jumping gears

[jayce]

hi all ive been building my own bikes for a few years now but now i have a problem. just turned my cycle to a 20 speed bought all new parts when shifting between 5-8 its seems to jump sometimes up and then down ive tried little tweeks but nothing any suggestions

 

[gbb]

Sounds as though youy've tried all the normal things jayce.
Is the back wheel in straight ? Sounds stupid, but i struggled to set up a 9 speed a while ago. It just wouldnt have it...even going by the book. Over and over i tried.....then for some reason that eludes me now, i had the back wheel out, when i put it back in, it all adjusted up first time

Alignment may be that much more important with 9 and 10 speed systems...

 

[jayce]

im using a kmc x10 chain wonder if the shimano is a bit narrower it looks like its catching on the next cog then flicking up or when the smallest adjustment it jumps downwards im doing the smallest tweeks ive had a t*t full now . want to take a hammer to it

 

[Chrisz]

Have you tried a new/skinnier chain?

 

[jayce]

phoned a local dealer and he said all 10 speed chains a the same width which is 5.88mm

 

[Baggy]

I use a KMC 10 speed with my Campagnolo set up and it works better than the original Campy chain.

Annoying as it is, you could try riding it for a while and it might then settle down?

 

[jayce]

i was thinking that or i might try and clean the chain its very sticky im thinking it might be just catching the cog and lifting making it jump a bit . as all of its new could be that

 

[Chrisz]

i was thinking that or i might try and clean the chain its very sticky im thinking it might be just catching the cog and lifting making it jump a bit . as all of its new could be that

Sticky as in the links are stiff? Might be as well to get a new chain mate

 

[Steve Austin]

It will be the indexing.
check the bit on here about index setting
http://www.parktool.com/repair/readhowto.asp?id=64
I will almost guarantee its that

Happy riding

 

[PatrickPending]

I agree with the above, indexing and possibly the b- screw need setting up

 

[jayce]

Sticky as in the links are stiff? Might be as well to get a new chain mate

its all new kit everything

 

[Steve Austin]

Stiff links don't really affect shifting and indexing too much.
You can get stiff links on new chains. Run the pedals slowly backwards whilst stationary, any stiff links will make the dérailleur 'jump' or 'snatch' if there is a stiff link.

video link here

 

[jayce]

had a tinker this morn took the cable off reset the b screw little tweeks with the mech shifting up and down seems normal now so hope thats it . so thanks to all for the input . il have a crack this afternoon to see if its ok under pressure cheers