More money spent =more speed ?

[Parrot of Doom]

I can tell you for a fact that an older 36-spoke wheel will be a fair bit slower than a modern 18-spoke wheel.

[mrandy]

Parrot of Doom said:

I can tell you for a fact that an older 36-spoke wheel will be a fair bit slower than a modern 18-spoke wheel.

yup wheels and tyres make more difference than most people know

[a11y_m]

mrandy said:

Parrot of Doom said:

I can tell you for a fact that an older 36-spoke wheel will be a fair bit slower than a modern 18-spoke wheel.

yup wheels and tyres make more difference than most people know

Agree - the difference wheel weight makes to accelaration is more noticeable than I ever imagined. Although I noticed this most changing to dual-ply DH tyres (approx 600g/tyre heavier) on my full-susser MTB, the same principle applies.

[Busamav]

The 28 spoke wheels I had were fitted with Wolber Piste tubs and were just a dream to ride on .

[Busamav]

Parsnip said:

Busamav said:

If you havent got the legs you aint going to go fast on anything , I suspect a disc wheel could infact make some people slower .

My pb for a 25 was set on my old vitus training bike with just a set of 28's and my legs feeling good on the day,

although one year I focused on the club 25 championship , tapered my training , borrowed an aero helmet and a deep rim front wheel to go with my Zipp disc and rode to a win , I put that down to my mind and legs being ready for it.

Depends how much you won by - if it was a few seconds over someone riding a standard bike with standard rims, the speed you bought had something to do with it - sticking with the same scenario, if you left it all out on the course, would you have won without the bling hardware? No. (obviously if you crushed everyone by a few minutes and they all had uber TT rigs too, then it is a moot point, but you see where I am coming from, no?)

.

Sorry Parsnip , I should have put a after my last sentence

[Parrot of Doom]

mrandy said:

Parrot of Doom said:

I can tell you for a fact that an older 36-spoke wheel will be a fair bit slower than a modern 18-spoke wheel.

yup wheels and tyres make more difference than most people know

Don't forget increased drag from more spokes.

[HundredthIdiot]

For road bikes anyway, wheel differences are neligible.

http://www.rouesartisanales.com/article-15505311.h...

[mrandy]

HundredthIdiot said:

For road bikes anyway, wheel differences are neligible.

http://www.rouesartisanales.com/article-15505311.h...

Thats an aerodynamic test,most road courses go round corners and up hills ,accelerate and decelerate.
Rotating mass makes a huge difference and so do lightweight low rolling resistence tyres

[HundredthIdiot]

mrandy said:

HundredthIdiot said:

For road bikes anyway, wheel differences are neligible.

http://www.rouesartisanales.com/article-15505311.h...

Thats an aerodynamic test,most road courses go round corners and up hills ,accelerate and decelerate.
Rotating mass makes a huge difference and so do lightweight low rolling resistence tyres

The first part is an aerodynamic test. The links at the bottom of the page cover inertia, lateral stiffness, and bearing resistance.

[HundredthIdiot]

Also, old vs new (PDF).

[HundredthIdiot]

Also, water-filled tyres up Alpe d’Huez.

[Parrot of Doom]

mrandy said:

HundredthIdiot said:

For road bikes anyway, wheel differences are neligible.

http://www.rouesartisanales.com/article-15505311.h...

Thats an aerodynamic test,most road courses go round corners and up hills ,accelerate and decelerate.
Rotating mass makes a huge difference and so do lightweight low rolling resistence tyres

That's an interesting link, thanks. It does, however, confirm that spoke count is important.

[HundredthIdiot]

Parrot of Doom said:

It does, however, confirm that spoke count is important.

Yes, in the context of a wheel. In the context of the whole system, square root of f'all.

Disclosure: I run <1400g 50mm carbon rims with 20/24 aero spokes.

Edited by HundredthIdiot on Thursday 16th December 16:04

[mrandy]

from riding experience the difference when on a bike between a 32 spoke and 28 spoke wheel is very noticeable and I doubt its placebo effect.Heavy wheels feel dead ,lighter with better tyres feel completely alive.

Edited by mrandy on Thursday 16th December 16:37

[Parsnip]

HundredthIdiot said:

For road bikes anyway, wheel differences are neligible.

http://www.rouesartisanales.com/article-15505311.h...

Im looking at that and seeing a possible gain of 15W per wheel (with a disc and a 1080 front, you would be looking at even more) unless I'm missing something.

30 free watts is negligible? 30W is massive.

One study published in the German Tour magazine Jan 2007

They put Uwe Peschel on a normal bike:

Needed Watts for Speed = 45 km/h :

Stevens San Remo bike with normal handlebar 465 Watts needed to go 45 km/h
Same bike Hands down the drops: 406 watts needed
Same bikeEaston Aeroforce bar: 369 Watts
Same bike Triathlon position (5.5 cm lower bar, saddle forwards): 360 Watts
Same bike Triathlon position (5.5 cm lower bar, saddle forwards) and
carbon Tri spoke wheels front and rear: 345 Watt

Cervelo + Tri spoke front 328 Watts
Cervelo + Tri spoke front + disk rear wheel : 320
Cervelo + Tri spoke front + disk rear wheel +Giro helmet: 317
Cervelo + Tri spoke front + disk rear wheel +Giro helmet + speed suit: 307
Cervelo + Tri spoke front + disk rear wheel +Giro helmet + speed suit +
saddle 3 cm further back: 293 Watts

465 watts is absolutely massive - tour rider TT specialist territory. 293 Watts is close to what I can hold for an hour - the differences are far from negligible - they are huge. Without trying to sound too blunt, anyone who says that you can't buy speed has no idea what they are talking about.

[HundredthIdiot]

Parsnip said:

HundredthIdiot said:

For road bikes anyway, wheel differences are neligible.

http://www.rouesartisanales.com/article-15505311.h...

Im looking at that and seeing a possible gain of 15W per wheel (with a disc and a 1080 front, you would be looking at even more) unless I'm missing something.

30 free watts is negligible? 30W is massive.

It doesn't add up quite like that due to rear wheel shielding but yes, 30W would be a lot. Unfortunately that's 30W at 50kph, which might require over 500W depending on position.

TTs are a particularly extreme case involving the interplay of aerodynamics, muscle recruitment and equipment choices.

Take a given (experienced) rider with a known position in which he is comfortable. Build one bike up using state of the art technology (aero frame, aero wheels etc) for loadsa money (say £10k). Build another bike up for a grand using the same geometry and position but a round tubed steel frame, 32 spoke box section wheels and so on. What's the difference in speed at a given power output (say 300W)? Not massive, I'd say. 1-2kph? Of course, that is relevant in a competitive TT, but for most riders those thousands of pounds would be better spent on power meters, coaching, wind tunnel testing...any number of things, if you're talking about "buying speed".

For less extreme situations (e.g. road racing) the differences are much more marginal, since you can't use disc wheels, aero helmets and so on, and (more critically) because the rider contributes a proportionately greater amount of drag than in a TT.

In my very ordinary class of road racing, power outputs average about 250W and speeds around 38kph, which obviously includes peleton effects. If I go on a solo break I might be doing (say) 39kph at 320W for 5 minutes. If the difference between cheapo box section wheels F&R and Zipp 404s is 15W at 50kph, then it's probably about 8W at 39kph, or about 2.5%. That's not a lot.

Empirically, there are plenty of protour races where riders in well equipped teams choose shallow section alloy wheels because they offer better braking on descents. If aero wheels were such a clear-cut winner in the real world, you wouldn't see that.

And then there's commuting....

[HundredthIdiot]

To be briefer, I suppose I'm saying that "money can buy speed" is a misleading statement for the average amateur club racer who TTs a few times a year, who might be weighing up the the choice between sticking a cheap set of alloy clip-ons on his road bike or spunking thousands of pounds on a fully kitted out TT rig.

It is perfectly possible to be competitive with cheap gear, that's all.

[Parsnip]

Don't get me wrong, if you are on a limited budget you need to look at bang for your buck purchases - for TTing, clip-ons and an aero helmet will make a big difference for not much cash. A power meter used properly is also one of the best cost/return buys you can make.

I use TTing as an example because A)it shows the extreme differences kit can make and B)it is more measurable than other types of riding - if two riders average 300W for a 40K TT and one does 58.35 and the other 1.03.19 then you can see where the differences came from - if this guy carried out his study with a power meter and his power was the same for every ride, and the crap bike was faster, then that would actually mean something. As it stands, there is no scientific basis whatsoever for what his conclusions are - as I said above, a Fiat punto going at 50mph will beat a R15 going at 49mph - doesn't really mean anything.

The title of the thread is "More money spent = more speed ?" and the answer is more often than not "yes" (a entry level roadie will be quicker onroad than a top of the range DH bike for example, but you see my point)

My point is that anyone who says you can't buy speed is talking complete rubbish - like the bloke doing his study and half of the people in this thread.

[Fatman2]

Parsnip said:

HundredthIdiot said:

For road bikes anyway, wheel differences are neligible.
http://www.rouesartisanales.com/article-15505311.h...

Im looking at that and seeing a possible gain of 15W per wheel (with a disc and a 1080 front, you would be looking at even more) unless I'm missing something.
30 free watts is negligible? 30W is massive.

One study published in the German Tour magazine Jan 2007
They put Uwe Peschel on a normal bike:

Needed Watts for Speed = 45 km/h :

Stevens San Remo bike with normal handlebar 465 Watts needed to go 45 km/h
Same bike Hands down the drops: 406 watts needed
Same bikeEaston Aeroforce bar: 369 Watts
Same bike Triathlon position (5.5 cm lower bar, saddle forwards): 360 Watts
Same bike Triathlon position (5.5 cm lower bar, saddle forwards) and
carbon Tri spoke wheels front and rear: 345 Watt

Cervelo + Tri spoke front 328 Watts
Cervelo + Tri spoke front + disk rear wheel : 320
Cervelo + Tri spoke front + disk rear wheel +Giro helmet: 317
Cervelo + Tri spoke front + disk rear wheel +Giro helmet + speed suit: 307
Cervelo + Tri spoke front + disk rear wheel +Giro helmet + speed suit +
saddle 3 cm further back: 293 Watts

465 watts is absolutely massive - tour rider TT specialist territory. 293 Watts is close to what I can hold for an hour - the differences are far from negligible - they are huge. Without trying to sound too blunt, anyone who says that you can't buy speed has no idea what they are talking about.

Not trying to start any arguments but just some observations.

As has been mentioned already, you wouldn't save 30W from both wheels as the rear wheel is shielded. Also you will never normally see 50km/h head on but more like 50km/h over a possible range of 360 degrees. To be completely fair and impartial you have to assume 360 degrees of wind, in which case deep section rims with oval spokes will be a nightmare half the time (side winds) and not much benefit for a quarter of the time when the wind is behind you (and more wind resistance would be beneficial from the tailwind). Thus for any scenario that is truly fair the benefits from having expensive aero wheels etc. cannot be fully utilised all of the time

Sadly no wheel manufacturer or other research institute will do a wind tunnel test to see how much power you would waste from fighting side winds but one thing is patently obvious. If a narrow wheel makes such a massive difference in a head wind then it certainly stands to reason that such deep sections and wide spokes will fare horrendously when presented with a 50km/h wind side on. After all a disc wheel has a 25x larger surface area than it’s frontal area so will act like a sail.

I also found the study interesting. If we neglect the cost of the aero bars (you could get a similar position from two bits of broom handle costing nothing ) the biggest gains come from achieving a decent aero position i.e. 465watts to 360watts.

Going from the totally standard bike to a full on Cervelo saves a grand total of 53 watts (you can’t really count the extra 14watts due to additional positioning), which is not great given the amount of money you’d have to spend on a Cervelo + all the extras. 53watts is quite a lot but as I’ve mentioned before though there is no mention regarding the test conditions so it is difficult to draw any meaningful conclusions.

I realise you’re pro ‘money buys speed’ but I must have no idea because I’m yet to be convinced, unless we’re talking about a straight line TT with an ‘ideal’ headwind scenario.

Edited by Fatman2 on Saturday 18th December 01:32

[b2hbm]

I'm a bit split on the "money buys speed" thing. I reckon on the controlled environment of an indoor track it's perfectly true that aero bikes/wheels/etc are a notable improvement, in fact I can't think of a sensible argument against it.

But on the road, like the previous poster, I'm less convinced. All the equipment tests I've ever seen were conducted with either direct headwind or slightly inclined (5-10deg) wind and as we all know, this isn't a real world situation.

If you think of a 45 or 90deg side wind at 15-20mph, then something like a low spoke count wheel should still be better than a 32/36 spoke wheel so the argument is valid and hence money does buy speed (although maybe not as much as you think). And to some extent I'm also convinced by the clothing you wear, tight, slippery fabrics against conventional loose clothing for example.

But I'm less convinced when we come to deep section aero frames or rims because a 20mph side wind is going to make you more interested in staying upright than making progress. Taking it to extremes, you sometimes see riders with 2 disc wheels on track but I've never seen anyone riding a front disc on the road.

Going back to the original post about the good Dr, well, that's just typical "must fill a column" reporting for you. The guy wanted to get his name in his professional publication (BMJ) and needed an angle, so he picked on his bike commute to illustrate an entirely different point about medicines. And I agree with him, you don't need a £1000 bike to average 15mph.

(But I'd like to see him average 25mph on his £50 clunker )