gears jumping

mr_joe0606

hello

i have resently fitted a shimano 105 group set to my winter bike but i i can not for the world off me get the indexing right.

its a compact with a 11-28 rear. when its in the 28 sproket and start shifting down its fine till just past center of the cassette. then it will skip 2 gears. when i try shifting up the cable is to slack so i tighten it up and the when shifting up its fine till top 3 gears then it will just jump to 28 gear.

i am thinking that my chain is to tight

Reg73

I think the first thing to do is get a decent spell check. Ignoring the total lack of capital letters and punctuation, there's a further 12 spelling errors. Not normally in the spelling police, but Jeez...

kentphil

Is it a completely brand new group set? If some parts are more worn than others then this may cause the skipping your describing.

Mad_Malx

Like KentPhil says. Good cassette with worn chain or vice versa will cause problems.

Reg73 wrote:

I think the first thing to do is get a decent spell check. Ignoring the total lack of capital letters and punctuation, there's a further 12 spelling errors. Not normally in the spelling police, but Jeez...

So you joined the forum for this first post? Did you mean to join EnglishRadar?

Edit - and I think you mean 'there are'

keef66

It's possible the OP is dyslexic?

Anyway, he came her for bike advice, not remedial grammar.

Worn / new chain / cassette combos can cause skipping in certain gears, but not cause it to muck up the indexing.

Odd indexing issues are frequently:

1) bent mech hanger
2) Cable fraying / snagging somewhere; with Shimano 105 the cable often starts to fray inside the shifter and it's a good idea to replace it before it goes too far
3) Cable routed incorrectly at the clamp bolt on the rear mech

wiganwarriors

Hey. I was having the exact same issue. My problem was a bent hanger that eventually was broken by the mechanic due to the fact it was that out of alignment. it was replaced and indexing is as it should be for Ultegra spot on.

gozzy

If your gears aren't indexing properly, watch this video and follow what he does, then do it to your bike.

http://www.youtube.com/watch?v=SkzvfCaIbyQ

bradzin

I have a similar problem. Was going to start a new topic but it fits in here.

I have just replaced my 2300 drivetrain; with a sora chainset, cassette, rear mech and chain.

I cannot get the gears to index properly.

It will work OK on the smaller sprockets but as it moves up the cassette to larger sprockets the indexing goes out and the gears 'chatter' or jump 2 at a time. When moving down the cassette it will sometimes jump 2 sprockets at a time. Also the gears will work Ok on the smallest chainring but then be out when on the middle chain ring (its a triple chainset).

I have indexed gears before but really struggling with this one.

I have 8spd levers and cassette but 9spd chainset, but don't think that should have any major effect.

How can I tell if the mech hanger is bent?
Any other advice on things to try before a give in and take it to the bike shop?!

onbike 1939

It does sound like a bent hanger but this is sometimes difficult to spot. There is a tool which does the job but if you have another rear wheel you can use this. By removing the RD and then screwing the threaded axle of the spare wheel into the vacated socket of the RD (the original and spare wheels now in parallel) it's possible to see if the Hanger is plumb using the original wheel as your guide.

gozzy

Or your hanger is loose. Give the bolts a good tighten and try again.