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Oversized Swinging Arm Pivot

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Having stripped down the Swinging Arm on my '72 Roadster I am faced with having to fit a 0.010" oversized spindle to take out excess play.  Can anyone recommend a source of 0.885" hand reamers please??

Seasons Greetings to all

RickP

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You need an expanding reamer to do this job, make sure its sharp and do it in stages, dont try to take the .010"out in one go.

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Thank you Peter.  Nice little job to do quietly over the holidays. 

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Richard,

Consider also that the swinging arm is best clamped securely so that it doesn't move, if you do use an expanding reamer the best method could be to clamp the work on a pillar drill table and turn the tool in the chuck by hand if possible. Use plenty of cutting oil and your finishing cuts should be much smaller than the first ones made. Remember that 0.10" is one hundredth of an inch, it's better to remove too little and come back to it later if you're unsure.

Well all that is fine but a bit of a faff perhaps, so as I type I'm wondering why you aren't fitting new bushes and spindle? If I have I reasoned your thinking and method incorrectly then apologies but the proper service kit is available from RGM the link is provided below

 

tps://www.rgmnorton.co.uk/dept/swinging-arm-fittings-commando_d01159.htm

 

Hi Graham,

the fundamental problem is the excess wear in the Engine/ Gearbox cradle spindle tube.   I really need to replace the cradle but they have been out of stock with AN for sometime and they are unable to say when they will be available again.  I purchased a spindle service kit from  RGM (inc a 0.010” oversized spindle) my thinking being that the oversized spindle would improve matters (admittedly it really needs something even larger than +0.010) particularly if done inconjunction with the Kegler clamps I’ve already fitted.  Do you think I’m wasting  my time trying the oversized spindle?  

 

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Ah, I hadn't considered that Richard!. I am a bit stumped as to what to recommend for the best as we are talking about very small tolerances here but I would personally go for replacement components if possible in the interests of safety and having confidence in the machine on the road. I have had a look on eBay and there are some cradles on there so have a look and be your own judge?

When you mention A N I take it that you refer to Andover Norton? The link below points to a replacement cradle as being in stock on their site? 

Good Luck and have a Good Christmas

Andover Norton - GEARBOX CRADLE - COTTERED & ADJ - 06.6972 (andover-norton.co.uk)

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Thanks Graham.  I’m not sure what the differences are but the cradle listed for the ‘72 is part number 06.4060 which is def out of stock.  I’ll contact AN after the holidays and enquire about the potential to use the later cradle.

 

merry christmas

Rick

 

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Bugger!  Sorry about that Rick. Ultimately not my decision but having thought about it you need this to be right when it's done. If my Commando had the same problem I'd replace the cradle, pin and bushes and not have to worry about it again. I have found many times that the most expensive route is the cheapest one long term.

All the best over the festive period!

Graham

 

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The worn tube is not that big of a deal. The main problem to solve is preventing the pin from moving freely as old timers like us know the 72 cradle tube were sloppy fit from new. Many 72 commandos were a bad fit.

The better fix over the kluger clamps is to weld on the REAR of the cradle tube some fine thread nuts at each end, inboard of the cradle plates. This was the suggested INOA fix here in the US before the popularization of the kluger clamps. I repaired mine in 1987 an still all is well for a very few $

The only benefit of the kluger clams is you don't remove the cradle.

Then a "standard" size swing arm pin goes in and forced forward with a bolt/screw.   Refrain from other suggestion to drill and tap the swing arm and pull it to the rear. Ask any educated engineer why? The late model swing arm flats are probably to narrow compare to the wider spacing of the welded on fine thread 1/4-28 nuts..

IMO do NOT ream the SA hole bigger

 

 


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