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Re: importance of tyre aero vs rolling resistance data [Tom A.] [ In reply to ]
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>>Baah...tire width (i.e. NEED to be wider for handling) is over-rated IMHO, even for fast crits.


Really? If you're basing that statement on a non-technical course at slower speed, I'll agree. But otherwise, I'll always take a wider tire.
Last edited by: Carl Spackler: Mar 23, 12 8:17
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Re: importance of tyre aero vs rolling resistance data [jackmott] [ In reply to ]
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You don't want to keep up with the local studs in a crit, ideally , when you make you move you want to gain time on every corner. One of you local studs is faster in the corners than the rest, and i bet he wins quite a few races because of it.

Styrrell
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Re: importance of tyre aero vs rolling resistance data [styrrell] [ In reply to ]
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styrrell wrote:
You don't want to keep up with the local studs in a crit, ideally , when you make you move you want to gain time on every corner. One of you local studs is faster in the corners than the rest, and i bet he wins quite a few races because of it.

its not an issue yet, as I'm still a non starter aerobically against the cat3s =) (But I do gain time on them in every corner, thank science)



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
Last edited by: jackmott: Mar 23, 12 8:08
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Re: importance of tyre aero vs rolling resistance data [styrrell] [ In reply to ]
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styrrell wrote:
Assuming you aren't a complete non starter fitness-wise, success in crits comes down to 2 factors. Reading a race and bike handling. I don't doubt the best bike handlers in the world could out corner anyone on ST on skinney tires with crappy rubber, but for most of us anything that can give us a bit more cornering confidence and speed is going to overcome the aero advantage of a narrow tire.

Since I started this whole tangent on tire width and handling, I figured I'd respond to this...I wasn't talking about "skinney(sic) tires with crappy rubber". What I was saying is that width is not necessarily mutually exclusive of good handling. There actually are skinny tires WITH good rubber.

Yes, there are narrow tires that wouldn't give me the best confidence diving into a corner at speed...but, the tires I mentioned above are not amongst them. Seriously, I had zero thoughts of "I sure wish I'd run wider tires so I didn't have to back off in these corners", mostly because...well, I didn't need to ;-)

http://bikeblather.blogspot.com/
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Re: importance of tyre aero vs rolling resistance data [Carl Spackler] [ In reply to ]
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Carl Spackler wrote:
>>Baah...tire width (i.e. NEED to be wider for handling) is over-rated IMHO, even for fast crits.


Really? If you're basing that statement on a non-technical course at slower speed, I'll agree. But otherwise, I'll always take a wider tire.

Nope...granted, the last course I did was somewhat non-technical ("D-shaped", 1km loop), but it definitely was not "slower speed". Come on down to SoCal and we'll show you what "crit speed" means :-)

You should come down next weekend for the Buellton "Avenue of the Flags" crit. HUGE purse in that one :-)

http://bikeblather.blogspot.com/
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Re: importance of tyre aero vs rolling resistance data [Tom A.] [ In reply to ]
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Right, a D shape is not technical. That's why your comment was hardly relevant across a broad spectrum.

I "know what crit speed means" in So Cal, thanks. Mostly leave them to DeMarchi, Gary and their lot, other than when helping my teammate, a current masters national crit champ.
Last edited by: Carl Spackler: Mar 23, 12 11:01
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Re: importance of tyre aero vs rolling resistance data [Tom A.] [ In reply to ]
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Thats fine, but physics is physics and for the same rubber and tire construction, a wider tire will have a higher ultimate traction limit. Their really isn't a point in arguing that. It isn't going to be huge with a 20 vs 23 tire and it isn't going to matter if you corner at a speed lower than the max possible with the 20, but if you can explore the limits of tire adhesion a tire with higher limits will be faster.

And I never said that skinny tires were exclusive of good rubber, my point was, again, that most riders don't explore the max cornering forces anyways in which case tire selection doesn't matter.

Styrrell
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Re: importance of tyre aero vs rolling resistance data [styrrell] [ In reply to ]
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styrrell wrote:
a wider tire will have a higher ultimate traction limit.

oh that definitely is not true *in general* though it may be true for any reasonable range of road bike widths (I haven't any idea).



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
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Re: importance of tyre aero vs rolling resistance data [jackmott] [ In reply to ]
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it may be true for any reasonable range of road bike widths

Were we discussing another situation?

Styrrell
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Re: importance of tyre aero vs rolling resistance data [styrrell] [ In reply to ]
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styrrell wrote:
it may be true for any reasonable range of road bike widths

Were we discussing another situation?

anyone got the balls to get the g-meter and skate pads out?

I don't!



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
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Re: importance of tyre aero vs rolling resistance data [jackmott] [ In reply to ]
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jackmott wrote:
zipps website indicates 21 for the 404 and 808, 23 for the 303

Where? I can't seem to find it.
Last edited by: matto: Mar 24, 12 20:02
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Re: importance of tyre aero vs rolling resistance data [brynjulf] [ In reply to ]
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I'm sure it's buried in here somewhere, but I'm trying to get to the bottom line in terms of real world speed difference; so maybe someone can help me out. Let's take a real world example and all you math geniuses tell me the time savings in these two scenarios. Assumption for starting point is 140lb rider, relatively flat course with some cross wind, and typical speed for half IM around 21 mph. Current setup is Zipp FP60 with disc cover, Mich Pro3Race, and butyl tubes.

1). Pick a better tire (clincher) and a good latex tube to improve crr. What is the improvement in crr; and most importantly... how much time savings does that equate to in a half IM?

2). Now pick a better wheelset (e.g. Zipp Firecrest), same scenario as above. What time savings (approx) would that provide over the FP60 with wheelcover?

Please base this on actual data and numbers, not "I bought brand new Zipp's and I got 2 mph faster immediately"...

And no, I'm not being trite; I really think that some hard numbers around real world time savings would be very helpful to many that left physics behind a long time ago : )
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Re: importance of tyre aero vs rolling resistance data [pocolocoman] [ In reply to ]
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Monday morning bump...
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Re: importance of tyre aero vs rolling resistance data [pocolocoman] [ In reply to ]
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nobody?...
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Re: importance of tyre aero vs rolling resistance data [Tom A.] [ In reply to ]
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Tom A. wrote:
valdlaw wrote:
Tom A. wrote:
Canadian wrote:
If we were to test additional tires then those tires may have rolling resistance values that counter any aero benefit you may gain, OR perhaps the tires lack grip in corners or in wet conditions. If a tire doesn't corner well and the rider on the bike knows that, they will be hesitant going into corners. In a race like a crit where you can have dozens of corners, holding back on every corner will cost you far more time than a 50gram aero benefit.


Baah...tire width (i.e. NEED to be wider for handling) is over-rated IMHO, even for fast crits. For example, just a few weeks ago a rode a TT on a Sunday with a 20C Supersonic on the front Jet 90 and a 21C Specialized S-Works Mondo Open on the rear Jet 90 (both narrow rims). I had a crit to race the following Saturday, and being lazy I decided the only mod to the wheels was to remove the cover. I never felt that my tire choice held me back in the crit :-)

If one chooses wisely, it IS possible to get low Crr AND good handling properties in a narrow tire (or, at least what is considered now-a-days to be narrow...heck, it wasn't long ago that everyone raced RRs and crits on 18C and 19C tires!)


Interesting tire choice Tom. I can still get my hand on the open tubular 21 but the 23 is gone. I know Al had roller data on the 23 but is there anything on e 21 that you know of? I think if the crr is similar the 21 would probably be faster than the 23 on the FC 808 which is still apparently relatively faster with a narrow tire. Thoughts? BTW are you pleased with what you've seen from the supersonic on the front? Do you think it would be a good choice for the FC as well or would you stick with the R4 Aero?


I guess you missed this: http://forum.slowtwitch.com/...ring=roller;#3819430 ;-)

Due to the shape of the tread (i.e. Specialized's "dual radius" thing...the center of the tread is flattened out) I probably wouldn't run an S-Works Mondo Open on a front application.

The SS works nicely on front...both in TTs AND in crits ;-) I'd be interested to see how it tests out on an FC404 or FC808...


Ok I got my hands on the closeout Mondo Opens 21's and 23's for 35 bucks a piece. I've been thinking about the front aero application issue for the 404FC on my Venge-I've had Conti 4000s front and rear. The aero data suggests the thinner tires work best on the FC rim. You've also said that the good Crr makes up a lot for the aero deficit. Given those factors wouldn't you still expect the Open mondo 21 ( and maybe even the 23) to outperform the 4000S?
Last edited by: valdlaw: Mar 29, 12 18:06
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Re: importance of tyre aero vs rolling resistance data [Tom A.] [ In reply to ]
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So it makes more sense for me to run a 21c tire on my 808FC for triathlon races with not as many turns? What if I'm 170 lbs. would it make more sense to run a 23c instead because of my weight? I'm not sure the 21c would be as stable, plus if I blow a tire it's more likely my carbon wheel could get damaged. If anything I was thinking of going with a 25c Cont. 4000S tire...would that make me slower from an aero standpoint? I could possibly run less air pressure in my tires running a 25c tire so I'm curious of that analysis or thought process. Also, what tire pressure are we talking about here in all these tests? Isn't that a huge variable in the performance of a tire during a race?

Any feedback would be cool. Thx
Last edited by: motoxxx: Mar 29, 12 18:25
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Re: importance of tyre aero vs rolling resistance data [valdlaw] [ In reply to ]
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valdlaw wrote:
Tom A. wrote:
valdlaw wrote:
Tom A. wrote:
Canadian wrote:
If we were to test additional tires then those tires may have rolling resistance values that counter any aero benefit you may gain, OR perhaps the tires lack grip in corners or in wet conditions. If a tire doesn't corner well and the rider on the bike knows that, they will be hesitant going into corners. In a race like a crit where you can have dozens of corners, holding back on every corner will cost you far more time than a 50gram aero benefit.


Baah...tire width (i.e. NEED to be wider for handling) is over-rated IMHO, even for fast crits. For example, just a few weeks ago a rode a TT on a Sunday with a 20C Supersonic on the front Jet 90 and a 21C Specialized S-Works Mondo Open on the rear Jet 90 (both narrow rims). I had a crit to race the following Saturday, and being lazy I decided the only mod to the wheels was to remove the cover. I never felt that my tire choice held me back in the crit :-)

If one chooses wisely, it IS possible to get low Crr AND good handling properties in a narrow tire (or, at least what is considered now-a-days to be narrow...heck, it wasn't long ago that everyone raced RRs and crits on 18C and 19C tires!)


Interesting tire choice Tom. I can still get my hand on the open tubular 21 but the 23 is gone. I know Al had roller data on the 23 but is there anything on e 21 that you know of? I think if the crr is similar the 21 would probably be faster than the 23 on the FC 808 which is still apparently relatively faster with a narrow tire. Thoughts? BTW are you pleased with what you've seen from the supersonic on the front? Do you think it would be a good choice for the FC as well or would you stick with the R4 Aero?


I guess you missed this: http://forum.slowtwitch.com/...ring=roller;#3819430 ;-)

Due to the shape of the tread (i.e. Specialized's "dual radius" thing...the center of the tread is flattened out) I probably wouldn't run an S-Works Mondo Open on a front application.

The SS works nicely on front...both in TTs AND in crits ;-) I'd be interested to see how it tests out on an FC404 or FC808...


Ok I got my hands on the closeout Mondo Opens 21's and 23's for 35 bucks a piece. I've been thinking about the front aero application issue for the 404FC on my Venge-I've had Conti 4000s front and rear. The aero data suggests the thinner tires work best on the FC rim. You've also said that the good Crr makes up a lot for the aero deficit. Given those factors wouldn't you still expect the Open mondo 21 ( and maybe even the 23) to outperform the 4000S?

On a front? Probably not. The S-Works Mondo Opens have a "flattened" tread profile and a couple of small ridges along the sides...sort of the opposite of the nice parabolic shape that would work well as a leading edge. With a frame that shelters the leading edge of the rear tire, I wouldn't hesitate to use it as a rear though.

That said, you're talking about a Venge (i.e. a road bike)...and I've been known to run the 21C S-Works Mondo Opens front and rear on my Jet 90s for crits and RRs. They are REALLY nice RR tires :-)

http://bikeblather.blogspot.com/
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Re: importance of tyre aero vs rolling resistance data [Tom A.] [ In reply to ]
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Tom A. wrote:
valdlaw wrote:
Tom A. wrote:
valdlaw wrote:
Tom A. wrote:
Canadian wrote:
If we were to test additional tires then those tires may have rolling resistance values that counter any aero benefit you may gain, OR perhaps the tires lack grip in corners or in wet conditions. If a tire doesn't corner well and the rider on the bike knows that, they will be hesitant going into corners. In a race like a crit where you can have dozens of corners, holding back on every corner will cost you far more time than a 50gram aero benefit.


Baah...tire width (i.e. NEED to be wider for handling) is over-rated IMHO, even for fast crits. For example, just a few weeks ago a rode a TT on a Sunday with a 20C Supersonic on the front Jet 90 and a 21C Specialized S-Works Mondo Open on the rear Jet 90 (both narrow rims). I had a crit to race the following Saturday, and being lazy I decided the only mod to the wheels was to remove the cover. I never felt that my tire choice held me back in the crit :-)

If one chooses wisely, it IS possible to get low Crr AND good handling properties in a narrow tire (or, at least what is considered now-a-days to be narrow...heck, it wasn't long ago that everyone raced RRs and crits on 18C and 19C tires!)


Interesting tire choice Tom. I can still get my hand on the open tubular 21 but the 23 is gone. I know Al had roller data on the 23 but is there anything on e 21 that you know of? I think if the crr is similar the 21 would probably be faster than the 23 on the FC 808 which is still apparently relatively faster with a narrow tire. Thoughts? BTW are you pleased with what you've seen from the supersonic on the front? Do you think it would be a good choice for the FC as well or would you stick with the R4 Aero?


I guess you missed this: http://forum.slowtwitch.com/...ring=roller;#3819430 ;-)

Due to the shape of the tread (i.e. Specialized's "dual radius" thing...the center of the tread is flattened out) I probably wouldn't run an S-Works Mondo Open on a front application.

The SS works nicely on front...both in TTs AND in crits ;-) I'd be interested to see how it tests out on an FC404 or FC808...


Ok I got my hands on the closeout Mondo Opens 21's and 23's for 35 bucks a piece. I've been thinking about the front aero application issue for the 404FC on my Venge-I've had Conti 4000s front and rear. The aero data suggests the thinner tires work best on the FC rim. You've also said that the good Crr makes up a lot for the aero deficit. Given those factors wouldn't you still expect the Open mondo 21 ( and maybe even the 23) to outperform the 4000S?

On a front? Probably not. The S-Works Mondo Opens have a "flattened" tread profile and a couple of small ridges along the sides...sort of the opposite of the nice parabolic shape that would work well as a leading edge. With a frame that shelters the leading edge of the rear tire, I wouldn't hesitate to use it as a rear though.

That said, you're talking about a Venge (i.e. a road bike)...and I've been known to run the 21C S-Works Mondo Opens front and rear on my Jet 90s for crits and RRs. They are REALLY nice RR tires :-)

Well do you think the 21's would be better than the 23's as I have both. Perhaps leave the 4000s on the front? Which way would you go?
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Re: importance of tyre aero vs rolling resistance data [valdlaw] [ In reply to ]
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valdlaw wrote:
Well do you think the 21's would be better than the 23's as I have both. Perhaps leave the 4000s on the front? Which way would you go?

What's the event?

http://bikeblather.blogspot.com/
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Re: importance of tyre aero vs rolling resistance data [Tom A.] [ In reply to ]
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Group rides, some RR's, even some training. I guess I'm looking for a do it all setup to minimize changing setups.
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Re: importance of tyre aero vs rolling resistance data [valdlaw] [ In reply to ]
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valdlaw wrote:
Group rides, some RR's, even some training. I guess I'm looking for a do it all setup to minimize changing setups.

In that case, I'd leave the 4000S's on there...

http://bikeblather.blogspot.com/
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Re: importance of tyre aero vs rolling resistance data [Tom A.] [ In reply to ]
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Tom A. wrote:
valdlaw wrote:
Group rides, some RR's, even some training. I guess I'm looking for a do it all setup to minimize changing setups.


In that case, I'd leave the 4000S's on there...

I was kind of hoping that you might say that - less work for me ;) I'll plan to use the 21's as the rear tire on my FC808's on the TT bike then - I have an R4Aero on the front. Have you found the 21's to be fairly robust as a rear tire? I have only ever used the 23's and they seemed to do hold up pretty well as compared to the R4 Aero which I'm a bit squeamish to try again, particularly since I'll be training on it as well.'
As always, thanks for your help!
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Re: importance of tyre aero vs rolling resistance data [valdlaw] [ In reply to ]
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valdlaw wrote:
Have you found the 21's to be fairly robust as a rear tire?

Yes. They're pretty much the same as the 23s (which they should be considering the constructions).

http://bikeblather.blogspot.com/
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Re: importance of tyre aero vs rolling resistance data [Tom A.] [ In reply to ]
Quote | Reply
Tom A. wrote:
valdlaw wrote:
Tom A. wrote:
valdlaw wrote:
Tom A. wrote:
Canadian wrote:
If we were to test additional tires then those tires may have rolling resistance values that counter any aero benefit you may gain, OR perhaps the tires lack grip in corners or in wet conditions. If a tire doesn't corner well and the rider on the bike knows that, they will be hesitant going into corners. In a race like a crit where you can have dozens of corners, holding back on every corner will cost you far more time than a 50gram aero benefit.


Baah...tire width (i.e. NEED to be wider for handling) is over-rated IMHO, even for fast crits. For example, just a few weeks ago a rode a TT on a Sunday with a 20C Supersonic on the front Jet 90 and a 21C Specialized S-Works Mondo Open on the rear Jet 90 (both narrow rims). I had a crit to race the following Saturday, and being lazy I decided the only mod to the wheels was to remove the cover. I never felt that my tire choice held me back in the crit :-)

If one chooses wisely, it IS possible to get low Crr AND good handling properties in a narrow tire (or, at least what is considered now-a-days to be narrow...heck, it wasn't long ago that everyone raced RRs and crits on 18C and 19C tires!)


Interesting tire choice Tom. I can still get my hand on the open tubular 21 but the 23 is gone. I know Al had roller data on the 23 but is there anything on e 21 that you know of? I think if the crr is similar the 21 would probably be faster than the 23 on the FC 808 which is still apparently relatively faster with a narrow tire. Thoughts? BTW are you pleased with what you've seen from the supersonic on the front? Do you think it would be a good choice for the FC as well or would you stick with the R4 Aero?


I guess you missed this: http://forum.slowtwitch.com/...ring=roller;#3819430 ;-)

Due to the shape of the tread (i.e. Specialized's "dual radius" thing...the center of the tread is flattened out) I probably wouldn't run an S-Works Mondo Open on a front application.

The SS works nicely on front...both in TTs AND in crits ;-) I'd be interested to see how it tests out on an FC404 or FC808...


Ok I got my hands on the closeout Mondo Opens 21's and 23's for 35 bucks a piece. I've been thinking about the front aero application issue for the 404FC on my Venge-I've had Conti 4000s front and rear. The aero data suggests the thinner tires work best on the FC rim. You've also said that the good Crr makes up a lot for the aero deficit. Given those factors wouldn't you still expect the Open mondo 21 ( and maybe even the 23) to outperform the 4000S?

On a front? Probably not. The S-Works Mondo Opens have a "flattened" tread profile and a couple of small ridges along the sides...sort of the opposite of the nice parabolic shape that would work well as a leading edge. With a frame that shelters the leading edge of the rear tire, I wouldn't hesitate to use it as a rear though.

That said, you're talking about a Venge (i.e. a road bike)...and I've been known to run the 21C S-Works Mondo Opens front and rear on my Jet 90s for crits and RRs. They are REALLY nice RR tires :-)

Tom I take it then that you'd use the Mondo 21's on race day as opposed to the 4000S? If so what's the advantage in your opinion?
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Re: importance of tyre aero vs rolling resistance data [valdlaw] [ In reply to ]
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valdlaw wrote:
Tom I take it then that you'd use the Mondo 21's on race day as opposed to the 4000S? If so what's the advantage in your opinion?

Depends on the race and depends on the wheels. :-) For my narrow Jet 90s and in a crit or road race, yes...the S-Works Mondo Open 21s. Why? Because I like them ;-)

Now then, just today I rode a crit on some "wide" wheels (I actually am lucky to be trying out some Flo 60 pre-production wheels) and for those I put a brand new Bontrager RXL Pro Open 23 on the front paired with an S-Works Mondo Open 23 on the rear. Vittoria latex tubes in both. That's a nice combo for a fast, 6 turn (well...actually 5 turns) crit. Good enough for me to win a $40 bottle of wine in a prime :-)



http://bikeblather.blogspot.com/
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