Fir rim question

[Jellybird3]

Hi all:

I recently picked up a new-to-me set of wheels with Fir Zenith rims. I can find almost no information online about these rims, other than on this forum, and I'm curious how big of a tire I can run.

Does anyone have any experience with these rims, specifically running anything wider than 23's?

Thanks.

[Mark McM]

I don't know the Fir Zenith wheels in particular, but clincher tire width compability is related to the inner width of the rim (width between the rim bead hooks). If you measure the rim inner width, you should be able to determine the tire widths that will work with the wheels.

Sheldon Brown's web site discussing this, including a chart which shows which width tires work with which rim widths:

http://sheldonbrown.com/tire-sizing.html#width

[Jellybird3]

There's a wealth of information on that website. Thanks for posting.

[redir]

I've got a set of Fir Mast rims built as a track wheelset. Great wheels and like your self I have found virtually no info on the web about them. It's an old Italian brand thats all I know.

[thinpin]

My wife has a pair of Zenith rims. She has run 25mm tyres on there with no issues. I believe they are 19mm rims so whatever an open pro takes these will match them.

[choke]

You shouldn't have any problem running as wide a tire as you want. I've ran 35s on Open4CDs without a hitch.

Back in the late 80s/early 90s the big thing for MTBs was skinny rims. Keith Bontrager cut down and re-rolled MA2/MA40 rims to make them 26". I have a set of those and have run 1.95s (49.5mm) on them from day one.