On 8 Dec 2004 06:34:13 -0800, "dkahn400" <
[email protected]> wrote:
>Martin Wilson wrote:
>
>> Maybe not enough chain tension or maybe the chain has stretched or
>> worn badly. You've probably knocked up a fair few miles there. Are
>> you a heavy rider? Lots of hills on route?
>
>The chain almost certainly has stretched, but this has nothing to do
>with the weight of the rider or the amount of hill climbing done.
>Stretching is caused by wear at the rollers and is accelerated by
>lubricating a dirty chain. The plates of the chain do not themselves
>stretch significantly.
>
Nothing to do with the weight of the rider and amount of hill
climbing?!
How do you work that out as it seems totally illogical. For a start
the chain would be under greater tension and would snap into the
sprocket grooves with greater force as it goes round because the
tension is greater and this would cause more wear to the rollers. I'll
admit the wear and tear is also heaviliy related to how the bike is
ridden and what gears are selected but it makes no sense to me to say
its not related to weight or hill climbing.
Your statement seems totally incorrect.
>> 1) Make sure there are no stiff links in the chain. Its a tighter
>> bend with the smaller cog/higher rear gear. Clean/degrease then
>> lubricate and make sure no stiff links.
>
>Good advice. A stiff link is a possibility. You can generally ease it
>by grasping the chain firmly either side of the stiff link and flexing
>the chain hard sideways in both directions.
>
>> 2) Making sure the wheel is as far back as possible in the frame
>> dropouts.
>
>I'd be very surprised if the OP's bike has horizontal dropouts.
>
Fair enough I made the point just in case it did as lots of bikes do
near the bottom end of pricing and don't know the OP's specific bike.
>> 5) Replace chain and possibly cassette :-(
>
>If the chain needs replacing the cassette definitely will. A new chain
>on a worn cassette will skip like mad.
>
You obviously live in a world where chains don't rust or have stiff
links that can't be freed up. There are times when a chain needs to be
replaced because only the chain is at fault. You don't need to replace
a cassette because your chain has permanent stiff links.
>> 6) Try a cheap bodge like removing 2 chain links to increase chain
>> tension if you can get away with this (i.e. have enough play across
>> the whole gear range to do this and chain may have slightly stretched
>> with use).
>
>This is risking damage if the rider selects the big/big combination,
>which admittedly he shouldn't do. If the chain has stretched that much
>then both it and the cassette need replacing.
If you've already checked that it would be ok before removing the
links as suggested then you shouldn't have any problems afterwards.
I have to say that I think the OP probably has a fairly common problem
because mountain bikes used on the road often face a lack of fast
gearing so you end up riding 60-70% of the time in the same gear.
He may have worn out the smallest sprocket on his cassette and chain
and nothing else. I don't know if he's fortunate enough to be able to
replace individual sprockets but if so he could probably get away with
just replacing the smallest sprocket.
If he does have to replace the whole cassette now would be time to get
a better range of gears. Possibly his existing cassette has 13 or 12
teeth on its smallest sprocket and he should definitely think about
getting one with 11 teeth at the bottom end. He'll go a bit faster and
enjoy cycling a bit more and save himself a bit of time. Perhaps with
the time saved he can do a bit of overtime to help pay for the
upgrade.