SP crankshaft and alternator

Hi folks,

I’ve had a spare crankshaft together with complete alternator lurking in my loft for years now but the bike it was a spare for has long since gone (Steve R may remember it from the Southern Rally - it was a 851/SP4 creation with some nice Corsa Ohlins forks, mag wheels, etc). Anyway, wondered if anyone is interested before I get it down to take pictures, etc? It is virtually brand new and never used by me - I got it from John Fuller in a partial swap for my old 851 engine which he was going to try to put into his Monster.

Take it easy,


I remember the bike very well Martin it was a beautiful piece of kit, didn’t you sell it to but one of those fugly 999’s?
Is the SP Crank a 16 spline item and what’s the width of the rotor?

I got all excited then hoping it would be a 916SP crank. :frowning:

Steve P

Hi Steve, I did sell the bike but not to raise funds for the ‘fuggly’ (perhaps I’ll name it that!). It wasn’t getting used and space was running out - having said that refound batchelor-dom meant space reappeared - hey-ho. I’ve got a little fuggly as well as a trackday mount and that’s becoming a bit of a project bike.

No the crank isn’t 16 spline it’s 15 (I’ve just got it out of the loft and checked). The rotor is (about) 76mm diameter and 47mm long between castleations (if that makes sense?). How else can I identify it?


Hi Martin,
I need to check but would you sell the rotor on it’s own? TBH I don’t think it’s anything that special as they were also fitted to the 600SS and possibly the 750SS’s.
The cranks no use to me as I’ve gone down the longer stroke/more power and more grunt at lower revs on my bike.
My home brewed 851/916 is kicking out more power than my mates JHP tuned 926cc SP(4)S and it’s peaking at around 2,000 rpm lower. :smiley:
I’ve got all the parts now to build either a 955 or 984cc, but I’d like another 916 or 916SP/SPS crank to play with.

Steve R


I’ve sent you a PM.

Martin M