rear wheel

[custard]

Hi All
Just put a new rear disc on, put the wheel back on and thought I would put the bike on the centre stand, start the bike, and give the wheel a bit of a turn just to check everything was turning ok. Done this and discovered that when the bike is in gear and with the back wheel spinning of the ground, it make quite a lot of knocking and noise, IS THIS NORMAL???

Thanks

 

[haydw]

As far as I am aware yes- there is no weight on the suspension so the swingarm / final drive angle is not where it should be.

Mine did it when it was in SSB testing the gear sensor- bike was on its stand going through gears- mechanic said perfectly normal as the shaft is not in line but is when riding.

 

[RickG]

Yes, that's normal. A combintion of the backlash in the gears, the way U/J's transmit power when at an angle and the big thumps of power from a twin all combine to make the unloaded transmission sound like a pair of iron robots sh**ging on a tin roof. If you repeat the experiment and very gently put the brakes on to load the transmission you'll find most of the racket will cease.

 

[littleredrooster]

Running the bike in gear on the stand is one of the worst things you can do to the transmission. It puts huge alternating inertia forces through the components, and makes the noise you describe. It's like opening and closing the throttle 2400 times per minute.

 

[GSmonkey]

yep - it'll sound like a box of spanners.

http://en.wikipedia.org/wiki/Backlash_(engineering)