chain or gears ?.

jacklad

New Member
on a ride this evening i had the problem of my chain jerking on the middle cog on the front of my front triple when driving down with the right foot. also when changing onto the granny ring the chain slipped totally off a number of times.

any feedback would be wonderful. as, when it comes to the mechanics of a bike i'm thick as they come.
the bike is a ridley eos and has done around 1100 miles.
thanks in advance.
 

Fattman

Active Member
Location
Roydon, Essex
I would humbly suggest that maybe your cables have 'stretched' - after 1100 miles they might need a little adjusting.

The derailleur has a spring which tries to push the cage & therefore the chain down to the small chainring (cog). The cage is moved the other way by the gear cable which is pulled back against this spring and held at certain points by the 'click' of the shifting mechanism in the STI brake/shifter. If things have slackened/slipped a bit, the click will be holding the cable at a point where the derailleur is not properly lined up with the chainring.

The eos seems to come with Tiagra kit, which is jolly good. If you look where the cable coming out of the left-hand shifter meets the 'downtube' you should find a handy barrel adjuster. This can increase or release the tension on the cable, bringing the derailleur back in line with the chainrings.

Shift the rear gear into a middle cog at the back, then shift down to the granny ring to release the tension on the gear cable. Now rotate the barrel adjust a quarter turn anti-clockwise ("undoing it" as though opening a tap) and try shifting your front gear up to the middle ring, then up to the big ring. Basically, try repeating this a few times either way, quarter turns up and/or down, until it's shifting nicely.

The way I remember it is that it is counter-intuitive; "undoing" the cable adjuster tightens the cable - ie pulls it away from the way the spring wants to go.

Only hesitation is that it happens when pushing on the right foot - it may be that this coincides with the 'ramps' that make the chain move smoothly from one ring to the next, and it's catching cos of the misalignment.

hth
 

hut27

New Member
Location
Norfolk
Hello All, New here, So go easy on me. I didn't know how to start a new Thread and this one seemed close to what I need to know ,So here goes. I have bought a SH Giant Expression I think a DX model. Problem is Bottom Bracket is loose and definitely needs Tightening or Replacing. The Chain makes a noise and sometimes comes off. I like the Ride Position and would like to get bike fixed. I have tried to contact Giant but they don't reply to my emails and 'nor 'phone me back when they said they will. Ialso need a new front Aluminium mudguard and the Flimsy Plastic Chainguard. The only name I can see on the heads of what look like the Bolts to hold BB altogether is PROWHEEL. Help.
 

Tynan

Veteran
Location
e4
how old is the bike, BB's coming loose is rare I think, the bearing may have gone which would mean the BB itself being tight but the pedals feeling wobbly, that might casue problems with the chain although you may need to follow the instructions above too to adjust the gear shifting.

New mudguards need ordering and paying for

A bike shop is usually the first port of call for this sort of thing, try and go to an actual bike shop rather than a Halfords ty[e store
 

hut27

New Member
Location
Norfolk
Thanks for reply, I Think I read in Bike Spec' BB Casette type, Which to me means sealed unit and needs a new one. I have no idea of age, Serial # is C35FU441. If that means anything. I tried to order new Mudguard from GIANT but I can't get a reply from them. It seems to me that maybe they only want to sell new Bikes.
 

battered

Über Member
Local bike shop will sell you guards, advise on BB type, sell you the parts, sell you the tools if you want to DIY or fit them if you don't. It's all good.:biggrin:
 

hut27

New Member
Location
Norfolk
battered said:
Local bike shop will sell you guards, advise on BB type, sell you the parts, sell you the tools if you want to DIY or fit them if you don't. It's all good.:biggrin:

Thanks, Will try my local Bike shop,Iv'e used it before when doing up my Raleigh Superbe, which I might add was a lot easier to work on. No special tools needed etc. Will let you know how I get on.
 
Top Bottom