Please help gearing problem on 2nd hand bike ;-(

[jamin2005]

Hi, wonder if anyone can help me, i bought a 2nd hand Giant Boulder and im having a nightmare trying to tune the gears to change up and down the rear cog with 1 click of the rapid fire shifter.

been playing for 5 hours yesterday adjusting the cable tension but cant get it right, i came to the conclusion something has been changed from the original kit on the bike maybe some part of the gearing is not compatible with another.

Took the bike down to halfords and was told the problem if i have an 8 speed shifter and a 7 speed rear cog.

Now ordered these to hopefully resolve the problem:

SHIMANO STX RC 7 SPEED SHIFTERS

from merlincycles.co.uk.

rather than try to explain what model each part is ill try to upload pictures below, please could anyone tell me if anything here is not compatible or if the new shifter will work ok with this setup?

thanks very much for reading all this - pics:

http://img.photobucket.com/albums/v412/bclothier/bike/IMGP2666.jpg
http://img.photobucket.com/albums/v412/bclothier/bike/IMGP2669.jpg
http://img.photobucket.com/albums/v412/bclothier/bike/IMGP2670.jpg
http://img.photobucket.com/albums/v412/bclothier/bike/IMGP2671.jpg
http://img.photobucket.com/albums/v412/bclothier/bike/IMGP2672.jpg
http://img.photobucket.com/albums/v412/bclothier/bike/IMGP2674.jpg
http://img.photobucket.com/albums/v412/bclothier/bike/IMGP2675.jpg

 

[boudreaux]

It all works.However, shimano 7 and 8 speed coc spacing is close enough that a 8 speed shifter usually works with 7 speed cogs. You may have a bent derailer hanger or ginked RD. Try the repair section at www.parktool.cm for derailer adjustment.

 

[jamin2005]

Thanks for the reply boudreaux, so if it should work with the 8 speed shifter, how should it operate? ie when going up the cogs ( small to big ) the best i could get was the chain going up one cog per click of the shifter to cog 6 then needed to clicks to move upto cog 7. moving down sometimes needed 1 or 2 clicks to jump down a cog.

it did seem that each click of the shifter didn't quite move the deralier. maybe it is a bit bent, looks straight to the eye but i guess a little amount can make a big difference.

Ill have a look at those repair guides, thanks for that ;-)

hhmmm may i didn't need to get those 7 speed shifters then :-( was hoping thats what it was

thanks again