Why do better wheel sets work better?

[merlin6014]

Ive gone from a 2000g wheelset (shimano r501s) to a 1330g carbon wheelset and the difference is night and day. I am absolutely smashing pr's. Its particularly noticeable uphill. Definaty worth the money.

[biker jk]

Ive gone from a 2000g wheelset (shimano r501s) to a 1330g carbon wheelset and the difference is night and day. I am absolutely smashing pr's. Its particularly noticeable uphill. Definaty worth the money.

My fastest average on a 76km ride I do every week was achieved using a 2kg wheelset with a bike weighing 10.5kg. It included 625m of climbing (but admittedly no long climbs). My other bikes are at least 2kg lighter and have wheelsets weighing around 500g less.

[Nobody]

Some might find the following link interesting in regard to wheel weight and speed (read the comments too).
http://www.training4cyclists.com/how-mu ... lpe-dhuez/

[Xplora]

I don't want to go nuclear in a spectacular winstow meltdown, I really just wanted to make the point that if we are trying to GAIN SPEED, then wheel weight and rotational acceleration should not be at the forefront of our thinking - it will be things like stiffness and trueness and "aero" that make the most difference to your experience, but here is the kicker - you cannot put those things into numbers. Rim depth and weight are easy to market, but have little bearing on the feel of the wheel. Get your ENVE 6.7s because they are HAWT and have good hubs and good aero (you'd hope at that price), not because they are lighter than Zipps or HED. It's the X factor which can't be tested without taking them for a spin.

[merlin6014]

Well biker jk not doubting you but i can only speak for my own experience. Im not even talking a subtle difference, the bike accelerates a LOT faster with my lighter wheels on.

[Xplora]

Could it be a stiffness/true difference though? Let's not beat around the bush though - that's a very big difference in wheel weight and probably a big jump in build quality to match so it could be hard to isolate just to weight?

[winstonw]

I don't want to go nuclear in a spectacular winstow meltdown,

hahaha...the blind leading the bling.
keep worshipping your false Gods, and ignoring the significance of real world variable wind yaw and velocity.
those blog charts are the source of much amusement at Enve.

[ausrandoman]

I got all excited when I saw "winstonw" at the end of the thread. I thought maybe he had answered my earlier question:

"Alpine Classic Extreme. (Note: most of this route is little affected by wind)
Target time 11 hours. (I have grey hair and bifocals)
1500 gram non-aero wheels or 1900 gram, 80 mm deep section, 20/24 conventional spoke wheels.

Which will be faster? "

Look, I'll settle for an answer with a recommendation for particular wheels. I'll drop the request for numerical evidence.

[alex]

I got all excited when I saw "winstonw" at the end of the thread. I thought maybe he had answered my earlier question:

"Alpine Classic Extreme. (Note: most of this route is little affected by wind)
Target time 11 hours. (I have grey hair and bifocals)
1500 gram non-aero wheels or 1900 gram, 80 mm deep section, 20/24 conventional spoke wheels.

Which will be faster? "

Look, I'll settle for an answer with a recommendation for particular wheels. I'll drop the request for numerical evidence.

the ones that look better

[Philipthelam]

I got all excited when I saw "winstonw" at the end of the thread. I thought maybe he had answered my earlier question:

"Alpine Classic Extreme. (Note: most of this route is little affected by wind)
Target time 11 hours. (I have grey hair and bifocals)
1500 gram non-aero wheels or 1900 gram, 80 mm deep section, 20/24 conventional spoke wheels.

Which will be faster? "

Look, I'll settle for an answer with a recommendation for particular wheels. I'll drop the request for numerical evidence.

the ones that look better

As they say... Red is always faster

[mikesbytes]

I've seen that table before and what confuses me is the performance improvement of going from disc wheel to 3 spoke wheel

[sblack]

I've seen that table before and what confuses me is the performance improvement of going from disc wheel to 3 spoke wheel

That lines up with a chart I remember seeing from HED. Note that they specify 0 degrees yaw. HED, comparing their disc to H3 had a chart showing that at very small yaw angle the H3 outperformed the disc marginally but once outside that small range the disc took over and outperformed the H3 by a considerable margin.

edit: can't find the nice table that let's you choose the two for a direct comparison but compare the chart (click on the aero tab) for the disc to the H3 and H3D and you can see the three spokes ahead from 0 to 5 degrees then the disc comes into it's own.

[sumgy]

I will have to make sure I dont ride any of the Strava routes you guys do.

IMO unless you are racing 32 spoke handbuilts are all you need.
I always laugh when I read threads about "fast wheels" and people running light weight race tyres on them for basically "Strava racing".

I have 2 sets of 32 hole hand built wheels that I use for every day riding along with a set of Fulcrum 1s and a set of Mad Fiber's that I race on.
The Fulcrum's and MF's dont get used for anything except racing even though they are way lighter.

[ohexploitable]

Ive gone from a 2000g wheelset (shimano r501s) to a 1330g carbon wheelset and the difference is night and day. I am absolutely smashing pr's. Its particularly noticeable uphill. Definaty worth the money.

"Ive gone from a 2000g wheelset (shimano r501s) to a 1330g carbon wheelset and the difference is night and day. My wallet is a lot emptier and I am riding faster purely because for a small part, the placebo makes me feel better but mostly because I'm fitter than I was before."

[mikesbytes]

I've seen that table before and what confuses me is the performance improvement of going from disc wheel to 3 spoke wheel

That lines up with a chart I remember seeing from HED. Note that they specify 0 degrees yaw. HED, comparing their disc to H3 had a chart showing that at very small yaw angle the H3 outperformed the disc marginally but once outside that small range the disc took over and outperformed the H3 by a considerable margin.

edit: can't find the nice table that let's you choose the two for a direct comparison but compare the chart (click on the aero tab) for the disc to the H3 and H3D and you can see the three spokes ahead from 0 to 5 degrees then the disc comes into it's own.

Thanks, just goes to show you need the full picture, I've raced on a borrowed HED tri spoke clinchers. The owner of the wheels has since brought a HED disc wheel.

Based on those figures, are you better off with a rear tri spoke or a disc wheel on the velodrome?

[Xplora]

How do you know if your tuck is good or not? LMAO

I do a fair bit of commuting on the triHard bars and I've even modified the supports to get the bars down under the handlebars (as opposed to above them), and I'm pretty sure carbon shoes has done more to support my speed than the triHard positioning? Speeds around 38-40kmh...

[Red Rider]

How do you know if your tuck is good or not? LMAO

I do a fair bit of commuting on the triHard bars and I've even modified the supports to get the bars down under the handlebars (as opposed to above them), and I'm pretty sure carbon shoes has done more to support my speed than the triHard positioning? Speeds around 38-40kmh...

At those speeds about 85% of your energy goes into overcoming wind resistance, that is why a good aero position is so important. Aero wheels, frame etc also help with this of course.

[Xplora]

How do you know if your tuck is good or not? LMAO

I do a fair bit of commuting on the triHard bars and I've even modified the supports to get the bars down under the handlebars (as opposed to above them), and I'm pretty sure carbon shoes has done more to support my speed than the triHard positioning? Speeds around 38-40kmh...

At those speeds about 85% of your energy goes into overcoming wind resistance, that is why a good aero position is so important. Aero wheels, frame etc also help with this of course.

But how do you know if it's optimised or not? The wind is so variable, I don't think I could really say one position is faster than another?

[winstonw]

But how do you know if it's optimised or not? The wind is so variable, I don't think I could really say one position is faster than another?

according to the gang, aero-coach.com knows if its optimized, no matter the variability in wind speed or yaw.
why not part with the $s and find out.
you might ask about asymmetrical tri-bar positioning with variable winds, while you are at it.

[snortin]

But how do you know if it's optimised or not? The wind is so variable, I don't think I could really say one position is faster than another?

If you read the table it states that it involves wind tunnel testing to optimise your tuck position. I would expect that this would involve you riding in the wind tunnel and checking power relative to maintaining a certain speed. I would also imagine that it would be quite easy to adjust the wind angle. All seems pretty straight forward to me. A bigger issue is that you would need to try to keep that position for the entire event - and train in that same position to ensure that you are able to produce maximum power.

A bigger issue though is that there is obviously a trade-off between getting aero (within the "rules) and producing power. There will be a "sweet-spot" where any further gains in aero position are lost by the rider not being able to produce as much power.

As for winstonw, I suspect that some of what aerocoach might offer is optimising this relationship. Seems like what a good coach should be doing - no???

I would expect that if you really wanted to get into the nitty gritty, you would do all the testing to find out the optimised positions for differing yaw, and then check what was measured in terms of wind for your particular course prior to start and use your test information accordingly?

But my guess is that yo could do wind tunnel testing to ensure you optimise your position OVER THE WIDEST POSSIBLE RANGE of wind angles, given the constraint of trying to maximise power. Then setup your bike and try to maintain your position accordingly.

[winstonw]

I would expect that if you really wanted to get into the nitty gritty, you would do all the testing to find out the optimised positions for differing yaw, and then check what was measured in terms of wind for your particular course prior to start and use your test information accordingly?

not only "differing" yaw, but simultaneous variable wind velocity.
let us know when you find a coach that has the algorithms to model that.
I don't know of any, though apparently wheel builders like Enve base their designs on this stuff. Though some might write it off as marketing blurb.

[high_tea]

How do you know if your tuck is good or not? LMAO

I do a fair bit of commuting on the triHard bars and I've even modified the supports to get the bars down under the handlebars (as opposed to above them), and I'm pretty sure carbon shoes has done more to support my speed than the triHard positioning? Speeds around 38-40kmh...

With a stopwatch. This is not a flippant remark. You want to go faster, the effect has to show up, repeatably, on a stopwatch. Intermediate metrics are all very well, but "faster" should show up on the clock, or what's the point?

[snortin]

I would expect that if you really wanted to get into the nitty gritty, you would do all the testing to find out the optimised positions for differing yaw, and then check what was measured in terms of wind for your particular course prior to start and use your test information accordingly?

not only "differing" yaw, but simultaneous variable wind velocity.
let us know when you find a coach that has the algorithms to model that.
I don't know of any, though apparently wheel builders like Enve base their designs on this stuff. Though some might write it off as marketing blurb.

Why would the coach need to have an algorithm? We were talking about using the wind tunnel. In the wind tunnel, change yaw and wind speed (velocity implies both a speed and direction). Check the effect of the changes on your power (measurable via powermeter). Fine tune your position so that it offers the best possible fit (ie maximise power for a given aero position) over the range of conditions you wish to apply it to (ie those you are most likely to encounter).

I suspect that you might find that the optimum aero position whilst still producing the maximum power would for all intents and purposes be independent of wind yaw and speed. But for wheels choose the ones that have the best correlation to reduced drag over the conditions you expect to encounter during your event.

[Xplora]

With a stopwatch.

I don't think I can reliably test that by myself - sadly enough I just don't find enough "stability" in efforts vs speeds. I cranked the Fitzwilliam Sprint segment I created with maximum effort including a blitz through the traffic lights and up the hill, and I actually went faster this week without any powerful effort on the first 400m, keeping at 48-50kmh for the remaining kilometre. I have considered the possibility that I'm too stretched out to maintain power though. New stem?

[winstonw]

I suspect that you might find that the optimum aero position whilst still producing the maximum power would for all intents and purposes be independent of wind yaw and speed. But for wheels choose the ones that have the best correlation to reduced drag over the conditions you expect to encounter during your event.

I've read a paper that shows asymmetrical aero positioning offers performance significant smaller CdA for variable velocity/yaw angles.
The majority of aero tests don't acknowledge this. They just presume CdA varies minimally for all unstable yaw/velocity combos , and use an average for the same rider position. This is the problem though isn't it. The maths to accurately model real world conditions are complex, and presumptions are made to simplify.
The point I was flamed for on another thread is the very reason wheel manufacturers don't make one aero wheel (a full disk). Obviously they realize drag is not a constant across all yaw/velocity combos and unstable states of each.