Are any hubs faster than others?
Moderator: robbosmans
We spend a lot of time and money on building or buying wheels that are more aerodynamic and/or lighter, but what about the rolling resistance of the hubs? Are any hubs faster than others? Is something like a Chris King, DT Swiss 240, or Carbon Ti, faster than a Bitex or Novatec? What has less rolling resistance when coasting (freewheeling)? Do ratchets or pawls have less resistance?
2015 Wilier Zero.7 Rim - 6.37kg
2020 Trek Emonda SLR-7 Disc - 6.86kg
2023 Specialized SL7 - 7.18kg
2020 Trek Emonda SLR-7 Disc - 6.86kg
2023 Specialized SL7 - 7.18kg
-
- Posts: 12570
- Joined: Mon Jul 24, 2017 12:02 pm
We're talking about maybe a watt between an average hub and the best hub at 250W...and it mostly comes down to the bearing seals and grease fill. Bearing drag scales fairly linearly with speed. Aero drag is a much bigger deal.
Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓ Broad Selection ✓ Worldwide Delivery ✓
www.starbike.com
-
- Posts: 22
- Joined: Mon Jul 06, 2020 11:23 am
Gokiso hubs are bar-none the fastest, but also heavy and expensive.
I can't imagine you're actually saving more than a watt or so.
It is entertaining to watch a Gokiso wheel spin and spin and spin, though.
I can't imagine you're actually saving more than a watt or so.
It is entertaining to watch a Gokiso wheel spin and spin and spin, though.
You would have differences but they have never been properly measured or published.
- measuring hub friction under no load is not representative of much, measuring under load is not really easy.
- based on the design, you have hubs that spin super freely but when you put a QR on them you stress the axle and squeeze the bearings and don’t have a smooth spin anymore.
- freewheels have different drags, Tour used to measure it and indeed you had substantial differences between brands. But can recall you could draw a conclusion… I also don’t recall brands coming with original Freewheel design (rotor, those brands putting magnet on the pawls) publishing any real estimation on gains.
- measuring hub friction under no load is not representative of much, measuring under load is not really easy.
- based on the design, you have hubs that spin super freely but when you put a QR on them you stress the axle and squeeze the bearings and don’t have a smooth spin anymore.
- freewheels have different drags, Tour used to measure it and indeed you had substantial differences between brands. But can recall you could draw a conclusion… I also don’t recall brands coming with original Freewheel design (rotor, those brands putting magnet on the pawls) publishing any real estimation on gains.
I suspect the aero characteristics of the hub have more influence than the mechanical drag.
Bearing type, size, placement, load, lube, seal type etc.. will all have an influence on mechanical drag. As will hub shell and axle design/tolerance, material choice etc.
Bearing type, size, placement, load, lube, seal type etc.. will all have an influence on mechanical drag. As will hub shell and axle design/tolerance, material choice etc.
Mark
dromarti.com
dromarti.com
-
- Posts: 540
- Joined: Tue Jan 16, 2018 4:39 pm
think what you will about Hambini more recent video's but his earlier work was sound:
https://www.hambini.com/testing-to-find ... heel-hubs/
https://www.hambini.com/testing-to-find ... heel-hubs/
Some say pour 10ml water out of your bottle to save that last bit of the weight. Sorry, i go one step further, i tend to the rider off my bikes.
n+1...14 last time i checked, but i lost count
n+1...14 last time i checked, but i lost count
Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓ Broad Selection ✓ Worldwide Delivery ✓
www.starbike.com