Real-World Aero Testing: Giro Aerohead Ultimate vs Lazer Tardiz & Profile Design FC25 vs FC35

Please note that this is an impartial video with no paid content. The opinions expressed here are my own.

To help me become a faster time trialist, I am testing the equipment I have available to find out which are the fastest for me. Today I'm testing the difference between a Giro Aerohead Ultimate MIPS TT helmet compared to a Lazer Tardiz helmet, and the difference between the Profile Design FC-25 bottle and the FC-35 bottle.

To test this, I rode 2 laps of the Losail International circuit in Qatar; approximately 10.5km at identical, consistent power (274W). The only difference between the runs was either the helmet or the bottle.

Test 1 - Giro Ultimate + FC35
Test 2 - Giro Ultimate + FC25
Test 3 - Lazer Tardiz + FC25

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Test Activity:

All the same equipment was used apart from the items tested.
My TT Set-Up:
Bike: Phian 3.0
Wheels: PlanetX Selcof Tubular Trispoke and Disc with 25mm Zipp tubs
Powermeter: Garmin Vector 2 dual sided pedal based meter
Skinsuit: Team GB, TT, full length arms
Shoe Covers: Castelli aero covers
Gloves: Castelli aero TT gloves

[eltrangkista]

Nice video Mr. Tom, keep them coming :)

[joyridaz]

I wonder if using the Dow tube bottle to drink would incur a larger penalty?

[satpalmodinagar]

I think this setup gives same result, thanks for nice video bro🚵👍👍👍

[xiaohe]

Hello, could you test the Met Codatronca helmet and make a comparison? We do not find any currently. Thank you

[patricky]

Great video! may I know the explanation why taping the tail part of the tardiz can make it more aerodynamic?

[RickRubinesque]

I'd like to see areo helmet vs regular helmet vs no helmet.

[TheGinger]

Did air temperature, air pressure and wind speed remain the same between runs?

[Livi]

did you happen to test your bike without either hydration system on that day to see if the FC25/35 actually makes the total system slower/faster?

[rickescobanas]

is FC35 UCI-legal should you set it up on TT bike? Thanks

[SuperPathfinder]

intersting had the same ideas did prep up the old Tardis as you did and it's defenetly faster with the vents and tail closed. No offencen :) - ur taping (esp tail) looks rather quick, i also taped the side vents half. I wonder if u improve the job if the result would be even better. I just experiment with taping the back vent. around 3 seconds on 10 k so up to 12 seconds loss on 40. Pretty good for an old well vented helmet - impressive. Oh i don't have the visor.
Are the reults stable? I guess if its hot the tardis might be still an option? In the real world probably 5 runs might me good. Bike radar said the met drone might be even faster for some...

[ShamiehAdam]

Just what I was looking for in deciding if I should drop $200 switching from the Lazer to the Giro. That's almost a minute at IM distance, but I'm still not sure if it's worth it...

I've been hunting around for the lens/shield for the Lazer, but no luck... I'd love to know the time difference between the shield vs no shield (and even the tape if you are so gracious). Cheers!

[EricRidesDirt]

Do you have the results published somewhere?

[Yamaha_Bolt]

FC 25 slower is a fatigue effect, you need an ABAB design

[mindciller]

Seems small. Until you lose by 12 seconds