Boulder vs. Carre

Every bike in the studio gets compared to my Boulder Brevet simply because it fits me so perfectly. It’s interesting comparing the Boulder with the Carre.

To make a fair evaluation of the geometry and size, the camera is set up on a tripod to ensure that the shooting angle and position is exactly the same between both bikes. The floor is also marked for positioning of the bikes. Because they are resting in a bike stand, some correction for “squareness” is necessary. The photos were slightly rotated in post processing so that the wheels are parallel to the picture frame. Furthermore, the Carre has been nudged so that the bottom brackets are aligned to the Boulder by superimposing the two photographs.

Here is the “control” shot of the Boulder for comparison of tube positioning, geometry, and length.

The green lines indicate a rough tracing of the Boulder tubes, which I’ve drawn on an overlay.

The overlay drawing of the Boulder tubing has been superimposed over the Carre frame. Although the wheel base is a little longer on the Boulder, and more importantly a greater difference between the lower trail Boulder fork and that of the Carre,  I was still a bit surprised to see that there’s not as much difference in bottom bracket height or drop as I’d anticipated.

With 700 x 25 tires, the standover is nearly the same as the Boulder. I anticipate running 700 x 28 so there will be some difference in the final build. It’s also worth noting that the top tube is one centimeter shorter on the Carre: 58cm as compared to 59cm on the Boulder.

This is not to say that I expect the rides to be similar. The two bikes are clearly designed for different purposes, but I’m a researcher and find it useful to compare against known factors, quantities, and considerations. My initial thinking has not changed, despite some similarities to the Boulder geometry: The Carre frame is more of a road bike design, and the available space for wider tires convinces me that it’s probably a CX model. Despite the eBay listing, I don’t see anything that screams “randonneur” to me at all.

Next up: the build.

Wild Hair.

I had a wild hair the other day. (I wonder if anyone else uses this phrase to mean that one is pursuing a sudden, compulsive, and possibly irrational idea…or is it  something my Dad made up, along with a thousand and one other odd and personal colloquialisms?)

Anyway, wild hairs….I had one recently. The afternoon’s task was to organize the bikes and parts and other cycling related detritus hanging about the place. One of those things literally hanging about is the 80’s era Katakura Silk road bike, pictured above as a sort of Sportif model. This is the second one I’ve owned, the first having left my garage a couple decades back. Not long after acquiring this one I realized I had become a member of a small and rather exclusive club of enthusiastic chrome Silk owners. I discovered this when a couple of them reached out to me to share information about their bike. One of those enthusiasts bemoaned the fact that there was only room enough to fit a 700 x 25 tire, and despite my proclivity to never take such statements of fact as gospel I never attempted to fit anything wider than a 25. And thus, after a time I found myself riding the Silk less and less. I even went so far as to put it up for sale a few months ago.

So: The wild hair. As I stood staring at a row of bikes lining my ceiling, my gaze fell upon two that were side by side – the Silk and the elegant looking 650b Cycles Toussaint Velo-Routier. I have enjoyed the VR but unlike my Boulder, it never seems to “want” to go faster and I’ve been considering tearing it down, selling the frame, and using the kit to build up a 650b with a little more spirited ride. Out of curiosity, I pulled the wheel set from the two bikes and swapped in the 650b wheels on the Silk. I don’t really know what I was thinking would happen, but I certainly wasn’t imagining that they’d just pop right in place with plenty of spin room…but after removing the short reach Superbe brake calipers they did precisely that.

What the hell, I thought. This isn’t supposed to happen. And certainly it shouldn’t be that easy. I decided to see if there’d be adequate room for fenders, thinking that no doubt would be the end of things. But a rough placement made it very clear that I had ample room for the 650b x 38 tires and mud guards.

Which is how I found myself tearing down two otherwise perfectly functioning bikes, hanging one naked fork and frame, and transferring nearly the entire kit from one over to the other. Measuring spacing and lengths along the way I was surprised to find that a roughly fit build indicated I could achieve nearly the same fit and positioning as on my Boulder. The Boulder is set up for me for maximum comfort and fits me perfectly. Although there are certainly differences between the two, the major points of contact relative to the rider and to bike frame geometry are essentially the same. (See illustration below for comparison. The Boulder geometry is indicated by the red line overlaying the photo of the Silk.) Toe overlap at the front fender is minimal, and similar to the clearance on the Boulder.

As with all of my bikes, I’ve made some effort to research the background of the makers. There’s not a lot of information available about Katakura Silk which I find peculiar because they were a major player, sometimes likened to a Japanese version of Raleigh. What information I could find was a little sketchy, but a couple of catalogs had been posted online and seemed to indicate that some models were built with sportif or randonneuring characteristics in mind.

As I indulged my wild hair, I thought it would be interesting to conduct a new online search for Katakura Silk. I hadn’t done so in a couple of years and I figured – correctly, as it turned out – that new information might have been shared with the world. Two gold mines were discovered in fairly short order, the first being links to Katakura Silk catalogs I’d not had access to a few years ago.

Of particular interest to me is this catalog page from 1986 that features both sportif (Grand Sport) and Randonneuse models of Katakura Silk. The Randonneuse model is fitted with 650 x 38 tires! Although this version is designed for cantilever brakes and has posts to accommodate them – which my PX model does not – it didn’t take a huge leap of faith for me to speculate that if Katakura was designing one model to fit 650b, perhaps other models could also accommodate that size as well. After all, why retool the whole line?

Cycles Peugeot states that the French randonneur aesthetic was introduced to Japan in the 1960’s, and certainly there has been a very enthusiastic following in the years since that time. As readers of Bicycle Quarterly know, the Japanese have taken this model, tailored it into a distinctly Japanese-taste randonneur, and brought about notable improvements such as the Rinko system of packing a bike for travel.

The second gold mine was found at the Cycles Grand Bois website where I discovered a couple of Katakura Silk bike restorations featured in their online gallery. The bike below was transformed from this:

Into this:

If I interpret the details correctly, this bike was restored for a Mr. Sekishima from Hiroshima in 2009. It’s a very beautiful and tastefully elegant re-interpretation. Importantly, I feel I have permission to take my Katakura Silk and lean in this direction.

Which leaves me, for the moment, considering next moves. Roughly fitted out and positioned, here is where I am with my re-imagined Katakura Silk:

I cannot accurately fit the fenders and constructeur-style rear rack until I’ve installed brake calipers. Because the frame was drilled for 700c wheels, I must rely upon long-reach brakes. This leaves me with a couple of options. I could have gone with Dia-Compe 750 center-pulls. These have the look of a randonneur bike. I also prefer center-pulls over other brake caliper designs. They would have allowed me, I think, to use a small French front rack I have in my parts bin. And to be honest, I’m not really certain why I didn’t go this route…perhaps there will be a follow up to this article a few months down the line, detailing how I changed to center-pull brake levers…

For the time being though, I decided to use dual pivot long reach Tektro R559 side pull calipers. Others have used these very successfully for 650b conversions, and if I decide to change to center-pulls I should have no problem finding someone to take the Tektro brakes off my hands.

I’ve run out of red cable housing, which I will need in order to complete the build. The calipers should arrive at the same time as the housing. All in all, this has been a relatively simple conversion. If the ride quality is typical of high volume/low pressure 650b, and if the frame responds on those tires as it did with the narrower 700c tires – i.e., if I can achieve a cushy, spirited ride – then I’ll be very happy indeed. Aesthetically, I think I can build a bike respectful of the Japanese spirit of randonneuring. This greatly appeals to me. Functionally, I’m hoping for a bike that meets my needs for comfort, spirit, and the occasional crappy road. Let’s face it: If I could only have one bike ever, the Boulder is my bicycle. I’m good with that. But I love to experiment with my other rides, and I’m feeling like this could make the Katakura Silk a more ridable member of my bike stable, without any loss of the class it already has.