One of my bikes has mounted a Shimano Roller Brake (BR-IM35 FF in my case). These brakes on my bike are basically not working anymore and I would like to replace them (it's not a cable issue. They were already bad when I bought the bike, I've never worried about greasing them and now they are null...)
My problem is now to find which one to choose. There's more than one version but I haven't found anywhere what is the difference between them (besides the price!). For example these websites have some examples:
What I can guess is that the IM denomination comes from "Inter M": https://bike.shimano.com/en-EU/technologies/component/details/shimano-inter-m
I've found these other discussion but no answer: Difference between BR-IM and BR-C Shimano drum brakes?
And on the Shimano website there's no information whatsoever. I've even tried the spanish, american and japanese website :D. I've found googling only some assembly drawing like this one for my brakes: http://si.shimano.com/pdfs/ev/EV-BR-IM35-FF-2776.pdf
Does anyone have any idea?! Are they still on production?
And well, if you're ending up on this discussion, you'll find some information on the might Sheldon Brown page: https://www.sheldonbrown.com/rollerbrakes.html