Re: DeRosa Merak Rear Brake Problem

On 1/3/2025 8:00 PM, Jeff Liebermann wrote:

On Fri, 3 Jan 2025 08:27:09 -0500, Zen Cycle <funkmaster@hotmail.com>
wrote:
 

Of the 3 frames tom posted which have valid links, only the De Rosa has
the configuration we're discussing.

 Thanks.  I'm still having difficulties visualizing a B-Stay.  I tried
searching for a photo of a rear brake mount (both caliper and disk)
but couldn't find anything that matches Tom's description.  I'm not
sure that anyone uses caliper brakes on a carbon fiber frame without
also using an aluminum insert to reinforce the carbon fiber.  When I
search for it, all that appears are photos of carbon fiber caliper
brakes:
<https://www.google.com/search?num=10&q=caliper+bicycle+brakes+on+carbon+fiber+frame&udm=2>
Granted, there are carbon fiber caliper brakes, but those don't seem
like the brakes that Tom is using.  For example:
<https://bikerumor.com/ciamillo-is-back-with-insanely-lightweight-carbon-fiber-lekki8-road-brake-calipers/>
 I guess I'll just wait for Tom to post a photo of his DeRosa Merak.
 

The Canyon and TreK are both full
carbon lugless designs. The Giant TCR series never used a hybrid
carbon/Al construction. As for the DeRosa, the seat stay assembly is
likely a generic component sourced from a Taiwanese vendor.  As I
mentioned, "B-Stay" is a Colnago trademarked marketing term for their
design. Tommy is attempting to genericize the term.

 I'm not sure Colnago has a trademark (or wordmark) on B-Stay.  I
searched the USPTO site which found 6552 that were active, none of
which are registered to Colnago.
<http://tmsearch.uspto.gov>
General Search = B-Stay
Refine Search = Colnago
To demonstrate that the search works, try "Trek" in the Refine Search
box.
 

"B-stay" is Colnago's name for a monostay, popularized by Keith Bontrager starting 1985 (his were steel).
https://www.flickr.com/photos/cyclart/5640932051/
A monostay is a seatstay assembly which is only one tube above the brake mount:
https://www.jimbobsbikebuildz.com/uploads/1/4/6/5/146525512/img-2669.jpg
(I linked that photo yesterday)
The carbon assembly as shown, or with extended upper carbon portion, is a commodity produced by several vendors; Reynolds, Deda, Columbus besides everyone and his brother in china.
There is seldom (or none? I don't know of any) a metal liner as the depth of the carbon brake mount is adequate without them.
I don't know from trademark but Colnago uses, or did 15 years ago anyway, the "B Stay" name on their monostays:
https://www.roadbikereview.com/attachments/img_1298-jpeg.497324/
The obsessive Colnago types on roadbikereview.com indicate that Colnago began using these in 2001:
https://www.roadbikereview.com/threads/colnago-c40-b-stay-serial-number.387136/
--
Andrew Muzi
am@yellowjersey.org
Open every day since 1 April, 1971