A 180 crank is a single plane, look down the end of the crankshaft. the crankpins are in a single plane its not rocket surgery.
Gregs crankshaft is a 180 crank
https://en.wikipedia.org/wiki/Crossplane
pay special attention to the last paragraph.
Wouldn't it run better if it made some power every time the piston came to the top?
Don't you look at my accountant.
He's the only one I've got.
Hmmm. My understanding was skewed it seems. I'd never thought of it past the firing times. But that makes sense to think of it from a mechanical view down the crank.
So TDM and TRX are cross plane then. Those are quite a nice motor. Wonder why the R1 was so horrid.
Possibly because having ensured that they had lower torque losses because of the spacing of power impulses, they decided that they didn't need as much flywheel....It would be interesting to try one with more crank weight.
Watching one of the few C-P R1's racing at levels last season, it was apparent that there was very little extra throttle needed to go from all the tyre could take to serious wheelspin. A vigorous rider could and did get it sideways and spinning too often for comfort.
I rode a mates R1M back roads around wairarapa and it was the easiest thing to ride fast I've ever been on. Way too easy for semblance of safety. Never ridden the newer standard R1 to compare.
Don't you look at my accountant.
He's the only one I've got.
You're right about firing pattern for the R1, 0°,90°,180°,270°. Followed by the exhaust strokes in the same order. Apparently no inertia, a blip of the throttle is instant. The R1 crank can roll freely on a table. Colin Edward's did this on the promotion of the cross plane crank back in the day. The whole concept was aimed at tyre recovery between pulses as a twin does. The crank is said to be heavier and stronger to handle the extra stresses caused by its design and firing pattern.
PS I have no idea of the firing order, no reason it couldn't be standard.
I'd love to know the firing pattern of the current triple if anyone knows. Crossplane maybe ?
flashg
Google helped
flashg
Meh, calling a 120deg triple a crossplane crank is like calling the sky blue. it's the only seriously practical way of balancing a triple.
And yes, I know all about the 180deg flatplane crank Laverdas. Worked on them, like them, but they're not smooth by comparison to a 120.
Marketing departments aren't famous for letting facts or common sense get in the way of a promotion
There are currently 2 users browsing this thread. (0 members and 2 guests)
Bookmarks