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General Category => Maintenance => Topic started by: las1200 on January 28, 2011, 10:40:24 AM

Title: moving rear wheel
Post by: las1200 on January 28, 2011, 10:40:24 AM
Hi FJ's!

Noticed rear wheel rotates gently if bike is running in neutral and in central stand position (off the ground)...
See no difference if I push cluch in.
Never noticed this before. Is this ok?
Title: Re: moving rear wheel
Post by: weymouth399 on January 28, 2011, 10:48:18 AM
A lot of bikes do this, my Fj doesn't.
Has the bike sat for any amount of time, possibly clutch drag from sticking clutch.
Bob W
Title: Re: moving rear wheel
Post by: las1200 on January 28, 2011, 10:55:31 AM
The clutch stick's fairly easy, say 24h stop.
Maybe thick oil? Cold weather perhaps...
Title: Re: moving rear wheel
Post by: weymouth399 on January 28, 2011, 11:05:15 AM
under 50 degrees I use 10/30
over 50 degrees 20/40-50 just dino oil (OK let the shit fly) (popcorn) in both the bike or racecar.
Also I just put 5/20 in the racecar for under 40 degrees worked fine. It can be cold in charlotte this time of year.   :bad: :crazy:
Bob W
Title: Re: moving rear wheel
Post by: craigo on January 28, 2011, 11:44:12 AM
Mine did it when I had the 16 inch wheel on her.  Now that I have a 17 inch, it seems to have stopped.  Just did an oil change as well using synthetic oil.  That may also have something to do with it also. 

Never bothered the bike nor me so I never worried about it.

CraigO
90FJ1200
Title: Re: moving rear wheel
Post by: mz_rider on January 28, 2011, 12:10:16 PM
Quote from: las1200 on January 28, 2011, 10:40:24 AM
Hi FJ's!

Noticed rear wheel rotates gently if bike is running in neutral and in central stand position (off the ground)...
See no difference if I push cluch in.
Never noticed this before. Is this ok?


There is a slight tendency for the rear wheel to rotate in neutral because of the way motorcycle gearboxes work. As I recall from stripping a gearbox (not FJ) a pair of gears are engaged in neutral. The input gear is being driven by the input shaft but the output gear is not driving its shaft. It is spinning on its needle rollers. There is therefore a slight force caused by the viscosity of the oil between the spinning gear and the static shaft. Some bikes don't spin their wheels because the resistance in the wheel bearings, chain, brakes etc is greater than the small force trying to turn the wheel. I hope some of this makes sense.

Stuart 
Title: Re: moving rear wheel
Post by: andyb on January 28, 2011, 12:13:38 PM
It's normal.

In the trans, there's gears that slide freely around the shafts, and those that slide up and down the shafts but are locked into position in the rotating direction.  They slide together, you're in gear, basically.  But there isn't a bearing between those that freewheel and the shaft, so some force is going to go between the two (if by no other effect than from the shearing stress on the oil between the shaft and gear).  So yeah, don't worry so much.
Title: Re: moving rear wheel
Post by: Mark Olson on January 28, 2011, 01:21:25 PM
Quote from: craigo on January 28, 2011, 11:44:12 AM
Mine did it when I had the 16 inch wheel on her.  Now that I have a 17 inch, it seems to have stopped.  Just did an oil change as well using synthetic oil.  That may also have something to do with it also. 

Never bothered the bike nor me so I never worried about it.

CraigO
90FJ1200

put a few miles on it . after everything gets loose , it will rotate again.
Title: Re: moving rear wheel
Post by: FJmonkey on January 28, 2011, 06:46:23 PM
My 86' does this when it is cold. After warm up and shifting through the gears I can shift to neutral and it won't turn while on the center stand. Cold to warm, oil (15/50 I think) & wet clutch...Maybe some Amsoil can fix it when it is cold??? It really does not bother me as I am not affected by it when I am sitting on it. I hope to try the 17" upgrade to see if that helps.
Title: Re: moving rear wheel
Post by: andyb on January 29, 2011, 02:26:17 AM
Is it really a huge problem?  I mean, it's not like it spins with much force, it doesn't attract small children or nuns, and it's really not that often that I will put the bike on the centerstand, while running, in neutral, unattended in the first place.

So, turn it off maybe, or stay with it so you can shoo away the small children and nuns who are likely to stick their fingers in the rotating parts?
Title: Re: moving rear wheel
Post by: las1200 on January 30, 2011, 10:36:53 AM
I think she's eager to go on a ride! :mocking: