LCGB Forums

Hi

I've just been fitting a new Varitronic system to my scooter, it has an Li crank taper.

Following instructions and using the supplied nut and spring washer I was trying to torque it up to 50 ft lbs as specified and all of a sudden things started getting easier instead of harder..... I removed the flywheel again to find the nut has begun to strip it's threads and the washer had started digging in to the flywheel..... The crank threads fortunately don't look as though they've suffered too much thankfully..... Any ideas what I may have done wrong? I'm pretty sure the torque wrench is ok, it's only a year or so old and hardly used (Draper)...... I nearly s*** myself and just hope I haven't done something stupid or knackered anything beyond repair.

I'd be really grateful if anyone can advise please, thanks in advance..

Left hand thread, most toque wrenches only function/click on a right hand thread unless you have a push through type drive on the end of the torque wrench.

So I'm guessing you've over tightened the nut and stripped the thread as the torque wrench will not click.

Oh Arse..... Schoolboy error, I didn't realise that. What a berk.... I just hope it hasn't done any structural damage to the flywheel, I can get another nut.

Ah well, live and learn. Thanks for your reply, won't be doing that again,

Cheers,

Hugh.

Pretty sure all draper torque wrenches have settings for both left and right hand threads, in fact I have 3 different makes of torque wrenches and they are all able to read for both right and left threaded settings.

Donnie wrote:Pretty sure all draper torque wrenches have settings for both left and right hand threads, in fact I have 3 different makes of torque wrenches and they are all able to read for both right and left threaded settings.

You might be right, but generally torque wrenches with a reversable ratchet don't necessarily measure torque in reverse (left handed thread)
you usually need to buy a torque wrench with a push through drive.

http://www.toolstop.co.uk/norbar-13047- ... -mod-p4971

I have one of those with the bendy scale on, should have used that had I realised. Have now dug it out and ordered new flywheel nut. My Clarke one clearly doesn't work on left hand threads!

Hughieboy wrote:I have one of those with the bendy scale on, should have used that had I realised. Have now dug it out and ordered new flywheel nut. My Clarke one clearly doesn't work on left hand threads!

Like this one ?



That was the very first type of torque wrench I owned, I bought it around 1980.

Mine was Draper and I think it cost around £10 which was very cheap and it torques both clockwise and anti clockwise.

Yep, just like that one! I guess they're accurate?

I've got two others a small Draper one and larger Clarke one depending on how small/large the setting needs to be. Not worth buying a whole new one just for left hand threads..... Wish I'd used it in the first place though! (Doh!)

yep thats one of the ones I have