Would new wheels really make a difference to my speed?

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Samuel D
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Re: Would new wheels really make a difference to my speed?

Post by Samuel D »

Racingt wrote: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.

Or perhaps not. Since drag is proportional to speed squared and therefore power to overcome that drag to speed cubed, consider what your claim would imply about the contribution of wheel drag as a proportion of your total drag.

You might gain 2 MPH at 150 MPH, but not at speeds you have ever pedalled.
Samuel D
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Re: Would new wheels really make a difference to my speed?

Post by Samuel D »

(Cross-posted with Brucey’s similar argument.)
iandriver
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Re: Would new wheels really make a difference to my speed?

Post by iandriver »

I always like the very honest blurb on the specialized website about their 3k plus venge frameset. Saving about 45 seconds over their lower level but still very racy frameset over 40kms. https://www.specialized.com/gb/en/s-wor ... et/p/65218 Presumably this is if the sort of speeds that the pro peleton moves at.

If less than a minute over 25 odd miles is important to you, only you can say. I personally wouldn't expect miracles for a wheel change, if it's a decent enough set of wheels you are starting from. In practice you may only be able to tell the difference with a stop watch, over 40k.
Supporter of the A10 corridor cycling campaign serving Royston to Cambridge http://a10corridorcycle.com. Never knew gardening secateurs were an essential part of the on bike tool kit until I took up campaigning.....
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Cugel
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Re: Would new wheels really make a difference to my speed?

Post by Cugel »

Brucey wrote:
Racingt wrote: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


You are confusing actual speed with perceived speed. When one has splashed cash of 3000 nicker on a wheelset, one is obliged to feel at least 2mph faster. If it was me, I would feel 5mph faster .... but I have a vivid imagination. :-)

Cugel
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Samuel D
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Re: Would new wheels really make a difference to my speed?

Post by Samuel D »

A friend (knowingly) talks about proving his latest marginal gain on the first ride after acquiring it. It seems to work … for a ride or so. Maybe not to the tune of 2 MPH.
Racingt
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Re: Would new wheels really make a difference to my speed?

Post by Racingt »

Brucey wrote:
Racingt wrote: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


Sorry Bruce, I think you are talking nonsense. Surely a time trial bike with carbon discs is at least 2mph faster than the same bike with 36 spoke open pros?
I'm just speaking as I found it, I did say perhaps 2mph faster to give the OP some impression of advantage to be gained for price. I just find threads that have personal experiences to be more useful than armchair theorising,
alexnharvey
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Re: Would new wheels really make a difference to my speed?

Post by alexnharvey »

Post yur Strava dude.
Brucey
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Re: Would new wheels really make a difference to my speed?

Post by Brucey »

TT bikes are faster for sure, but mainly because you sit on them differently, as per the photos I posted upthread. The bike itself accounts for roughly 10% of the total aero drag. If you are doing (say) 25mph and you get rid of the drag of the bike entirely you won't go 2mph faster.

cheers
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Cugel
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Re: Would new wheels really make a difference to my speed?

Post by Cugel »

Brucey wrote:TT bikes are faster for sure, but mainly because you sit on them differently, as per the photos I posted upthread. The bike itself accounts for roughly 10% of the total aero drag. If you are doing (say) 25mph and you get rid of the drag of the bike entirely you won't go 2mph faster.

cheers

Long ago, when road racing, I did TTs as a sort of training for breakaways and getting-back-on solo riding at speed. I did the TTs on my road bike, since that would be what I was road racing.

A lad I knew was selling his rather swish TT bike for very little (£150) despite it being made of exotic Columbus tubing with Campag Record gubbins. It did have a small front wheel, though, to get the front end lower and thus the rider lower. I put aero bars on it and did a few TTs on that, just for fun. I was slower than on the road bike.

This was confusing at first, since I was definitely in a more aero position. Sadly, it didn't suit my physique, which is of the not-so-supple type. I couldn't get the power out as I could on the road bike.

So I might have benefited from aero wheels on the road bike. A few lads tried putting in a rear disc wheel but did no better (on their road bike). Many complained of the racket they made. The also tended to weight a ton, so only a flat course was going to see any improvement at all ... assuming a gust of side wind didn't deposit you on the verge or under the wheels of a passing lorry.

Some TTers did have low profile frames with disc wheels and those queer helmets. They sometimes went fast but we roadies always enjoyed the ones who went slow, despite all their gear.

These days I don't give a toss about my average speed or anything other than the cycling .... which does include trying to drop the others up the hills and winning the sprint for the village sign. But that's just olde pharts having fun and doesn't require a technology-based marginal gain, especially one of 40 seconds over an hour at 25mph. :-)

Cugel
“Practical men who believe themselves to be quite exempt from any intellectual influence are usually the slaves of some defunct economist”.
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Brucey
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Re: Would new wheels really make a difference to my speed?

Post by Brucey »

I had a similarly frustrating experience; I was able to put out a very healthy amount of power when climbing, and not at all bad on (say) the hoods either, but try as I might I couldn't get close to that amount when in any kind of aero TT position. I was usually highly uncomfortable when trying, to boot. Hence my earlier comments about specific training for TT work. I eventually tried to bully myself into being able to make power whilst using tri-bars etc by building something that aped a full TT position as a 'ride to work' bike. After several thousand miles of such effort I had improved but I was barely any more comfortable or more powerful than I had been when I started; at that rate of progress it seemed I would be an old man by the time I was 'fast'.

At that stage I was ready to pack it in; I enjoyed riding my bike normally, so other 'training rides' were not 100% masochism by any means. However I struggled to find much in the way of redeeming qualities when it came to training for full-on TT efforts.

This page is worth a look;

https://www.cyclingpowerlab.com/cyclingaerodynamics.aspx

there are some nice photos (from early in 2008, prior to the TdF that year) of Carlos Sastre in a wind tunnel, in positions that look not wildly different but result in CdA figures of 0.26 and 0.25 respectively. That difference is worth about 42 seconds over an hour-long TT; the difference between winning and losing the TdF, potentially.

cheers
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Canuk
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Re: Would new wheels really make a difference to my speed?

Post by Canuk »

I saw Graeme O'Bree break the British 10 mile record on his 'funny bike' before the Superman position he adopted later. I think he came back in just over 18 minutes. I've never seen anyone ride so fast on a bike.

There were sniggers and much cajoling at the outlandish design before the start, but at the finish almost everyone was open mouthed in awe. He had taken a minute off the previous record. It was a perfect night, midsummer, no wind and still warm in the early evening. He came sprinting over the finish line at well over 40 mph. Its all about position on a TT bike. Seat over or just in front of the bottom Bracket and as low and little frontal area with the bars at the front.

Not my idea of happy cycling, but I admire those who make of it a science.
colin54
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Re: Would new wheels really make a difference to my speed?

Post by colin54 »

Canuk wrote:I saw Graeme O'Bree break the British 10 mile record on his 'funny bike' before the Superman position he adopted later. I think he came back in just over 18 minutes. I've never seen anyone ride so fast on a bike.

I saw this a while back , Graham Obree doing back to back comparisons of his bikes against UCI

standard bikes (1993 and modern) in a wind tunnel.



https://www.youtube.com/watch?v=oJ9H0INZ2_s
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reohn2
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Re: Would new wheels really make a difference to my speed?

Post by reohn2 »

Cugel wrote:
You are confusing actual speed with perceived speed. When one has splashed cash of 3000 nicker on a wheelset, one is obliged to feel at least 2mph faster. If it was me, I would feel 5mph faster .... but I have a vivid imagination. :-)

Cugel

If I were spending 3000 nicker on a wheelset it would be 40mph faster,as they'd be attached to a motorbike for that kind of money :shock:
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reohn2
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Re: Would new wheels really make a difference to my speed?

Post by reohn2 »

Racingt wrote:
Sorry Bruce, I think you are talking nonsense. Surely a time trial bike with carbon discs is at least 2mph faster than the same bike with 36 spoke open pros?
I'm just speaking as I found it, I did say perhaps 2mph faster to give the OP some impression of advantage to be gained for price. I just find threads that have personal experiences to be more useful than armchair theorising,


I find all these aero speed gains go out the window in a crosswind,which are inevitable to a greater or lesser dagree most of the time
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Brucey
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Re: Would new wheels really make a difference to my speed?

Post by Brucey »

Racingt wrote:
Sorry Bruce, I think you are talking nonsense. Surely a time trial bike with carbon discs is at least 2mph faster than the same bike with 36 spoke open pros?
I'm just speaking as I found it, I did say perhaps 2mph faster to give the OP some impression of advantage to be gained for price. I just find threads that have personal experiences to be more useful than armchair theorising,


what you call 'armchair theorising' is better known as physics, and is backed up with thousands of hours of testing.

That your 'impression' is of a +2mph gain says more about wishful thinking and a slightly overactive imagination than anything else.... :wink:

Wheels are a 'perfect upgrade product' (thus filling cycling magazines with both advertorial content and of course plenty of paid ads) in that most cyclists need (or at least will get use out of) spare wheels anyway, they don't need any great skill to fit, and they can (especially if they have deep rims, the deeper the better in fact) make your bike look obviously different to how it used to be.

Once they are fitted you can bask in the adulation of others and imagine you are going as fast as you like.....

Bling-bling!

cheers
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