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Sturmey archer gear change.

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Hi guys

My 1931 Model 20 has a 4 speed Sturmey hand change fitted. The box inside is in lovely condition as is the clutch.

The problem is when the bike is not running the gearchange works perfectly, but when riding, when I am in first gear trying to shift to second, it is almost impossible to shift. As if locked in gear.

I have taken to pull away in second for the meantime, which isn't a problem.

Any ideas? Dogs?

Cheers

Paul N.

I removed the camplate plunger to eliminate that. As it has a gate change on the tank, it works 

ok without it.

As I said it shifts perfectly when not running. 

Paul

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...that could cause your problem. Gears can't unload to shift.

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As Michael said, a draggy clutch is normally the first suspect ,however your comments seem to  suggest the clutch is in good order?. Is there clearance between the back of the clutch and the end of the gear  box sleeve gear?. Look for wear marks indicating heavy  contact once assembled.

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I remember the late 20's flat tanker had the clutch retained differently from later 30's bikes.  Has the clutch started to make a bid for freedom? The one I rode did.

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I spent a long time getting the cluch lifting cleanly. (6 spring sturmey).

When the clutch lever is pulled in, the mainshaft by design gets pulled across by the clutch and the thrust washer pushes onto the sleeve gear. This does put a drag on the gearbox, so much so that if the rear wheel is turned, the clutch will try turning too. I can't see a way around this and think it is the root of my problem.

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....that you have confirmed a dragging clutch. 

 


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