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Final Drive
Posted: Sat Mar 04, 2017 12:32 am
by fontana
I may be wrong, but to me it seems that the R1200S was BMW's last stab at a shaft drive sports bike.
They seem to have given up now, and use chains like everyone else.
Is this driven by image because many still associate shaft drive with pipe and slipper tourers ?
Or is it that it's really just not possible to build a "proper" sports motorcycle using anything but a chain final drive.
Sorry if this seems like a question with a glaringly obvious answer, but I'm curious to know,
Re: Final Drive
Posted: Sat Mar 04, 2017 9:16 am
by Grip Fast
The disadvantages of shaft drive as I see it are:
Cost - shaft drive is more expensive to manufacture than chain drive.
Performance - sports bikes are all about performance, and shaft drive is power-sapping compared to chain drive (well maintained chain drive, that is).
Weight - as above, weight is an issue when looking for performance and handling (though the R12S is not heavy).
Torque effect - maybe this affects high-power sports bikes more than big touring bikes. Also effect on rear suspension performance is greater than chain drive, I believe.
Demand - long distance touring types want low-maintenance, clean, reliable shaft drive, sports bike riders are looking for performance and handling for their Sunday morning blast (no, that's not a dig at sports bike riders - I sometimes do a Sunday morning blast).
Thinking about it over breakfast, that's my tuppence-worth. Taking the bait - what's the glaringly obvious answer?
Re: Final Drive
Posted: Sat Mar 04, 2017 3:54 pm
by slparry
HP2S or the new R nine t Racer could both qualify as shaft sports bikes, as can the r1200r and the r1200rs
Re: Final Drive
Posted: Sat Mar 04, 2017 10:18 pm
by fontana
slparry wrote:the new R nine t Racer could both qualify as shaft sports bikes, as can the r1200r and the r1200rs
Those are sporty bikes but I'm talking sports bikes in the context of the likes of Ducati's Pannigale, Yamaha R1, et al.
The S1000RR is the only bike BMW make that can compete in that company, and it's chain drive.
Re: Final Drive
Posted: Sun Mar 05, 2017 9:42 am
by slparry
The bikes I mentioned are more akin to the R1200S you started the post with.
They've never done a shaft drive bike that could hold a candle to an S1000RR. Power losses, weight, inability to easily change ratios for varying tracks I guess. And being a bike that would likely be used as a track bike means many get chains and sprockets pampered compared to living on the road ... at a guess
Re: Final Drive
Posted: Sun Mar 05, 2017 10:05 am
by fontana
Yes, actually I agree that in the case of the R1200R which I've ridden, there is definitely a case that shaft drive could be used in the sports bike application.
That thing is a devastatingly effective tool.
I just think by now, in the 21st century, we should have moved on from bicycle technology, where the chain has it's routes in the days when bikes were just motorised bicycles.
Same goes for forks actually.