Good stuff

This all raises the discussion that we really need a way to get independent testing.

We are being soooooo misinformed from various sources.

Not specifically but I assume the range was indicative of the the various combinations or yae angle, rim depth, and tire width.

Can you say who the vendor is ? Sounds like they are on top of things.

Parcours. Lots of good info on the website.

Cool. I have seen their white papers and one of their folks even chimed into some threads.

If I look at the DT Swiss/Swiss Side info, I don’t find things add up for the vendors claiming 28mm+ optimal setups.

I may have tests queued up in the future. I am really curious

Not familiar with the findings. What are questioning our of curiosity?

I watched a video on YouTube (non scientific) where two guys were testing different size tires (Victoria next) in 28c and 32c and 34c. All on the same rim and adjusted for optimal tire pressure. Attempted a timed circuit with consistent wattage. The 32c was the fastest on both...by a fair margin.

Now this may be fraught with variables as I can't imagine wind, humidity, cornering ,etc would be the same in all conditions, but the numbers were surprisingly consistent between both riders.

May also suggest that is some instances the aero drag may not be as penal for various wheels or once you've already breached the 'optimal' width anyway.

This is very interesting. How is vibration affected by pressure, does in affect amplitude or frequency? What range of frequencies are you analysing?

We are still pulling together all the data and I'm 90% sure we will want to ride a few more types of road before coming to conclusions. We will eventually share, I am just not sure what the best format of that is to give info and receive actionable feedback.

I am not sure our analysis in the frequency domain is complete. We definitely need a few more rides to separate road types, equipment placement, sampling rates.....there is a long list. We spent all this time filtering out vibration to get things like road incline, and now we want it back :-).

Amplitudes are very obviously impacted. Just that has value but we want more. Frequency, to be further investigated. If you have ideas, i'm all ears and willing to measure.

I did a few test with a MEMS accelerometer sampling at 500hz and I did not draw any clear conclusions. I am not sure that's the right accelerometer to use. I would guess frequency will be dependent on speed and also type of surface but I don't know if the tyres will have any effect on f (certainly they will affect the amplitude). I would like to test and analyse higher frequencies, but at the moment I don't have the right sensors. What range were you analysing?

We have a few sensors and can sample at 10x that. But there is a lot more to it than the sample rate.
Putting the sensor in the right place and bringing the data all together is a lot of fun. We need accelerometer sampling for dummies thread :-)

With the BRR data out now showing the Pro Speed as the fastest tire ever, I don't think we need a list anymore, it's down to the GP 5000 S TR for training or races on bad roads, or a decision between the 5000 TT or Pro Speed for all other racing/tris/TTs, with the 5000 TT being the more conservative choice and the Pro Speed the nice roads/YOLO choice.


Veloflex Record falls out of consideration.

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Amateur recreational hobbyist cyclist
https://www.strava.com/athletes/337152
https://vimeo.com/user11846099

i respect whatever your view is. but i must ask again. (since BRR data is in.) same answer? if you trained on corsa pro speeds - true tubeless - and had the same no-flat experience, would that change your mind? (i, like you, would need to be convinced of its durability.)

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Dan Empfield
aka Slowman

I would personally lean more towards a middle ground - run them in a tri but with air liners in to cut down the types of puncture I’d be vulnerable to. This all said, I’d be more cavalier based on racing distance. If it were a sprint, oly or 70.3, I’d run the Vittorias, but if it were the kind of high value/risk event I’d only do once or twice a season like an IM, I’d go with Xav’s suggestion.

500Hz is enough to see something. How good is your timing on the 500 samples per second? Here a very early test I did some time ago

https://forum.slowtwitch.com/...ost=7741796#p7741796

I trained on Corsa Pro Speeds this week actually! No issues to report so far. Regarding training and racing on the same tyre we saw that Corsa Speeds (the old version) wore out and the Crr increased over time, so I'd want to know that wasn't going to happen to the Corsa Pro Speed before I left them on a bike the entire time for both training and racing. GP5000 TTs aren't like this as far as we've established.

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AeroCoach UK
http://www.aero-coach.co.uk

thanks for the answer. i'll be interested to know your progress with this tire.

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Dan Empfield
aka Slowman

Interesting, hadn’t considered a “lifetime” for the nominal performance. Is there any early info you can share on e.g. how many miles before a significant loss is observed, and what that loss (watts, %, etc) is estimated to be?