Deeper rear wheel / staggered rim depth, aero gainz?

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spartacus
Posts: 1048
Joined: Mon Apr 04, 2011 6:53 pm

by spartacus

Say I have 40mm wheels front and rear. Would going to a 60mm rear wheel be worthwhile at all as far as a small increase in speed and preserving handling characteristics on high speed descents?

by Weenie


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TobinHatesYou
Posts: 12444
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

spartacus wrote:
Thu Mar 09, 2023 11:36 pm
Say I have 40mm wheels front and rear. Would going to a 60mm rear wheel be worthwhile at all as far as a small increase in speed and preserving handling characteristics on high speed descents?

The difference will be imperceptible going from 50/50 to 50/60 imo. 40/60 makes no sense to me. I would only ever ride 40s in a hilly road race.

spartacus
Posts: 1048
Joined: Mon Apr 04, 2011 6:53 pm

by spartacus

It makes sense if you have a 60mm rear wheel and a 40mm wheel set :noidea:

Also I'm pretty sure that has been sold as a set by reynolds iirc?

TobinHatesYou
Posts: 12444
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

spartacus wrote:
Fri Mar 10, 2023 4:28 am
It makes sense if you have a 60mm rear wheel and a 40mm wheel set :noidea:

Also I'm pretty sure that has been sold as a set by reynolds iirc?

I mean okay sure if that's what you already have. Going from 40mm rear to 60mm rear might be good for ~1W at 45km/h.

spartacus
Posts: 1048
Joined: Mon Apr 04, 2011 6:53 pm

by spartacus

TobinHatesYou wrote:
Fri Mar 10, 2023 7:19 am
spartacus wrote:
Fri Mar 10, 2023 4:28 am
It makes sense if you have a 60mm rear wheel and a 40mm wheel set :noidea:

Also I'm pretty sure that has been sold as a set by reynolds iirc?

I mean okay sure if that's what you already have. Going from 40mm rear to 60mm rear might be good for ~1W at 45km/h.
So little huh? Is there data on this you've seen or know of?

I understand that the rear wheel is sheltered mostly under normal co dictions but I'm wondering if having the deeper rear wheel can give you some of the sailing effect under certain wind conditions you get from the deep wheelset.

spartacus
Posts: 1048
Joined: Mon Apr 04, 2011 6:53 pm

by spartacus

I guess I'll file this one under potential marginal gains that nobody has explored in depth... I'm going to try asking swissside if they have sailing effect data based on f/r. I'd like to assume someone has given the ubiquity of rear disc TT and tri wheels.

Turrifik
Posts: 98
Joined: Wed Nov 25, 2020 5:08 pm

by Turrifik

SwissSide has some helpful comparative data for different staggered setups of their Hadron^2 wheels, which are the same as the new DT Swiss 1100 Dicut wheels.

https://www.swissside.com/collections/h ... #configure

Image


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Nickldn
Posts: 1863
Joined: Mon Mar 25, 2019 12:35 am

by Nickldn

Turrifik wrote:
Sat Mar 11, 2023 1:57 pm
SwissSide has some helpful comparative data for different staggered setups of their Hadron^2 wheels, which are the same as the new DT Swiss 1100 Dicut wheels.

https://www.swissside.com/collections/h ... #configure

Image


Sent from my iPhone using Tapatalk
Wow what an eye opener! I can't believe there's only c. 6w between a pair of 50mm wheels and 80mm f/disk r at 45km/h.

Makes me think my 55mm Eastons are a sweet spot and no point ever upgrading to 80mms.
Giant Propel Advanced SL Red Etap 11s Easton EC90 wheels CeramicSpeed BB Zipp SL70 bars 6.5kg

Vitus ZX1 CRS Campy Chorus 12s Bora WTO 45 disk brake wheels Zipp SL70 bars 7.5kg

SL8 build with Craft CS5060 Wheels in progress

spartacus
Posts: 1048
Joined: Mon Apr 04, 2011 6:53 pm

by spartacus

Turrifik wrote:
Sat Mar 11, 2023 1:57 pm
SwissSide has some helpful comparative data for different staggered setups of their Hadron^2 wheels, which are the same as the new DT Swiss 1100 Dicut wheels.

https://www.swissside.com/collections/h ... #configure

Image


Sent from my iPhone using Tapatalk
Well that's something, thanks for posting

spartacus
Posts: 1048
Joined: Mon Apr 04, 2011 6:53 pm

by spartacus

Nickldn wrote:
Sat Mar 11, 2023 2:30 pm
Turrifik wrote:
Sat Mar 11, 2023 1:57 pm
SwissSide has some helpful comparative data for different staggered setups of their Hadron^2 wheels, which are the same as the new DT Swiss 1100 Dicut wheels.

https://www.swissside.com/collections/h ... #configure

Image


Sent from my iPhone using Tapatalk
Wow what an eye opener! I can't believe there's only c. 6w between a pair of 50mm wheels and 80mm f/disk r at 45km/h.

Makes me think my 55mm Eastons are a sweet spot and no point ever upgrading to 80mms.
I'm not so sure though because of the sail effect you can get at high yaw angles. Supposedly the disc wheel can provide 20-30w advantage in the right wind conditions, over an 80mm wheel:

https://forum.slowtwitch.com/forum/?pos ... 5#p7346345

I can't find much on the sailing effect of various normal wheel depths or front rear bias however. But I'm thinking the rear wheel sees less drag but also provides the same amount of sail as the front wheel.

Turrifik
Posts: 98
Joined: Wed Nov 25, 2020 5:08 pm

by Turrifik

spartacus wrote:
Turrifik wrote:
Sat Mar 11, 2023 1:57 pm
SwissSide has some helpful comparative data for different staggered setups of their Hadron^2 wheels, which are the same as the new DT Swiss 1100 Dicut wheels.

https://www.swissside.com/collections/h ... #configure

Image


Sent from my iPhone using Tapatalk
Well that's something, thanks for posting
Yep. Was a marginal gains eye opener for sure. Still didn’t stop me from ordering their 80/80 wheels Image


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spartacus
Posts: 1048
Joined: Mon Apr 04, 2011 6:53 pm

by spartacus

Here's the response from Swiss Side:

Thank you very much for your mail and kindly excuse my delayed reply.



With regards to your question, kindly note that the front wheel is by far the major generator of sailing effect because it sees the free-stream air speed and angle. So when there is a cross-wind, the front wheel generates the vast majority (>70% of the sailing effect). The rear wheel is less effective in terms of sailing effect for two reasons:

The airflow is slower and has less energy by the time it reaches the rear wheel,
The airflow angle is reduced (straightened) by the time it gets the rear wheel. Hence why aerodynamically the front wheel has more importance, particular in cross-winds.


I trust the above clarifies. By further questions, kindly let me know.

Wishing you a good day.

CN2
Posts: 27
Joined: Wed Oct 05, 2022 5:26 pm

by CN2

spartacus wrote:
Fri Mar 10, 2023 2:36 pm
TobinHatesYou wrote:
Fri Mar 10, 2023 7:19 am
spartacus wrote:
Fri Mar 10, 2023 4:28 am
It makes sense if you have a 60mm rear wheel and a 40mm wheel set :noidea:

Also I'm pretty sure that has been sold as a set by reynolds iirc?

I mean okay sure if that's what you already have. Going from 40mm rear to 60mm rear might be good for ~1W at 45km/h.
So little huh? Is there data on this you've seen or know of?

I understand that the rear wheel is sheltered mostly under normal co dictions but I'm wondering if having the deeper rear wheel can give you some of the sailing effect under certain wind conditions you get from the deep wheelset.
An aero-helmet would make more difference

The difference between an aero road helmet and a standard road helmet is around 6 watts at 45 km/h (3 watts at 35 km/h).

https://www.swissside.com/blogs/aero-ti ... met-choice

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

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