That's so cool that you got this to work on a race bike. I'd love to do a 650b on my Bridgestone RB-1 but I doubt I'd get a 38c tire in there; and if you can't go as fat as 38c, I'm skeptical that this conversion is worth doing.

You folks reminded me to make sure I have Gorilla Tape or similar in my tool bags.

That and a few tie wraps. I was riding down the California coast a few decades ago with a buddy, and one of his rear rack stays broke. We made it three more days with both liberally applied.

Right. Tie wraps. Thanks. I suppose some people use bailing wire.

Who ever heard of Gauloises with a filter? That ain't right. You think JP Sartre or Leonard Cohen smoked filtered Gauloises? If you're gonna do the thing, do the thing right and lose the filter.

I'm in the process of a 650b conversion on a Schwinn Tempo. I'm using the rims mentioned earlier in the thread from e-bay seller uglyrm and the Tektro long reach brakes. I alxso have a 3x9 drivetrain with bar ends. I'm out of town on business right now, this is the only picture I have, but I've put a set of Pari Moto 38's on there and they look and fit fine. haven't had a chance to ride this one yet, but looking forward to getting home and taking it for a spin.

Correct, smoking a filtered Gauloise is like riding a Singer w/ 'lectric shifting: Simply Not Done.

-Bandera

I love the saddle on the bike. This bike just looks comfy. I'll be curious to hear about the ride quality as well as the quality of those inexpensive 650b wheels.

Is smoking unfiltered Gauloises even a C&V thing? Heck this is America; if we're going to talk about bikes and recreational drugs we should do what the guys on repack hill did in Marin county and break out the weed. Bike riding in the US has a lot more to do with long haired pot heads smoking marijuana than it does fancy French cigarettes and French wine,

Though I'm the one that provided the link to the cheap wheels, I have not tried them.

I do have weinmann zac19 rims on my Holdsworth 650b conversion, wheels I built myself. The rims are easy to work with, just your basic double wall rim.

I have never been able to get my tires to seat on them quite right, though. Seating tires is not a personal speciality, so take that any way you like. Hetres, Col-de-la-vie, Cerf(?), I've used three different tires and couldn't get any of them to seat right.

Also had a pair of velocity rims, same problem. So, obviously, let's hope everyone else has better luck!

I think there's a rule against discussing illegal drugs, though. Perhaps in this historical context you could get away with it, but... Eh, I poke the hornets' nest enough in my own unwitting way, I'll leave that stick to you.

Well you may be right (so I'll move on to discussing the finer points of 650b wheels) but it was meant as a joke, it is what happened, and the stuff is being decriminalized in a lot of states at this point.

I bought a pack of Gauloises (the real thing in the blue pack, of course) after completing Paris-Brest-Paris last year.

And really, I don't know why you guys want to take the easy way toward 650B bliss, when there is potential for so much more self-discovery. I decided to try fat tires and fenders on the cheap to start, with 650A rims and Col de la Vie tires, shoving everything into a 700C racing frame, and not caring one whit about what the whole thing weighed. And after that didn't satisfy, building up another set of wheels (650B) with more tires, and replacing nearly every component. Much better, but now I need a custom fork with more rake for less trail. And after that, I'll want a lighter frame with vertical dropouts.

Then I'll be happy.

To get back on track the latest issue of BQ might be quite relevant:

"For those on a more limited budget, Steve Frey explains how he made a competent 650B randonneur bike out of an old Trek with few tools, learning the skills as he went."

-Bandera

It looks like I'll have to buy the latest copy of BQ! That is the way to go. The best price I've seen on silver 650b rims are soma weymouth at around $50 each. Tiagra hubs are pretty cheap and come in silver. Looks like I'll have to brush up on my wheel building skills.

He posts here occasionally as "lonesomesteve".

Anybody do a 650b conversion on a classic Trek with 38mm tires under fenders?



Bridgestone RB-1 650b conversion?



No pics for some reason, but I can get Soma B-Lines on there. They claim 38mm, but are closer to 36mm. True 38's would require your dimpler.

I've heard there is a fence somewhere, but gugie knocked it down... I'm not sure why anybody rides clinchers under 35mm.

Last year I started with the uglyrm 650b wheels for the RB-1, then bought a vintage 650b set to convert a bike for my friend (she loves it), then built a 650b set for the Trek. It happened to be the very first pair of wheels that I built myself and there are more 650b sets to come!

At first I thought all these 650b conversion people were nuts... now I can't find any of my marbles...

I've done 650b conversions on bikes that could only fit 650 x 32mm tires, but those are very nice Grand Bois tires and still give a much cushier ride than the max 700 x 25mm tires the bike would normally have.

Sweet. Which model Trek is this? Looks like you topped out at 36mm. I thought that 38mm was sort of the gold standard for conversions since that gives you the same diameter as 700 x 19c? Although it's hard to imagine 2 mm making a big difference.

I especially like the way you have the zeal hp pump mounted. That can be an issue with older bikes that lack a pump peg. How did you macgyver that?

How fat a tire can you fit on a RB-1? I'm skeptical that you can get close to 38mm on a racing bike.

Has heel strike been an issue? From what I've read, 650 x 38c gives you roughly the same diameter as 700 x 19c.

BikeCalc.com - How to calculate Bicycle Wheel Size

Does this give you heel strike problems?

I assume you mean toe-clip overlap, not heel strike? If so, no, it hasn't been a problem. From the chart you link to, the diameter of a 650B x 38mm wheel = 660mm while 700 x 25mm = 672mm, so we're talking smaller.

If you mean heel strike, I'm not sure how that's related, but I don't know much about touring bikes.

If you drop the BB, then the crank arm might clip the ground on a turn assuming you're pedaling; not an issue if you keep the arm up in a turn.

I had a bike once that I converted from 700c to 26 inch. Not a really bright idea I guess but I wanted to use a fatter tire. That bike had heel strike problems but that was a much more radical drop in the BB than we are talking about here.

This is the best discussion I've seen online of some of the measurements you need to take into account when doing a 650b conversion, https://www.bikeman.com/bikeman-blogs...sion-guidlines

Bottom bracket height is one variable you need to think about; drop it too much and pedal strike becomes a real possibility.

Right, "pedal strike," the pedal hitting the ground. Not a pretty thing. Especially nasty if you're riding a fixie.

"Heel strike" refers to interference between the rider's heel and the pannier. It was a common problem when bike touring became popular in the 1970's when a lot of the equipment wasn't optimized for the purpose. Chain stays were not long enough, luggage racks carried their weight too far forward, and panniers were too rectangular. After that, touring bikes got longer stays, luggage racks were redesigned to hold the weight farther back, and panniers now have a diagonal cut at the lower leading edge.




For what it's worth, here's my Holdsworth "531 Special" on a tour a couple years ago. This is a typical 1970's "race bike" with a short wheel base, and the luggage rack was a typical early 80's Jim Blackburn rack; it was retrofitted to serve as a tourer, I don't know when; so a classic candidate for heel strike. Nonetheless, heel strike was not a problem, owing to the design of the panniers and perhaps helped by my preference for shorter crank arms (165 mm). Here you see it with 650b Col-de-la-vie tires (38 mm). Pedal strike is also not a problem. Nor toeclip overlap, but then again I wasn't using toeclips.

Sorry for the confusion. '79 Trek 710 has 38mm Loup Loup Pass (accurate claim) Compass tires. '91 RB-1 has 38mm Soma B-Line tires (38mm claimed, 36-ish actual). How it fits all depends on the shape of the chainstays. I could get 700c 28mm tires on it, but the chainstay geometry doesn't spread out very fast behind the BB.

For the pump, I found a frame clamp peg, cut it down to the diameter of the seat stay and installed it. The peg part is located at the bolt so it was not too hard to cut it down, drill a new hole and mount it. Getting the length correct is the hard part. A little short isn't terrible, just open it up. But too long and you can't just redrill, you just end up making the bolt hole bigger so you have to use a shim instead.

FWIW, I haven't ever experienced pedal strike, but I don't often power through tight, fast corners.

If you're running a 650b x 38 mm tire or larger, pedal strike should be a non issue since that wheel and tire will have roughly the same diameter as a 700 x 20c (or perhaps a bit larger). The online sites are not in agreement on this when it comes to measuring wheel diameter but this is close enough.

This is very useful. I have a 1979 Trek 510 hanging on a hook in my workshop that I was thinking of using for a 650b conversion. I measured it out and thought it would work fine based on the measurements but it's good to know that you managed 38mm tires on your 1979 Trek 710. The 1979 710, 510, and 910 all have the same geometry; the difference is in the tubing. Do you think you could fit a 42 mm tire on your 1979 Trek 710?

And I'm really surprised (pleasantly) that you managed 38 mm tires on your 1991 RB-1 but your bike may have more clearance than my 1993 RB-1. I'd switch over in a heartbeat to 650bs if I could fit a 650b x 38mm tire on my RB-1 . . .