I am a hobby bicycle frame builder (Varco Cycles) and a full-time CNC Machinist. Upstate NYC Native.
My buddy Daniel wanted his 1971 Raleigh International converted to a 650b randonneur/commuter with a Wald front rack.
If you don't know what a randonneur is, randonneur means "to ramble" in French. In relation to cycling, randonneurs are basically ultra-distance cycling events that place more emphasis on the riding experience rather than the competition. So a randonneur-style bike is similarly built for long-distance, with a focus on comfort rather than aerodynamics.
A Typical Randonneur Build
Randos (for short) often have 650b wheels with larger, softer tires. These wheels are smaller in diameter than the typical 700c wheels used in road racing. However, with the larger tires, the overall diameter typically remains close to the diameter of a 700c racing bike. Going with the comfort theme, randos usually have a more relaxed head tube and more fork rake, making for less twitchy steering characteristics. This is especially important when randoneeuring because you would typically carry more gear on your bike via racks and bags. Rando bikes are usually built a bit heavier to support that added weight as well. Another feature typically found on rando bikes is the ability to mount fenders, so more clearance over the tire is typically needed to allow for the fenders.
Since we were starting with an existing frame and fork, this build wouldn't truly be a randonneur, so that's why it's called Project Dandonneur! The donor frame and fork are a 1971 Raleigh International. It had been repainted so it was not valuable as a vintage frameset at this point.
Daniel is a busy family man, so we met at my day job and discussed the project. He needed the rear end widened to fit a 135mm wide wheel, cantilever mounts brazed onto the frame and fork, rack mounts brazed on, and the existing struts modified that support the front rack itself. The rack would also need to be modified as well. This was my third time really working on a frame. I needed the brazing practice so this was perfect!
Excited to get going, I built a bottom bracket post, mounted it to a Bridgeport table, and adjusted the rear width to 135mm.
Randonneaur Brake Mounts
Next, it was onto brake mounts. I like this fixture and it works well but when time permits I’m going to make a better one. This was also the first time I tried Fillet Pro from Cycle Design. I’M A FAN! Fillet Pro flows into tight spots and also allows you to build up a nice fillet to support high-stress areas like brake mounts and dropouts. They say it's strong enough to fillet braze main tubes but that would be a lot of silver! Silver isn't cheap!
Rando Fork Adjustments
Onto the fork. In true randoneeur-style, the fork needs rack mounts. This is the first rack I’ve mounted so it is completely new to me. I haven’t ever owned a bike with a rack either. Dan was awesome in helping me with images for examples of exactly what he wanted. He wanted the mounts to be up near the brake mounts. French looking I suppose. I dig the idea though. The way I was thinking at first was to mount the rack struts to the wheel axle. But, with the rack mounted to the fork blade, if you got a flat tire you wouldn't have to fiddle around with the rack at all.
Rando: Built for Comfort and Speed from Tire to Tread
A real rando has those big smooth supple tires. To make Daniel's bike float like a magic carpet, I dimpled the chainstays to clear the new 650b x 42 meaty tires. I made a pair of vice grips so I could dimple built frames as opposed to dimpling the tubing before assembling the frame.
Daniel is an expert on the history of 650b tires. Kinda cool in a way because he can recommend a nice supple, high air volume tire for any use!
Mounting Rack: a Rando Necessity
With the frame and fork done my next step was mounting the rack. With Daniel's photos, links, and advice I decided that I couldn't use the existing mounts. The stock mounts were heavy, bent steel, adjustable kinda stuff. Basically, the rack needed some custom mounting. I machined this headset spacer / top rack mount on a 4-axis horizontal Haas CNC milling machine. Not bad having one of these around.
You’ll see how this works later.
The Wald rack came with some beastly mounting struts. I wasn’t about to use them to mount to this rack. They could withstand more weight than the bike could carry. I suppose you need to do this when selling bicycle racks though.
I wanted to go lighter and nicer. I ordered some 4130 tubing and solid stock to make a much better strut. I've seen some companies make rack tabs but I wanted to go the more custom route but still have them slightly adjustable. So I machined slots instead of holes.
In the picture below you can see the black Wald lower struts versus my tube machined parts.
Then I brazed 'em up using nails to keep them from moving. Ok, mainly from keeping my clumsy self from knocking glowing hot steel onto my workbench. Safety first kids!
Cleaned up and mounted. Coming along better than I had hoped! They are more of an instrument rather than a part. Ha! More for supporting a load while not taking up too much mass along the steering axis rather than a chunk of metal used to bludgeon.
Top Struts on the Rack
With the lower struts taken care of, I moved on to the top struts.
For the top, I knew how I was going to mount the rack from the bottom and I knew how I was going to mount the upper mount to the bike, however, in between was another story. I scratched my head a little, searched the internet a little, but came up with an easy way to tie it all together. At least it sounded easy in my head.
I made the parts without an issue but fixturing them to braze together was another story. I couldn't nail them together so I found some regular old wire, a vice, a c-clamp, and a piece of 80/20 extrusion that I mad machined into cheap vee blocks. Gosh darn it, it worked!
Again, confusing now, but keep on scrolling and it’ll all come together.
I had to put some mounting slots in the back mounting plate of the rack and what a better way to do so than the tombstone fixture on the horizontal machine. If you don't have a CNC horizontal machining center at your disposal you're really missing out. Sometimes I feel lucky to be a CNC machinist.
Now that the upper struts are brazed, the rack has mounting slots and the upper mount are all done, these next few pictures should clarify the confusion.
And a Rando Was Born!
Well, here is the finished product. Randonneur-ish, Commuter-ish, Vintage-ish, sure! All that. Daniel has already told me that he is going to get a poodle so he can carry it on the rack. Can’t wait for pictures of that.
Since finishing this bike Daniel uses it as his main commuter through the Portland suburbs, onto the train, and into town.
This project brought me a load of new challenges and I greatly appreciate his patience with my learning curve. I hope he continues to love the bike for years! I learned so much about randonneurs. This style of bike is something I've seen many times, but it was Daniel really opened my eyes to what they're really all about—the ride.
There were times I swore I would never do another rack again, but now I'm confident that I can make it work and look cool in the process. Heck, I would even consider modifying a classic frameset of my own for similar duty.
I really love the idea of randonneuring. I would love to take a trip up into the SoCal mountains and camp out. A Rando/Commuter mod like this COULD be in my future. But do I need another bike? Do I have the room in the garage? I may need to apply the old N+1 rule here.
Wear your helmet and ride safe!
Have a question or comment? I would love to discuss this project with anyone interested. Please leave a comment below.
Allan Varcoe on December 03, 2017:
Hey, glad you like it. Yeah it's hard for me to buy an "Off the shelf" bike and just ride it without changing SOMETHING. Ha!
I'd love to see what you did on your 650b conversion.
Ardot from Canada on December 03, 2017:
Nice work! I admire your skill and resistance to just dump a load of cash on a new bike.
If you're like me there is no bike that exists that matches our style!
I just did something similar to my vintage 26" MTB.
I converted to 650b with drop bars and disc brakes, It now looks suspiciously identical to a modern day "adventure bike" hmmmm.....