650B conversion

From time to time I’m asked about off the shelf options for 650B bikes.  A lot of people have heard about the advantages that larger section tires can offer, but aren’t ready to take the plunge and invest in a custom bike.  A few good options are on the market now from Velo-Orange, Soma, Boulder, and La Confrérie des 650 for example.  I’ve assembled a few and their owners are very pleased.

There’s also another option: conversions.  Many bikes that were built for 700C or 27inch wheels can be made to work with 650B.  Often this means a bike that was no longer being ridden, perhaps even on the way to a landfill, will see many more miles of use.  Of course not every bike is a good candidate for conversion, a poorly done conversion looks cobbled together and may not work very well.  Sometimes though, it’s just a question of making a few frame modifications so that the end result is a bike that has as few compromises as possible.

A couple years ago a fellow cycling club member brought me an old Trek he had recently purchased.  I don’t recall how much he paid, certainly less than two hundred dollars.  He also brought a box full of components that had been removed from an early 90s vintage mountain bike.  The Trek frame was in good shape, and its dimensions were correct in terms of fitting the rider.  I installed a pair of 650B wheels with 42mm tires.  The distance from the top of the tire to the underside of the fork crown looked good.  The tire cleared the fork side to side as well, not by as much as it would on one of my custom forks, but adequate.  The bottom bracket height was a few millimeters lower than stock, but again, acceptable. Things weren’t so easy when it came to the rear wheel.  Even with the wheel pulled all the way back in the dropouts, the tire still lightly touched both chainstays yet it was much too far from the chainstay bridge for correct fender placement.  A poor conversion could have been done simply by using smaller tires, but we wanted this one to be right.

After I completely disassembled the bike, I removed both the chainstay and seatstay bridge, and spread the rear dropouts to 135mm to fit the hub provided by the customer.  Then I made some deep indentations in the chainstays to increase tire clearance, and finally installed new bridges with fender mounts the correct distance from the tire.


Here’s what the increased chainstay clearance looks like from below.

I also added brake bosses for cantilever brakes (more repurposed mountain bike parts), a rear brake cable stop, some shifter bosses, and a pump peg.


Brake bosses, cable stop, and seatstay bridge.

After an inexpensive black powdercoat, the bike was ready to reassemble.  I built new wheels for it using the old Shimano mountain bike hub, and a Schmidt front.  I think the wheels were the most expensive part of the whole project.  Wheels and tires are no place to save money, but that’s a subject for another post!  Fenders, a chain, handlebar tape, and a stem were the only other new parts purchased.  I never got a picture of the finished bike, but the customer loved it and rode it later that summer on his first 1000km brevet.

A couple weeks ago the bike came back for some upgrades and some overdue routine maintenance.  Long harsh winters had taken their toll on the braking surface of the lightweight rims, and the old seven speed drivetrain wasn’t doing well either so it was time for some upgrades: a ten speed freehub body and cassette, new shifters, derailleurs, crankset, and rims.  While I was at it, I washed and waxed the frame.

Maybe you have a similar old bike lurking in a dark corner of the basement or languishing in the attic.  Could it be a conversion candidate?


Finished product: a solid and dependable 650B randonneuring bike for a fraction of the cost of a custom.



Recent completions:

Things have been busy around here lately.  One of my favorite things about this job is seeing my customers see their new bikes for the first time.  Here are the three most recent deliveries, beginning with Ilsina’s new custom.  This one has all the bells and whistles, from a stem cap USB charger, to a connectorless Schmidt hub, to detachable lowriders.




Detachable lowriders.


Fork crown and front brake detail.


Rear brake and fender mount.

Next on the list is David’s Boulder All Road.  He brought me the frame and fork and I sourced all the parts, built the wheels, and assembled the bike.  I think it came out great!


To complete the list, a quick assembly project.  Mark brought me his new Ritchey P-650b and a box of parts.  I turned it into a lovely new mountain bike for him.



I hope Ilsina, David, and Mark have as much fun with their new bikes as I did!  Back to work now, stay tuned for more!





The future is bright!

The Centro board of directors announced today that The Bike Stand will close as of the end of the month. Although I’ve been nearly full-time at Thompson Custom Bicycles since September, and only part time at The Bike Stand, this is bittersweet. I’ll miss checking in with the same customers I’ve been serving for 22 years.
I’m excited to start working 100% at Thompson Custom Bicycles beginning March 2. Those of you with a custom bicycle on order, this doesn’t affect my production schedule, except that it just might be faster. I may also be available for some bicycle repairs, so please call or email if there’s something you need.

Henrik’s cyclocross bike

Kids growing up nowadays don’t get outside enough.  We hear this regularly, from educators, from healthcare providers, from the media.  One of my oldest friends and riding partners had a son a few years ago and I knew that  this little boy was not going to be one of those kids who never goes outside.  I listened to stories as the years passed, about his first time skiing, his first pedal strokes on a bicycle, his love of fresh foods…  It seemed natural that he would start racing bicycles soon after he learned how to ride one.  Eventually he got more serious, stronger, faster, and then informed his father that he needed a bike with drop handlebars.  His parents and I decided it was time for him to get his first real racing bicycle.  I set to work building the smallest bicycle I have ever built.

I found a source for 24 x 1 3/8″ tires and rims, donated a pair of hubs, and built the wheels.  This needed to happen first because I had only a rough idea what actual diameter they would be- they just aren’t something one sees everyday!  With the finished wheels and an inseam measurement, I was able to do a frame drawing.  The idea was to make the bike as big as possible so that Henrik can ride if for more than one season.  He’s growing very quickly and it would be a real shame if it was too small six months after he got it.  All the frame materials were things I had laying around the shop.  A Reynolds 531 down tube and seat tube, an unknown top tube which may have even been removed from a larger frame at some point, fork blades I had mistakenly cut too short for another project, etc.  I figured once all the conceptual problems of making a bike so much smaller than usual were solved, the construction would progress rapidly.  Then I tried to set up my frame jig.  Sure enough, it wouldn’t adjust that small!  I scratched my head for awhile and devised a way to hold all the tubes where they needed to go.


Look at that tiny little seat tube!





With a 700c wheel in the background for scale.




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All done! Photo courtesy Doug Rosenfield.




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Henrik and his bike. Photo courtesy Doug Rosenfield.




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Happy builder and happy 8 year old! Photo courtesy Doug Rosenfield.

Henrik has raced it several times.  Now that cyclocross season is over, the knobbies will be switched out for road tires.


Mark’s bike is famous!

Sierra Nevada Brewing ran a television advertisement earlier this year that equated craft brewing to the building of handmade bicycles.  I know a lot of cyclists who are rather fond of a pint now and then, so hey, why not?  My good friend Joe Platzner stars in the ad, and his shop serves as the backdrop, but the finished product shown at the end is the bike I built for Mark.  Click on the photo below to see the ad.  All of us who were involved had a good time and wound up with a couple cases of beer.  DSC00004

Vacation pt 4: Paris to Rouen

The Parisian metropolis is no fun to try and escape by bicycle, especially if you don’t know your way very well.  My friend Olivier advised me to take a train to Gisors and ride to Rouen from there.  He even outlined the best route and loaned me a map.  It was a beautiful ride and I arrived at Alain’s house that afternoon hungry and in need of a shower, but really happy.  Alain and I have many friends in common and have corresponded via Facebook for a long time, but we had never actually met face to face. He and his wife Nicole provided a wonderful meal and we talked so late I could hardly keep my eyes open.  The next morning, Alain and I went for a bike ride.  We stopped numerous times to take photos or simply enjoy the view.


Manoir de VILLERS

When most people think of the river Seine, they think of Paris, Notre Dame, and stone bridges.  Downstream from Paris though, the Seine flows back and forth through Normandy in great hairpin loops.  Our ride required us to cross the river several times and there are free ferries at many points.


Ferry across the Seine

The ferries don’t run at lunch time.  We had planned to eat in a particular restaurant, but missed the last pre-lunch ferry by perhaps 20-30 seconds.  The two choices at that point were to ride a very long way around, or have a beer in the bar next to the ferry dock.  Actually I think we had two beers and a sandwich.



The next day on my way out of town, I visited the grave of one of the greatest racing cyclists that ever lived, Jacques Anquetil.  It’s in a church yard, just down the street from Alain and Nicole’s house and I never would have known if they hadn’t mentioned it.  The stop earned my passing notice on the local news website.

At this point, I only had a few more days in France before it was time to fly home.  My plan was to ride from Quincampoix back to Guingamp over a period of two or three days, but after wasting several hours being lost, then getting soaked in a rainstorm, I took the train instead.  Vacation is all about having fun, I reasoned, and up until now I had been having lots of fun.  Better off to take the train and spend a few more wonderful days with friends than to suffer needlessly in a wet tent on a long solo ride!

Vacation pt 3: Switzerland

I was only able to spend a few days in Switzerland. Luc and Val showed me some wonderful highlights. Here are a few, in no particular order.


Charlie Chaplin spent 25 years in Switzerland. A statue in Vevey commemorates his presence there.


Hiking in the mountains.


Wild Narcissus blooming. This is a really big tourist deal for a couple weeks, and then it’s over until next year. I was quite lucky to arrive at the height of their beauty.

All too soon, I had to leave my lovely hosts.  They gave me a ride over the French border in their car and then I continued on to Dijon by bike.  From there, I took the train to Paris to visit another friend for a few hours of good conversation and a lovely meal.


Sunset view from a friend’s apartment in Paris.

Stay tuned for the next installment where I visit a randonneuring friend near Rouen and stumble across the final resting place of one of the greatest bicycle racers that ever lived!