[ohffs]

An astonishing machine. See what you mean about that idler wheel design, it looks optimistic. Also the split-link in that chain

 

[ohffs]

Ah, it just looked under-engineered. I thought the weakness with the idler would be its rather flimsy adjustable mount, which looks like it'd flex under stress. I thought it would need a triangular carrier made of plate - two mounts at the bottom - with a tensioner adjustment slot on one mount.

I guess such a small idler is going to rev so fast and present a high load to small bearings. A bigger one would allow a larger spindle with larger bearings and use of an off the shelf output shaft sprocket. But maybe there isn't the offset to allow all that.

 

[ohffs]

Having seen that pic, I'd say you're right. Wow, that poor chain looks like it's been through a furnace.

EDIT: Idle thought : at 10k engine rpm in top (.91) that poor little 14T idler is going to be doing ~ (10,000 * 22/(14 * .91) = ~17,270rpm.