As per title plus a 'please'.
for £3.99 on ebay I wouldn't bother making your own.
this looks like a good (albeit not homemade) solution...
[url= http://www.bikerumor.com/2010/09/03/tomac-k-edge-release-most-technogically-advanced-anti-chainsuck-device-ever/ ]http://www.bikerumor.com/2010/09/03/tomac-k-edge-release-most-technogically-advanced-anti-chainsuck-device-ever/[/url]
Please define "Chain suck"....
Is it where your chain falls off and gets rammed in between the small chain ring and the bottom bracket?
Please define "Chain suck"....
Its where the chain stays stuck to your chain rings and is hooked up (or 'sukced') inbetween the chainring and the chain-stay.
Caused by worn rings and a dirty drive train. Many say its also due to frame design but that is more a factor in the outcome not the cause of the chain sticking to the rings (ie. badly gouged chainstays).
More of a concern is getting it rammed between small chainring and the chainstay, gougeing the shit out of it and making you wonder whther you've borked your frame.
I've got one that came with the dekerf that looks does the trick but looks very home made. 2 to 3mm (2.5mm??) ally plate with hacksaw cutouts per chainring, 2 threaded inserts in frame and 2 oversized holes in the plate + washers to allow alignment with chainrinrings before tightening. Does the trick lovely.
Edit: missed the last post between starting mine, answering the phone, and finishing. I'll post a pic of mine when I get home, if I remember!
