: 8 Apr 2012, 4:32pm
by Barrenfluffit
Thanks, your reply prompted me to look more closely at the mechanism. Now removed and sat in the utrasonic bath / degreaser. Without the cable attached it certainly comes far enough inboard so it looks as though adjustment is feasible.
:)

Re: Manual gear changing; the ad hoc approach.

Posted: 8 Apr 2012, 8:58pm
by cycleruk
I know you have the mech' off at the moment, but If you disconnect the cable does the chain drop onto the small ring?

Re: Manual gear changing; the ad hoc approach.

Posted: 8 Apr 2012, 9:45pm
by Barrenfluffit
Looking more closely it appeared that the end of the bolt at the bottom of the cage was fouling the mudguard preventing it moving all the way inboard. One small notch later and I appear to have full adjustment. :D

thanks for your input everyone.

Re: Manual gear changing; the ad hoc approach.

Posted: 9 Apr 2012, 5:10pm
by Steve Kish
Oops too late! :oops: :mrgreen: