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View Full Version : My home made chain tensioner

takai
27-05-2007, 05:34 PM
Ok, with all the talk of chain tensioners flying around, and the seriously exorbitant prices some of the companies charge for chain devices i decided to make my own. Its just a simple one, based on the old DMR Chain Reactor and the Blackspire Stinger designs.

Currently it bolts in underneath the BB, and is constructed from 3mm plate ally, and reasonably light. I need to chuck the pulley up on a lathe in order to reduce the size of the granny ring area, but other than that it works pretty well. Ive also drilled a hole in the tensioner so i can add a bolt to the ISCG at a later stage, as i dont have any M6 button head bolts currently.

All up it took about 30mins to design and build, and then a few minutes to fit. A far cry from the $200 odd that E13 and many others want for a chain guide.

http://gallery2.plebeians.net/d/8706-2/20070527_Custom_Bike_Bits-0020.JPG

http://gallery2.plebeians.net/d/8721-2/20070527_Custom_Bike_Bits-0025.JPG
hayd
27-05-2007, 05:51 PM
How close does the metal plate to the tire? Is there any risk that a new tire with a bit more tread would touch it?

Other than that good job, looks great
takai
27-05-2007, 05:54 PM
Admittedly it is pretty damn close
http://gallery2.plebeians.net/d/8718-2/20070527_Custom_Bike_Bits-0024.JPG

But thats more to do with my spacers issue which is detailed on another thread. When i was looking at making it a lot of the chain tensioners ran this close, if not closer to the rear wheel.

Worst comes to worst though ill just make a new one, since the $10 worth of 3mm plate got me 1.8m of it.
bransly
27-05-2007, 05:59 PM
whoa thats sick! it's amazing how you made the fit so precise and sleak! where abouts did you get the roller from? was it off an old device?
pcmicro
27-05-2007, 06:15 PM
well heres my attempt its ment for a single speed.
takai
27-05-2007, 08:30 PM
whoa thats sick! it's amazing how you made the fit so precise and sleak! where abouts did you get the roller from? was it off an old device?

Making it precise just requires practice in making things from aluminum.
Such as this airbox on my race car:

http://gallery2.plebeians.net/d/6159-2/IMG_0015_003.JPG
http://gallery2.plebeians.net/d/5496-2/IMG_0014_002.JPG

And indeed building the entire car from a stock shell.

The roller was just from my not-so-local bike store (Mitcham Cycles, cheers guys)