Front/rear flat ratio

Not if you're fixing it yourself in the rain.

But it's very close to 2:1 rear:front for me. The theory is the front
wheel throws up things that had been lying flat.

me said:

Is it everyone's experience that rear road tires get flats while
riding more often than front ones? It sure is mine, and I wonder
why. Seems like the front should go flat more since it's the first
to encounter the sharp objects. Anyone care to theorize?

Not that I mind the ratio...I'd much rather have a rear than a front
tire go flat on me.

Jobst says it's because the front wheel kicks up the penetrating agent right
before the rear wheel runs over it. Envision a nail on its side, spun about
with angular velocity omega. If it is kicked up just right, the nail will
spin 90 or 270 degrees around orthogonal to the plane of the road, and say
hi to the rear tire. That's an instant goner. With glass, it becomes
embedded until a few revolutions later when it's forced past the tire casing
and into the tube. SSSssSSSssSSsssSSssSSssSSss goes the tube.

--
Phil, Squid-in-Training

me said:

Is it everyone's experience that rear road tires get flats while
riding more often than front ones? It sure is mine, and I wonder
why. Seems like the front should go flat more since it's the first
to encounter the sharp objects. Anyone care to theorize?

It's because the rear wheel is a bit bigger PITA to remove. (That's also
why more drive-side spokes break than non-d-s.)

HTH, Realist Bill

me said:

Is it everyone's experience that rear road tires get flats while riding more
often than front ones? It sure is mine, and I wonder why. Seems like the
front should go flat more since it's the first to encounter the sharp
objects. Anyone care to theorize?

Not that I mind the ratio...I'd much rather have a rear than a front tire go
flat on me.

Unless you're on the brakes, the rear tire has more weight on it;
that's the important factor in my opinion.
--
Typoes are a feature, not a bug.
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me said:

Is it everyone's experience that rear road tires get flats while riding more
often than front ones? It sure is mine, and I wonder why. Seems like the
front should go flat more since it's the first to encounter the sharp
objects. Anyone care to theorize?

another factor:
When you dodge with the front wheel the rear wheel doesn't exactly follow,
so the rear may still go right over the debris.

Andre

Whatever the reason my ratio has been at least 5:1... maybe 10:1... I
seem to always get a flat in the rear tire. Front tire kicks stuff up
that then gets embedded in the back one, more weight on the back...
plus it may be related to fact that I wear out rear tires at least 3
times as fast as the fronts... driving and squirming forces may also
help embed sharp objects.

me said:

Is it everyone's experience that rear road tires get flats while riding more
often than front ones? It sure is mine, and I wonder why. Seems like the
front should go flat more since it's the first to encounter the sharp
objects. Anyone care to theorize?

More weight on the rear tire.

JT

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Per me:

Quoted message said:

Is it everyone's experience that rear road tires get flats while riding more
often than front ones? It sure is mine, and I wonder why. Seems like the
front should go flat more since it's the first to encounter the sharp
objects. Anyone care to theorize?

Based on MTB experience, I think it's the added weight.

The idea about the front wheel throwing the object so that it penetrates the
rear wheel sounds logical for a road situation, but most of my MTB punctures are
from thorns...so the "throwing" effect is not there and my rear tire flats
noticeably more often than the front.

When I rode on the road a lot, many of my flats were shards of glass that worked
their way deep enough into the tire to finally puncture the tube. Seems like
that process is accelerated by lots of weight on the tire...
--
PeteCresswell

(PeteCresswell) said:

Per me:

Quoted message said:

Is it everyone's experience that rear road tires get flats while
riding more often than front ones? It sure is mine, and I wonder
why. Seems like the front should go flat more since it's the first
to encounter the sharp objects. Anyone care to theorize?

Based on MTB experience, I think it's the added weight.

But don't you tend to pinch-flat the front at least as often as the rear due
to bashing into rock edges and stuff? I can minimize that if I /see/ the
obstacle in time to unweight the front wheel, but on some trails it's
practically unavoidable (at least for my ham-footed skills). You're right,
though, then the REAR tire often takes the hit, and pssssssttt...

Quoted message said:

The idea about the front wheel throwing the object so that it
penetrates the rear wheel sounds logical for a road situation, but
most of my MTB punctures are from thorns...so the "throwing" effect
is not there and my rear tire flats noticeably more often than the
front.

Same here. I often can steer around a thorny patch or whatever, but the
rear wheel rolls right through it.

Quoted message said:

When I rode on the road a lot, many of my flats were shards of glass
that worked their way deep enough into the tire to finally puncture
the tube. Seems like that process is accelerated by lots of weight
on the tire...

Yup.

Bill "hit a nasty glass field other day, but Pro Races ain't flat (yet)" S.

Per Sorni:

Quoted message said:

But don't you tend to pinch-flat the front at least as often as the rear due
to bashing into rock edges and stuff?

I've only pinch flatted once so far. I'm about 220#, run my tires at 35-40
PSI; but I use fairly high-volume tires (WTB Mutano Raptors size 55/55).

OTOH, my skill level is somewhere between beginner and pathetic and if there's a
choice between a technical route and an easy route I'll take the easy route
every time... so there may not be as many challenges to the tires as with
somebody else.
--
PeteCresswell

Squid-in-Training said:

me said:

Is it everyone's experience that rear road tires get flats while
riding more often than front ones? It sure is mine, and I wonder
why. Seems like the front should go flat more since it's the first
to encounter the sharp objects. Anyone care to theorize?

Not that I mind the ratio...I'd much rather have a rear than a front
tire go flat on me.

Jobst says it's because the front wheel kicks up the penetrating agent right
before the rear wheel runs over it. Envision a nail on its side, spun about
with angular velocity omega. If it is kicked up just right, the nail will
spin 90 or 270 degrees around orthogonal to the plane of the road, and say
hi to the rear tire. That's an instant goner. With glass, it becomes
embedded until a few revolutions later when it's forced past the tire casing
and into the tube. SSSssSSSssSSsssSSssSSssSSss goes the tube.

I totally subscribe to--but hate--that theory.

A few months ago, riding straight line on a city street, I had a rear
blowout. Turns out, I hit a difficult-to-see replacement blade for a
utility knife--one of those trapezoidal-shaped deals.

It must have been laying flat, but the front tire set it up on some
measure of acute angle just enough to slice perfectly perpendicularly
through the rear tire. Game over.

Luckily, I knew of an LBS about two blocks away ... though I *did* ask
them if this was their little marketing scheme ;-)

Sorni said:

It's because the rear wheel is a bit bigger PITA to remove. (That's also
why more drive-side spokes break than non-d-s.)

I was going to post "Sod's Law", but you beat me to it ;-)

Sorni said:

(PeteCresswell) said:

Per me:

Quoted message said:

Is it everyone's experience that rear road tires get flats while
riding more often than front ones? It sure is mine, and I wonder
why. Seems like the front should go flat more since it's the first
to encounter the sharp objects. Anyone care to theorize?

Based on MTB experience, I think it's the added weight.

But don't you tend to pinch-flat the front at least as often as the
rear due to bashing into rock edges and stuff? I can minimize that
if I /see/ the obstacle in time to unweight the front wheel, but on
some trails it's practically unavoidable (at least for my ham-footed
skills). You're right, though, then the REAR tire often takes the
hit, and pssssssttt...

I ran 15psi during a flattish MTB race with 2.0 tires and dented my rim
slightly on a root, but didn't pinch the ultralight tube, probably because
I'm 135lb. This was on a full rigid SS. It was sweet though because I got
4th out of 8 in the men's collegiate Bs, but that's only because the course
was flat and somewhat technical. If there are any long, straight uphills,
I'm out. Plus, it was an easy bike to hop due to the 19lb weight.

Quoted message said:

Quoted message said:

The idea about the front wheel throwing the object so that it
penetrates the rear wheel sounds logical for a road situation, but
most of my MTB punctures are from thorns...so the "throwing" effect
is not there and my rear tire flats noticeably more often than the
front.

Same here. I often can steer around a thorny patch or whatever, but
the rear wheel rolls right through it.

Quoted message said:

When I rode on the road a lot, many of my flats were shards of glass
that worked their way deep enough into the tire to finally puncture
the tube. Seems like that process is accelerated by lots of weight
on the tire...

Yup.

Bill "hit a nasty glass field other day, but Pro Races ain't flat
(yet)" S.

--
Phil, Squid-in-Training

Ron Ruff said:

Whatever the reason my ratio has been at least 5:1... maybe 10:1... I
seem to always get a flat in the rear tire. Front tire kicks stuff up
that then gets embedded in the back one, more weight on the back...
plus it may be related to fact that I wear out rear tires at least 3
times as fast as the fronts... driving and squirming forces may also
help embed sharp objects.

I get pinch flats on the rear (which hasn't happened in years) and
puncture flats on the front. The front tire never seems to kick stuff
up, whatever it runs over seems to stick in it. So at this point I get
probably 20 front flats to 1 rear flat.

Greg

--
"All my time I spent in heaven
Revelries of dance and wine
Waking to the sound of laughter
Up I'd rise and kiss the sky" - The Mekons

G.T. said:

I get pinch flats on the rear (which hasn't happened in years) and
puncture flats on the front. The front tire never seems to kick stuff
up, whatever it runs over seems to stick in it. So at this point I get
probably 20 front flats to 1 rear flat.

I haven't gotten a pinch flat in a long time... I guess I know where
all the potholes are by now. Still, I get all the flats on the rear...
including one yesterday. I ride through a lot of glass and debris...
when the alternative is playing chicken with 18 wheelers...

On Sun, 19 Mar 2006 08:03:41 GMT, "Sorni" <[email hidden]>

Quoted message said:

me said:

Is it everyone's experience that rear road tires get flats while
riding more often than front ones? It sure is mine, and I wonder
why. Seems like the front should go flat more since it's the first
to encounter the sharp objects. Anyone care to theorize?

It's because the rear wheel is a bit bigger PITA to remove. (That's also
why more drive-side spokes break than non-d-s.)

Note also the number of bikes built with a QR on the front but not the
back. And, last night, a special award to the rear brake with the
nearly frozen cable that made the whole process just that much more
special.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

In article <[email hidden]>,

(PeteCresswell) said:

Per me:

Quoted message said:

Is it everyone's experience that rear road tires get flats while riding more
often than front ones? It sure is mine, and I wonder why. Seems like the
front should go flat more since it's the first to encounter the sharp
objects. Anyone care to theorize?

Based on MTB experience, I think it's the added weight.

The idea about the front wheel throwing the object so that it penetrates the
rear wheel sounds logical for a road situation, but most of my MTB punctures are
from thorns...so the "throwing" effect is not there and my rear tire flats
noticeably more often than the front.

Why is the throwing effect not active for off-road riding?

[...]

--
Michael Press

Michael Press said:

In article <[email hidden]>,

(PeteCresswell) said:

Per me:

Quoted message said:

Is it everyone's experience that rear road tires get flats while
riding more often than front ones? It sure is mine, and I wonder
why. Seems like the front should go flat more since it's the first
to encounter the sharp objects. Anyone care to theorize?

Based on MTB experience, I think it's the added weight.

The idea about the front wheel throwing the object so that it
penetrates the rear wheel sounds logical for a road situation, but
most of my MTB punctures are from thorns...so the "throwing" effect
is not there and my rear tire flats noticeably more often than the
front.

Why is the throwing effect not active for off-road riding?

If Pete is referring to thorns still on a branch or bush, then the branch or
bush wouldn't get thrown around from the front tire running over it. A
single detached thorn, maybe, but not the whole branch.

--
Phil, Squid-in-Training

Per Phil, Squid-in-Training:

Quoted message said:

If Pete is referring to thorns still on a branch or bush, then the branch or
bush wouldn't get thrown around from the front tire running over it. A
single detached thorn, maybe, but not the whole branch.

Typically old dried-up raspberry fronds laying out of sight under a thin
covering of other stuff...
--
PeteCresswell