Wide Mt. Bike Tires vs. Thin Tires

wrote in message
oups.com...
For the sake of this discussion assume that all things are equal
regarding quality of parts. I have an inexpensive mt bike with the
standard fairly wide tires and am thinking of getting a new inexpensive
26 in. bike however this one has the very thin tires. The mt. bike
tires appear to be at least three times as wide and possibly 4. Since
there is much less friction associated with the thin tires and remember
all things considered equal can I assume that the same energy and
exertion that I put into pedaling the mt. bike will be at the very
least 2 or more times effective when pedaling the bike with the very
thin tires.


So by putting tires half as wide on my car I should get twice the mileage?
Narrower, non-knobby tires (slicks) will have a positive effect on the watts
(energy) needed to go the same speed on your bike as your current knobby
(standard fairly wide) tires.

I would recommend High-Tech_Cycling Second Edition by Edmund R. Burke, Ed.
and http://www.analyticcycling.com/ForcesTires_Page.html as references...

Play with the Numbers for the model (site referenced above). I ran a 2.1
inch tire (Touring Tubular) in the model against a Premium Clincher (road
tire) and found that I would be 80 seconds behind the Premium Clincher after
30,000 meters (30 kilometers) all things being equal. I'm sure that knobby
tires would have a larger impact but still not what you are assuming. Wind
resistance / bike position, drive train friction, rotational weight of the
tires / type of tires and wheels and bicycle stability all figure into how
much power/energy/watts is needed to push you down the road.

My recommendation would be buy some slicks for your mtb, the narrower the
better. Slicks usually allow you to run a higher pressure that regular
knobbies.

-p

On Mon, 7 Mar 2005 17:14:19 -0800, David wrote:

If you're gonna do 95% pavement, 5% light dirt, and want to be faster on
the road, buy this tire, from these guys:
http://harriscyclery.net/site/itemdetails.cfm?ID=1320

If you decide to do loose dirt, or serious MTBing, spend a few minutes
to put your knobbies back on.

Yeah, that's what I thought once. Eventually I found myself on on a "light
dirt" trail with slick tires, needing to brake. The bike quickly slid off
the trail, and once in the grass the brakes were completely inneffective
(as the tires couldn't grip at all). The rest was inevitable.

If you're going to ride slicks, put the knobbies back on ANYTIME you go
off-road.

This guy felt the slicks made a huge difference vs light tread. While I
agree it does vs semi-slicks (with knobby sides), I don't feel it makes a
lot of difference against tires with light thread and no knobs. A lot of
its perception, I suppose.

--
-BB-
To e-mail me, unmunge my address

"BB" wrote in message ...

If you're going to ride slicks, put the knobbies back on ANYTIME you go
off-road.

If you're going to have one bike, and do both road and real dirt, you can just swap the
back tire for the road--leave the front knobby on all the time. It's the rear knobby that
wears out fastest, and slows you the most. And you're much more secure in the dirt with
a knobby front, whatever you have in back. So you're can ride a lot of stuff without
doing the tire change.

But I still ride my road bike in the dirt sometimes, skinny road tires at both ends.

Per BB:
Eventually I found myself on on a "light
dirt" trail with slick tires, needing to brake. The bike quickly slid off
the trail, and once in the grass the brakes were completely inneffective
(as the tires couldn't grip at all). The rest was inevitable.

If you're going to ride slicks, put the knobbies back on ANYTIME you go
off-road.

That's the reason I like some tread on my front wheel no matter what. Did a
couple face plants already when I forgot...

For "road" use I run a 1.25" slick on the back, but a 1.25" knobby cross tire on
the front.
--
PeteCresswell

Nokian Gazzaloddi 26 x 2.6.










Shaun aRe - What?!?!?

On Mon, 7 Mar 2005 22:26:01 -0800, David wrote:

If you're going to have one bike, and do both road and real dirt, you
can just swap the back tire for the road--leave the front knobby on all
the time. It's the rear knobby that wears out fastest, and slows you the
most.

As long as you don't have any fast road turns or any dirt climbing to
speak of, that should work. The knobby front will give you the best
turning & stopping power in the dirt, but will reduce these same
capabilities on the road. It makes sense that most efficient rear tire
would be the one with the least tread necessary to get sufficient grip on
the dirt trails.

My closest dirt riding is a three-mile climb away (and a very fast winding
trip back down), and the turns coming back down gets REAL squirrely if I
have knobs on the front tire. The last thing I want to do is crash on a
road at 35mph, so I change to a treaded (not knobby) front tire if I'm
going up there, which works OK even with a knobby tire on the back.

--
-BB-
To e-mail me, unmunge my address

On 7 Mar 2005 08:02:50 -0800, wrote:

For the sake of this discussion assume that all things are equal
regarding quality of parts. I have an inexpensive mt bike with the
standard fairly wide tires and am thinking of getting a new inexpensive
26 in. bike however this one has the very thin tires. The mt. bike
tires appear to be at least three times as wide and possibly 4. Since
there is much less friction associated with the thin tires and remember
all things considered equal can I assume that the same energy and
exertion that I put into pedaling the mt. bike will be at the very
least 2 or more times effective when pedaling the bike with the very
thin tires.

You won't go wrong with the Avocet 1.9" city slicks someone here
mentioned. They are fine tires.

However, if I may make a suggestion also, "Been there, done that." I
even have two new unused ones on my tire rack in the cellar that will
probably sit there another year.

Even better, may I suggest you get two 1.0" Tom Slicks from
Performance Bike. About $17 each, sometimes they go on sale. 1.0"
tubes (hard to find in shops, I've found, but Performance and Nashbar
have them). Run 100 psi in them. You now have what is essentially a
road bike as far as rolling resistance is concerned. It will feel like
a new machine. Of course, if you can get a set of spare wheels, just
have one with the slicks and one with knobbies, and you now have two
bikes for one, with no changing of tires. That's what I have on one of
my Treks. When I travel, I only have to take one bike but am ready for
any kind of riding.

Old Timer

Old Timer wrote:
On 7 Mar 2005 08:02:50 -0800, wrote:

For the sake of this discussion assume that all things are equal
regarding quality of parts. I have an inexpensive mt bike with the
standard fairly wide tires and am thinking of getting a new
inexpensive 26 in. bike however this one has the very thin tires.
The mt. bike tires appear to be at least three times as wide and
possibly 4. Since there is much less friction associated with the
thin tires and remember all things considered equal can I assume
that the same energy and exertion that I put into pedaling the mt.
bike will be at the very least 2 or more times effective when
pedaling the bike with the very thin tires.

You won't go wrong with the Avocet 1.9" city slicks someone here
mentioned. They are fine tires.

However, if I may make a suggestion also, "Been there, done that." I
even have two new unused ones on my tire rack in the cellar that will
probably sit there another year.

Even better, may I suggest you get two 1.0" Tom Slicks from
Performance Bike. About $17 each, sometimes they go on sale. 1.0"
tubes (hard to find in shops, I've found, but Performance and Nashbar
have them). Run 100 psi in them. You now have what is essentially a
road bike as far as rolling resistance is concerned. It will feel like
a new machine. Of course, if you can get a set of spare wheels, just
have one with the slicks and one with knobbies, and you now have two
bikes for one, with no changing of tires. That's what I have on one of
my Treks. When I travel, I only have to take one bike but am ready for
any kind of riding.

Don't forget the likely spacer-on-one-of-the-axles adjustment for adjustment
free shifting.

--
Phil, Squid-in-Training