Bicycle Mechanics - non metal parts

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sevenhills

06-11-10, 01:40 PM

Hi

I was just looking in my local motor store and a cheap cycle that was on display had a plastic crank, I was quite surprised.
Is this ok, or is it just done for cost cutting?

S

Asi

06-11-10, 02:00 PM

I had seen a lot of plastic cranks on supermarket bikes (very cheap <60$, the whole bike is 60$) and with plastic brake levers, and others. But many of the "plastic cranks" are really from metal coated with a thick plastic housing (of 3-10mm thick).

"Exceptionally" low quality that is ;)

LarDasse74

06-11-10, 03:00 PM

Very cheap bikes have this. I am pretty sure it is just to make it look like a more expensive crank as better ones have much fatter aluminum arms.

Lots of cheap bikes have steel cranks which are quite skinny little things without plastic and I suspect this is what it underneatht he plastic on the bike you saw.

XO1

06-11-10, 08:19 PM

Indeed. There are no plastic cranks per se, just cheap steel cranks covered in plastic to disguise the fact they are pot metal steel.