I've followed this discussion with a lot of interest and a smile. Through the years in my shop, selling most of the top european framesets, and a number of frames from american builders: Columbine, Della Santa, Baylis, Chris Pauley, Glenn Erickson, Dave Tesch, JimRedcay, Tom Kellogg, Bruce Gordon, Jeff Richman, Tom Ritchey, Greg Diamond, Ross Schafer, Cuevas, Dave Moulton to mention a few...I've seen a more than a few bikes crack or come apart. I would venture that the ratio of failures of silver brazed to brass is about 50/50. The most common failure has been right rear dropout. The second biggest area of failure ishead tube cracks on the left side of the lower headtube lug on short point small investment cast lugs. Third is seat cluster binder bolts that have been overtightened or when the seatstays are attached to the seatbinder bolt. Most of theses failures have been on brass brazed frames, as brass is more commonly used for this style stay attachment. Back in the days when you had to sent in a test tube set to be certified to build 753 which supposedly only could be silver brazed, . Dave Tesch sent off his test joints brass brazed just to prove he could do it. I like my Singer frames, but I also like everything else I have. Interrelated are fit of the rider on the frame and specific frame geometry, and build details. There's a lovely Columbine at Joe Bell's shop with elaborate lugs that I had built for me in 1983. It was the first fancy Columbine. John was out of lightweight Renyolds toptubes when he put that bike together for me, so I ok'ed a 19/21 top tube to get the bike in time for the Davis Double century. That choice made a much stiffer and less forgiving bike than my previous Columbine and while that frame was beautiful to look at, it wasn't much fun for me at 178 lbs....Today, at 225 lbs, it might be just perfect. LOL! When people come to me for a fitting, I have them bring their present bike as a benchmark to see what they're doing and what the limitations of that position might be for them under different circumstances, and what kind of fatigue they feel on a longer ride for them. Next I try to find out what they want to do with the frame, what kinds of rides, how aggressive they are, what their goals are.... The best bikes to me are the ones that disappear when you ride, that you don't have to think about, that don't have any annoying characteristics that take you from enjoying your surroundings to the niggling problems of the bike. If I can, I take the client out for a ride and see what the skill level is. Then, factoring necessary frame geometry to achieve good fit and safe handling under adverse circumstances, I plan the frame design, the diameters, gauge, taper of the tubing., construction details, etc. It is hard to quantify whether a frame made to measure is better riding than a stock framesoff the showroom. I've had a bunch of them made for me through the years, sometimes varying the geometry, sometimes gauage of tubing, sometimes mixing tubing sometimes testing two or three custom bikes with different tube sets and identical geometry. Is there any such thing as an objective road bike test? When I send clients out to shop for off the shelf bikes after I've put them on the sizing machine, I encourage them to take a plumb bob, a tape measure and their wheels with the tires pumped up to rated pressure to eliminate some variables, and to measure the frame against guidelines that seem appropriate for their use. Those guidelines include seatube legnth, setback of seattube, front center, chainstay length, set-forward( amount of top tube ahead of centerline of a plumb bob dropped from the toptube through the bb axle center measured on level ground), stem length, stem rise. bar width. Knowing where the seat height and setback needs to be is a great tool for qualifying or disqualifying a prospective mount , especially for a smaller rider, as many seattubes on small frames are steep. Frank Berto once did an tire article for Bicycling Magazine that I built the wheels for. Frank and his crew went cross country trading wheels and deciding which tires rode best. When he got backafter the ride and took his pressure guage in to Standard Oil where he worked as an engineer, he was horrified to find out that the pump gasuge he used read shy about 10 %. Surpisingly enough, but understandable in light of this subsequent discover, all the riders liked the Michelin 50 tire which had the biggest cross section and was least affected by the drop in pressure. This could be an endless thread, but I do have to go pack and ship some freewheels so I have to continue these thoughts later ...
Paul Brown
Cycle Dynamics
Santa Rosa, CA