What difference would a 115g saving in tyre weight make?

[[email protected]]

On 30 Aug 2006 12:32:55 -0700, "bfd" <[email protected]> wrote:

>
>[email protected] wrote:
>> On 30 Aug 2006 10:59:00 -0700, "bfd" <[email protected]> wrote:
>>
>> >
>> >Tim McNamara wrote:
>> >> In article <[email protected]>,
>> >> Artoi <[email protected]> wrote:
>> >>
>> >> > My bike presently has a set of Conti UltraSport 700cX25. If I change
>> >> > it to a set of new Grand Prix 4000 with a saving of 115g/tyre, what
>> >> > practical differences would I be able to feel during my rides? Is it
>> >> > a weight saving that'll be obvious?
>> >>
>> >> No.
>> >>
>> >> Put it this way- do you notice the difference between full and empty
>> >> water bottles? A 24 ounce water bottle weighs its own weight plus 710
>> >> grams for the water, more than 6 times the weight savings of the lighter
>> >> tire. If you don't notice the difference between a full and empty water
>> >> bottle, you won't notice the lighter tire.
>> >
>> >Come on Tim, we all know that water bottle is NOT *rotating weight*....
>>
>> Dear BFD,
>>
>> Does splashing weight count?
>>
>I don't know, ask Floyd Landis. Then again, doped or not, he probably
>was, he did power up those 5 climbs using powertap hub which easily
>adds over a pound to the bike. Didn't seem to hurt him. Of course, if
>you're doped up, probably nothing short of a bulldozer would...

Dear BFD,

Actually, I meant splashing around inside the bottle.

Cheers,

Carl Fogel

 

[Tim McNamara]

In article <[email protected]>,
"bfd" <[email protected]> wrote:

> Tim McNamara wrote:
> > In article
> > <[email protected]>,
> > Artoi <[email protected]> wrote:
> >
> > > My bike presently has a set of Conti UltraSport 700cX25. If I
> > > change it to a set of new Grand Prix 4000 with a saving of
> > > 115g/tyre, what practical differences would I be able to feel
> > > during my rides? Is it a weight saving that'll be obvious?
> >
> > No.
> >
> > Put it this way- do you notice the difference between full and
> > empty water bottles? A 24 ounce water bottle weighs its own weight
> > plus 710 grams for the water, more than 6 times the weight savings
> > of the lighter tire. If you don't notice the difference between a
> > full and empty water bottle, you won't notice the lighter tire.
>
> Come on Tim, we all know that water bottle is NOT *rotating
> weight*....

LOL! Speak for your own water bottles! :-D

 

[[email protected]]

bfd wrote:
> [email protected] wrote:
> > On 30 Aug 2006 10:59:00 -0700, "bfd" <[email protected]> wrote:
> >
> > >
> > >Tim McNamara wrote:
> > >> In article <[email protected]>,
> > >> Artoi <[email protected]> wrote:
> > >>
> > >> > My bike presently has a set of Conti UltraSport 700cX25. If I change
> > >> > it to a set of new Grand Prix 4000 with a saving of 115g/tyre, what
> > >> > practical differences would I be able to feel during my rides? Is it
> > >> > a weight saving that'll be obvious?
> > >>
> > >> No.
> > >>
> > >> Put it this way- do you notice the difference between full and empty
> > >> water bottles? A 24 ounce water bottle weighs its own weight plus 710
> > >> grams for the water, more than 6 times the weight savings of the lighter
> > >> tire. If you don't notice the difference between a full and empty water
> > >> bottle, you won't notice the lighter tire.
> > >
> > >Come on Tim, we all know that water bottle is NOT *rotating weight*....
> >
> > Dear BFD,
> >
> > Does splashing weight count?
> >
> I don't know, ask Floyd Landis. Then again, doped or not, he probably
> was, he did power up those 5 climbs using powertap hub which easily
> adds over a pound to the bike.

But, his bike was probably still at the UCI limit(i.e., they used a
Powertap hub in lieu of "ballast" to make the weight limit).

> Didn't seem to hurt him. Of course, if
> you're doped up, probably nothing short of a bulldozer would...

 

[Artoi]

In article <[email protected]>,
Tim McNamara <[email protected]> wrote:

> In article <[email protected]>,
> Artoi <[email protected]> wrote:
>
> > My bike presently has a set of Conti UltraSport 700cX25. If I change
> > it to a set of new Grand Prix 4000 with a saving of 115g/tyre, what
> > practical differences would I be able to feel during my rides? Is it
> > a weight saving that'll be obvious?
>
> No.
>
> Put it this way- do you notice the difference between full and empty
> water bottles? A 24 ounce water bottle weighs its own weight plus 710
> grams for the water, more than 6 times the weight savings of the lighter
> tire. If you don't notice the difference between a full and empty water
> bottle, you won't notice the lighter tire.

But aren't we talking about dynamic weights here on the wheels?
--

 

[[email protected]]

On Wed, 30 Aug 2006 22:27:12 GMT, Artoi <[email protected]> wrote:

>In article <[email protected]>,
> Tim McNamara <[email protected]> wrote:
>
>> In article <[email protected]>,
>> Artoi <[email protected]> wrote:
>>
>> > My bike presently has a set of Conti UltraSport 700cX25. If I change
>> > it to a set of new Grand Prix 4000 with a saving of 115g/tyre, what
>> > practical differences would I be able to feel during my rides? Is it
>> > a weight saving that'll be obvious?
>>
>> No.
>>
>> Put it this way- do you notice the difference between full and empty
>> water bottles? A 24 ounce water bottle weighs its own weight plus 710
>> grams for the water, more than 6 times the weight savings of the lighter
>> tire. If you don't notice the difference between a full and empty water
>> bottle, you won't notice the lighter tire.
>
>But aren't we talking about dynamic weights here on the wheels?

Dear Artoi,

Yes, the tires are spinning as well as moving foward.

But we're talking about extremely small rotating masses, 230 grams
total, on a bicycle and rider that have a combined mass of about
68,200 to 100,000 grams (150 to 220 pounds).

How fast you accelerate is governed by the force that you can apply
and the mass that you're trying to accelerate. Even doubled for
rotation, the difference here is less than 500 grams /68,200 for a 135
pound rider and a 15 pound bike--that's about 0.7%.

On level ground, that only matters when you're accelerating. Once you
reach cruising speed, the extra mass doesn't slow you down.

(Technically, the extra 500 grams increases the rolling resistance
ever so slightly, but few speed calculators offer enough decimals to
pursue that.)

When you climb at a steady speed, there's only the extra weight, no
doubling--you're raising an extra 0.35% up the hill. (And some of what
you lose is regained on the way back down.)

So yes, the rotating mass on a tire counts for more than the same mass
on a seat post. But neither counts for much because neither is
significant compared to the total mass of bicycle and rider. To
calculate the advantage, you need a lot of decimal places.

Cheers,

Carl Fogel

 

[Artoi]

In article <[email protected]>,
"Art Harris" <[email protected]> wrote:

> Artoi wrote:
> > I was more interested in the dynamic effect of tyre weight. Just curious
> > what 115g/wheel difference would make to the ride.
> >
> Ah, I think you mean "rotating weight" or rotational inertia. At a
> steady speed, it will make no difference at all. When accelerating, it
> theoretically makes a difference, but in cycling the effect is very,
> very small (unless you are doing explosive accelerations).

Thanks to all who chipped in with their wisdom in this thread and I'll
be keeping that $100 in my pocket as a result.

Gosh, looks like that there's nothing really worth upgrading on my new
bike. It must be just perfect!

Maybe I should redirect that saving to buy everyone here some beer...
--

 

[Ron Ruff]

[email protected] wrote:
> So, in the end I settled on lighter wheels, and few extra grams on
> tyres for puncture resistance - and that worked a treat.

Light wheels have a negligible effect on speed and acceleration (maybe
you could "feel" a difference, though), but the effect of different
tires' rolling resistance is *not* trivial. This has been discussed
many times here, and twice recently that I know about. Of the tires you
mentioned the Pro2s are the best... if those are the ones you are
using, then you made a good choice.

 

[RonSonic]

On Wed, 30 Aug 2006 22:39:30 GMT, Artoi <[email protected]> wrote:

>In article <[email protected]>,
> "Art Harris" <[email protected]> wrote:
>
>> Artoi wrote:
>> > I was more interested in the dynamic effect of tyre weight. Just curious
>> > what 115g/wheel difference would make to the ride.
>> >
>> Ah, I think you mean "rotating weight" or rotational inertia. At a
>> steady speed, it will make no difference at all. When accelerating, it
>> theoretically makes a difference, but in cycling the effect is very,
>> very small (unless you are doing explosive accelerations).
>
>Thanks to all who chipped in with their wisdom in this thread and I'll
>be keeping that $100 in my pocket as a result.
>
>Gosh, looks like that there's nothing really worth upgrading on my new
>bike. It must be just perfect!
>
>Maybe I should redirect that saving to buy everyone here some beer...

Hey guys, it finally worked!!!!

ROn

 

[RonSonic]

On Wed, 30 Aug 2006 22:27:12 GMT, Artoi <[email protected]> wrote:

>In article <[email protected]>,
> Tim McNamara <[email protected]> wrote:
>
>> In article <[email protected]>,
>> Artoi <[email protected]> wrote:
>>
>> > My bike presently has a set of Conti UltraSport 700cX25. If I change
>> > it to a set of new Grand Prix 4000 with a saving of 115g/tyre, what
>> > practical differences would I be able to feel during my rides? Is it
>> > a weight saving that'll be obvious?
>>
>> No.
>>
>> Put it this way- do you notice the difference between full and empty
>> water bottles? A 24 ounce water bottle weighs its own weight plus 710
>> grams for the water, more than 6 times the weight savings of the lighter
>> tire. If you don't notice the difference between a full and empty water
>> bottle, you won't notice the lighter tire.
>
>But aren't we talking about dynamic weights here on the wheels?

So multiply the weight times pi and it's still relatively negligable. Back in
the range of that full water bottle we were just talking about. Now Michael
Rasmussen will drop his water bottles at the beginning of a climb, but unless
you're racing against someone like him there's no need to worry much about it.

Of course, sexy wheels are indeed sexy, so get 'em if they make you ride better.

Ron

 

[Tim McNamara]

In article <[email protected]>,
RonSonic <[email protected]> wrote:

> On Wed, 30 Aug 2006 22:39:30 GMT, Artoi <[email protected]> wrote:
>
> >In article <[email protected]>,
> > "Art Harris" <[email protected]> wrote:
> >
> >> Artoi wrote:
> >> > I was more interested in the dynamic effect of tyre weight. Just
> >> > curious what 115g/wheel difference would make to the ride.
> >> >
> >> Ah, I think you mean "rotating weight" or rotational inertia. At a
> >> steady speed, it will make no difference at all. When
> >> accelerating, it theoretically makes a difference, but in cycling
> >> the effect is very, very small (unless you are doing explosive
> >> accelerations).
> >
> >Thanks to all who chipped in with their wisdom in this thread and
> >I'll be keeping that $100 in my pocket as a result.
> >
> >Gosh, looks like that there's nothing really worth upgrading on my
> >new bike. It must be just perfect!
> >
> >Maybe I should redirect that saving to buy everyone here some
> >beer...
>
> Hey guys, it finally worked!!!!

Woo hoo!

 

[Ron Ruff]

RonSonic wrote:
> Of course, sexy wheels are indeed sexy, so get 'em if they make you ride better.

I thought they were supposed to get us chicks...

?

 

[John Forrest Tomlinson]

On Wed, 30 Aug 2006 20:08:57 -0600, [email protected] wrote:

>If you did the sprint 100 times (once every kilometer), you'd end up
>with a 22 meter, 2 second lead.

In a race, if you told me there was equipment that could reliably give
me that advantage for some reasonable cost, I'd take it. a tenth of a
second is enough. Or even less -- the objective is be ahead of the
other guys.

JT

****************************
Remove "remove" to reply
Visit http://www.jt10000.com
****************************

 

[[email protected]]

On Wed, 30 Aug 2006 23:54:37 -0400, John Forrest Tomlinson
<[email protected]> wrote:

>On Wed, 30 Aug 2006 20:08:57 -0600, [email protected] wrote:
>
>>If you did the sprint 100 times (once every kilometer), you'd end up
>>with a 22 meter, 2 second lead.
>
>In a race, if you told me there was equipment that could reliably give
>me that advantage for some reasonable cost, I'd take it. a tenth of a
>second is enough. Or even less -- the objective is be ahead of the
>other guys.
>
>JT
>
>****************************
>Remove "remove" to reply
>Visit http://www.jt10000.com
>****************************

Dear John,

Unfortunately, the 2 second improvement in 100 kilometers is only for
your time with theoretical tires that weigh 250 grams less than your
real tires--and that's if you do 100 550 watt sprints during the race.

If you could do a hundred 550 watt sprints out of corners in a 100 km
ride, you wouldn't need a 2 second lead to beat anyone.

Cheers,

Carl Fogel

 

[RonSonic]

On Wed, 30 Aug 2006 22:29:47 -0600, [email protected] wrote:

>On Wed, 30 Aug 2006 23:54:37 -0400, John Forrest Tomlinson
><[email protected]> wrote:
>
>>On Wed, 30 Aug 2006 20:08:57 -0600, [email protected] wrote:
>>
>>>If you did the sprint 100 times (once every kilometer), you'd end up
>>>with a 22 meter, 2 second lead.
>>
>>In a race, if you told me there was equipment that could reliably give
>>me that advantage for some reasonable cost, I'd take it. a tenth of a
>>second is enough. Or even less -- the objective is be ahead of the
>>other guys.
>>
>>JT
>>
>>****************************
>>Remove "remove" to reply
>>Visit http://www.jt10000.com
>>****************************
>
>Dear John,
>
>Unfortunately, the 2 second improvement in 100 kilometers is only for
>your time with theoretical tires that weigh 250 grams less than your
>real tires--and that's if you do 100 550 watt sprints during the race.
>
>If you could do a hundred 550 watt sprints out of corners in a 100 km
>ride, you wouldn't need a 2 second lead to beat anyone.

But that's not the point. Even if it is only one sprint, the final sprint and he
can obtain ANY advantage, it is worthwhile. We don't need 2 seconds, .05 seconds
is enough.

Ron

 

[Blair P. Houghton]

Ron Ruff wrote:
> RonSonic wrote:
> > Of course, sexy wheels are indeed sexy, so get 'em if they make you ride better.
>
> I thought they were supposed to get us chicks...

Only after you wear them out a few times removing your spare tire.

--Blair

 

[[email protected]]

On Thu, 31 Aug 2006 00:34:49 -0400, RonSonic
<[email protected]> wrote:

>On Wed, 30 Aug 2006 22:29:47 -0600, [email protected] wrote:
>
>>On Wed, 30 Aug 2006 23:54:37 -0400, John Forrest Tomlinson
>><[email protected]> wrote:
>>
>>>On Wed, 30 Aug 2006 20:08:57 -0600, [email protected] wrote:
>>>
>>>>If you did the sprint 100 times (once every kilometer), you'd end up
>>>>with a 22 meter, 2 second lead.
>>>
>>>In a race, if you told me there was equipment that could reliably give
>>>me that advantage for some reasonable cost, I'd take it. a tenth of a
>>>second is enough. Or even less -- the objective is be ahead of the
>>>other guys.
>>>
>>>JT
>>>
>>>****************************
>>>Remove "remove" to reply
>>>Visit http://www.jt10000.com
>>>****************************
>>
>>Dear John,
>>
>>Unfortunately, the 2 second improvement in 100 kilometers is only for
>>your time with theoretical tires that weigh 250 grams less than your
>>real tires--and that's if you do 100 550 watt sprints during the race.
>>
>>If you could do a hundred 550 watt sprints out of corners in a 100 km
>>ride, you wouldn't need a 2 second lead to beat anyone.
>
>But that's not the point. Even if it is only one sprint, the final sprint and he
>can obtain ANY advantage, it is worthwhile. We don't need 2 seconds, .05 seconds
>is enough.
>
>Ron

Dear Ron,

If the other rider is 0.06 seconds ahead of you, a pair of tires that
(theoretically) improve your time by 0.05 seconds will not be enough.

We often let our desire to "obtain ANY advantage" blind us to the fact
that the other rider may simply have a single big advantage that we
can't buy and attach to our bicycle (unless we hire him).

Cheers,

Carl Fogel

 

[Chalo]

Artoi wrote:
>
> My bike presently has a set of Conti UltraSport 700cX25. If I change it
> to a set of new Grand Prix 4000 with a saving of 115g/tyre, what
> practical differences would I be able to feel during my rides? Is it a
> weight saving that'll be obvious?

It might help you build your biceps. Inflating a lot of high-pressure
tires by the roadside with a frame pump can be pretty good exercise.
You'll likely be able to step up your tube patching performance to the
next level, too.

Chalo

 

[Artoi]

In article <[email protected]>,
"Chalo" <[email protected]> wrote:

> Artoi wrote:
> >
> > My bike presently has a set of Conti UltraSport 700cX25. If I change it
> > to a set of new Grand Prix 4000 with a saving of 115g/tyre, what
> > practical differences would I be able to feel during my rides? Is it a
> > weight saving that'll be obvious?
>
> It might help you build your biceps. Inflating a lot of high-pressure
> tires by the roadside with a frame pump can be pretty good exercise.
> You'll likely be able to step up your tube patching performance to the
> next level, too.

Hey, hey, now you know how I like to exercise...
--

 

[Ron Ruff]

John Forrest Tomlinson wrote:
> In a normal criterium many riders can put out that 550 watts of peak
> power (perhaps for a second or two) many many times. It's not rare.
> If by sprint you mean 10 or 15 seconds at that power, then yeah,
> that's hard.

According to Coggan's power profiles, a normal rider can produce 4
times their 20min max power for a duration of 5s, and a little over
double for 1 minute. So for a middling Cat3 crit rider it might look
like this:

20min= 300W
1min= 620W
5s= 1200W

This is only one instance, but I'm pretty sure that I could do 550W for
10 or 15s over and over for a long time... provided I had a decent
recovery in between.

 

[41]

Tim McNamara wrote:

> Table like these only format correctly if you use spaces rather than
> tabs.

Thank Google. Those were spaces.