San Fairy Ann Cycle Club

Rob, I did start by saying that not everything you read in the press is 100% factual (and I think CW are worse than most on this count) but in the tubular test the Reynolds wheel tested (basically the same shape as the clincher "Assaults") were best in test (you only listed the clincher results). I fully appreciate the variables and limitations of their test, but essentially for me what the whole test proved was there is very little difference between the wheels tested (at least in the somewhat irrelevant situation of an velodrome as the wheels tested were all road wheels not track wheels). Their "test results" had only a limited influence on the overall score they gave each wheelset and I'm sure they consider value for money, weight, build quality when considering their overall score.

For what it's worth, I tend to buy cycling kit that I can get a good deal on and I also tend to go for stuff that I think looks nice (let's be honest that's what most of us do), has a reputation for reliability and has good back up from the supplier in the UK in terms of warranty support etc. I'm certain that the rider is the biggest factor in going fast or not. Hence I tend to spend the limited time I have available training rather than worrying about incremental differences in weight or aerodynamics at different yaw angles.

I would imagine for Phill's requirements for a wheelset (i.e. to be used for road racing) then weight and stiffness will be of greater consideration than aerodynamics anyway as a lot of time is spent in a bunch and a road bike position is less aero than say a TT bike anyway so the overall affect of a few watts here or there due to the wheels will be insignificant or at least less significant that the weight saved which will help with acceleration and climbing). £877 cheaper and almost 400g lighter. Doesn't take a genius does it?

Oh, and I'd say that anything written on line is even less likely to be factual that what's written in print, particularly on forums. I have absolutely no idea what I'm talking about, but doesn't stop me giving my opinion (as proven here)

Nice graphics btw on the tri spoke, but what does it mean? I assume this "proves" that it's an aero wheel? My gut feel from having ridden TTs on both my Reynolds front wheel and my Hed trispoke is that there is very little difference between the two other than the Hed keeps wanting to throw me in the hedges and the Reynolds doesn't.

DamianCairns wrote:Rob, I did start by saying that not everything you read in the press is 100% factual (and I think CW are worse than most on this count) but in the tubular test the Reynolds wheel tested (basically the same shape as the clincher "Assaults") were best in test (you only listed the clincher results).

I was listing clinchers because they showed how 'remarkable' their results were that a box section beat off all the other challengers!

I fully appreciate the variables and limitations of their test, but essentially for me what the whole test proved was there is very little difference between the wheels tested

An eg.6W difference is irrelevant? That's the difference between a rusted up chain and a new one!

For what it's worth, I tend to buy cycling kit that I can get a good deal on and I also tend to go for stuff that I think looks nice (let's be honest that's what most of us do), has a reputation for reliability and has good back up from the supplier in the UK in terms of warranty support etc. I'm certain that the rider is the biggest factor in going fast or not.

Whilst I agree that the rider is the most important bit, lots of small differences can make a big difference. Also, it does tend to focus the mind though when you miss a target by 11 secs!

Hence I tend to spend the limited time I have available training rather than worrying about incremental differences in weight or aerodynamics at different yaw angles.

And I'm an unemployed aerodynamicist; I think my over-analysis this was nearly inevitable!

DamianCairns wrote:I would imagine for Phill's requirements for a wheelset (i.e. to be used for road racing) then weight and stiffness will be of greater consideration than aerodynamics anyway as a lot of time is spent in a bunch and a road bike position is less aero than say a TT bike anyway so the overall affect of a few watts here or there due to the wheels will be insignificant or at least less significant that the weight saved which will help with acceleration and climbing). £877 cheaper and almost 400g lighter. Doesn't take a genius does it?

FWIW, someone worked out that a heavy set of aero wheels was of more benefit than a set of (of I think) Kysiriums up until the grade hits about 8%. From memory, didn't Dave end up in a breakaway in all the races where he did well last season?

Nice graphics btw on the tri spoke, but what does it mean? I assume this "proves" that it's an aero wheel?

It's showing the pressure spike that comes from forcing a large spoke through narrow fork blades.

My gut feel from having ridden TTs on both my Reynolds front wheel and my Hed trispoke is that there is very little difference between the two other than the Hed keeps wanting to throw me in the hedges and the Reynolds doesn't.

A trispoke tends to be best when it's unridable (huge sidewinds). If you compare the H3 to the Bora here (closest wheel to the Reynolds I would imagine), there's about 50grams of drag difference at lower yaw. That equates to about 0.5secs/km time saving.

As I said before, Reynolds wheels are good, just don't buy them if aerodynamics are your primary concern.

Good answers all round Rob.

As I am employed, I really ought to get back to work

Alright for some eh?

If someone can get me the cross section of a set of those wheels, I'll try and get a drag/yaw graph of it.

Well, you can't say I didn't warn you!

PS When are you doing that free aero-efficient positioning session you promised me, Rob!

I was about to tell you to send me some photos, but then thought that might not be a good idea!

Are you really sure you want me to tell you how to make yourself aerodynamic?

Rob
the test with 'wheels on a track' is so flawed it shouldn't be quoted- so 6watts difference doesn't exist so we shouldn't worry about a rusty chain.

The wind tunnel test was interesting in that cheap wheels were hardly any different from expensive wheels and sometimes better! Is 3/4/5/6 watts noticeable compared with all the other variable external factors?

There is obviously a large 'placebo effect' when we ride our bikes and if you told someone a wheel of a particular shape was far superior they would believe you. If they spent alot on kit they would percieve it to be better-similar to the Hawthorne effect.
I tend to agree with Damian in that the effort is better concentrated on more critical factors such as clothing postion training etc.etc
The Reynolds Attack weigh 1450 grams- mine do! (not 1500 1525 1550) and combined with their average aerodynamics are an excellent wheel but would be a little better with oval spokes i guess.

Anyhow an interesting discussion alot of useful information

There is obviously a large 'placebo effect' when we ride our bikes

Which is why in the '60s when the accepted wisdom (craze?) was for drilling holes in everything to reduce weight riders who did this went faster. What the effect of turning brake levers, chainrings and even handlebar stems into colanders did to the aerodynamics doesn't bear thinking about.

Perhaps Rob could work it out

No, perhaps he couldn't!

Bit beyond me, I'm afraid, all this high tech equipment! The lightest pair of wheels I ever rode on were my first pair of sprints in 1950. I thought I'd get the date in, in case someone mentioned "pennyfarthings" and a reference to an old git! Those wheels were given me by the great Frank Southall, and had pre-war bamboo rims. They had double-fixed hubs and were held in place by "butterfly" wing nuts - no quick release in those days! Some riders got to the turn on a lowish gear into the wind, then changed the wheel over to the high sprocket for the wind-assisted return. Most courses were straight out and home with a dead turn in the middle of the road. Nobody rode gears in time trials then.
Thought you might like to hear some "old twoddle"!
Regards
Pete Wall

simoncharlesworth wrote:The wind tunnel test was interesting in that cheap wheels were hardly any different from expensive wheels and sometimes better! Is 3/4/5/6 watts noticeable compared with all the other variable external factors?

Bear in mind that the average person will knock out about 250W for a 25 mile TT. So 5W is 2% of their total power. How much do you think you will increase your power by going out training on a single ride?

I've done some basic number crunching and a rider doing low drag rider doing 30mph with box section wheels would do 30.3mph with Boras and 30.6mph with 808 tubs. This means gaining 3/4 sec per mile for the Boras and 1.5secs/mile for the 808s based on a rider doing 30mph with box section wheels. The speed increased and time saved would be greater at lower speeds.

Bearing in mind the "average person" probably dos'nt ride a bike too much if at all I think 250 watts for an hour is a bit ambitious!

I thought you had gone missing, Mike! Welcome back to the forum.

Dave S wrote:I thought you had gone missing, Mike! Welcome back to the forum.

Cheers Dave!,missed you too