64mm stroke crank with 125mm rod

[Adam_Winstone]

^... agree 100% but the question is WHO and HOW MUCH? (mainly about crank webs, rather than casing work)

Adam

[Rich_T]

^... agree 100% but the question is WHO and HOW MUCH? (mainly about crank webs, rather than casing work)

Adam

I've just seen what this crank is for on the Rotax 300 posting. Alpha I'd go too but they'd be expensive for a one off crank, I'd guess you'd be looking at circa £500-£600 and I reckon they'd be reluctant to do it because of the high risk of it failing. There might be an option to design a cheap conversion around a stock 60mm crank with a welded eccentric pin and a serious amount of tungsten counter weight but its far from ideal and the last thing you want to do is stick an India Electronic on the end.

The cranks for my LC cylinder are 60 stroke, 102 diametre, 60mm wide and use CR250 rods. Those are roughly the proportions you should be aiming at.

[RManson]

You guys have vocalized all of my concerns. Shelling out the dough to get a one-off crank only to have it go 'boom' is not something I'm willing to live with. If it requires extra labor to fit something that will last, so be it.

Rich_T has a crank with wider webs that sounds like it may be perfect for this situation, although it won't have the 64mm stroke, his are 60. I guess I can modify the cases to lower the barrel to suit? I'll keep you guys posted!

Oh, and if you're interested, here's the build thread for the rest of the project...

http://scooterotica.org/forum/viewtopic ... 30&t=24797

[RManson]

Got the crank sorted thanks to Martin at Chiselspeed. 64mm stroke with a 125mm rod. Cost was 290 pounds and I supplied the rod, which was about 30 pounds.

[Adam_Winstone]

Cool, ta.