Thursday, October 15, 2009
The Perfect Chain Idler/Tensioner
My Uncle, (speaking with anonymity) educates me on a product. A product I have found to be extremely useful for anyone who has had a skateboard wheel chain tensioner blow out!
Ultra high molecular weight polyethylene (UHMWPE), also known as high-performance polyethylene (HPPE). I found this to be a very tough material, with the highest impact strength of any thermoplastic presently made. It is highly resistant to corrosive chemicals. It has extremely low moisture absorption, has a very low coefficient of friction, is self-lubricating, and is highly resistant to abrasion (more resistant to abrasion than carbon steel). Its coefficient of friction is significantly lower than that of nylon and is comparable to that of Teflon, but UHMWPE has better abrasion resistance than Teflon. It is odorless, tasteless, and nontoxic.
This block of polyethylene,
plus a pair of .3125" (5/16") x 0.875" single row - double sealed radial high speed bearings,
produces the best, low friction, self lubricating chain tensioner.