bikemig 

There are some older threads on this but nothing that has been kept up-to-date.

I've been thinking of doing a 650b conversion for long distance endurance riding. I know that's kind of an in thing at this point and I like the idea of fat cushy tires for a long day on the road. I'm sitting on a 1978 Trek 510 (it's a full ishiwata 022 frameset) that would make a fine 650b bike and I'm fence sitting on whether to do the conversion or not.

I'm curious who's done a 650b conversion, your experiences in making the conversion, and pics, of course, are always welcome, . Details please as to what worked and what didn't is helpful as well.

Moe Zhoost

Check out my recent post. I'm curious whether my picture is now showing up.

The conversion went well, but there were a few challenges. I was worried about the brake reach, but the Tektros solved that. I did have to dimple the inside of the chain stays for tire clearance. This ended up being less daunting than I expected too.

bikemig 

Your post got me thinking about my project. Why don't you post some pics here as well? It looks like a great job.

gugie 

I think you know which side of the fence I'm sitting on. ;-) If you want pix, just click on my flickr link, I got lots of 'em.

The number one question: have you test fitted a set of 650b wheels mounted with a fat tire? Catalog sez you have 44.5cm chainstays. Depending on the fork blade length you shouldn't have an issue there, I would think.

It all depends on how much you're willing to spend. If all you want to do is a 650b conversion, all you need are a set of wheels, pick your tires, and find some brakes that work. You can find wheelsets under $200. You'd want to spread the dropouts to 130, IMO, so you can use those modern wheels.

My recommendation would be to spend your money on good tires for best bang for the buck.

PM me if you have specific questions. You can dip your feet into 650b or jump in full rando.

bikemig 

Yeah I measured the bike so this "should" work. I wish I had a set of wheels to try this out with though. Where can you find 650b 130mm wheelsets designed for caliper breaks for under $200? The cheapest I've found are these

Suzue 650b Trekking and Commuting Wheelset

They're not bad but run closer to $300.

ThermionicScott 

I seem to remember a thread here (or was it on the 650B list?) where people were offering to lend spare 650B wheels for trial-fitting. You might consider posting an ISO for that, maybe someone in central IA has one. It would be a little cheaper than buying a set of wheels.

Tandem Tom

I did a 650b conversion using my 1983 Schwinn Super le Tour. Built my own wheel set using Velo Orange rims and Shimano 600 hub set(used). I also used the Tektro 559 long reach brakes but changed out the front to a 800 as I need a bit more reach. The other item worth doing was swapping the Tektro pades with Kool Stop Salmon. My bike has moustache bars with bar end shifters(friction). We, my wife and I, recently rode from Pittsburgh to DC and the bike rode great! It is almost my favorite! I have a Miyata 610 1980 vintage I plan to build up for my wife as a 650b bike. It will get sandblasted and a new paint job this winter.

rhm

The cheap wheels are from an eBay seller called uglyrm. The rims are Weinmann zac19. Use that info if this link doesn't work:



Of course you will also need tires to do a test run. Panaracer Col-de-la-Vie are decent and probably the cheapest tires I'd get for this size. But I had one fail on me rather catastrophically, not long after I'd been screaming down a long hill out of the Adirondack mountains... front tire side wall failure, had it blown while I was on the bike, that could have been ugly.

I agree with @gugie, it's pretty easy to get your feet wet without committing yourself, and well worth that modest investment; if you don't like out you can probably sell the wheels for approximately your cost.

My Holdsworth conversion was just such an experiment. Now I've ridden it enough to declare the experiment a success, and I'm going to the next level (with a little help from @gugie).

rhm

If you want to get into randonneuring, I recommend against investing in gear until you've done a few 200k rides at a minimum. You do not need 650b tires, dynamo lighting, front rack mounted bag with map case etc to determine if the sport is for you. When you want to do a 300k you will need lights, but still not necessarily dynamo lights.

gugie 

I got a set of those wheels awhile back, they're not bad, especially at that price. Don't cheap out on the tires, though. The Gran Bois Hetres at 42mm wide may seem pricy at $60 ea, but you can't beat the ride. There's competition now at that size through SOMA, Velo Orange, and others. Used Hetres go for less than 50% discount over new at the 650b Google Group, so you could always recoup at least part of your investment.

I'd be you have some long reach brakes in your pile 'o bits, if you want to keep your investment low for a "trial run".

bikemig 

That's a great price. Wow, I was balking at paying $300 more for a wheelset to try this out but this may push me to do it.

Panaracer has a good selection of 650b tires as well; the panaracer 650b x 38c gravel king tires look pretty sweet and weigh a righteous 310 grams, https://www.amazon.com/Panaracer-Gra.../dp/B01498ZRZQ

The best conversion advice I've seen for building one is this from pikeman, 650B Conversion Guidlines

It has some pretty useful measurements for trying to figure out whether this will work but you never know for sure until you've sunk you money into the project,

bikemig 

I agree; this is an expensive way to figure out whether you like the sport. I know I like multi day trips, though, and 650b wheels seem pretty sweet when spending long days in the saddle.

rhm

When considering what tire for a multi-day tour, I would definitely consider whether a replacement tire --anything that fits-- will be available if you need it. If you need a new tire in the middle of nowhere, 700c is going to be easier to find than 650b. Better a crappy 700c tire than no 650b tire at all!

bikemig 

Agreed. On a multi-day tour (I was thinking of the kind where a van carries your gear), I'd bring a spare folding tire and some tubes. But yes, you'd be responsible for carrying replacements since they will not be easy to come by in smaller towns and cities. It might not be a good choice, for that reason, for self supported touring.

AZORCH

I had a relatively painless conversion experience last year, which I wrote about on The Early Morning Cyclist last September. I shared a bit more here and here and in a more recent iteration here.

My good fortune was that the Katakura Silk I'm using as a 650b canvas almost seems to have been designed for the conversion. I am having to use really long reach brakes, but they work quite acceptably. Honestly, this was mostly a parts swap.

bikemig 

Very cool; thanks for sharing and linking. I'm concerned about whether my project bike has enough room under the brakes; I'm fairly confident it has enough room between the fork blades and chain stays for a 38c-42c tire.

gugie 

I understand the thinking behind bringing a spare folding tire, but have yet to find anybody that's really needed one short of a transcontinental or worldwide tour - one that's measured in months instead of days or even weeks. Most any casing tear can be booted.

I liken the odds of needing that folding tire about the same as needing a spare rear derailleur. If out of adjustment, it's possible to wrap one into the spokes - yet we don't bring rear derailleurs as spares, do we?

When I plan a bike trip, I always make note of bike shops along the way. In our modern world, a new tire is no more than an overnight shipment away, unless you're going out in the wilderness on gravel for a few days.

Risk/reward ratio is pretty, pretty, pretty low, IMO. If you've got a support vehicle, by all means bring up to a complete bike!

rhm

Well, you may be right about booting tires; necessity is the mother of invention, after all. To my mind this is a question not of how likely is tire failure, but of how much do you worry about things that might go wrong? When my new col-de-la-vie tire failed on the last day of an 8-day tour a couple years ago, it did not look like something I could boot, but then again I had a spare tire with me, so the opportunity was wasted. I changed my tire and did not worry.

I did a one-night camping trip with my kids several years ago and on the second day my son wiped out on a turn. A few miles later his derailleur broke in two, just below the mounting bolt. I did not have a spare derailleur with me, but I did have a chain tool! He did the rest of the ride on a single speed.

rccardr 

I got a massive sidewall cut on the NEW rear Gravel King on the Pelizzoli on mile 19 of this year's Cino Heroica. Bad enough that I tossed the tire when I got back home, but with a gaff tape inside repair it lasted the remaining 90 very bumpy, gravel covered miles.

Two years ago I ran across a piece of broken terra cotta tile on the shoulder of the road down in the Outer Banks, cut most of the way across and totally through the tread on the rear of my Vittoria Open Corsa CX. Took three days for a replacement tire to arrive, but the dollar bill I used to boot the slice helped me make it almost that long.

So I'm more of a believer in using a boot than I was before.

Andy_K 

Can you even see the fence from where you are?

gugie 

I've heard rumor...

bikemig 

Isn't the C&V approved way to do a 650b conversion is to (a) first buy the dang wheels (get expensive ones that you want to keep and ride) to see if the conversion works and (b) buy the dang bike (soma grand randonneur? the new velo orange polyvalent 4? ) if it doesn't?

nlerner

I have three 650B conversions in the current fleet. My most recent is a Fuji 12-S. It was quite straightforward in that it had a ton of clearance for 650B x 38mm tires, and I used Weinmann 750 center pull brakes. I've only taken it out for one real shake-down ride, so I haven't yet decided if it's going to be a keeper:

IMG_0906

The 650B conversion that I've put the most miles on of any in my fleet is a '97 Lemond Buenos Aires. I had to dimpled the chain stays a bit to get it to fit 38mm tires and use Tektro long-reach dual-pivot brakes.

IMG_0214.JPG

The third is an early 70s St. Etienne frame powder coated gloss black and equipped with a porteur rack. This one was originally fitted for 27" wheels, but Weinmann 750 brakes give me enough reach:

IMAGE_6313C651-AA06-4125-B14C-BA63FF20DEFA.JPG

Bandera

The real C&V way is to buy a genuine Herse or Singer, dress like these guys and smoke Galouise.

-Bandera

bikemig 

I'm sticking to the red wine; it has lots of antioxidants. It's sort of like grape juice only on steroids,