Road wheels – will I notice a difference?

Do I ask myself questions and then answer them? Sometimes 😛

If you know thw moment of interia of bike wheel you will see that changes in angular velocity of the wheel to give its proper term do not take as much energy as you might think. The stark reality is wheel weight makes a small difference on a hill but you can almost ignore the contribution of the moment of interia as it small compared to the kinetic energy in the rest of the bike and rider. People sweat the small stuff for a seconds gain on strava like we are pro’s or something.

Deciding on a wheelset based ln weight is bad selection. Gram pinching on a wheel i drtoduced comprismises. Hubs with small bearings are light but the bearing wear out quickly especially in the wet. For low cost hubs there is little better tha miche primato’s or shimano ultegra but these are nlt light hubs. Light rims get light in two ways by thining down the brake track (stans apha 340 lr ryde pulse sprint) or by thinning down the spoke nipple bed, well that is alot of rims. One of the few rims that thumbs it nose at being weight weenie and is all sensible is the h plus son archetype.

You can have a senisble 1700g wheelset with the archetype rim or one that is 300g lighter with lighter rims and hubs with smaller bearings. Do you really think you will be any faster in a meaningful way unless you spend on a deep aero wheelset. Will the ride be any more enjoyable or is all keeping up with the jones.

In short the more you try to justify a new purchase the more you will. You have to decide what you want. Depenable for very long time or a wheelset that requires more hub maintance or a rim that wears out quicker, maybe both.

heavier riders descending quickly towards a pub meal, which is acceleration due to gravy

damn, no like button 🙁

Oh and those that say i have 5k on a set of wheels and they are still going strong that great but 5000 miles is not alot in the grand scheme of things. For some that is less than 6 months riding.

You’re wrong. HTH

I don’t tend to do sums in order to have social interactions – quite capable of managing those without involving any maths. The trouble with this “common sense and experience” you speak of though is when you apply it to areas where sums are more useful – it tends to condradict the sums, and you know what, the laws of physics also apply to bicycles.

I mentioned that in my earlier post. You correctly identify that a heavier wheel is beneficial (by a very small amount, more than lost in the noise) in smoothing this out. You also correctly identify that the speed variation during a pedal stroke is greater when climbing than on the flat. You’re so, so close to putting those together and correctly identifying that a heavier wheel is actually less of a disadvantage when climbing than a heavier frame because of the small advantage to smoothing out the speed variation. Which neatly contradicts your earlier post 😉

You’re wrong. HTH

Right, GCSE books out the window, Gravity is a Force, but what you experience pulling you towards earth is the Gravitation Acceleration constant (9.81ms-2 in this case) multiplied by your mass.

In laymans terms, to say that “Gravity is a Force” implies that it is a constant. The constant is the Gravitational Acceleration (on earth at least, ignoring the variations on how close to the equator you are or not) which is what I was (if you are being pedantic) incorrectly referring to.

For instance, the Force (due to gravity) that my road bike exerts onto the ground is approximately 1/10th that of what I do (my bike being sub 8kg, me being just over 80 right now).

People sweat the small stuff for a seconds gain on strava like we are pro’s or something.

Agreed

If you know thw moment of interia of bike wheel you will see that changes in angular velocity of the wheel to give its proper term do not take as much energy as you might think. The stark reality is wheel weight makes a small difference on a hill but you can almost ignore the contribution of the moment of interia as it small compared to the kinetic energy in the rest of the bike and rider.

There’s as many people out there, if not more, riding around on 50mm+ deep section wheels that will only see the speeds where an aero wheel will make any benefit when they’re descending a hill, not on the flat, as there are obsessing over light weight wheels.

I’d argue that no matter how small the performance benefit, unless you’re capable of averaging speeds where aero wheels give you a benefit, if you’re going to upgrade your wheels, then losing some weight is preferable to going aero.

Deciding on a wheelset based ln weight is bad selection. Gram pinching on a wheel i drtoduced comprismises. Hubs with small bearings are light but the bearing wear out quickly especially in the wet. For low cost hubs there is little better tha miche primato’s or shimano ultegra but these are nlt light hubs. Light rims get light in two ways by thining down the brake track (stans apha 340 lr ryde pulse sprint) or by thinning down the spoke nipple bed, well that is alot of rims. One of the few rims that thumbs it nose at being weight weenie and is all sensible is the h plus son archetype.

I’m with you on this. Personally, having tried some of the lighter options out there, wheel stifness is far more important to me than ultimate lightweight. I’ve ridden way too many different flexy wheels to know that I’d rather take a slight weight penalty for longevity, and the ability to get ouf the saddle and sprint and the rim to not rub on the brake blocks or the chainstays constantly.

In short the more you try to justify a new purchase the more you will.

The whole bike industry in the UK, and in many other countries, is largely built on this premise! Far be it for someone that works in the industry to knock it…

You’re so, so close to putting those together and correctly identifying that a heavier wheel is actually less of a disadvantage when climbing than a heavier frame because of the small advantage to smoothing out the speed variation. Which neatly contradicts your earlier post

LOL

I’ve got a set of SRAM S80’s I’m selling at the moment on behalf of a friend… You’re more than welcome to borrow them first to show me how much quicker they make you up a hill!

😉

Isn’t it all about having wheels that are just a joy to ride? Make you want to go out on them tomorrow, not worry about the harshness, fragility, lack of braking, being blown sideways?

When I got my first set of “tubs ‘n sprints” many moons ago (when the alternative was 27″ x 1 1/4″) all the old guys told me that I would need to learn to ride all over again because my pedalling style would be too choppy.

What about spokes? Will I be able to feel the aerodynamic advantages of bladed spokes on climbs? And if so, how much faster will they make me?

Aero benefit of bladed spokes is debatable. Benefits are mostly weight and strength apparently.

I think he might have been being sarcastic mrblobby.

Some good options here:

CRC Spring Wheel Clear Out

When I bought my (second hand) road bike, it had Ksyrium SL wheels. They’re about 1,600g, I think, so not that light by modern standards. They were fine, then the rims wore out. It was impossible to get replacement rims (because they were more than five years old…). Needed wheels in a hurry for a big ride, had little money, so bunged the Mavics on ebay as Spares or Repair and bought some dirt-cheap Shimano snotters from Merlin. They were £80 IIRC, and weigh the best part of 2kg.

I noticed the difference for roughly the first ten minutes. If there actually is a performance difference it’s not one I can measure. Subjectively, the bike’s marginally harder to hang back up in the shed 😉

I think he might have been being sarcastic mrblobby.

It’s getting increasingly difficult to tell these days! 😳

bm0p700f – Member
Oh and those that say i have 5k on a set of wheels and they are still going strong that great but 5000 miles is not alot in the grand scheme of things. For some that is less than 6 months riding.

Don’t be silly. This is STW, that’s a lifetime mileage that is 😀

So at what speed does aero wheels add benefit. Ive read 18mph to 20mph on different links. That is quite a margin…

I’ve read it’s above 18mph but also read that it’s an exponential benefit so the faster you go the bigger the benefit.

1mph. Actually that’s probably a bit high.

Aero drag goes with the square of speed and power required with the cube, so the power required to force a wheel through the air at 20mph is 2.4 times the power required at 15mph. That doesn’t mean there is no benefit at 15mph, simply that at some point other factors become more dominant (rolling resistance and bearing drag are proportional to speed, so more significant at lower speeds).

A more sensible answer is that anything above 10mph is enough to get some benefit, above 15mph is enough to be significant. It’s certainly a lot lower speeds than generally assumed.

Cervelo[/url], who may have a vested interest, on aero gains and speeds

Most people are going to struggle to notice a difference with aero wheels. Everything else on the bike is the same, and the wheels don’t contribute much to drag anyway. You’re better off getting yourself a bit lower and tucking your elbows in.

This is always a good read:

Aero benefits over 40km of various equipment[/url]

Skimmed through this thread as I have a rather urgent need for wheels for next weekend’s Flanders trip. I’ve run RS80 C24 for 3.5 years and spoke went pop today. Now I can get them rebuilt, and I will but it isn’t going to happen in the next four days. They’re lovely wheels too. Now my question is, go aero and have the pick of both when I get the RS80 rebuilt or just go same again? Is around 250g increase for an aero set going to be noticeable in the main unless I do some serious climbing?

My 2p, based on VFM and not racing:

Tubeless feels great.
Low rim weight feels great. Hub weight less so.
Aero makes v little difference at the speeds most of is ride at.

My my alpha/sokin/105/std butted spoke build works great for me, £250 parts and 1550gm IIRC, I see no point in spending more.

It’s getting increasingly difficult to tell these days!

I was making the point, somewhat sardonically, that people are now applying some sort of rationalised marginal gains justification to buying expensive road wheels for – and I’m quoting the OP here: no racing, just sportives and Strava

Don’t get me wrong, I have no beef with people buying very nice, very expensive wheels for their bikes, but some of the justifications being dragged out seem a little fanciful, even given that Strava top-tens are on the line. Anyway… I’m sorry if my question appeared to be plausible, it wasn’t in any way my intention 🙂

I’ve got some aero wheels.

They look well cool.

HTH