Dylansbob 

Anyone know if an Easton EC70 carbon fork will clear a 38c 650b tire (or I guess vice-versa)? I bought a 853 framed KHS a few months ago from the co-op with the vision of making it into a 650b coversion. Of course, I still need to find a fork that will work and I saw a deal on the EC70 fork. I'm probably just going to run the cheap ZAC19 rims when the time comes, which I think are ~23mm wide.

nwbikeman

A 38c tire will not clear on most 700c sized carbon forks as most will only go to 26c and maybe 28c as the clearance is getting a lot tighter on the newer race bike frames and forks. I have seen some 700c forks out now that will clear a 38c tire with fenders. Recently an IRD Tange carbon fork with eyelets, But 650B tires and wheels are virtually obsolete here in tyhe states. Raleigh sold a bike about 15yrs ago with this size. I wouldn't recommend it just for parts available to you and finding a brake that has the reach and enough clearance to work.

Dylansbob 

Actually there are multiple 650B tires out now, Panaracer alone make 3 or 4 different models. As far as brakes go, that's what Tektro R556s are for.

I just need to find out what the inside width is on that particular fork. If I know that, I can get a pretty good idea if the wheel/tire combo will fit that. Height isn't an issue as the smaller diameter wheel/fatter tire works out to about the same rolling diameter of a 700x23.

shelbyfv

The measurement needed is 320mm from the axle center. It needs 42mm space to clear a 38mm 650B. Maybe someone has one they can measure for you.

Dylansbob 

Awesome.

That's exactly the info I was looking for. I'll email the shop that has the deal on them and see if they are willing to measure it for me.