Chain drive in bath of oil

SunnY S

SunnY S

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Just reading up on BMWs latest scooters. Its a 647cc parallel twin.

Seems to make sense to me. Curious, why a typical, modern motorcycle wouldn't benefit from this?

Cost? Complexity?



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That cast chain case probably weighs a fair bit, and a lot of that weight is unsprung, too.
 
I know that a motorcycle manufacturer somewhere actually sold a bike this way, many years ago. I can't remember exactly who or when, though.

Edit: What the ... apparently Harley did this as recently as 1984.
 
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Yamaha had a 920cc v twin that had an enclosed chain, although I don't think it was oil bathed.
 
On a scooter yeah, on a sport bike nah. The weight and movement of the oil would mess with stability IMO. Not to mention that a chain is a lot more likely to snap/fail under 100-200hp acceleration then on a scooter and id hate to see the repair bill if it did inside the swingarm.
 
It looks like the swing arm pivot is the same as the sprocket centre line unlike most bikes, therefore the chain slack will remain constant with suspension movement allowing it to be adjusted relatively snug.
If your 200 hp sports bike breaks its chain it will likely wad up and do some serious damage to your engine rather than simply fall off.
 
It was oem for a few bikes many years ago.It's mostly about the ugly chaincase i think.
 
Why not just go shaft drive? Seal technology has vasly improved
 
Tripletrouble said:
It looks like the swing arm pivot is the same as the sprocket centre line unlike most bikes, therefore the chain slack will remain constant with suspension movement allowing it to be adjusted relatively snug.
Click to expand...

This, plus the fact that the rear arm pivot point is the output shaft means the chain can be sealed completely (the chain cover would just require o-rings around the output shaft and rear axle).
 
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