What's in a wheel?

[Tin Pot]

Great, so you are home in time to watch Eastenders

I'll spend 1/2 an hour longer on the road and put the money saved on wheels towards a weekend away.

7hrs in the saddle IS a weekend away!

 

[Yellow Saddle]

It was just an anecdote about my experience buying replacement wheels, not The Theory of Everything. Get over yersel.

OK, so it was complete and repeated nonsense then.

 

[beastie]

OK, so it was complete and repeated nonsense then.

Did I insult your mum in a previous life or something? Or are you just, perhaps a little bit troll yourself.

 

[Tim Hall]

Did I insult your mum in a previous life or something? Or are you just, perhaps a little bit troll yourself.

In future make sure your anecdotes can be cross referenced to a peer reviewed respected journal.

 

[Ajax Bay]

Is it really worth forking out hundreds of pounds for the sake of going 1 mph faster? Please explain as it really baffles me.
@Tin Pot said:

113 miles at 15mph = ~7.5hrs in the saddle
113 miles at 16mph = ~7hrs in the saddle

Not clear whether you're saying that spending half an hour less IS worth a couple of hundred pounds; or that it ISN'T.
Also you are implying a reduction in loss of generated watts by one pair of wheels over another, over 113 miles. Is this your practical experience? do share.

 

[Tin Pot]

Is it really worth forking out hundreds of pounds for the sake of going 1 mph faster? Please explain as it really baffles me.
@Tin Pot said:

113 miles at 15mph = ~7.5hrs in the saddle
113 miles at 16mph = ~7hrs in the saddle

Not clear whether you're saying that spending half an hour less IS worth a couple of hundred pounds; or that it ISN'T.
Also you are implying a reduction in loss of generated watts by one pair of wheels over another, over 113 miles. Is this your practical experience? do share.

It's a value judgement. Tyred now has enough information to make that judgement.

Somehow I think you aren't really interested in whether the attributes of wheels can increase speed for a given input...go on admit it you're amongst friends here

 

[beastie]

In future make sure your anecdotes can be cross referenced to a peer reviewed respected journal.

It's in at New Scientist, but for some reason the editor is yet to publish it......

 

[Ajax Bay]

I think you aren't really interested in whether the attributes of wheels can increase speed for a given input

Of course a good set of wheels can allow an increase in speed, if only through the psychological boost it seems to give some (brief) contributors above. But 1.6kph better? In the spirit of friendly 'chat' here goes:

On a flat ride at 15mph the drag is 60w (say) and the other power required is 32w. At 16mph the power required to overcome drag increases by 1.21 (16cubed /15 cubed) to 72w.
Will a set of replacement wheels suitable for a 113 mile ride give you a 15% aero improvement (I'm massively over-allowing for some other benefits (lighter weight (though negligible in the body plus bike mass sum) rolling resistance to do with the hub and the rim rolling compliance))? Let's use @beastie 's original set of Alex R500s as the base - and keep all else the same, including tyres.

Please could you suggest wheels that will approach that kind of improvement? The point is that OP's original question is flawed: you won't get a 1mph advantage from a better set of wheels (for normal riding on normal roads for, as you suggest (why?) 113 miles). Or will you?

It's a value judgement. Tyred now has enough information to make that judgement.

But the information you've offered him is invalid, offering him something which is not actually achievable.

 

[Tin Pot]

Of course a good set of wheels can allow an increase in speed, if only through the psychological boost it seems to give some (brief) contributors above. But 1.6kph better? In the spirit of friendly 'chat' here goes:

On a flat ride at 15mph the drag is 60w (say) and the other power required is 32w. At 16mph the power required to overcome drag increases by 1.21 (16cubed /15 cubed) to 72w.
Will a set of replacement wheels suitable for a 113 mile ride give you a 15% aero improvement (I'm massively over-allowing for some other benefits (lighter weight (though negligible in the body plus bike mass sum) rolling resistance to do with the hub and the rim rolling compliance))? Let's use @beastie 's original set of Alex R500s as the base - and keep all else the same, including tyres.

Please could you suggest wheels that will approach that kind of improvement? The point is that OP's original question is flawed: you won't get a 1mph advantage from a better set of wheels (for normal riding on normal roads for, as you suggest (why?) 113 miles). Or will you?

But the information you've offered him is invalid, offering him something which is not actually achievable.

I'll warn you, I've argued the scoring value of spin rates on golf balls varying swing speed, AoA and smash factor

The argument is not invalid because it complies with the assumptions in the posit - If a wheelsets costs hundreds of pounds and you only get a 1mph increase its not worth it.

I have not postulated that, the OP has. So within that, my response is logically correct.

So, if we set aside the tools of formal debate and logical fallacy for a second, and the subjective value judgement of cost/benefit, we can get to the root:

What cycling efficiency benefits can be bought?

Have a look see here:

Road bike, helmet, tribike, clip on bars and near the end aero wheels:
http://www.bikeradar.com/news/article/how-aero-is-aero-19273/

Some interesting stuff on tyres here:
http://www.cyclingpowerlab.com/TyreSelection.aspx

And, increased efficiency through more expensive lubrication(I can't find the original article I read):
https://roadcyclinguk.com/reviews/m...dynamic-chain-lube-review#rA2c4m3kF3Od7t40.97

And because you are likely to notice there is no consistency in measurement in the industry:
http://www.sciencedirect.com/science/article/pii/S1877705811009714

 

[nickyboy]

Of course a good set of wheels can allow an increase in speed, if only through the psychological boost it seems to give some (brief) contributors above. But 1.6kph better? In the spirit of friendly 'chat' here goes:

On a flat ride at 15mph the drag is 60w (say) and the other power required is 32w. At 16mph the power required to overcome drag increases by 1.21 (16cubed /15 cubed) to 72w.
Will a set of replacement wheels suitable for a 113 mile ride give you a 15% aero improvement (I'm massively over-allowing for some other benefits (lighter weight (though negligible in the body plus bike mass sum) rolling resistance to do with the hub and the rim rolling compliance))? Let's use @beastie 's original set of Alex R500s as the base - and keep all else the same, including tyres.

Please could you suggest wheels that will approach that kind of improvement? The point is that OP's original question is flawed: you won't get a 1mph advantage from a better set of wheels (for normal riding on normal roads for, as you suggest (why?) 113 miles). Or will you?

But the information you've offered him is invalid, offering him something which is not actually achievable.

I'm interested in the cubed calculation. Wind resistance is proportional to the velocity squared. Of course you need extra watts to get up to the target speed (ie 16 not 15). But once at that speed the additional work required is 16 squared / 15 squared I think

Anyway...fancy wheels are quicker....a bit. But most of it's placebo and you're much more likely to wreck them by hitting a pothole. At least nobody's seriously trying to make the acceleration argument...or even worse the hill climbing argument

 

[Ajax Bay]

@nickyboy Yes additional WORK is related to 'v squared' (ie the energy you have to put in against drag (force to keep going at) at a speed) but POWER is related to v cubed, the rate of work to counter that drag. Assumes air speed and cycle speed are the same - ie no wind.

 

[Flick of the Elbow]

Road bike, helmet, tribike, clip on bars and near the end aero wheels:
http://www.bikeradar.com/news/article/how-aero-is-aero-19273/

Blimey, even their starting point is more aero than what I used to ride. Never mind the heavy steel frame and the 6 speed block ! Can't help wondering how much faster my PB's would have been if I'd had today's kit then. On the basis of these tables it sounds like even my 10 time would be a good 2 mins faster !

 

[chriswoody]

113 miles at 15mph = ~7.5hrs in the saddle
113 miles at 16mph = ~7hrs in the saddle

Ok I get it, I can spend an extra half hour in the cafe and still get home at the same time.

However because I spent all that extra cash on the wheels I can't afford cake and coffee. Bugger, lifes full of difficult decisions.

 

[Tin Pot]

Ok I get it, I can spend an extra half hour in the cafe and still get home at the same time.

However because I spent all that extra cash on the wheels I can't afford cake and coffee. Bugger, lifes full of difficult decisions.

In my case, I could take a thirty minute nap before starting the marathon. Hmm, now that could be worth a ton or two.

 

[bonsaibilly]

So I only read the first of those learned articles, which led me to conclude that if I could afford a posh carbon bike (I can't) and could cycle 10 km at a steady 26 mph (I can't) then a pair of expensive more aerodynamic wheels would make less difference than any other, much cheaper, aero solution.

Hmmm.

Other hand, I recently bought the Racing 5s and not the "more aero" Quattros (same price) because they look better in my humble opinion. That is all. BB