RACING GEOMETRY ?

[datakoll]

The discussion "FAT TIRE" asks: does a 35mm tire fit on a racing geometry frame ?

If a standard racing frame is modified to accept a 35mm tire is that frame no longer competitive on a local or national level ?

[Dan O]

On Apr 17, 8:18 pm, datakoll <datak...@yahoo.com> wrote:
> The discussion "FAT TIRE" asks: does a 35mm tire fit on a racing geometry frame ?
>
> If a standard racing frame is modified to accept a 35mm tire is that frame no longer competitive on a local or national level ?

I like to think it's not about the bike, and that the right rider can
show up and win on a well-tuned Free Spirit 10-speed, but all else
being the same, why not optimize? Who knows, though - give it a shot
and see what happens.

[AMuzi]

datakoll wrote:
> The discussion "FAT TIRE" asks: does a 35mm tire fit on a racing geometry frame ?
>
> If a standard racing frame is modified to accept a 35mm tire is that frame no longer competitive on a local or national level ?

Nope.

Modern standard race bikes use a 450 caliper which cannot
span a 700-35 tire.

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

[Jay Beattie]

On Apr 17, 9:24 pm, AMuzi <a...@yellowjersey.org> wrote:
> datakoll wrote:
> > The discussion "FAT TIRE" asks: does a 35mm tire fit on a racing geometry frame ?
>
> > If a standard racing frame is modified to accept a 35mm tire is that frame no longer competitive on a local or national level ?
>
> Nope.
>
> Modern standard race bikes use a 450 caliper which cannot
> span a 700-35 tire.

True, but "competitive on a local level" is really broad -- I've seen
guys at Cat 4 races on CX bikes with cantilevers and skinny tires --
and they did just fine, particularly since some modern CX bikes weigh
several pounds less than my lightest racing bike of yore. -- Jay
Beattie.

[Sir Ridesalot]

On Apr 17, 11:18 pm, datakoll <datak...@yahoo.com> wrote:
> The discussion "FAT TIRE" asks: does a 35mm tire fit on a racing geometry frame ?
>
> If a standard racing frame is modified to accept a 35mm tire is that frame no longer competitive on a local or national level ?

Can you even modify a modern racing frame to take a 35 mm tire without
seriously weakening the front fork or the rear chainstays? specially
on a dedicated racing carbon fiber frameset. Andrewhas posted links to
images that show what happens if a tiree rubs an aluminium or carbon
fibre part for very long = cuts right through it.

Increasing tire size from 25mm to 35 mm is going to remove a fair bit
of material on a lot of dedicated road racing framesets.

Cheers

[datakoll]

ahhhhhh s

forget the caliper already....which like the 2 step discusion is interesting...

1)does widening the frame,

2)adding a 35mm tire and rim

as seperate elements in discussion

slow the bike (not Superman)

does widening frame alter handling ? approach to corners, balance into power for 2 contact pathes...isthis significant ?


or is a wider contact patch the only considered factor ?


I would imagine a wonk has ground out numbers for energy lost comparing 35mm to uh what's standard.

Energy lost, as Dano and Boonen, is not race position lost. Only suggests race position lost.

[Dan O]

On Apr 18, 7:12 am, datakoll <datak...@yahoo.com> wrote:
> ahhhhhh s
>
> forget the caliper already....which like the 2 step discusion is interesting...
>

That was my thinking (brakes? racing?)

> 1)does widening the frame,
>
> 2)adding a 35mm tire and rim
>
> as seperate elements in discussion
>
> slow the bike (not Superman)
>

You really wouldn't think it would be by much...

> does widening frame alter handling ? approach to corners, balance into power for 2 contact pathes...isthis significant ?
>

... hmmmm... that's harder for me to say...

> or is a wider contact patch the only considered factor ?
>
> I would imagine a wonk has ground out numbers for energy lost comparing 35mm to uh what's standard.
>
> Energy lost, as Dano and Boonen, is not race position lost. Only suggests race position lost.

That's why I prefaced with, "I like to think it's not about the
bike". Racing is very mental. Anything that bugs the racer - makes
him *think* he may have the slightest disadvantage *can* translate to
positions lost, IMO and IME.

[datakoll]

I've never ridden below a 32mm tire. But the % difference between 35 and what 28 is....I''ll loook it up but there's a square root in there.

idea is does offering the 35 alternative significantly detract from the performance of a 28 or lower rear tired frame ? so much so its no longer use able for competition ?

I assume in 'FAT TIRE' this was discussed but findin it ...

[Dan O]

I am no expert, but...

When I was a kid, rode 20 x 1 7/8. (Discovered relatively late in
childhood that pumping them up *really* made it easier to get going
faster.)

As a teenager, finally got on 26 x 1 3/8 tires, and then even rode a
10-speed w/ 27 x 1 1/8 - this latter is what I would call "skinny
tires", and they seemed faster than bigger diameter tires (and had a
higher rated pressure specification on the side, so... )

When I started riding (more) again in early adulthood, I had a sweet
(brand spanking new) entry-level Miyata w/ 27 x ~1 1/8 (?) That bike
was awesomely springy yet just right tight, and pumped up to spec
seemed to have low rolling resistance (went fast).

When I started riding again in later adulthood I had a Trek 400 from
same era as the Miyata, similar bike w/ similarly sporty feel - 700C x
28 mm tires - I would still call these "skinny tires".

Then I got the Surly LHT that came stock w/ 35 or 37 mm tires (don't
remember exact spec, btu they were *not* skinny tires. Bouncier, but
not really plush (Conti Contact Sport) - kind of stiffish. I replaced
these w/ Vittoria Randonneur Pro 32 mm (had run Randonneur 28's on the
Trek) - ahhhhh... great balance of bounce and tighter and responsive
and plush.

Oh... meanwhile I ahd gotten the '89 Miyata 914 (the bike I could
never afford when new) w/ 23 mm tires. These were definitely "skinny
tires" - almost felt like riding on a rim strip or something (they
were pretty nice Vittoria Rubino Pro road tires).

*Anyway*... I categorize 28's as skinny tires, and 32's as not skinny
tires - more "versatile" (I tend to got off road about every chance I
get). I had to sell the 914 :-(, but my plan for it was to try 25 mm
Vittoria Diamantes, which I think would have been perfect.

[AMuzi]

Well, designers do all that and more. Sematically, that is
not a 'modification'. It's a different bicycle.

To clear a 700-35 starting with modern road racing frame
design means a taller fork, concomitant change in head
angle, probably different crown (or different bend for
crownless designs), CS/DT angle changes at BB to retain same
drop, different shape chainstay, most probably longer
chainstay (check CS angle again, in re drop) higher brake
bridge or brake bosses, possible seatstay changes. These are
not trivial "at home, night before my event" modifications.

Whether one rider or another prefers a wider tire for any
given ride I leave to others to decide. I can say quite
certainly that no modern road racing bicycle will take a
pair of 700-35 tires.

[Sir Ridesalot]

I have a md-1980's to late-1980's Miele road racing geometry bike with
Tange Infinity tubing. When I put the 30 mm tires on it I notice a
fair bit of difference between them and the 25 mm tires it's normally
shod with. It was designed for 27" wheels which s why I can a) put 30
mm tires on it or b) put full fenders on it but not both a and b. With
the 30 mm tires it's really comfortable on on dirt roads andrail-trail
around here.

Cheers

[Frank Krygowski]

Seems to me the changes at the rear are what's difficult. With
composites, modifying chainstays to clear 32mm vs 23mm definitely means
a new frame.

At the front, it seems to me it would mean just a new fork (which is
what James seems to be planning, if he does it). The 12mm tire width
increase probably means only a 6mm wheel+tire radius increase, so the
fork blades need to only 6mm longer. In the same frame, that would
generate roughly a 0.2 degree change in head angle. Seems any handling
effect of that tiny change could be covered by choosing a slightly
different fork rake. Similarly, if you kept the rest of the frame
dimensions (except rear clearance) unchanged, the bottom bracket would
raise maybe 2.5mm, which doesn't sound critical.

> Whether one rider or another prefers a wider tire for any given ride I
> leave to others to decide. I can say quite certainly that no modern road
> racing bicycle will take a pair of 700-35 tires.

Yep.

--
- Frank Krygowski

[datakoll]

On Wednesday, April 18, 2012 12:28:25 PM UTC-6, AMuzi wrote:
> datakoll wrote:
> > ahhhhhh s

VERY INTERESTING....REALLY...

[datakoll]

cool...very interesting...I'm impressed...

idea was: with Boonen as background and formula racing...if

say last years Paris-Ruba frames were made with an allowance for the 35 tire,
would the 35 added frame be significantly slower on a straight level road tahn the narrower BAU models ?

[AMuzi]

When we came in to this thread, I noted that Paris Roubaix
machines are every different from the racing bicycles used
for the rest of the season.


Here it is, from 10 April, when Frank asked about fork
clearance and I replied:

Paris Roubaix machines are not like other race bikes:
http://ukcyclesport.com/images/stories/prbx2010bike/prbx15.jpg

click 'next photo' to see the series here:
http://www.cyclingnews.com/features/photos/race-tech-more-bikes-from-paris-roubaix/168515

[Radey Shouman]

So you're saying that all these poor abandonded race bikes (picture an
adopt-a-greyhound ad here) need is a dose of 650B?

--

[datakoll]

I read your replies as not evasive but occuring on a level beyond my bike background knowledge. How true.

When 36 went on abt 1/2 steps, my wall clock went ditto. Welcome...

Butbubut, if Boonen why not elsewhere and if no significant penalty accures for wider design application, as with 35 tires, then there may be other mods in this direction.

can you project wider design apps ?

[datakoll]

My appraoch was, does the peloton lock into a bike type, geometry type, even riding style/pattern.

Boonen's mod was available prior but the nickname is big tom right ? Muscles the extra patch. This is what 36 was after in 1/2 step.

Andrew makes the point there's only one P-R, Why one, why not 5 o 6 ? Too rough and tumble for the TdF stylists ?

Fran K argues the 35 is lost in the noise. Prob not: riders as a large group if not individually, are sensitive to advantages as changes in form.

The noise goes like this: if 10 riders ride to the front in 3 races including 3 who never ride there with 34 tires and red bandanas then in race 4 you'll see 2 more riders with red bandanas noise or no noise.

Next year prob see many meaty riders trying a bit more rubber and other friction producing devices eg red bandana

Time for a wing ?

eyeyyehahhah I was at the first turn for the first lap of winged F1 in the US at Watkins.

I regreted not bringing my giant Snoopy ballon.

Deveopment in Euro cycling, would it bring development into our cycles ?

[James]

On 19/04/12 14:47, datakoll wrote:

> Andrew makes the point there's only one P-R, Why one, why not 5 o 6 ? Too rough and tumble for the TdF stylists ?

http://search.cyclingnews.com/?q=cobbles

"The Spring classics season opens with races that are famed for the
quality - or lack thereof - of their roads Tour of Flanders
Gent-Wevelgem and of course Paris-Roubaix are notorious for the cobbled
sectors that routinely wreck bikes"

I doubt this is an exhaustive list. I think Le Tour has had cobbles in
the past too.

--
JS.

[datakoll]

Are cobbles definitive ? Have the Romans eliminated all bad Euro asphalt, gravel, dirt ?