Excessive chain slack

[Sasakura]

Just got my NC24 and had to take it straight to the garage as it had no MOT. Had new tyres front and back and a few other things to pass that, only advisory was the exhaust being a bit tatty nothing major. Took it straight from the garage on a 2 hour trip (I'm aware I'm insane) to go watch some racing.

I didnt check the chain before I picked it up, but I cant imagine they'd have let it go in the condition i found it returning from watching. Chain was practically coming off the bottom fairing! Decided that since i was still 75 miles from home with no breakdown cover to ride it slowly home. Chain proceeded to fall off going round a deep roundabout luckily not catching anywhere, think it took a front tooth off at this point. Stuck it back on by hand, which wasnt hard.. and managed to get it somewhere safe...

Enough yarn, anyone got any ideas what could cause such stretch/slack in only a few hours riding? So far I've got:

*knackered chain
*knackered hub
*rear not tightened properly

(couldnt get lists to work )


Any suggestions before i start tearing apart my garage?!

edit: will put some photos up when i pick it up before it goes back to the garage

[Neosophist]

Rear hub not tightened properly?

Although in my experiences of this the chain always got very tight when the rear-hub wasn't bolted in properly.

There are only 2 x 12mm bolts on the rear that clamp the hub up.

Stick an allen-key or suitable pry-bar in the chain adjuster and see if you can rotate the hub... helps to have the rear lifted off teh floor.. get someone to pivot the bike on the side-stand if you dont have a paddock stand.

[Sasakura]

Have got it back to the garage now. They removed the rear wheel using the lugs so didnt touch the hub at all. Previous owner must not have tightened the main hub nut properly?

Pincher bolts were both tight, but the LH one wasnt flush with the actual body so probably isnt doing it's job properly, although I tried moving the hub and it didnt budge.

Ordered new chain+sprocks, hope the garage can figure out if anything's broken then. Probably going to reserve a spot soon, poor thing's been in the garage for so long >_<




A bit low you think?

[Jashdown]

Wow that's incredibly loose!

I thought mine was bad..

When tensioning the chain with the c spanner, do you just have to loosen the one pinch bolt and then rotate the adjuster with the c spanner? Does the wheel have to be off the ground?

[hardnutdvd]

i think it is easier with the wheel off the ground but i'm sure it can be done without the paddock stand.
your correct in thinking its just a case of loosening the pinch bolt, adjusting with a c-spanner and tightening the bolt back back up..

[CMSMJ1]

Wow that's incredibly loose!

I thought mine was bad..

When tensioning the chain with the c spanner, do you just have to loosen the one pinch bolt and then rotate the adjuster with the c spanner? Does the wheel have to be off the ground?

It is an NC24 in the OP. Howevermf or NC30, yes, undo the axle bolt and rotate using the C spanner. Wheel does not have to be off the ground

[Neosophist]

The hub-nut has nothing to do with adjust the hub, only to remove it. The pinch bolt or bolts if you have an NC24/30 are what you use to move the hub.

The NC24 has two x 12mm pinch bolts.. both need to be quite tight, just becuase you can't turn the hub by hand.. you don't have nearly 30ft-lbs of torque from the chain pulling at you.

The NC30 has only 1 x 14mm pinch bolt.

Slacken off either the 1 or 2 pinch bolts depending on bike.

The wheel doesn't have to be off the ground but it does make it a lot easier to move if it is, I always either paddock stand the bike or get a friend to pivot the bike over a little on the side-stand to lift the rear wheel.

The NC30 uses a C-spanner to adjust the bike, the NC24 you can use a screw-driver or allen-key or suitablly thick pokey-stick in the slots.

The NC30 adjuster is outside the hub between the chain and the hub and looks like a big castellated nut thats quite thin.

The NC24 adjuster in in the hub itself, if you look at the rear of the swingingarm and then look slightly underneath between your pinch bolts youll see the adjuster.

[Sasakura]

I had a poke at the hub before I sent it in and I couldnt get it to budge, although I wasnt putting that much effort into it. Did notice that the available hole was looking quite worn =__=

Will update when the garage gets back to me, hopefully new pinch nuts in cleaned holes will stop this happening again.