i put 20 ss on 808, fit does not loof too bad, only thing of note is i need a smaller latex tube size and the result is that the front wheel is almost 10mm shorter, so in esence lowered front end 4-5mm. will require adjusting bars and saddle if i stay on this route. not going to 20mm on rear
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Re: New Crr roller data [jeffp]
[ In reply to ]
Re: New Crr roller data [jeffp]
[ In reply to ]
That would be sweet. I don't think I'm the only one interested in 20mm vs. 23mm SuperSonic aerodynamic performance on a new wide rim.
Re: New Crr roller data [MTM]
[ In reply to ]
The Crr difference seems to be ~1W for one wheel, which is probably less than the aerodynamic difference between the sizes, at least if looking at some of the Zipp graphs for the 303FC.
One thing to consider is that the 20mm tire would normally be pumped to a higher pressure... I think even to achieve a similar vibration response. Not sure about that, though.
One thing to consider is that the 20mm tire would normally be pumped to a higher pressure... I think even to achieve a similar vibration response. Not sure about that, though.
Re: New Crr roller data [MTM]
[ In reply to ]
MTM wrote:
That would be sweet. I don't think I'm the only one interested in 20mm vs. 23mm SuperSonic aerodynamic performance on a new wide rim.I put both a Bonty R4 and a 20mm SuperSonic on an 808 FC. I couldn't figure out which looked more aero. The SuperSonic was narrower but made a less smooth transition than the R4.
So is the difference between the top tires, combining bot aero and crr effects, going to be large enough that one could measure with self testing and the golden cheeta software? Or will it be in the noise? I'd think subtle body positions on the bike and changes in wind patterns throughout the day would dominate the difference between say the top 5 tires?
Assuming that's true, the best one can do is look at this data, eyeball the aerodynamics, make a decision move on?
Re: New Crr roller data [rruff]
[ In reply to ]
rruff wrote:
The Crr difference seems to be ~1W for one wheel, which is probably less than the aerodynamic difference between the sizes, at least if looking at some of the Zipp graphs for the 303FC. One thing to consider is that the 20mm tire would normally be pumped to a higher pressure... I think even to achieve a similar vibration response. Not sure about that, though.
Yes, probably. Not sure it would affect things too much. Perhaps the 23mm is better if the surface is sufficiently rough/bad.
Re: New Crr roller data [matto]
[ In reply to ]
matto wrote:
MTM wrote:
That would be sweet. I don't think I'm the only one interested in 20mm vs. 23mm SuperSonic aerodynamic performance on a new wide rim.I put both a Bonty R4 and a 20mm SuperSonic on an 808 FC. I couldn't figure out which looked more aero. The SuperSonic was narrower but made a less smooth transition than the R4.
So is the difference between the top tires, combining bot aero and crr effects, going to be large enough that one could measure with self testing and the golden cheeta software? Or will it be in the noise? I'd think subtle body positions on the bike and changes in wind patterns throughout the day would dominate the difference between say the top 5 tires?
Assuming that's true, the best one can do is look at this data, eyeball the aerodynamics, make a decision move on?
Probably next to impossible to tell which of those two tires is actually more aero without windtunnel or very stringent field testing. Could probably even depend on yaw. Based on the various Crr tests I've seen I feel confident that the 20mm SuperSonic is the faster overall tire, though.
Regarding field testing, it likely depends on your protocol and how meticulous you are. If not very meticulous you will probably have a very hard time to tell the difference between the five best tires. If you have any wind and are not measuring it precisely, forget about finding differences smaller than, say 5 watts.
Re: New Crr roller data [Tom A.]
[ In reply to ]
I'm in need of a new rear tire as my 290 TPI Evo CX's are going to seed and making me flat-nervous. Might as well get some faster rubber in the process. :)
It looks like I can get Conti SS's 23's for slightly less than Evo Tri's. (unless I can convince some teammates to join in a tire/tube buying spree)
So, in your estimation, which would you use attached to a 23mm wide rim (on the rear wheel) for tri's?
Read: given the closeness in RR, which would you assume is more durable?
The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important.
-Albert J. Nock
It looks like I can get Conti SS's 23's for slightly less than Evo Tri's. (unless I can convince some teammates to join in a tire/tube buying spree)
So, in your estimation, which would you use attached to a 23mm wide rim (on the rear wheel) for tri's?
Read: given the closeness in RR, which would you assume is more durable?
The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important.
-Albert J. Nock
Re: New Crr roller data [Derf]
[ In reply to ]
The Evo Tri probably has better tread life... the SS is only good for <500mi on the rear... under me anyway. Puncture resistance is probably a toss up. Even though they have no vectran belt, the SS tires aren't that fragile.
I've done some more tests and I'd give the SS the clear Crr edge. The more I run it the faster it gets. It had been laying around for a couple years, so maybe there is an aging and re-break-in thing going on... pure speculation.
Another thing... the Vittorias are very nice tires... they just look and feel better crafted than the Continentals.
I've done some more tests and I'd give the SS the clear Crr edge. The more I run it the faster it gets. It had been laying around for a couple years, so maybe there is an aging and re-break-in thing going on... pure speculation.
Another thing... the Vittorias are very nice tires... they just look and feel better crafted than the Continentals.
Re: New Crr roller data [Derf]
[ In reply to ]
Derf wrote:
I'm in need of a new rear tire as my 290 TPI Evo CX's are going to seed and making me flat-nervous. Might as well get some faster rubber in the process. :) It looks like I can get Conti SS's 23's for slightly less than Evo Tri's. (unless I can convince some teammates to join in a tire/tube buying spree)
So, in your estimation, which would you use attached to a 23mm wide rim (on the rear wheel) for tri's?
Read: given the closeness in RR, which would you assume is more durable?
I think the EVO tri actually has a puncture belt (it's hard to tell from the Vittoria literature any more)...whereas, the SS does not. I'm pretty sure the EVO Slick has one as well, and it's virtually tied with the EVO Tri.
http://bikeblather.blogspot.com/
Re: New Crr roller data [rruff]
[ In reply to ]
Forgot to reply after your's and Tom's posts. Thank you both! I think I'm going to seek out a Vittoria for longer course racing (even if I'm being unfounded in my risk aversion), and use a SS that I'm getting from a friend (used once) for shorter course stuff.
The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important.
-Albert J. Nock
The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important.
-Albert J. Nock
Re: New Crr roller data [Derf]
[ In reply to ]
Regarding "risk aversion"... even though they don't have great puncture resistance, neither of these tires are going to fall apart on you.
Probably the best thing you can do to avoid punctures during a race is to stay in the lane and off the shoulder if you can. Vehicles naturally "sweep" the lane just by driving on it, but a lot of the crap ends up on the shoulder.
Probably the best thing you can do to avoid punctures during a race is to stay in the lane and off the shoulder if you can. Vehicles naturally "sweep" the lane just by driving on it, but a lot of the crap ends up on the shoulder.
Re: New Crr roller data [rruff]
[ In reply to ]
Was thinking Ron after I mounted up an attack last night - they are directional (arrow on the sidewall). Any chance that 2nd, poorer testing Attack, was mounted backward? Not sure it would make much of a difference?
____________________________________
Fatigue is biochemical, not biomechanical.
- Andrew Coggan, PhD
____________________________________
Fatigue is biochemical, not biomechanical.
- Andrew Coggan, PhD
Re: New Crr roller data [rroof]
[ In reply to ]
Nope. Doubt it would matter at all though. The grooves are just for style.
I'll soon have a new Attack and Force ready to test. I've also revised the protocol a little to reduce random errors, and I think I'll spend a day and test (or retest) every tire I have.
I'll soon have a new Attack and Force ready to test. I've also revised the protocol a little to reduce random errors, and I think I'll spend a day and test (or retest) every tire I have.
Re: New Crr roller data [Tom A.]
[ In reply to ]
digging up an old post... Tom, would you expect the tubular version of the SL to perform/have similar differences to to the tubular CX as you outlined below?
I'm looking for replacements for my tubular 23mm CX or tubular 21mm Tangente for my FC 808s. Wondering if a Crono might be doable for TTs.
Racing?
I ride them all the time!
Every ride, a thing of beauty.
Why ruin a great ride with cheap rubber?
The knock on the Vittoria EVO CX historically has been that it's not that durable and does not last that long. We ride on shitty roads, and I don't seem to get an unusual number of flats ( on average 1 - 3/year) and for the riding I do - a moderate amount - they last a full season of outdoor riding. That's fine for me.
The Conti GP 4000s is the one that intrigues me. It's close to the Vittoria's in rolling resistance, but reports seem to say it's more durable and lasts longer. Maybe I'll change things up this year and go with a set of bad-ass Conti GP 4000s 25's! :)
Take a look at the Vittoria EVO Corsa SL instead of the CX if you're considering the GP4000s. The tread compound is different than the CX (feels more like what was used on the Bontrager and Specialized "open tubular" models which were smokin' fast tires and had great durability and grip IME) and there's no "herringbone" tread pattern (it's slick, thus the "SL" moniker). I've found them to be fairly durable AND they handle better than the CXs IMHO. I've always found the CXs to handle a bit "wobbly" and the tread compound seems too soft and easily cut.
I haven't thrown one on the rollers yet (possibly this weekend), but I don't expect it to test "slow" either... ;-)
Eric Reid AeroFit | Instagram Portfolio
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I'm looking for replacements for my tubular 23mm CX or tubular 21mm Tangente for my FC 808s. Wondering if a Crono might be doable for TTs.
Tom A. wrote:
Fleck wrote:
I can't seem to get away from the Corsa Evo tire when it comes to racing Racing?
I ride them all the time!
Every ride, a thing of beauty.
Why ruin a great ride with cheap rubber?
The knock on the Vittoria EVO CX historically has been that it's not that durable and does not last that long. We ride on shitty roads, and I don't seem to get an unusual number of flats ( on average 1 - 3/year) and for the riding I do - a moderate amount - they last a full season of outdoor riding. That's fine for me.
The Conti GP 4000s is the one that intrigues me. It's close to the Vittoria's in rolling resistance, but reports seem to say it's more durable and lasts longer. Maybe I'll change things up this year and go with a set of bad-ass Conti GP 4000s 25's! :)
Take a look at the Vittoria EVO Corsa SL instead of the CX if you're considering the GP4000s. The tread compound is different than the CX (feels more like what was used on the Bontrager and Specialized "open tubular" models which were smokin' fast tires and had great durability and grip IME) and there's no "herringbone" tread pattern (it's slick, thus the "SL" moniker). I've found them to be fairly durable AND they handle better than the CXs IMHO. I've always found the CXs to handle a bit "wobbly" and the tread compound seems too soft and easily cut.
I haven't thrown one on the rollers yet (possibly this weekend), but I don't expect it to test "slow" either... ;-)
Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting
“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.â€
Re: New Crr roller data [ericM35-39]
[ In reply to ]
ericM35-39 wrote:
digging up an old post... Tom, would you expect the tubular version of the SL to perform/have similar differences to to the tubular CX as you outlined below?Yup.
http://bikeblather.blogspot.com/
Re: New Crr roller data [rruff]
[ In reply to ]
rruff wrote:
Nope. Doubt it would matter at all though. The grooves are just for style. I'll soon have a new Attack and Force ready to test. I've also revised the protocol a little to reduce random errors, and I think I'll spend a day and test (or retest) every tire I have.
Any chance the Pro4 Comp will make the test?
-------------------
Madison photographer Timothy Hughes | Instagram
Re: New Crr roller data [rruff]
[ In reply to ]
Wow, this is great information, thanks. As someone just starting to really focus on the little aspects of racing, in the real world, how much time would the best tire listed here save over the middle range tire such as the mich 4? seconds, minutes? Based on what I think are accurate calculations, it would equate to about 0.45 MPH. Does this sound right? Thanks for any feedback.
Last edited by:
mgratton33: Mar 10, 13 19:25
Re: New Crr roller data [Tom A.]
[ In reply to ]
Thanks
Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting
“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.â€
Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting
“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.â€
Re: New Crr roller data [Timtek]
[ In reply to ]
Not unless someone wants to send me theirs. I might be inspired to buy a Pro4 Comp *Limited*...
Re: New Crr roller data [mgratton33]
[ In reply to ]
Sounds about right.
Re: New Crr roller data [rruff]
[ In reply to ]
Wow, not only did I get the math right, but I may have also found a way to buy some speed. Half a mile per hour for $90 almost seems like a no brainer. Thanks again for the data and your time, it's very appreciated.
Re: New Crr roller data [MTM]
[ In reply to ]
MTM wrote:
That would be sweet. I don't think I'm the only one interested in 20mm vs. 23mm SuperSonic aerodynamic performance on a new wide rim.I answered this question here in this forum may be 2 years ago, just use the search option!
Re: New Crr roller data [BergHügi]
[ In reply to ]
BergHügi wrote:
MTM wrote:
That would be sweet. I don't think I'm the only one interested in 20mm vs. 23mm SuperSonic aerodynamic performance on a new wide rim.I answered this question here in this forum may be 2 years ago, just use the search option!
I almost forgot. But more data is usually better and having data at different yaw angles would also be neat :-)
Re: New Crr roller data [rruff]
[ In reply to ]
Ron, any knowledge about Vittoria Cronos? The tubular 20mm tested very fast with AFM, and now I see the new version is 22mm "to match better with wide rims" and has a puncture belt. Did the old one have a puncture belt?
best case, the Crono will have even less Crr for additional width but less aero due to the wider 22mm. Not a bad tire for the State TT Champs or something like that.
Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting
“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.â€
best case, the Crono will have even less Crr for additional width but less aero due to the wider 22mm. Not a bad tire for the State TT Champs or something like that.
Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting
“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.â€
The new one measures 21mm, and was lower in Crr in AFMs testing. The old didn't have a puncture strip. I've used a pair for a IM race with no issues and they still look new.
Styrrell
Styrrell