liverpool st. - broadgate circle

brucebanner

Hi, there's a person in broadgate cirlce in the morning who does various bikey things in the morning. Does anyone know how much he charges, roughly? I need to find out why my my chain in slipping when in the high gears and under high pressure, i.e., biggest chain ring and between the 1-3rd smallest sockets.

Also, when does he begin and end work?

Wrath Rob

Sounds like either the chain and cassette are worn or your gears need adjusting or you need to change how you use your gears and use the smaller front ring and middle gears instead. Bike gears don't tend to work to well at conflicting extremes, i.e. smallest front/smallest rear or largest front largest rear due to the alignment differences.

Its probably a combination of all 3 to be honest.

rjsterry

Big ring x small sprocket is fine, you're not crossing the chain there. Otherwise, it could be wear as WR said, or your chain could be too long - that gear combination will give a slacker chain than small ring x big sprocket

brucebanner

rjsterry wrote:

Big ring x small sprocket is fine, you're not crossing the chain there. Otherwise, it could be wear as WR said, or your chain could be too long - that gear combination will give a slacker chain than small ring x big sprocket

it's big chain ring and small sprocket. so, does that mean it just needs adjusting? how much is something like this likely to cost? i don't want to do it myself.

nyanza

Slipping under heavy load strongly suggests the cassette's worn - it's very common. Buy a cassette for about 20 quid (the cogs at the back) and the bloke will have a chainwhip (a nasty looking tool to hold the cassette still while he twists off the locknut) to remove the the old one and he can then just slide on the new one. It's a one minute job for anyone who knows what they are doing.

Look through the muck on your current cassette and you'll find some markings as to the model you need to replace it with. Alternatively, count the number of cogs (7,8 or 9 most likely, and count the teeth on the biggest and smallest cogs. eg. If it has 8 cogs and the biggest is 30 teeth and the smallest is 13 then you need to ask for an 8 speed 30-13 cassette. And if you change the cassette you need a new chain - another 10 or 15 quid. (You need a new chain as the old one will have worn and won't mesh with your new cassette teeth.)

However, just to be sure first, and without spending money, try adjusting the little barrel at the back of the derailleur (the arm that moves the chain up and down the cogs at the back) where the cable goes into it. Just a quarter turn at time. It's easy - just use your fingers - the barrel's designed for it. If there's no improvement it's almost certainly the cassette.