Originally Posted by
urbanknight
Basically, he did a crude test to see what happens when the chain falls off inside the big cog... and basically nothing really happened with or without the dork disc.
I get ya UB... It's hard to see... On my old PR-10 with it's old Campy derailleur skipping the chain off during a fast gear change can happen even when adjusted properly. Other times even with my 80's bikes when doing easy single track through high grass the derailleur can be nudged off during a shift. Of course that is quite infrequent. Lately I have been rethinking the old Dork Disk. I now have them on two of my bikes. I use them on the bikes that others may ride in that they may shift aggressively and flip that chain inward. This can happen more frequently when inexperienced riders use my non-indexed friction sifters. Of the three bikes I ride frequently one of them has a nice new clear plastic dork dish. Refusing to put a dork disk on the PR-10 my solution was to put a spacer inside the freewheel to give it a little more clearance... Ha
Of further note is the damage that comes from a slipped chain to the inner hub. If the rider keeps pedaling even a few turns the chain can do allot of damage to the spoke necks. In this picture I am trying to show that a jammed chain has caused small damage and abrasions to the most critical part of the spoke, the bend at the neck. I am now going to have to replace most of the spokes on this wheel.
