New wheels, new tires (difference between 700x25, 26, & 28?)

New wheels, new tires (difference between 700x25, 26, & 28?)

Post by Roger Zou » Wed, 16 Jun 2004 01:10:11


I've a heavy rider (240lbs). My current wheels (28 spokes on the rear) have
700x26c tires.

I've ordered a new wheelset due to spokes breaking on the rear (36 spokes on
the rear).  I'm thinking of putting 700x25c or 700x28c tires on this
one...will I notice any significant differences?  I'm buying the another
cassette for the new rear wheel that is exactly the same as the one on my
current wheel, just so I can ensure the bike rides basically the same with
either wheelset.

 
 
 

New wheels, new tires (difference between 700x25, 26, & 28?)

Post by Frank Krygowsk » Wed, 16 Jun 2004 12:59:32

Quote:

> I've a heavy rider (240lbs). My current wheels (28 spokes on the rear) have
> 700x26c tires.

> I've ordered a new wheelset due to spokes breaking on the rear (36 spokes on
> the rear).  I'm thinking of putting 700x25c or 700x28c tires on this
> one...will I notice any significant differences?

Personally, I'd go with at least 28.  If I had your weight, I'd probably
look at 32 mm, if it would clear the frame and brakes.

A narrow tire might give very slightly less rolling resistance on
perfectly smooth roads, but if the road has any significant roughness,
you'll probably be better off with a wider tire.

A wider tire (assuming you inflate it enough) also provides more
protection from pinch flats or "snake bite" flats.

--
--------------------+
Frank Krygowski   [To reply, remove rodent and vegetable dot com,
replace with cc.ysu dot edu]

 
 
 

New wheels, new tires (difference between 700x25, 26, & 28?)

Post by Roger Zou » Wed, 16 Jun 2004 13:25:18

::
::: I've a heavy rider (240lbs). My current wheels (28 spokes on the
::: rear) have 700x26c tires.
:::
::: I've ordered a new wheelset due to spokes breaking on the rear (36
::: spokes on the rear).  I'm thinking of putting 700x25c or 700x28c
::: tires on this one...will I notice any significant differences?
::
:: Personally, I'd go with at least 28.  If I had your weight, I'd
:: probably
:: look at 32 mm, if it would clear the frame and brakes.
::
:: A narrow tire might give very slightly less rolling resistance on
:: perfectly smooth roads, but if the road has any significant
:: roughness,
:: you'll probably be better off with a wider tire.
::
:: A wider tire (assuming you inflate it enough) also provides more
:: protection from pinch flats or "snake bite" flats.

Thanks, Frank.  I've already ordered some 26s, but when I current ones wear
out I'll move to something a bit bigger, if I haven't lost more weight by
then.

 
 
 

New wheels, new tires (difference between 700x25, 26, & 28?)

Post by Dennis Fergus » Thu, 17 Jun 2004 03:36:48



Quote:

>> I've a heavy rider (240lbs). My current wheels (28 spokes on the rear) have
>> 700x26c tires.

>> I've ordered a new wheelset due to spokes breaking on the rear (36 spokes on
>> the rear).  I'm thinking of putting 700x25c or 700x28c tires on this
>> one...will I notice any significant differences?

>Personally, I'd go with at least 28.  If I had your weight, I'd probably
>look at 32 mm, if it would clear the frame and brakes.

>A narrow tire might give very slightly less rolling resistance on
>perfectly smooth roads, but if the road has any significant roughness,
>you'll probably be better off with a wider tire.

That is not how I understand it.  If you take two tires which are
constructed the same, inflated to the same pressure and placed under
the same load, the widest tire will be the one with the least rolling
resistance since it is the tire which will deform the least at the
contact patch.  Racing tires are narrow for other reasons, like improved
aerodynamics and lower weight, qualities which are thought to be a good
tradeoff for the increased rolling resistance.  The fact that wider
tires deform less at similar inflation pressures and loads also makes
them less prone to pinch flats, which means that they can carry the
same loads at lower pressures (making them more comfortable at the
expense of rolling resistance) or, similarly, carry heavier loads at
the same inflation pressure.

Dennis Ferguson

 
 
 

New wheels, new tires (difference between 700x25, 26, & 28?)

Post by Rick Onania » Thu, 17 Jun 2004 04:44:12


Quote:

>Racing tires are narrow for other reasons, like improved
>aerodynamics and lower weight, qualities which are thought to be a good
>tradeoff for the increased rolling resistance.

Also because narrower tires can be inflated to higher pressure --
maybe enough to lower the rolling resistance beyond the fatter
tire's maximum pressure. You'd have to test individual tires at the
pressures you'd actually use them, I guess.
--
Rick Onanian
 
 
 

New wheels, new tires (difference between 700x25, 26, & 28?)

Post by curt » Thu, 17 Jun 2004 06:17:24


Quote:


> ::
> ::: I've a heavy rider (240lbs). My current wheels (28 spokes on the
> ::: rear) have 700x26c tires.
> :::
> ::: I've ordered a new wheelset due to spokes breaking on the rear (36
> ::: spokes on the rear).  I'm thinking of putting 700x25c or 700x28c
> ::: tires on this one...will I notice any significant differences?
> ::
> :: Personally, I'd go with at least 28.  If I had your weight, I'd
> :: probably
> :: look at 32 mm, if it would clear the frame and brakes.
> ::
> :: A narrow tire might give very slightly less rolling resistance on
> :: perfectly smooth roads, but if the road has any significant
> :: roughness,
> :: you'll probably be better off with a wider tire.
> ::
> :: A wider tire (assuming you inflate it enough) also provides more
> :: protection from pinch flats or "snake bite" flats.

> Thanks, Frank.  I've already ordered some 26s, but when I current ones
wear
> out I'll move to something a bit bigger, if I haven't lost more weight by
> then.

I am not sure, but when I replace my 25's, I will be looking at maximum
pressure.  I like to ride a hard tire personally.  120+.  I don't like to
get flats and I have had no problems with my 25's.  I have had 20 and even
19's many years ago and they were a real pain in the butt.  Flats all the
time.

I guess what I am saying is though, tire pressure is important as well,
IMHO.
Curt

 
 
 

New wheels, new tires (difference between 700x25, 26, & 28?)

Post by David L. Johnso » Thu, 17 Jun 2004 06:32:24

Quote:

> I've a heavy rider (240lbs). My current wheels (28 spokes on the rear) have
> 700x26c tires.

> I've ordered a new wheelset due to spokes breaking on the rear (36 spokes on
> the rear).  I'm thinking of putting 700x25c or 700x28c tires on this
> one...will I notice any significant differences?  

Well, the width of tires is somewhat open to interpretation.  One
manufacturer's 28 is another's 32, so it is hard to say whether or not you
will notice a difference.

That being said, certainly you will be better off with the 36-spoke
wheels.  24 is "no visible means of support" for someone in your range.

--

David L. Johnson

   __o   | What is objectionable, and what is dangerous about extremists is
 _`\(,_  | not that they are extreme, but that they are intolerant. --Robert
(_)/ (_) | F. Kennedy  

 
 
 

New wheels, new tires (difference between 700x25, 26, & 28?)

Post by David L. Johnso » Thu, 17 Jun 2004 06:35:09

Quote:




>>> I've a heavy rider (240lbs). My current wheels (28 spokes on the rear) have
>>> 700x26c tires.

>>> I've ordered a new wheelset due to spokes breaking on the rear (36 spokes on
>>> the rear).  I'm thinking of putting 700x25c or 700x28c tires on this
>>> one...will I notice any significant differences?

>>Personally, I'd go with at least 28.  If I had your weight, I'd probably
>>look at 32 mm, if it would clear the frame and brakes.

>>A narrow tire might give very slightly less rolling resistance on
>>perfectly smooth roads, but if the road has any significant roughness,
>>you'll probably be better off with a wider tire.

> That is not how I understand it.  If you take two tires which are
> constructed the same, inflated to the same pressure and placed under
> the same load, the widest tire will be the one with the least rolling
> resistance since it is the tire which will deform the least at the
> contact patch.  

Yes, but.  Thing is, a bigger tire does not need, and usually is not rated
for, as high a pressure as the skinnier tire.  So, riding each tire at the
rated max pressure, the skinny one will have less rolling resistance.

--

David L. Johnson

   __o   | Some people used to claim that, if enough monkeys sat in front of
 _`\(,_  | enough typewriters and typed long enough, eventually one of them
(_)/ (_) | would reproduce  the collected works of Shakespeare.  The
           internet has proven this not to  be the case.  

 
 
 

New wheels, new tires (difference between 700x25, 26, & 28?)

Post by Doug Purd » Thu, 17 Jun 2004 11:18:57


Quote:





> > ::
> > ::: I've a heavy rider (240lbs). My current wheels (28 spokes on the
> > ::: rear) have 700x26c tires.
> > :::
> > ::: I've ordered a new wheelset due to spokes breaking on the rear (36
> > ::: spokes on the rear).  I'm thinking of putting 700x25c or 700x28c
> > ::: tires on this one...will I notice any significant differences?
> > ::
> > :: Personally, I'd go with at least 28.  If I had your weight, I'd
> > :: probably
> > :: look at 32 mm, if it would clear the frame and brakes.
> > ::
> > :: A narrow tire might give very slightly less rolling resistance on
> > :: perfectly smooth roads, but if the road has any significant
> > :: roughness,
> > :: you'll probably be better off with a wider tire.
> > ::
> > :: A wider tire (assuming you inflate it enough) also provides more
> > :: protection from pinch flats or "snake bite" flats.

> > Thanks, Frank.  I've already ordered some 26s, but when I current ones
> wear
> > out I'll move to something a bit bigger, if I haven't lost more weight
by
> > then.

> I am not sure, but when I replace my 25's, I will be looking at maximum
> pressure.  I like to ride a hard tire personally.  120+.  I don't like to
> get flats and I have had no problems with my 25's.  I have had 20 and even
> 19's many years ago and they were a real pain in the butt.  Flats all the
> time.

> I guess what I am saying is though, tire pressure is important as well,
> IMHO.

I'm 230-250. I've ridden 25 to 37. The problem with the weight and high
pressure is that it puts a lot of strain on the wheels over bumps. Low
pressure gives flats, high pressure breaks wheels.

Wheels and components and builds come in different qualities. Just like 28c
tires could be very different, so could 36 spoke wheels. Some are very weak,
some, very strong.

Doug

 
 
 

New wheels, new tires (difference between 700x25, 26, & 28?)

Post by Steve Knigh » Thu, 17 Jun 2004 11:52:35

Quote:
>Thanks, Frank.  I've already ordered some 26s, but when I current ones wear
>out I'll move to something a bit bigger, if I haven't lost more weight by
>then.

I use 25's (that's the max that will fit my bike) and when I started I was 270
now 235) the only problems I had was when I did not keep them inflated to the
max psi. but my ride is a bit bumpy.

--
Knight-Toolworks & Custom Planes
Custom made wooden planes at reasonable prices
See http://www.knight-toolworks.com  For prices and ordering instructions.

 
 
 

New wheels, new tires (difference between 700x25, 26, & 28?)

Post by Steve Knigh » Thu, 17 Jun 2004 11:53:59

Quote:
>I'm 230-250. I've ridden 25 to 37. The problem with the weight and high
>pressure is that it puts a lot of strain on the wheels over bumps. Low
>pressure gives flats, high pressure breaks wheels.

I did not have a problem with bumps but the sidewalls would shred if I did not
keep them at 120. so I learned fast to keep the max pressure.

--
Knight-Toolworks & Custom Planes
Custom made wooden planes at reasonable prices
See http://www.knight-toolworks.com  For prices and ordering instructions.

 
 
 

New wheels, new tires (difference between 700x25, 26, & 28?)

Post by curt » Thu, 17 Jun 2004 12:09:36

Quote:
> > I am not sure, but when I replace my 25's, I will be looking at maximum
> > pressure.  I like to ride a hard tire personally.  120+.  I don't like
to
> > get flats and I have had no problems with my 25's.  I have had 20 and
even
> > 19's many years ago and they were a real pain in the butt.  Flats all
the
> > time.

> > I guess what I am saying is though, tire pressure is important as well,
> > IMHO.

> I'm 230-250. I've ridden 25 to 37. The problem with the weight and high
> pressure is that it puts a lot of strain on the wheels over bumps. Low
> pressure gives flats, high pressure breaks wheels.

> Wheels and components and builds come in different qualities. Just like
28c
> tires could be very different, so could 36 spoke wheels. Some are very
weak,
> some, very strong.

> Doug

Interesting.  I never thought of that.  I hope my rims are strong?????  They
are Campagnolo 6082 alloy t-6's.  Who knows?

Thanks for bringing that up.  I probably should do some more research on
this subject.
Curt

 
 
 

New wheels, new tires (difference between 700x25, 26, & 28?)

Post by Pete » Thu, 17 Jun 2004 12:03:07


Quote:

> Yes, but.  Thing is, a bigger tire does not need, and usually is not rated
> for, as high a pressure as the skinnier tire.  So, riding each tire at the
> rated max pressure, the skinny one will have less rolling resistance.

Yes but...the original comparison was between tires of the same construction
and pressure, but different sizes.

Hard to find that combination, maybe, but there it is.

Pete

 
 
 

New wheels, new tires (difference between 700x25, 26, & 28?)

Post by jobst.bra.. » Thu, 17 Jun 2004 12:37:28

Quote:
Frank Krygowski writes:
>> I've a heavy rider (240lbs). My current wheels (28 spokes on the
>> rear) have 700x26c tires.
>> I've ordered a new wheels due to spokes breaking on the rear (36
>> spokes on the rear).  I'm thinking of putting 700x25c or 700x28c
>> tires on this one...will I notice any significant differences?

This may not solve the spoke breakage problem, because that could lie
with the wheel builder, but 36-spoke is certainly along my thinking.

Quote:
> Personally, I'd go with at least 28.  If I had your weight, I'd
> probably look at 32 mm, if it would clear the frame and brakes.

I'm for that but why two different rim and hub types?  Get front and
rear 36-spoke wheels and ride the same tire front and rear.  If you
put on many miles, you'll realize that replacing tires, tubes, rims,
and spokes is a lot more convenient if they are the same front and
rear, although spoke length is probably a couple of mm different.

Quote:
> A narrow tire might give very slightly less rolling resistance on
> perfectly smooth roads, but if the road has any significant
> roughness, you'll probably be better off with a wider tire.

Very true but the smaller and necessarily harder tire puts more
vibrating stress, the stress that causes failures, to be exerted on
all components between road and saddle.

Quote:
> A wider tire (assuming you inflate it enough) also provides more
> protection from pinch flats or "snake bite" flats.

Of course, and cornering traction is better, if you do that sort of
thing, because more road contact is maintained over rough pavement.

I don't worry about how you will be judged for riding 36-spokes or
pedaling at cadences under 100 (as is common here).  Get out there

Ride bike!

Jobst Brandt

 
 
 

New wheels, new tires (difference between 700x25, 26, & 28?)

Post by jobst.bra.. » Thu, 17 Jun 2004 12:40:46

Quote:

>> Thanks, Frank.  I've already ordered some 26s, but when I current
>> ones wear out I'll move to something a bit bigger, if I haven't
>> lost more weight by then.
> I use 25's (that's the max that will fit my bike) and when I started
> I was 270 now 235) the only problems I had was when I did not keep
> them inflated to the max PSI but my ride is a bit bumpy.

That's a good reason not to by that kind of frame.  How do you ride on
wet roads or even or dirt roads with not enough clearance to fit the
nest larger tire (1mm in radius)?

Jobst Brandt