Hi, need help with bike issue

squigs

Hi All,
On the way to work this morning as I was pedaling, every now and again I would pedal and it would just go around without doing anything, then re engage itself and be fine. On the way home it was doing the same, just spinning with out doing anything, then after pedaling for a while it would start working again.
Anyone know of a fix?

Cheers
Squigs

paulorg

That sounds like the bearings could be going in the rear wheel, they tend to slip a few times before the whole thing goes and you can spin the pedals but get no forward motion whatsoever. If you are lucky a good service or replacing the bearings if possible will sort it out, if not (like me) it could be a new wheel job. Either way, don't stand on your pedals and get out of the saddle til you've had it looked at

squigs

cheers,
bearings only 3 weeks old replaced in last service, so will get sorted for free.

Weejie54

Wheel bearings would not cause slippage. The chain is engaged with a rear sprocket which is, in turn, connected to the freehub. This is connected to the neck bone - oops, connected to the hub and the pawls connect it to a splined sleeve shaft which drives the hub. Wheel bearings, if worn, would cause wheel wobble or roughness but the hub would still be driven. Really bad wear might cause the chain to jump sprockets.
It could be a loose cassette, worn outer splines (those that the cassette engages with) or a worn freehub. I would be checking this out before anything else. However, worn splines would likely be noisy and be felt through the drivetrain.
Check chainring bolts too.

paulorg

I'll bow to the greater knowledge on this. I'm only going by what the LBS told me when it happened to me. It shouldn't happen so soon after a service whatever it's cause is.

skyd0g

Weejie54 wrote:

Wheel bearings would not cause slippage. The chain is engaged with a rear sprocket which is, in turn, connected to the freehub. This is connected to the neck bone - oops, connected to the hub and the pawls connect it to a splined sleeve shaft which drives the hub. Wheel bearings, if worn, would cause wheel wobble or roughness but the hub would still be driven. Really bad wear might cause the chain to jump sprockets.
It could be a loose cassette, worn outer splines (those that the cassette engages with) or a worn freehub. I would be checking this out before anything else. However, worn splines would likely be noisy and be felt through the drivetrain.
Check chainring bolts too.

+1

Def not the bearings. Pawls/freehub/cassette not correctly tightened.

squigs

Cheers everyone,
taking to my store this morning to sort out, good guys up there so will keep you posted.

MattC59

my bet is that it's the pawls in the freehub not engaging.

If it was a worn chain / cassette / chainrings, you'd get a lot of noise as it slipped. A freehub that's not engaging will just let go. It could be that during the last service, they packed too much, or too thick a grease back into the freehub and this isn't allowing the pawls to spring back and engage in time for the next tooth.

If something's broken in the freehub, you'd hear it, a broken pawl makes an awful noise.

squigs

MattC59 wrote:

my bet is that it's the pawls in the freehub not engaging.

If it was a worn chain / cassette / chainrings, you'd get a lot of noise as it slipped. A freehub that's not engaging will just let go. It could be that during the last service, they packed too much, or too thick a grease back into the freehub and this isn't allowing the pawls to spring back and engage in time for the next tooth.

If something's broken in the freehub, you'd hear it, a broken pawl makes an awful noise.

Bingo,
just dropped bike off to Certini and they are fixing it under warranty.
Its the free hub.
I didnt even ask about the warranty, i thought it would be down to the mileage i had clocked up.
This is why I like this shop so much. Great customer service.