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Big end bearing. BSA or ALPHA?

If given a choice between a new BSA big end bearing or a new ALPHA big end bearing, which would you choose? I will need one for a M20 and a shop near me still has some BSA ones in the grease/wax coating from the 1960's. Are they of equal quality?

Re: Big end bearing. BSA or ALPHA?

A bearing dealer told me some time ago not to buy very old bearings.
He said that it is almost impossible to keep them in good condition over so many years. Even if they are fully covered in grease or whatever.
But others say it's no problem, so....

Re: Big end bearing. BSA or ALPHA?

I have had and fitted many original BSA big ends and have found the quality to be 100%...

However, as Mick points out it's all about storage with old parts and whether the original packing has maintained its integrity...

Basically, any corrosion on the bearing outer or crankpin roller track renders the big end effectively scrap IMO due to the potential for the surface to deteriorate further when put into service..

If your supplier is prepared to unwrap and inspect the big ends before sale to determine that they are good, or to reimburse you and take it back if you find problems yourself then I would go with an original myself....

If your supplier isn't prepared to stand by the condition and serviceability of what he's trying to sell I'd go with the Alpha assembly...Ian

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Re: Big end bearing. BSA or ALPHA?

Good advice Ian
If inspecting old stock look to the inside of the outer race. If there are light gray marks where the rollers have been positioned, walk away. A slow electrolytic reaction occurs and causes damage enough to matter. But if good condition. I would choose them first.

email (option): Dwrudd at lineone dot net

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