Anti-chainsuck plates are also pretty easy to make out of flat plate aluminum or stainless. All you really need is a vice and a hacksaw. A dremel tool helps too. You can also customize the plate for specific chainring size combinations - although I think the Bontrager had individual tabs that could be positioned independantly.
It might be interesting to post photos of other anti-chainsuck plates here: Bontrager, Klein, Ringle ... anything else?
every bontrager antichainsuck plate I have used has either bent and/or failed. The last time it locked up the chainring, so I stopped using them. I've had more or less the same experience with IRD antichainsuck devices. Replacing chains and chain rings in a timely fashion has helped me more than those devices.
Correct...which had an annoying habit of loosening on each of the 3 x allen bolts that held the individual (replaceable) plates in place.
I've only had one Bontrager chain suck plate, but I never bent it, and the bolts never loosened. That bike was my race bike, my commuter bike, my adventure bike, and my touring through Switzerland and Italy bike. The plate is still there and still not bent and the bolts are still tight. Anyway, here is a picture.
Dirt from last fall is nothing. Some of the dirt in that picture is probably from Switzerland in 96! Vintage bikes have vintage dirt.
Mountain bikers, hikers and horseback riders are not the enemy. Bulldozers are the enemy.