Author Topic: A7SS Main Bearing Ball or Roller?  (Read 333 times)

Offline Peter Gee

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A7SS Main Bearing Ball or Roller?
« on: 19.12. 2016 08:07 »
Hi guys, forgive my ignorance on the first ever BSA twin I have built. The bearing on my '57 A7SS, which engine showed every sign of never being opened, is a lipped roller LRJ30 + 2 shims,  very similar to that found on my 66 Triumph TR6. But I thought it was meant to be a ball journal? Comments?

Is having this LRJ30 going to cause difficulties in line reaming my new timing side bush, insofar as the drive bearing must be used as a pilot to do the line bore and LRJ is not a bearing that  the centre detached from the outer race, unlike a ball journal?

Thanks experts

Peter in Africa

Offline beezermacc

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Re: A7SS Main Bearing Ball or Roller?
« Reply #1 on: 19.12. 2016 08:13 »
Roller is correct. You can use the outer cage as a register for the line reaming process.
Priory Magnetos Ltd - A10 spares, magneto and dynamo refurbs.

Online edboy

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Re: A7SS Main Bearing Ball or Roller?
« Reply #2 on: 20.12. 2016 01:39 »
yes  thats what i do also except the new japanese ngk bearing is smaller diam than the old brit ones.