Spinning Wheel

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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thornebt
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Joined: Sun Apr 19, 2015 9:13 am
Location: Somerset, UK

Spinning Wheel

Post by thornebt »

I finally got my G80S back on the road today nearly two years after the crankpin broke. The bike has had a 'semi-restoration' - basically a spruce up with new paint etc. The job should have never taken this long. The timescale was drawn out due to family circumstances. Anyway, it was a great feeling to be riding the bike again on a beautiful summers day in Somerset. I probably did about thirty miles - hopefully long enough to prove it is basically sound as nothing broke!

However, when the bike is on the centre stand with the engine idling and in neutral the rear wheel spins round quite fast. I can stop it with my boot but it starts rotating immediately and gets up to speed. When the bike was last running a couple of years ago the wheel would just tick round slowly or stay still.

Before I remove the clutch cover on my newly painted chaincase I was hoping that someone can tell me what the likely cause is please. The clutch and gearbox work fine when on the road. If it's clutch pushrod adjustment that is required please make it really easy and tell me if it needs to be adjusted in or out.

Cheers. Bruce.
SPRIDDLER
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Re: Spinning Wheel

Post by SPRIDDLER »

thornebt wrote: The clutch and gearbox work fine when on the road. If it's clutch pushrod adjustment that is required please make it really easy and tell me if it needs to be adjusted in or out.
I take you mean that the clutch is engaged (unless you mean that the wheel is spinning with the clutch disengaged. I.e with the handlebar lever held in). The wheel will turn as you describe due to residual drag/friction within the various gears/shafts in and outside the 'box (even in Neutral). They all do that, Sir, in which case adjusting the clutch will have no effect.
Maybe when the wheel previously turned more slowly the rear brake was binding/rubbing a tad?
Glorious weather for riding, and worth the 2 year wait :)
'There is a tide in the affairs of men
Which taken at the flood............'
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thornebt
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Location: Somerset, UK

Re: Spinning Wheel

Post by thornebt »

Hi Neville. I guess I was just surprised that the rear wheel turned at such a speed. You're probably right - something was binding just enough to slow it down a couple of years ago. It's had a new rear chain, maybe as a result it is running smoother and reducing drag. Or maybe my newly greased rear wheel bearings could be causing it. Anyway I don't need to worry about it and that is good. Cheers. Bruce.
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Re: Spinning Wheel

Post by SPRIDDLER »

Yes, Bruce, the wheel will accelerate until it turns slightly slower than the speed of the final drive sprocket (due to drag on the smaller final drive sprocket driving the larger rear wheel sprocket) or alternatively, slightly slower than the clutch sprocket speed, depending upon where the drag is occurring.

"Nothing to see here. Move along".

Enjoy :beer:
'There is a tide in the affairs of men
Which taken at the flood............'
56G80S
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Re: Spinning Wheel

Post by 56G80S »

Yes, they all do that if you need a second opinion. Mine always has.

Johnny B
leswaller
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Location: Chipping Norton

Re: Spinning Wheel

Post by leswaller »

So does mine and my BSA and my Velo as well. Don't worry about it, it isn't going to cause any problems. If it annoys you take the bike off the centre stand before starting it
Les
Rules are for the obedience of fools and the guidance of the wise
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spookefoote1956
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Re: Spinning Wheel

Post by spookefoote1956 »

Stick a piece of card between the rear frame and the spokes. It will stop the wheel spinning and also make it sound like a new fangled multi when you race off down the road!
Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
"Creativity is your intelligence having fun" Albert Einstein
SPRIDDLER
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Re: Spinning Wheel

Post by SPRIDDLER »

spookefoote1956 wrote:Stick a piece of card between the rear frame and the spokes. It will stop the wheel spinning and also make it sound like a new fangled multi when you race off down the road!
You'd get a much better 'Yowllllll' from next door's cat, plus you'd be able to start eating home-grown lettuce and radishes again. (Don't ask...........
'There is a tide in the affairs of men
Which taken at the flood............'
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spookefoote1956
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Re: Spinning Wheel

Post by spookefoote1956 »

But if you put a plank up to a couple of bricks and do a jump all the girls will think you're well 'ard.
Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
"Creativity is your intelligence having fun" Albert Einstein
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