Friday, August 28, 2009

standard chainline causes grief on Cruzbike

Gah.It did it again!
I was going uphill. Switching to easier and easier granny gear.
I left the front chainring on the biggest ring - again.
With moderate force on chain, as it reached the biggest cog, the chain had least play for the tensioner, and also the most severe sideways bend.
And... jammed solid. Again.
I think maybe I need a longer chain. Another 30 bux.
I think either a smaller largest cog or a longer chain may be desirable for a Cruzbike.
This is making me fond of the idea of a straight chain line and gear hubs.
I think the 1/8" track chain has bushes that keep it from falling off sideways or flexing enough for a standard bike system.

http://en.wikipedia.org/wiki/Track_bicycle#Chain

Chain

"There are two common widths of single speed and fixed gear bicycle chains: 1/8 inch and 3/32 inch. The chainring, sprocket and chain should all be the same width. Although an 1/8-inch chain will work on a 3/32-inch chainring or sprocket, it is not ideal. A 3/32-inch chain will not work on a 1/8-inch chainring or sprocket. Because they do not need to shift from sprocket to sprocket, track chains use a full bushing to allow little flex and to be stronger. All bicycles with derailleur gears use bushingless chains which flex, making gear changing possible."

D: though a belt system would be sooo much lighter for a RWD recumbent.

Hmm. OK, the idea of getting a single custom toothed belt rated at at least 1000kpf made sounds... difficult AND expensive.
I know recumbent SWB RWD bikes are pretty niche.
But the weight savings of a toothed belt/ gear hub arrangement would be great.
I wonder what the smallest limited production run would be for this?
Of course, investing in this could result in me retiring with crates of the things in the basement still, LOL.

D: this would require a conversion kit that interacts with standard bicycle components.

As always, I doubt a big company rep will talk to a lone innovator, but I'll try.
Gates company seems promising...

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