recent problems with gears

[andyhunter]

i have been using shimano ultegra all my racing career to date (rear mech, front mech, cranks, bottom bracket, brake calipers, shifters) and never had any problems with it until the day i snapped my chain on a climb about a couple of months ago..i then took off the old cassette and placed a brand new one on(shimano ultegra) with a brand new chain (kmc) and the gears were alright for about two weeks before i started having a few indexing problems and noises here and there before the indexing was so bad i got my mate a bike mechanic to fix the gears but i wasn't completely happy as im a fan of smooth shifting and silent running which the shifting was ok and there was some noises here and there and again i had another indexing problem in a few weeks which i left my bike in to be serviced and replace the gear cable in a well known bike shop and when i took the bike out i had problems with the gears still not shifting 100% and not silent 100% as you could hear irritating noises when the chain was in certain sprockets on the cassette..so i then bought a brand new rear mech and front mech and left it in to another well known bike shop to put on the bike, replace the gear cable again, service the bike again and ensure everything sweet and make sure the shifting perfect or 90% at least..so today i took the bike out and the shifting is good but...theres loads of different levels of noises coming that what ever selection i have made the chain go in the front big ring or wee ring or on different sprockets on the cassette..i am truly baffled and don't no what the problem is :S..i thought it could be due to a lose bolt or bit of dirt between the stem and bars or seat post clamp and saddle making strange nosies when weight or force placed onto them but its not as they have been well cleaned and not over tightened..any help at all would be great .

 

[OLDSHUNTER]

is chain same as old one/ could be the difference?

 

[lukesdad]

It sounds as if it could be the chain , is it the same length as the old one.

 

[ultraviolet]

i would of replaced the chainrings just to be sure when replacing the chain/cassette

 

[peanut]

the front mech cage could have been bent or damaged when your chain broke. Theres a lot of force released when that happens.

Pity you don't do your own repairs. I would remove the chain and using a steel rule i would check the alignment of the rear mech hanger ,the jockey wheels and front mech cage to large chainring and check the chainrings have no run out etc. Then check all the cable ends are clean cut and check all the cables have smooth and gentle bends
Then reindex everything.

My new build 10 speed is absolutely silent and smooth.Its a complete dream whereas my 9 speed had clicks and buzzes and skiped occasionally .I must have adjusted it 3x before I found that the inner cable was rubbing on the bottom bracket shell causing friction . adjusted the cable guide and its perfect now

 

[accountantpete]

It'll be a process of elimination. I'd start by tipping the bike up and slowly turning the pedal checking how the chain settles on the socket for each gear.If the cable is grabbing then the chain will be making slight contact with the sockets either side before nestling in the correct socket.

 

[Will1985]

A bit of punctuatioin would be nice. TBH I switched off after reading "Shimano" anyway