brakes for 28mm tires?

My friend is still shopping for a bike. One sticking point: Seems like
most low- to mid-range road bikes come with dual pivot brakes (usually
Tektro, some Shimano) that won't open wide enough to clear an inflated
28mm tire. In local shops, I'm not seeing road bikes with V-brakes
(nor, of course, cantilevers). Not interested in discs.

Since she'll be doing a lot of riding on fairly bumpy roads or on
crushed limestone rail-trails, I think 28s are what she needs.

It seems a shame. From what I can tell, just a minor change to the
brake quick-release cam would allow them to open quite a bit farther.
And if there were a way to put two quick release devices in series, it
seems that could give more open clearance. But I don't see that's
possible with these dual-pivot sidepulls.

Any tips or ideas?


--
- Frank Krygowski

On 5/10/2016 5:49 PM, Frank Krygowski wrote:
My friend is still shopping for a bike. One sticking
point: Seems like most low- to mid-range road bikes come
with dual pivot brakes (usually Tektro, some Shimano) that
won't open wide enough to clear an inflated 28mm tire. In
local shops, I'm not seeing road bikes with V-brakes (nor,
of course, cantilevers). Not interested in discs.

Since she'll be doing a lot of riding on fairly bumpy roads
or on crushed limestone rail-trails, I think 28s are what
she needs.

It seems a shame. From what I can tell, just a minor change
to the brake quick-release cam would allow them to open
quite a bit farther. And if there were a way to put two
quick release devices in series, it seems that could give
more open clearance. But I don't see that's possible with
these dual-pivot sidepulls.

Any tips or ideas?



The modern standard 450 caliper can be positioned to just
clear a 28mm tire with the shoes all the way down. A
designer certainly could do a frame and fork geometry for
that- see Waterford with 27mm tire he
http://www.yellowjersey.org/WIDE27.JPG

But that would require some sort of reasonable market for
the bike, which probably doesn't exist in any significant
numbers.

Another stumbling point is the prevalence of standardized
road bike forks and no product manager wants to pee away a
pile of money on a special fork for one model with unproven
volume. Heck I'm even sympathetic to the idea yet I would
bet against such a project breaking even.

There are sport bikes with the next size 500 caliper such as
Gunnar Sport and Soma Smoothie ES, inter alia. Maybe look
more in that direction or an actual touring bike such as
Bianchi Volpe or its new relative Bianchi Lupo.


--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

Couldn't you add an in-line cable adjuster? Shimano even makes a model that has a lever-type quick release built in (SM-CB90), though it seems overpriced to me. If you used a cheaper in-line barrel adjuster, a few turns might give you the clearance you need. I believe there are some that are rated for use with brakes and not just shifters.

On 2016-05-10 15:49, Frank Krygowski wrote:
My friend is still shopping for a bike. One sticking point: Seems like
most low- to mid-range road bikes come with dual pivot brakes (usually
Tektro, some Shimano) that won't open wide enough to clear an inflated
28mm tire. In local shops, I'm not seeing road bikes with V-brakes
(nor, of course, cantilevers). Not interested in discs.

Since she'll be doing a lot of riding on fairly bumpy roads or on
crushed limestone rail-trails, I think 28s are what she needs.

It seems a shame. From what I can tell, just a minor change to the
brake quick-release cam would allow them to open quite a bit farther.
And if there were a way to put two quick release devices in series, it
seems that could give more open clearance. But I don't see that's
possible with these dual-pivot sidepulls.

Any tips or ideas?


I just took the calipers out to the garage. With the release up my
Shimano 600 brake opens to exactly 28mm, with the pad clearance adjusted
to normal lever reach. My road bike rims are currently 22mm wide on the
outside. That would mean you get 6mm more than the rim when the release
is open.

This was such a popular set in the 80's that it shouldn't be a problem
to obtain one. She should only need that for the front. Brake
performance with Koolstop Cross pads is nice (for rim brakes).

--
Regards, Joerg

http://www.analogconsultants.com/

On 5/10/2016 7:44 PM, Gary Young wrote:
Couldn't you add an in-line cable adjuster? Shimano even makes a model that has a lever-type quick release built in (SM-CB90), though it seems overpriced to me. If you used a cheaper in-line barrel adjuster, a few turns might give you the clearance you need. I believe there are some that are rated for use with brakes and not just shifters.

That looks like one potential solution I had in mind, but I couldn't
find it. Thanks!

Any feedback on these?


--
- Frank Krygowski

On 11/05/16 08:49, Frank Krygowski wrote:
My friend is still shopping for a bike. One sticking point: Seems like
most low- to mid-range road bikes come with dual pivot brakes (usually
Tektro, some Shimano) that won't open wide enough to clear an inflated
28mm tire. In local shops, I'm not seeing road bikes with V-brakes
(nor, of course, cantilevers). Not interested in discs.

Since she'll be doing a lot of riding on fairly bumpy roads or on
crushed limestone rail-trails, I think 28s are what she needs.

It seems a shame. From what I can tell, just a minor change to the
brake quick-release cam would allow them to open quite a bit farther.
And if there were a way to put two quick release devices in series, it
seems that could give more open clearance. But I don't see that's
possible with these dual-pivot sidepulls.

Any tips or ideas?



Become interested in discs? ;-)

Tyre width is irrelevant as far as the brake caliper is concerned.

Wheel removal doesn't require a quick release cam to be operated.

Upon wheel insertion, there is no quick release to forget to reset prior
to riding off and finding the brakes don't work.

Brakes will work well in the wet, and will not produce black Al oxide
slurry.

--
JS

On 11/05/16 08:49, Frank Krygowski wrote:
My friend is still shopping for a bike. One sticking point: Seems like
most low- to mid-range road bikes come with dual pivot brakes (usually
Tektro, some Shimano) that won't open wide enough to clear an inflated
28mm tire. In local shops, I'm not seeing road bikes with V-brakes
(nor, of course, cantilevers). Not interested in discs.

Since she'll be doing a lot of riding on fairly bumpy roads or on
crushed limestone rail-trails, I think 28s are what she needs.

It seems a shame. From what I can tell, just a minor change to the
brake quick-release cam would allow them to open quite a bit farther.
And if there were a way to put two quick release devices in series, it
seems that could give more open clearance. But I don't see that's
possible with these dual-pivot sidepulls.

Any tips or ideas?



FWIW, I use an advertised 25mm Michelin tyre on the rear wheel of my
road bike. It measures 27mm. The brake QR for Campag Ergo levers is on
the lever, not the brake caliper. With the brake QR "open", I can
easily fit the tyre mentioned above while the tyre is fully inflated.

--
JS

On Tue, 10 May 2016 18:49:01 -0400, Frank Krygowski
wrote:

My friend is still shopping for a bike. One sticking point: Seems like
most low- to mid-range road bikes come with dual pivot brakes (usually
Tektro, some Shimano) that won't open wide enough to clear an inflated
28mm tire. In local shops, I'm not seeing road bikes with V-brakes
(nor, of course, cantilevers). Not interested in discs.

Since she'll be doing a lot of riding on fairly bumpy roads or on
crushed limestone rail-trails, I think 28s are what she needs.

It seems a shame. From what I can tell, just a minor change to the
brake quick-release cam would allow them to open quite a bit farther.
And if there were a way to put two quick release devices in series, it
seems that could give more open clearance. But I don't see that's
possible with these dual-pivot sidepulls.

Any tips or ideas?

It is, perhaps, a bit of a kludge but if you use one of those "in
line" cable adjuster" gizmos you can screw the adjuster out as far as
possible then adjust the brakes at the brake. then if you open the
brakes "quick release you can open the brake spacing even more using
the inline adjuster.

I use them with V-brakes so that the V-brakes are usable with STI
levers.
--
cheers,

John B.

On 5/10/2016 7:12 PM, Frank Krygowski wrote:
On 5/10/2016 7:44 PM, Gary Young wrote:
Couldn't you add an in-line cable adjuster? Shimano even
makes a model that has a lever-type quick release built in
(SM-CB90), though it seems overpriced to me. If you used a
cheaper in-line barrel adjuster, a few turns might give
you the clearance you need. I believe there are some that
are rated for use with brakes and not just shifters.

That looks like one potential solution I had in mind, but I
couldn't find it. Thanks!

Any feedback on these?



Those were a new innovative solution twenty years ago.
http://yellowjersey.org/INLINE.JPG

They are now standard on many road bikes, even at the low
end of prices. Aftermarket set cheap at any LBS.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On 5/11/2016 8:02 AM, AMuzi wrote:
On 5/10/2016 7:12 PM, Frank Krygowski wrote:
On 5/10/2016 7:44 PM, Gary Young wrote:
Couldn't you add an in-line cable adjuster? Shimano even
makes a model that has a lever-type quick release built in
(SM-CB90), though it seems overpriced to me. If you used a
cheaper in-line barrel adjuster, a few turns might give
you the clearance you need. I believe there are some that
are rated for use with brakes and not just shifters.

That looks like one potential solution I had in mind, but I
couldn't find it. Thanks!

Any feedback on these?



Those were a new innovative solution twenty years ago.
http://yellowjersey.org/INLINE.JPG

They are now standard on many road bikes, even at the low end of prices.
Aftermarket set cheap at any LBS.

I like the quick release function in the ones Gary linked. For the
problem I'm addressing, that's much more important than just adjustability.

--
- Frank Krygowski