On 4/15/2021 9:49 PM, Sir Ridesalot wrote:
On Thursday, April 15, 2021 at 8:49:31 p.m. UTC-4, Frank Krygowski wrote:
On 4/15/2021 8:30 PM, jbeattie wrote:
On Thursday, April 15, 2021 at 4:31:19 PM UTC-7, wrote:
There is serious cost in building a massive frame fixture. You need to produce and sell
a large number of frames to amortize that cost. For a very low production volume it's not worth
doing and absolutely not necessary.

I've known several people who have built steel frames, At least two of those guys were
mechanical engineers, including a good friend of mine whom I consider to be the smartest
engineer I ever worked with. (We were in grad school together, and later I hired him to teach in
our program.) He did workshops on frame building at LAW conventions, back when they had
LAW conventions.

That guy built absolutely beautiful (concours d'elegance winning) single frames, plus several
tandems. Others built recumbents from instructions or, in one case, from the builder's own design. None of them used massive frame plates.

Tom's made it very clear that in addition to being a bumbling mechanic, he has little
understanding of the economics of manufacturing,

... You never really know what's under the paint -- or whether the joints are filled and not over-heated. I've seen beautiful bikes fall apart -- and bikes that were not so beautiful after you stripped off the paint (e.g. dynafile dings filled with brass in '70s Ritchey frames).

That brings up an interesting point: We can assess the beauty of a frame
according to our individual taste. But how do you know any particular
frame is really good? What matters in that evaluation?

If I stripped the paint off a well-used frame and saw a ding filled with
brass, I don't think it would bother me, assuming it hadn't caused a
failure. OTOH, overheating tubes can lead to failure - but how does one
tell before the failure occurs?

I'm the guy whose custom tandem had its fork blades suddenly break off.
The builder, Jim Bradford, substituted track gage fork blades in place
of tandem gage blades. I never bothered to weigh the fork, let alone
X-ray it, so that defect was hidden from me.

The blades broke maybe half an inch below the fork crown. I can't say if
that was evidence of overheating as well. Given that the wall thickness
was 1/3 what it should have been, any overheating was probably just
icing on the cake.

--
- Frank Krygowski

Did you sue the builder?

No. The bike was decades old when the forks finally failed. I tried
looking for Jim Bradford and was told he had fled to Canada.

Even if he were nearby, a lawsuit would not have made sense. Our
injuries were minor, as was the damage to the bike. (We were waiting for
friends to catch up with us and pedaling only about 10 mph.) The
replacement fork was not expensive.

--
- Frank Krygowski