I’m building a new hardtail and wanted to give 27.5+ a go. And I know fat rims seem to be the fashion anyway even for skinnier tyres. So what width rim would be optimal for a regular tyre but that would also work well for 3 inchers when I fancy it? 35mm work or too skinny for a 3?

35 internal might be a reasonable compromise for 2.4-2.8″, but I’d look at different wheelsets for 2.2 vs 3.0.

If it’s a 650 frame, do you have clearance for 3.0″ tyres?
If it’s a 650+ frame, won’t the BB be too low with 650×2.2?

He’s asking sensible questions.

I’d just add that 35mm with 2.8in tyres works good and seems to be a popular compromise choice. I don’t think I’d want wider tyres for my use (mucking about in the woods).

Good question. It’s a custom frame that’ll be for 27.5+ and 29er so maybe I should just got something that’ll be optimal for 3 inch but not too bulky…

Stans have a view on this…

That would put you on a Flow which is 29mm internal. You’d be a wee bit “out” at either end of the scale, though probably not enough to matter.

If you’re going 29/650+ you’ll need 2 wheelsets anyway?

Just get some 40mm internal 650s and around 25-28ish for the 29ers if you want to run 2.2?