Chain adjustment questions.

Hi all,
I'll keep this brief but hopefully informative - I've got a K1 naked curvy, with about 63 thousand on the clock. Over the last week I'd noticed changing down from 3rd, 2nd, neutral to 1st had become difficult, requiring a bit of fiddling (or pulling away in third!)

The chain had become very slack, and as this has been the cause of this gear-changing problem before, thought I'd try adjusting it myself (my usual in-house mechanic being unavailable). So, tightened it until it looked/felt right, but on rolling the bike back and forward there was an intermittent knock from underneath.

I think this is tight-spots in the chain 'snapping' round the sprocket, so decided to slacken off the chain a bit. Did this, took it for a test ride, and now can't change up out of 3rd!

So, given that I clearly shouldn't be allowed within six feet of a socket set, has anyone any advice on how to rectify this?

[Biker Biggles]

Start by lubing the gear lever where it pivots on the footrest.That is a common cause of shifting problems.Then sort the chain.There needs to be about 30cm of vertical slack measured in the middle of the bottom run of the chain.If there is a great deal of variation in this slack whe you measure different parts of the chain it is shot and needs a new one.

I suspect the chain is shot, it's done 16K which is the exact interval at which the last chain and sprocket were replaced.

Take your point about lubing the gear lever, but something I have done is now stopping me shift up which has never been an issue before.

Tension looks right (and I guess you mean 30mm rather than 30cm!), but could tension/wheel alignment now be my problem?

[rictus01]

good idea to check the pivot, but if that was better before you adjusted the chain, then it's unlikely the cause, likewise engine oil level can give gear shift problems.

If you chain has "tight spots" then they really need sorting first, a little wd40 or something of that nature and work them by hand until they move freely, don't forget to lube them afterwards (WD40 isn't lube), change adjustment is easily checked, sit on the bike and reach down with you left hand, in the middle of the lower run you should have and inch movement up and down without pushing it hard, that's close enough.

I see you're in Ewell, get really stuck and I'll be passing through Epsom Thursday evening at about 8.30-9pm if you want a hand.

Cheers Mark.

Thanks Mark, that's a really kind offer, but really not necessary - the resident mech will be be back by then so it can become his problem. I was hoping to sort it myself in the meantime though (kicking myself for having buggered it, and being punished by having to use the car for work!)

Thanks again for the info,
bhd.

[rictus01]

no worries, perhaps watch your resident mechanic and you'll know what to do the next time


Cheers Mark.

[Biker Biggles]

Originally Posted by bhd

I suspect the chain is shot, it's done 16K which is the exact interval at which the last chain and sprocket were replaced.

Take your point about lubing the gear lever, but something I have done is now stopping me shift up which has never been an issue before.

Tension looks right (and I guess you mean 30mm rather than 30cm!), but could tension/wheel alignment now be my problem?

Sorry 30mmYes
I noticed your problem started before you did the chain,getting worse over time.Thats why I suggested there might be another issue there.Worth checking everything related to it.

[punyXpress]

Are you wearing bulkier boots?
That may stop the gear lever centralising.

Originally Posted by Biker Biggles

Sorry 30mmYes
I noticed your problem started before you did the chain,getting worse over time.Thats why I suggested there might be another issue there.Worth checking everything related to it.

This is true, I may be seeing a cause and effect which aren't there - back to basics I think.
Thanks again,

Update - as I know you're all on the edge of your seat - I now can't change gear at all, having knocked the bike off the sidestand and snapped the end of the gear lever off!