Originally Posted by
jeirvine
"People with opinions just go around bothering each other"
-Budda
I could tolerate that if only they wouldn't bother everyone else too!
Originally Posted by
randyjawa
...What I know, if anything, is a product of trial, error and experience, not unqualified information from non-proven sources. That comment does not target jimmuller, who has impressed me with his, or her, ability to share information that is of a factual, and oft times, proven nature...
...
Few things about my experiment were equal. I went from 27" concave Weinmann rims with eyelets, clad with Michelain World Tour tires, to 700c tubulars. Both hub sets were Campagnolo high flange NR units, with stainless steel spokes.
First, thank you for the compliment. Second, trial, error and experience count for a lot. That's how one gets to be an expert! You have far more of it than I do. Book-larnin' goes only so far when it comes to making something work.
About those Weinmann Concave rims, we could look up the specs in Velobase or someplace, but my recollection is that they were very heavy. (Decades ago I had one on the rear of my UO8 for commuting through Cambridge. I never weighed it but I believe it made the bike feel sluggish. It lasted about a month before it pretzeled itself quite unexpectedly. So much for its supposed strength.) I don't know the World Tour tire, but from the name alone I would guess it to be heavier than a typical road tire. Finally, from the description of those 27" wheels I might even guess that it had thicker spokes, perhaps 2.2/2.0/2.2mm as compared to 2.0/1.8/2.0mm. Given those factors the 2.9lbs difference becomes more believable.
The OP's question was about brakes, but that's just part of the broader question of the 27" to 700c conversion issue. I have two bikes with 27" and I haven't converted them simply because I couldn't see any benefit. The biggest benefit would seem to be tire choices but I'm very happy with 27" Pasela TGs. Having the rim and tire at a slightly larger radius would increase its moment of inertia and thus may make it accelerate a
tiny bit less. Some people may be able to feel that. Since I'm not competing with anyone it doesn't matter to me. I'm about to start a new from-scratch build (details much later), but it will use 700c. Our '82 Peugeot tandem has 700c. So I'm not prejudiced either way.
As for the brakes fitting, do as GB says, just measure the extra reach available on the calipers.
A scientist, an engineer, and a mathematician were discussing bike wheels.
The scientist: Multiply the density of steel times the cross-sectional area of the spokes times the additional spoke length, times the number of spokes.
The engineer: Measure the weight of the two wheels.
The mathematician: Assume a spherical wheel...