I'm thinking about doing a 650b conversion on this bike:



Right now it has 27" wheels with 27x1 pasela's on it, with wide hammered honjo's. It originall had sewups though, so I think it will be like doing a 700-650 conversion. I'm thinking of converting it for a few reasons:

- because i want to try 650b
- i don't ride this bike enough, and it's built very similiar to this anyway, which I will ride more because the top tube is longer.
- I think as my "650b" bike with the wider tires, then getting some racks of some sort I will use it more, mainly for my commute probably.
- VO's sale is going on, so I can get a good deal on 650b rims and I'll probably get the switchable dyno hub as well. then I'm thinking sturmey archer 5 speed shifted by a bar end, keeping drops on this bike.

so I guess my questions are, looking at the bike, do you see any issues? I don't thinking finding period center pulls to reach 650b wheels will be an issue.

the bike has an abnormally short top tube as these fuji's seem to have.

I'm not sure what the bb height is.

Oh and, it will get red Hetre's.

any technical hurdles anyone is seeing here? Thoughts or comments?

I think it's just a matter of crunching the numbers. BB height (probably not an issue), chainstay, seatstay and fork crown clearance for the 42mm tires. Today I ordered the 126mm hub, switchable dynamo, leather wrap and a bunch of other stuff likely to get me in dutch with the wife.

You might be able to use Dia Compe 750 centerpulls, but I would probably just go with Tektros.

Clearance between the chainstays is the first thing that comes to mind if you're planning for Hetres. Neal Lerner kindly measured his with a caliper to answer that question for me
So make sure you've got at least 40mm plus some breathing room between the chainstays at *about* 26-27 inches from the dropouts.


5 speed IGH with Drop Bars would be a nice setup.

holiday, if you decide to ever go with triple let me know. I could find a home for that crankset (and pump and pedals and saddle and... )

right right, I do need to measure to make sure I can fit hetres. If I don't have clearance for them though I'd probably still just run a thinner 650b.

There's a 650B group in Google Groups, where there's lots of discussion on conversions. Bill P

I Would get a frame that was designed for larger tires. Fenders & 42mm tires may be a bit much for that frame

I'm as much for 650B conversions as the next guy, but it's not going to solve the top tube being too short (and that's what I liked about my '72 Fuji Finest, but I still sold it to khatfull). I also think you'll need brakes with some very, very long reach as I was running 700c wheels on my Finest, and they were fair amount of reach. That said, 700c wheels also offered a ton of clearance, so I say try some 700c wheels and 30mm Grand Bois tires on your Finest, and save the 650B conversion for another candidate (such as a late 70s Raleigh Competition GS).

Neal

I haven't built any wheels in a little bit, I'd be happy to lace 'em up for you once you get all of the bits together.

Not to deter mudboy from doing a wheel build for you, but Anthony King of Longleaf Bicycles offered the following on the 650B list:

Anthony is a V-O dealer and thus carries all their bits. He built up a set of wheels for me and did a terrific job.

Neal

I'm trying to picture the bike with 650b wheels and fat tyres and my first impression is that the bike might end up looking a little strange due to the size of the bike and the short top tube.

Hey, us long-legged fellas like fatties too, Dave.

+1

Neal makes a valid point about brakes.

I worked around the same issue on my conversion by using Drum Brake Hubs (aka Roller Brake). They stop as well as any other brake and no worries about brake reach.

True ;-)
I'm actually not so short myself i'm 185cm but the 650b bikes that i have owned have been around 54 - 56cm.
I normally think i can get away with smaller frames when i just use them for cruising around. I tend not to be too uncomfortable on smaller frames by the time i have pushed the seat back and added a longer stem and maybe i have short legs for my size!?

If ya can't fit Heaters, the Soma B-Line is a SWEET tire. Labeled as a 650x38b, it measures 35-36mm on my Zac19 rims. Smooth, fast, easy to install. Oh, and only $40.

SP
Bend, OR

Yeah, but if the Fuji top tube is too short, a Comp GS would be TOO SHORT!!! (like 57cm tt on a 65cm frame)

SP
Bend, OR

Diameter-wise, Hetres and fenders would work fine, since 650x42b is (theoretically) the same diameter as 700x23c. Width may be a whole nother can of worms, tho...

SP
Bend, OR

Noooooooooooooooooooo! Looks good as it is.

Scott

True. Chainstays, fender mounting etc. Could require quite a bit of work to make it worthwhile

Hmm, maybe that's why I liked my 60cm Competition GS! Top tube was 57cm (c-c). My Ebisu was custom sized for me: 60cm seat tube and 55cm top tube.

Neal

When I converted the Bridgestone 300 (originally 27") to 650A, I first considered 650B.
I ran the numbers and found the longest Tektro sidepulls would not reach.

looks good, but it hurts so much!! I used to have a beautiful Finest:

whoa, I don't think you meant inches. Or maybe you meant half of that?

So it turns out the issue wouldnt be the clearance between the chainstays but finding a brake caliper with about 80mm of reach. I'm not going to convert this frame to 650b but I might do a 700 conversion at some point and run wider tires.

I think the VO Polyvent is 20% off right now isnt it?

Huh.

Yeah, I had to put a lot of thought into getting the fenders to work well on my Shogun 650B conversion. Definitely not plug-n-play.

The best way to determine clearance is to measure the clearance at 320mm from the axle. If there's going to be any rubbing of the tire on the chainstay or fork blade, that's where it will be. My bike had about 47mm clearance both front and rear, so that was my green light for Hetres.

My Hetres are measuring a true 42mm on Velocity Synergy rims. I think the older Hetre lots were labeled 41; the new ones are marked 42.