Would new wheels really make a difference to my speed?

[Cugel]

A rancorous thread!

Whatever data is quoted, from the various testing sources and their various testing methods, no one suggests that much will be gained or lost in speed or journey time from changes of design in wheels that are generally well-built of good materials with proper functioning of the parts (hubs, spoke nip[ples et al). It's "40 seconds in a 25 mile TT at 25mph" sort of stuff. Hardly of interest to everyday cyclists.

What is clear is that the quality and build characteristics of wheels will make a difference in that those wheels that efficiently transfer pedalling energy without various hysteresis losses will perform better, in terms of speed & time-taken, than poorly built wheels of low functioning parts.

Here's an article from Cycling magazine that sums up various wheel design alternatives.

https://www.cyclist.co.uk/in-depth/1467 ... eight-rims

Personally I liked this quote as being most relevant to the discussion:

‘Based on experience, anecdotal evidence and being a bit of a fatty, I’d be more concerned about wheel flex,’ he says. ‘Most of the lightest wheels will be inherently more flexible for anyone other than a really skinny racing snake.

'Power transfer due to wheel stiffness is equally as important as having low weight, which is where most climbing wheels lose out, especially for riders like me, who are over 80kg.’

Cugel

[Brucey]

indeed. You would be amazed as how many people I see with 'fast wheels' that are losing them more time than they ever might gain; losses due to flex alone are difficult to see but it is pretty obvious that brakes rubbing up every hill is definitely going to slow you down.....

cheers

[hamster]

And while I don't race, it's invariably amusing to pass the lycra clad road cyclists on their £2k mount, while on an old steel mount, eating a pain au chocolate and hoping the 20kg shopping on the back is ok

They might be doing a recovery ride.

[peetee]

And while I don't race, it's invariably amusing to pass the lycra clad road cyclists on their £2k mount, while on an old steel mount, eating a pain au chocolate and hoping the 20kg shopping on the back is ok

They might be doing a recovery ride.

Eating a pain au Chocolate whilst on the move sounds like a recovery ride to me.

[thelawnet]

Personally I liked this quote as being most relevant to the discussion:

‘Based on experience, anecdotal evidence and being a bit of a fatty, I’d be more concerned about wheel flex,’ he says. ‘Most of the lightest wheels will be inherently more flexible for anyone other than a really skinny racing snake.

Here's something on this:

https://www.slowtwitch.com/Tech/Debunki ... _3449.html

My usual rear wheel was a stock deep-section carbon clincher with 20 thin aero spokes. While climbing very steep hills, the rim would rub the rear brake pads – which were shaved down – and the caliper was open as much as possible without the lever pulling to the bar. What to do? I exchanged the wheel for an identical one – except for the spoke count, which was 24.Interestingly, the brake rub went away. My suspicion is that the stiffness of both parts – the wheels and the frame – play together to make up a total system stiffness. Adding in a few spokes solved my problem.

Aren’t more spokes and thicker spokes heavier and less aerodynamic?

Yes, adding more spokes or thicker spokes adds weight and drag. That’s life. On the flip side, you’re losing power by flexing a wheel or rubbing the brake pads. I inquired with several different manufacturers about the aerodynamic cost of adding a few spokes (i.e. using 24 rear spokes instead of 20). All replied with the same answer: The aerodynamic cost is minimal. The weight penalty is minimal. You do gain a little bit of radial stiffness – which could be seen as ride harshness – but I argue that this is a non-issue, short of extreme cases.

Why, then, don’t they use more spokes? Two words – fashion and weight. Fewer spokes look cool, and look better on-paper to the gram counters. I agreed to keep any official comments off-the-record from all manufacturers in this regard… but all of them had similar answers - sex sells.

So the carbon rims are excessively stiff while the silly 20-spoke wheels are useless because even with shaved (!) brake pads they still flex into the brake pads.

My guess is that 24 spokes is still insufficient if you are not a brake pad shaver using deep, carbon rims.

[Cugel]

Personally I liked this quote as being most relevant to the discussion:

‘Based on experience, anecdotal evidence and being a bit of a fatty, I’d be more concerned about wheel flex,’ he says. ‘Most of the lightest wheels will be inherently more flexible for anyone other than a really skinny racing snake.

Here's something on this:

https://www.slowtwitch.com/Tech/Debunki ... _3449.html

My usual rear wheel was a stock deep-section carbon clincher with 20 thin aero spokes. While climbing very steep hills, the rim would rub the rear brake pads – which were shaved down – and the caliper was open as much as possible without the lever pulling to the bar. What to do? I exchanged the wheel for an identical one – except for the spoke count, which was 24.Interestingly, the brake rub went away. My suspicion is that the stiffness of both parts – the wheels and the frame – play together to make up a total system stiffness. Adding in a few spokes solved my problem.

Aren’t more spokes and thicker spokes heavier and less aerodynamic?

Yes, adding more spokes or thicker spokes adds weight and drag. That’s life. On the flip side, you’re losing power by flexing a wheel or rubbing the brake pads. I inquired with several different manufacturers about the aerodynamic cost of adding a few spokes (i.e. using 24 rear spokes instead of 20). All replied with the same answer: The aerodynamic cost is minimal. The weight penalty is minimal. You do gain a little bit of radial stiffness – which could be seen as ride harshness – but I argue that this is a non-issue, short of extreme cases.

Why, then, don’t they use more spokes? Two words – fashion and weight. Fewer spokes look cool, and look better on-paper to the gram counters. I agreed to keep any official comments off-the-record from all manufacturers in this regard… but all of them had similar answers - sex sells.

So the carbon rims are excessively stiff while the silly 20-spoke wheels are useless because even with shaved (!) brake pads they still flex into the brake pads.

My guess is that 24 spokes is still insufficient if you are not a brake pad shaver using deep, carbon rims.

A common sight and a common complaint amongst the fashion victims of my club! But there are exceptions; and other causes of poor wheel performance viz-a-viz the energy transfer from pedal to road.

I once had a pair of Campag Croce D'Aune wheels that cost a bit, had "aero" profiles and looked very bling. Their cup & cone bearings weren't so good - or rather, the ability of the hubs to keep water out of them wasn't. A friend I habitually did long rides with told me he could tell the difference between these wheels and some other sealed-hub Shimano wheels of similar build (36 spoke 3X with the same tyres) because I was always noticeably slower freewheeling downhill on the Campags. I hadn't noticed myself but the poor bearings were eating not just gravity-watts but also my pedalling watts.

I currently have a pair of Superstar Pave 28 wheels (20-24 spokes, front-back) and a pair of HED Ardennes (16-20 spokes, front back). The HEDs are 150gms lighter (pair) than the Superstars with identical rim widths *& heights; also the same tyres (Schwalbe Ultremo 28mm). The HEDs are noticeably stiffer and feel a bit faster, despite having less spokes. They are, though, built very tight. Neither wheelset rubs the brakes under heavy-thrust.

Cugel

[thelawnet]

I currently have a pair of Superstar Pave 28 wheels (20-24 spokes, front-back) and a pair of HED Ardennes (16-20 spokes, front back). The HEDs are 150gms lighter (pair) than the Superstars with identical rim widths *& heights; also the same tyres (Schwalbe Ultremo 28mm). The HEDs are noticeably stiffer and feel a bit faster, despite having less spokes. They are, though, built very tight. Neither wheelset rubs the brakes under heavy-thrust.

Both of these have alloy rims and neither are deep section, so flex isn't the issue it would be with carbon bling.

[Brucey]

re CdA hubs; presumably these were for a screw-on freewheel? [I don't know if they made a cassette hub or not in CdA...?]

These components, like many preceding campag hubs were (IIRC) short on seals but were otherwise a mixture of Record and Chorus quality bits. The idea of the groupset was that it was aimed at the weekend rider who rode for fun , mostly in good weather, who wanted something more modern but would otherwise be riding NR for example. This meant a polished finish (which responded well to elbow grease) on many parts and no seals for free-running-ness. So the pedals for example were built like the then current record ones (with triple bearings etc) but where the record ones had a contact seal the CdA ones didn't. It may well have been the same deal with the hubs.

Like most other hubs of this type they would be susceptible to being adjusted wrongly; if there was no free play in the bearings with the QR slack, they were set too tightly and would bind when the QR was fully tight. The slightest roughness in the bearings (through corrosion) and the bearings could become draggy. Also, both screw-on freewheel and cassette versions of campag hubs have the RH bearings positioned unfavourably (for cup and cone bearings) so if they are set too slack the balls scuff and this will also be draggy. [The RH bearing in campag cassette hubs has almost invariably used smaller ball bearings too; this makes for more bearing drag than in bearings that have larger balls in them.]

If the hubs were noticably draggy then there are three possible reasons

1) that the bearings were badly adjusted (and already slightly pitted/scuffed)
2) that the ( presumably screw-on) freewheel was draggy for some reason
3) that there was 'something else' wrong; for example a cracked axle.

Asides from the things mentioned above, there is no particular reason why CdA hubs ought to have been draggy.

cheers

[Cugel]

re CdA hubs; presumably these were for a screw-on freewheel? [I don't know if they made a cassette hub or not in CdA...?]

These components, like many preceding campag hubs were (IIRC) short on seals but were otherwise a mixture of Record and Chorus quality bits. The idea of the groupset was that it was aimed at the weekend rider who rode for fun , mostly in good weather, who wanted something more modern but would otherwise be riding NR for example. This meant a polished finish (which responded well to elbow grease) on many parts and no seals for free-running-ness. So the pedals for example were built like the then current record ones (with triple bearings etc) but where the record ones had a contact seal the CdA ones didn't. It may well have been the same deal with the hubs.

Like most other hubs of this type they would be susceptible to being adjusted wrongly; if there was no free play in the bearings with the QR slack, they were set too tightly and would bind when the QR was fully tight. The slightest roughness in the bearings (through corrosion) and the bearings could become draggy. Also, both screw-on freewheel and cassette versions of campag hubs have the RH bearings positioned unfavourably (for cup and cone bearings) so if they are set too slack the balls scuff and this will also be draggy. [The RH bearing in campag cassette hubs has almost invariably used smaller ball bearings too; this makes for more bearing drag than in bearings that have larger balls in them.]

If the hubs were noticably draggy then there are three possible reasons

1) that the bearings were badly adjusted (and already slightly pitted/scuffed)
2) that the ( presumably screw-on) freewheel was draggy for some reason
3) that there was 'something else' wrong; for example a cracked axle.

Asides from the things mentioned above, there is no particular reason why CdA hubs ought to have been draggy.

cheers

The Campag Croce D'Aune cones & cups were adjusted to be free running. If anything, they went slack too often. The main problem was the lack of seals, as well as something about the design that seemed to draw water into the bearings.

The hub had a small hole with a spring-clip band having a small protrusion on it's inside face to locate into the hole. This wee hole was used to pump in grease to the whole axle assembly, which I did regularly (Campag white grease for the purpose, supposedly "waterproof"). One pumped it in until old grease squeezed out of the axle ends, thus signalling that the bearing were now loaded with fresh grease.

Despite this, water got in anyway. The bearings and the faces of the cups and cones degraded as a result. Once I'd realised that they couldn't/wouldn't stay smooth, I got rid. But I had them for a couple of years, even renewing the cones and BBs. But they wouldn't be fettled and soon got pitted again.

The Shimano 600 sealed hub wheels I got at about the same time are still running today, nearly three decades later, despite never having been opened to renew BBs, grease or anything else. (I haven't used them much for the last 15 years, mind). They must have done thousands and thousands of miles but still feel smooth; and never needed adjusting to take out play. The hub ends are covered in a large grey cap of something that feels like polyurethane. I suspect that there may be additional seals inside those. Presumably there are high grade components inside; and they were very well greased or otherwise lubricated when assembled by Shimano.

Cugel

[Brucey]

6400 series shimano 600 hubs were one of the first shimano models to have full lip seals. They are well sealed enough that, when new, you can run them in oil and it doesn't come out too fast.

BITD I had similar problems as you describe with CdA with unsealed hubs of all kinds; these days I use better grease and have fewer problems with similar kit. I suspect that they may now use a different kind (or amount) of salt on the roads in winter too; that makes a big difference.

cheers

[amediasatex]

I currently have a pair of Superstar Pave 28 wheels (20-24 spokes, front-back) and a pair of HED Ardennes (16-20 spokes, front back). The HEDs are 150gms lighter (pair) than the Superstars with identical rim widths *& heights; also the same tyres (Schwalbe Ultremo 28mm). The HEDs are noticeably stiffer and feel a bit faster, despite having less spokes. They are, though, built very tight. Neither wheelset rubs the brakes under heavy-thrust.

Both of these have alloy rims and neither are deep section, so flex isn't the issue it would be with carbon bling.

Not restricted to carbon by any means, deep and stiff alu rims if built with a few too few (?!) spokes also suffer.

I have two otherwise identical pairs of wheels built for my fast bike, they're both based on normal/low flange hubs and both built with 24 spokes rear, 20 front, the only difference between them is one pair are built up with a rim of 24mm depth, and the other pair use the same rims but in 38mm depth.

The wheels with the deeper rims make a lot more frequent contact with the brake pads under heavy load than the shallower rims, and 38mm isn't even very deep really. It seems initially counter intuitive that that would be the case as the deeper rim is stiffer than the shallow one, but that's exactly why it rubs, there aren't enough spokes to keep keep the wheel from flexing under load, so the whole rim (or a bigger section of it) deflects sideways. With the shallower rim there's more local deformation of the rim so overall less of it deflects sideways and it barely if ever rubs.

These are reasonably nice and lightweight clincher wheels ~1360g for the shallow ones and ~1480g for the deep ones, and the deep ones specifically perform wheel at speed when tapping along in a chaingang, but they both suffer when sprinting or when climbing hard. They were built as a bit of an experiment to test some gear out before I considered if I'd be happy building similar sets for others, but overall they're a bit of a disappointment and I'd not build another similar set again (I'd use more spokes next time for sure, and probably thicker ones too!) and I'm very picky about when I use these wheels as for most riding I have other wheels that are better all-rounders.

Any theoretical speed difference (under ideal conditions) is so marginal that it's not worth worrying about. If you're into chasing marginal gains and you think a better set of wheels might mean you come 2nd in your next cat2 race Vs 3rd, then perhaps it's time to look into it, along with other ways to make (probably more significant) gains, but for a normal rider, no point.

TL:DR version? for most riding (not racing) a decently light but durable set of wheels with a sensible number of spokes are the best option.

[Brucey]

that mirrors my own experience pretty well.

Some deep section rims (heavy ones obvs) are so stiff they don't work like 'normal' rims any more; under dead weight loads the spokes at the top of the wheel get noticeably tighter.....(as well as the spokes at the bottom of the wheel getting slacker as normal).

With rims like these it is easy enough to build a wheel that is radially stiff enough but you still need plenty of spokes (more than is currently popular in so-called 'upgrade wheelsets'....) to provided adequate lateral stiffness.

cheers

[Samuel D]

A lot of cyclists around Paris and in particular on the Longchamp circuit (which has a climb) solve this problem by semi-permanently flipping up their brake’s quick-release lever. You’d think they’d be better off adjusting the cable, but I suppose that’s a complicated request when they hand over their bike for its periodic “service”.

[Racingt]

My personal experience, without reading the entire thread, I have owned a pair of wheels that currently retail around £3k.
They were fantastic, and I could push one gear higher, so perhaps 2mph faster.
I beleive a 5kg weight loss would have had the same effect. Given a choice, I’d go for extra miles and weight loss every time.
Of course the best solution is both, but that wasn’t possible due work commitments (which enabled the wheel purchase in the first place!)

[Brucey]

My personal experience, without reading the entire thread, I have owned a pair of wheels that currently retail around £3k.
They were fantastic, and I could push one gear higher, so perhaps 2mph faster. ....

ah-huh..... to go 2mph faster through aerodynamic improvements alone, you would have to not just improve the wheels, you would have to aerodynamically improve the whole bike so that its drag is about, er, .....

zero.

cheers