Thumper Club Forum
Club House => Chatter => Topic started by: iansoady on May 04, 2018, 09:46:40 AM
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Those of us with chain primary drive know how hard it is to tighten up or remove the crankshaft nut. Suggestions include putting the bike in top gear and standing on the rear brake, putting a bar between the spokes of the back wheel (ugh!) or jamming something unyielding between the primary chain and engine sprocket (double ugh!)
The most effective method is to use a sprag between the engine and clutch sprockets. This is simply a bar which fits between the teeth on the 2 sprockets in such a way that when you rotate the nut, the bar pushes against the sprockets in the opposite direction to the force the chain is exerting. I've used this successfully on may bikes - the latest being the ES2 (pictured). Purists would round off the ends of the bar but an ordinary chunk of mild steel or alloy seems to work OK for me.
The picture shows the sprag in the tightening position.
(http://www.iansoady.org.uk/Norton/images/sprag.jpg)
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Aye Ian,
That image brings back memories of wrestling with my old AJS 18S underneath the interchange at the M6 Junction 44 in a thunderstorm in August 1975. The dynamo moved sideways into the path of the primary chain! :( Absolute carnage and the pressed steel chaincase a little bent. However, managed to fix things up with a kindly local giving pillion assistance to obtain a primary chain, before carrying on to Killington Lake for a night kipping under the stars.
It is a bit different when doing the same operation on the helical gears of the Ducati singles! ;)
Hope you make good progress with the Easy2.
My regards, Bill
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Simple and effective. Thanks ian :)
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Yes, Matchless / Ajay dynamos are a disaster waiting to happen.....
Progress steady - I hope to have it up & running in the next few weeks then start to think about what I want to do to it over the winter (yes I know it's a little while off but I like to be prepared.....)
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Electric or pneumatic hammer gun no good? The electric one beat the 2004 Enfield massive nut. Now I have a compressor I'd be tempted to let a pneumatic one from work fall into the boot of the repmobile one Friday afternoon.
Everything on the CB is tiny. Just been fitting the electrics for my jacket and even my big screwdrivers were towards the front of the tray after the Bullet :)
Andy
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Aye Andy and Ian,
A CB? ??? What is the new bit of kit, please?
I would agree with you, when in the workshop, the electric or air hammer gun have never been known to fail, but the tightening with the torque wrench still requires a similar piece of apparatus.
As for the AJS/Matchy chains, my option would be to go for one of the more modern alternator models. I have also seen one fitted with a magneto and an alternator, giving the best of both worlds. Bit like an SRX! ;D
My regards, Bill