I'm skeptical you could fit a true 700x38 in there. On my '83 620, I have good clearance with an actual 32mm tire (Performance Metro "35"), but not enough room for a fender. On a previous 27" --> 700c conversion (an old Fuji S10S), I could fit a true 35mm Pasela in there, but it was nearly scraping the brake caliper undersides.
On Trek conversions I've read about, most folks struggle to fit a 42mm Hetre in there. 650B x 38mm is an easier fit, which I think typically also allows for fenders. Eric Daume bikingtoplay.blogspot.com On Thu, Aug 28, 2014 at 8:03 PM, cbone97 <cbon...@gmail.com> wrote: > So after selling my Sam (sniff sniff), I scored a 1985 Trek 420 with 27" > wheels. It's a beautiful lugged frame that looks like it was barely ridden > and I can't wait to get my collection of Rivy parts on it: SunRace > thumbshifter (singular, no front der), Dirt Drop stem, fancy drilled Tektro > levers, etc. > > Here's the hard part. I'm a hefty lad and need/want a fatter tire than > the fattest 27"ers made. The Trek has a rear hub spacing of 126mm and I > don't really want to cold set it to 130mm. At 126mm, options seem limited > to freewheel hubs. I'm ok with that, but all the prebuilt 700c 126mm > wheelsets have skinny rims for skinny tires. So it seems I need a custom > rear wheel - 126mm hub with a rim that will accommodate 38-50mm tires. > > If I'm going to have a rear wheel built on a 126mm hub, would it be > preferable to go 650b or 700c? Can I really get that much more air volume > with 650b tires? My rough measurements suggest that with 700c the rear > will fit 38mm tires. With 700c, I might? even fit a 50mm Big Ben on the > front a and a little Ben on the rear. While 650b theoretically will allow > a bigger tire, I'm not sure a 650b Big Ben will fit the rear, which might > put me > > Assuming that the Silvers will work for either size (reach the 650b rims), > which size might be best? I think either would be fine/ok, am I forgetting > anything? Should I REALLY not rule out cold setting to 130mm and going > with a freehub wheel? > > Thanks! > > -- > You received this message because you are subscribed to the Google Groups > "RBW Owners Bunch" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to rbw-owners-bunch+unsubscr...@googlegroups.com. > To post to this group, send email to rbw-owners-bunch@googlegroups.com. > Visit this group at http://groups.google.com/group/rbw-owners-bunch. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
