Zipp High Desert Speed Challenge

Based on the feedback from many posts about Zipp disc wheels, and also from many posts about the EXP fortunes available with the TOW stage 4, I’m going to assume everyone is hyped for the Zipp High Desert Speed Challenge this weekend.

2 days, free wheels for 2 lucky contenders, a special TT race, what more could you ask for? Let’s do this in all cats for all the luck. My trike would look the bomb with an 858 on the rear.


Well that was fun, completed my first heat. And what would a Zipp Disc Race be on Zwift without some Disc wheel controversy? At least in the one race I was in, it appeared as though the wheel setups for all was random. I got lucky and was equipped with the 858/Disc. Oh yeah!

are wheels unlocked as well, or just the kit?

Just the kit and one entry into the random draw for a set of 858’s in real life for Cat’s A and B. Kit and entry for bars and stem in Cat C.

Women can do all 3 races, men can only do A and C.

I’m assuming multiple attempts in say Cat A would generate multiple entries into the draw for 858’s.

I was thinking the same, or was it based on Level?

I am the one in front.

Eric from ZwiftInsider was in my heat and he had them as well, so I thought maybe level had something to do with it, maybe it does, still inconclusive. I’m only level 31 so I’m not even able to purchase the 808/disc or 858/disc in the drop shop but I had them. It’s a Zwift mystery.

I think everyone seeing his self with the 858/super9.

Anything else would be very unfair, since this is a race.

Don’t forget, what you see on zwift is not what others see on zwift.


Omg, that was SO MUCH FUN! This was my first TT race, and I loved every single second of it! I’m thinking of doing it again tomorrow! I looked so fast, I think it made me work harder than I thought I could!


I did this even t at 12:30 on 4th April. I loved the TT format but I’m totally confused by the Zwift physics/algorithm!

For my event I rode a steady threshold pace and average 325W, I came 5th overall in a time of 1:13:05 I weigh 88kg so my average power/weight was 3.7W/kg. First place averaged 301W in a time of 1:09:48 over 3 minutes quicker with an average power to weight of 4.3W/kg. For a pan-flat course brute power should outweigh power/weight like it does IRL. A friend of mine observed the same thing, he averaged 333W and finished in a time of 1:08:34 yet another rider in his event finished with a similar time at an average of 230W - There’s something wrong here has anyone else noticed this or is it just me?


It’s pretty much w/kg on Zwift. This TT (and this week’s ToW stage 5) have “high altitude” adjustment, to make everyone go faster than normal.

Try to time travel this same distance without the event edge and let us know how it goes.

Yes It’s not as IRL.
But just as a statistical contribute I’m 63 kg @165cm and I scored 1h 13’ 54" @234w.
That’s 3.7 w/k too.


  • It’s not pancake flat.
  • It’s not necessarily the greatest W/kg that wins.
  • It’s not necessarily the greatest raw wattage that wins.

For the latter two, Don’t believe me. Go check some results on ZwiftPower. For example:

That said, I too am curious as to the physics at play. Height appears to be a factor?! Didn’t ZwiftInsider show that to be true?

Height should be the main factor on a TT flat race, height is used to calculate your Cda (frontal drag area)

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I would expect it to be, but was not sure if Zwift incorporated it into the model or not. It would appear they have done so which is as it should be and a good thing.

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I guess it’s.

With 234w @1.65m @63kg I slightly (4") outperformed a 236w @59kg @1.78m guy …


Quick question…did you all unlock the zipp kit at the end of the event? Zwift crashed on exit and didn’t get any unlock confirmation it there was one. Thanks.

The “Garage” icon showed that there was something new in there, I didn’t check it but assume that was the kit.

Edit… yes it is :+1:

Well, that does explain quite a lot…

As a heavier rider, I fully expect to struggle on the climbs. But I also expected to have some advantage on the flats, and that never did seem to be the case.

So, how much do I need to weight dope to level the playing field against a 65 kg rider on Tempus Fugit…?

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See above…

First of all, while mostly flat, it’s not pan flat. Second of all, height is a consideration. So, height, weight, watts are all variables that the user can control. The remaining variables are fixed. Zwift combines all of these inputs in the model to determine your speed.

That’s simply NOT true. Has been debated to the dead, but facts are that the inner algorithms are by far a lot more complexes than w/kg, and the inner algorithms are mostly correct regards on ride physics.

W/kg are just the end-user dumbed down view and are NOT actually used on computing your speed.