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Acceptable crank runout

Posted: Fri Jul 03, 2015 11:06 pm
by coaster
Hi, this is linked to my other thread 'Avanti Woes' but I thought it's a subject worthy of it's own thread. In order to check the cranks in my ailing Avanti and the spare TS1, I mounted my dial gauge so that it measured the runout at the extreme end of the taper. The Avanti crank reads 0.06mm and the TS1 reads 0.04mm. Are either of these within tolerance? FWI, the Avanti was running smoothly with little vibration and the TS1 vibrated quite a lot :?

Cheers

Colin

Re: Acceptable crank runout

Posted: Fri Jul 03, 2015 11:29 pm
by coaster
Just ran those numbers through a converter and they work out to 0.0023" (2.3 thou) and 0.0015" (1.5 thou) which sound pretty good to me :?

Re: Acceptable crank runout

Posted: Fri Jul 03, 2015 11:46 pm
by wack 63
Max runout is 0.04 mm , I aim for 0.02mm or better using a jig.

Re: Acceptable crank runout

Posted: Sat Jul 04, 2015 12:35 am
by coaster
Cheers Wack

Re: Acceptable crank runout

Posted: Sat Jul 04, 2015 7:11 am
by Lambretta Sash
They seem ok, I prefer under 3 thou but also check where the bearings run which needs to be as close to 0.

Re: Acceptable crank runout

Posted: Sat Jul 04, 2015 7:44 am
by coaster
Thanks or the replies chaps, due to the time constraints I'm going with the TS1 engine as it is but will swap a few parts over like the flywheel and chain case (GP type clutch). Get it in the scoot today, give it some miles tomorrow and then Europe on Friday8-)

Thanks

Colin