I have a Univega Gran Rally that I'd like to outfit with wider tires and fenders for the rough roads and weather here. Originally I was going to convert to 650b, but after doing some research it seems one of the most recommended rims (A23) isn't even available and the cost with some nice Grand Bois tires is likely to approach getting a "new" CV bike with larger clearances. Of course I'd need to purchase new 700c tires if I went that route.

What makes more sense... conversion or different bike that can take larger 700c tires?

Tell us more about your Univega. Does it have 27 inch wheels or 700?

Hi nazcalines, with a bit more information we could give better advice. Have you done all the measurements to figure out if it is feasible to convert your Univega to 650B? Brake reach, clearance between chainstays and fork blades, etc? What about clearance for fenders? I think the 650B google user group (just google that) has a helpful spreadsheet of actual tire widths on different rims.

Many 650B people (myself included) use wheels built with Velocity Synergy rims.

Sounds like a good candidate for conversion to me. 700c with skinny ties and short-reach brakes are most likely to produce a nice 650 conversion; you won't have much to worry about with bb height, finding suitable brakes, or fitting medium 650b tires on there. Can we get a "before" pic?

I put this combination through the Custom Wheelbuilder website at Universal Cycles: https://www.universalcycles.com/wheelkit.php

Hubs Shimano Tiagra 4600

Rims Velocity Synergy 650b Rims

Spokes Wheelsmith Straight Guage Stainless Spokes

Your Total: $253.52
Price includes labor for building wheels.
Shipping price will be calculated at checkout.

Hmmm, a coupla/few beers have my brains rattled and my fingers loose, but I'm not sure I'm following your logic. It kinda sounds like a slam-dunk to me. IF (intentional caps) your Univega has suitable clearance for 650b, I'd think a 650b conversion would be easier, cheaper and less time-consuming than trying to find a CV 700c with wider clearances and building that out. You can get a new set of decent 650b wheels for $150 shipped, longer-reach centerpulls for $20-$30 and better-than-basic 650b tires new for $75-$80/pr, from ebay. Figure under $300 all-in for a solid, reliable conversion.

A new "new" (intentional double "new") CV bike with larger clearances can cost nearly as much unless you're scouring garage sales/CL and are lucky. Even then, like you said, you'd probably still have to buy decent wider tires. Not to mention whatever else needs to be replaced. Most 700c bikes with larger clearances will be 70s-era if affordable, or '80s touring models, which don't tend to be cheap. Not at all a universal rule, but an affordable 40+ yr-old bike may likely need a bunch o' parts replaced.

I guess there's an actual dollar value in there somewhere. If the 650b conversion is $300 and good wide 700c tires will be the same $75-$80/pr (since you mentioned GB Cypres, I'm thinking better than Pasela, less than GB), if you can find a suitable 700c bike that doesn't need anything else replaced, for less than $200 shipped, the "new" 700c option would be cheaper. But even though there are plenty of us here who found a mint $50-$60 700c whatever just around the corner, you're the one that has to take the time and energy to find the right bargain for yourself.

There are good 650B tires at 38mm wide: Soma B-Lines, Pacenti Pari-Motos, and Grand Bois Lierre. If the Univega could fit those, I think the conversion would make for a great ride. You might still be happy with a good 32mm tire (Grand Bois Cypress), and that would certainly be an improvement over your current setup.

I just measured my 38mm Soma B-Lines, as best I can tell the fattest part of the tire is around 310-320mm from the axle center.

Thanks for the replies guys. I agree it seems like a good candidate for conversion. The main reason I'm hesitant is that the conversion will probably end up twice what the bike originally cost. I really like the bike though, so it's probably worth it.

One more question: The bike has 36 hole suntour sealed bearing hubs that seem to be nice enough. If I build the new 650b rims onto these would the old Araya rims be worth anything?

Before pic:

Keep in mind that you can always port the wheels over to another build in the future. If the parts we put on our bikes had to make perfect financial sense, we'd pretty much all be hoofing it around town.

I'd keep the 700c wheels complete, and build the 650b set around different hubs. But this brings up another question: what's the group on the Univega like? If it's an indexed Suntour group with cassette hubs, I might reverse my advice re: keeping the 700c wheels intact...

I say ride this, enjoy it for what it is and save your money for the 650b specific bike.

It's just the hubs/freewheel that are Suntour. Derailleurs/shifters are Shimano 600.

It's enjoyable as-is, but I think it would be even nicer with larger tires.

nazcalines - I converted an '81 Fuji S12S frame that originally used 27" wheels. It was considered middle of the line at the time and was a mix of cro moly straight gauge main tubes with hi ten for the forks and stays. I still considered it worthwhile even though I had most of the parts on hand - if starting from scratch the total cost would have been about 2000.00 including the frame but if I ever decide to buy say the Rawland Stag or Soma Grand Randonneur ( only because of the low trail geometry ) I can simply use everything on the Fuji. As it stands it is a great riding bike and I may just keep it simply because of that and it is vintage. I met two cyclists on Sunday riding Surly LHTs ( 26" wheels ) from Edmonton, Alberta on their way to Mexico and then South America and one of them tried the Fuji and really liked it a lot ( the tires are Soma B lines ). I gather he wants to convert a 1985 Trek 500 series over to 650b as a randonneur bike.

If they bike in question can't fit 42mm Hetres, it would seem you would be missing a lot of the 650b experience. I have not ridden them but those who have swear there is little point to using anything else for 650b.

This is not right. Many people such as VintageRide with his Fuji and my own Bianchi conversion have great results with 38mm tires such as the Soma B-Lines. My converted bike is just as fast, way more comfortable, more versatile, and it handles better. Simply way more fun to ride all around.

I have to agree - I am using Hetres on a Rivendell Bleriot and if anything the ride on the Fuji is just as good with the Somas, in fact from my experience the lighter standard gauge tubing on the Fuji provides a more forgiving ride than the stiffer partially O.S. tubing on the Bleriot unless I have the tire pressures on the low side. So obviously frame geometry and type of tubing does contribute a noticeable difference, at least in my case.