I posted previously that I intend to rebuild my Roberts frame. The Roberts was the first quality bike I owned and, even today, is the most comfortable ride. It is handbuilt using double-butted Reynolds 531 carbon steel tubing commonly used in the 1960s on top-end touring and racing bicycles (and to form the front subframes on the Jaguar). This material is strong but forgiving providing a comfortable ride. In addition, the frame is built with a longer wheelbase and lower center of gravity making longer rides more cushioned and less tiring.
This frame has been rebuilt several times. First, as a touring bike. Then, as a training machine with light weight tubular rims. And then, as a commuter with standard wheels and fenders. This time I want to rebuild it as a touring bike, a bike equipped for long rides, a randonneuring bike using index gearing with easy-to-operate shifting integrated into the brake levers. I will continue to use some of the original parts. The Campagnolo headset. The Brooks saddle. Maybe the Cinelli handlebars although they are intended more for the track. But the drivetrain and wheelset will be updated.
Wheel sizes and gearing has change dramatically since the Roberts was built. It was designed for 27′ wheels and 6 gear freewheels. Today, the standard is 700 C wheels for road bikes and 8, 9 10 and even 11 speed cassettes are available. The 700 C wheel is smaller in diameter than the 27″ wheel (1979 mm vs 1954 mm) and modern hubs are wider to accommodate larger cogsets (126 mm vs 130 mm). These size differences present two challenges. Standard reach dual pivot caliper rim brakes do not reach the rim of the smaller 700 C wheel. Although long reach brakes are available, they mount differently than the side-pull brakes manufactured in the 1960s. I will return to this challenge in a subsequent post. The second challlenge, the subject of this post, is the spacing between the wheel dropouts where the hub meets the frame needs to be widened to support the modern hubs.
The beauty of steel frames is that they can be bent, adjusted to accommodate today’s wider hubs. In my case, the Roberts is only 4 mm, (2 mm on each side) narrower than necessary. This is relatively minor and easy to do. In fact, I could do this myself using a 2×4 and a piece of string. Sheldon Brown provides on-line instructions for the do-it-yourselfers. I considered doing this but, after consultation with several experienced mechanics, decided instead to engage an experienced frame builder using tools designed for the job. There is some risk that frame joints may break when the stays are spread and I did not want to jeopardize the project on such a good frame. Also, you must insure the opening is properly centered on the frame and the dropouts must also be realigned or the wheel will not roll true. It was worth the $45 to have the job completed professionally. When I picked the frame up, the frame builder told me it took him longer than expected. The steel was stronger than he had worked with previously and he had to spread the stays wider than he was used to. This was a comforting thought. Despite being over 30 years old this frame is still strong. Here is a well deserved shout out to Cambie Cycles for a job well done.
The next step is to select a groupset or, as my Italian friends prefer, a gruppo – integrated brake & shift levers, dual pivot front & rear brakes, front & rear derailleurs, compact crankset, bottom bracket, chain and cassette. I prefer to have matching components, particularly on this bike. This search will be the subject of a subsequent post.
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