Ariel Owners Motorcycle Club

IF you are using the Later Piston pin size the bush will be very thick and bronze is quite dense. If the later rods are the same length I'd consider using one of them The VG rods use the same pin 29-30 on (Tapered ends and uncaged rollers).. Nev

nevhunter wrote: ↑Tue Feb 14, 2023 2:41 am the bush will be very thick and bronze is quite dense.

That's true, but in the end what matters is the balance factor. The discussion of the balance factor in my 1928 Ariel with original rod, bronze bush and modern piston takes 4-1/2 pages in my "shop manual" so I can't repeat it here but, coincidentally, the heavy bronze bush along with the lighter modern piston resulted in the correct 60% balance factor (more precisely, 59.2%). However, that was with an Omega piston. Had I used the 81 gram heavier Gandini piston the balance factor would have been 66%. The only way to correctly proceed is to weigh the components and calculate the balance factor, as per the discussion that starts on p. 125 of:

https://www.amazon.com/Ariel-Chronicles ... B0BN61Z6H1

I'm using the piston that was in the bike - 1" gudgeon pin. Its all good to use again.

Yes I even made a new one (1") and found when the end pads were pressed in the pin enlarged about .005" and had to be lapped to size afterwards. The end pads were aluminium,. Nev