Re: DeRosa Merak Rear Brake Problem

On Fri, 3 Jan 2025 20:50:34 -0600, AMuzi <am@yellowjersey.org> wrote:

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

Got it and thanks for the clarification.  I must confess that this is
the first time I've hear B-stay or monostay.  I've seen many such seat
stays, but didn't know the name.

I checked to see if there was a registered trademark (or service mark)
for monostay and again found nothing:
<http://tmsearch.uspto.gov>
General Search = Monostay
Refine Search = Colnago
I have no idea what's happening.  There should be a trademark listing
even if it was expired, abandoned or cancelled.

(I linked that photo yesterday)

Sorry, I missed it.  I've been rather busy for the last few days and
haven't had much time to read, much less comment, in RBT.  I'm
typically 100 to 200 articles behind.  At the same time, the number of
articles per day seems to have increased dramatically.  I also mark
large blocks of articles as "read" because the discussion topic was of
little interest.  All this is almost a guarantee that I'll miss
something important.

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.

Looks like "wishbone" seat stay is another popular name:
<https://www.google.com/search?q=wishbone+seat+stays&udm=2>
The trademark is owned by Jennifer McIver of New Zealand and covers a
wide variety of toys and games including bicycles.
<https://tsdr.uspto.gov/#caseNumber=77419493&caseSearchType=US_APPLICATION&caseType=DEFAULT&searchType=statusSearch>
Click on "Goods and Services" for the list.

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.

"Mounting caliper brakes on carbon frame?"
<https://weightweenies.starbike.com/forum/viewtopic.php?t=154801>
"There is usually an alloy insert for the brake bolt to pass through
in carbon frames (I can’t think of any that don’t off hand)."

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/

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Jeff Liebermann                 jeffl@cruzio.com
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