Hi,
Can anybody help with the torque setting on the big end for a model 6?
Tim
same as I said there
A common fallacy is that 1920s bike makers makers set torque settings and published workshop manuals. They did not. Use a 12inch extension bar and common sense.
Trying to retro apply modern thinking to a near 100yr old machine rarely works.
Hi Tim,
I have to agree with Kbryt; torque settings are a (relatively) modern phenomenon and you need to use a bit of nouse - although it is true to say that settings are generally largely based on thread diameter, so for a given size and material there is a given setting. But in Sunbeam's day, correct torque was achieved by manufacturing spanners to a length that afforded enough leverage to complement the effort an average man could exert - but I'm certainly not convinced about the old tales of doing up crankpin nuts with 3 foot long spanners in the factories...
The only torque figures I recall reading for pre-1960s bike are from Indian, who suggested 75 lb/foot for cast iron flywheels and 100 lb/foot for Z metal (which was presumably a steel alloy).
Nowadays some people recommend pressing the wheels together and simply tightening the nuts to a degree that will keep them there, using loctite to prevent slackening. Torque settings are more relevant where the shafts are tapered without a shoulder (like Indian) where it's necessary to get them tight but not deform (stretch) the taper. The Sunbeams I have built have a taper but butt up to a shoulder, so you could press and lock them. It's also worth checking the clearance on the crankcase main bearing bosses, it's best to leave the points of the nuts at 3/9 o'clock, if they are at 12/6 they may strike the cases.
Cheers Rick