TheKillerPenguin

I've been thinking about this for a while, and I'm wondering if upgrading my wheelset to something lighter wouldn't actually affect me as much as I think. Of course, heavy wheels spin up slower and aren't as good for climbing as lightweight wheels are, but if you can get them going, they don't want to stop spinning. It seems to me that this would essentially keep the advantages of a lightweight wheel set down to a minimum, as I don't think they would hold speed as well on the flats.

Lightweight wheels would be good for things that demand quick acceleration, like Crits. But are their advantages as obvious or important over the course of a road race? If you're going 50 miles, I'd think you'd be holding pretty high speeds for a long distance, and a heavier rim would help you to maintain that speed more easily, especially up small rises where the inertia of the wheelset won't let them slow down.

So, what common sense tells me is that heavier wheelsets may be just as good as lighter wheelsets for things such as Road Races and Time Trials, as the benefits of quicker acceleration and better climbing are kept in check by the heavier rims' willingness to keep speed on flats and over small rollers. Crits, due to the constant accelerations, favor lighter wheels that spin up faster.

But, a week or two ago, I tested out a six/13, and the weight of the wheels was significantly less than my Gipiemme Grecial Parades. It had a pair of Ksyriums on it, and they felt like they accelerated very quickly and held speed really well. This goes against what I think would be possible , since a lighter rim has less inertia, and therefore won't spin as long.

So, a few questions.
Is my common sense correct, in that heavier rims are just as good for races that don't demand constant acceleration like crits do?

is it possible to make a lightweight wheel that holds speed as well as a heavy wheel, and if so, how is it done? Does being aero allow a lighter wheelset to hold speed as well as a less aero heavy wheelset? And are the best wheelsets both light and aero?

Specifically, I'm curious as to how my Gipiemme Grecial Parade wheelset compares to the Ksyrium SL. I know mine are heavier, but they have less spokes, and they are bladed, which I would think would allow mine to hold speed as well if not better than the Ksyriums. Now, I'm not looking to upgrade my wheelset specifically to Ksyriums, but they do seem to be the standard wheels of racers everywhere, so they must be doing something right.

53-11_alltheway

The thing is total weight is probably the most important thing in climbing (as long as it is stiff enough)

Low moment of inertia may help you in slow speed (0-10 mph acceleration), but aero is more important for high speed acceleration.

Furthermore all this talk about light rim being better for climbing because of summing up the accelerations is BS too. Greater rim weight (same total wheel weight) means the wheel will also loses less speed in between choppy pedal strokes too.

cryogenic

My wheels are pretty lightweight and 30mm deep with bladed spokes... I have absolutely no problems keeping them spinning for a good while.. Heck, they seem to want to roll forever. I love my wheels

steveknight

I always wonder how the weight of the wheels and the pressure of the wheels on the ground works. it's easy to see how weight works when a wheel spins free of the ground. but when you have 75# ro so on each wheel how is the weight working then? unless your going pretty fast wheels are not spinning super fast either.

allgoo19

The guy won many races on this bike and it's got 36 spoke wheels. Did he wish having lighter wheels? I don't know. Probably he was too busy working on his legs to think about it.

53-11_alltheway

Yeah, a lot things have changed since then though.

They used crazy light tubular rims (fiamme Ergal) with those 36 spokes too.

cryogenic

you just can't resist a wheel thread, can ya?

53-11_alltheway

At road bike review it's the only forum I even look at or post on. https://forums.roadbikereview.com/forumdisplay.php?f=95

cryogenic

fair enough... wheels are a very interesting topic if you ask me... after all, we wouldn't go anywhere without them!

operator

We need a sticky that says.
Lighter wheels are for racers online.
Then inside it says, anyone posting another wheel weight discussion is to be banned.

Smoothie104

There is no advantage to heavier wheels, unless they are more aerodynamic than than the lighter set. If the sets have the same drag co effiecients, the lighter ones will always be faster. Unless the race was simply down hill.

53-11_alltheway

LOL....WTF?

Let's go back to straight guage hi-ten for all our bicycle frame tubes while we are at it too?

TheKillerPenguin

Well, I thought this thread might be more well thought out than the average "lighter wheels" thread, and hoped it would spawn some good discussion on the subject.

sparknote_s

You are always under acceleration when biking. There is always friction, which slows you down. You have to accelerate to hold a certain speed.

Changes in inertia are insignificant, as this site says: https://www.biketechreview.com/archive/wheel_theory.htm

Aerodynamics are #1.

Now take science out of it and think of it this way. If there was an advantage to heavier wheels, you would pay more for heavy wheels and less for lighter wheels. Not the other way around. I'm sure wheel-makers have already taken this into consideration, benefits of heavy and light wheels.

watchman

I would hazard a guess that unless you have a really heavy rim, the inertia generated by it versus a lighter rim would not be that noticeable. I would put more value in the quallity of your hubs/bearings, those with the least friction would slow down less. I think a decent weight rim taking durability into play combined with a high quality hub would be the best investment.

caotropheus

Wheels, weight and performace. Heavy or not, if anyone is willing to sponsor me a pair of these beauties https://www.reynoldscomposites.com/Stratus-DVUL.asp I will be most pleased

slvoid

A weight difference of 500 grams won't make much difference if your whole system is moving at like 75,000+ grams on flat ground. But when you're trying to spin up those wheels, they will matter when you accelerate, come out of a corner, get checked up and have to make your way to the front of the pack, go up a hill, or sprint to the finish line (not many people I see win races by being 2-3 miles ahead of everyone else alone).

I suspect you will probably get much more advantage with the aero zip 404's at 1700 grams over the ksyrium sl's at 1500 grams.

slvoid

I'll do anything for a set of these wheels... anything.

slvoid

2005 Sci-Con Elan Tubular Holder Seat Bag $17.99

The Elan Tubular Holder bag has all of the style and quality constuction of the standard Elan, but it's bigger. It's called the Tubular Holder because it was built to be sizeable enough to hold a tubular tire, but in reality most folks will use it to carry the larger emergency provisons required for epic rides: You can easily fit 2 tubes, 2 tire irons, a patch kit, and a multitool. Available in Black only. 720 cubic centimeters.

chinamn

I guess it comes down to this, Force = Mass * Accelleration, so the more mass a wheel has the more force it requires to achieve a certain accelleration.

Momentum is P = Mass * Velocity, thus the more mass at a certain velocity has more momentum compared to something lighter.

Momentum only helps when you acheive that speed since MAss and velocity are porporationate, either having more mass or more velocity gives you teh same momentum. Therefore its better to have less mass.

However what it comes down to is accelleration. In a race isnt what matter is accelleration to speed up the hill or catch up to your opponent?? Since you are accelerating alot, i would rather have the lighter wheels.

I guess compare this to a truck and sports car, whihc is better?

my58vw

It is hard to answer this without looking at particular wheels. Assuming aerodynamics are the same then the light wheel is going to be better. Now for example you take my two expensive wheelsets, the carbones and the race x lite aeros. They both to 40 grams weight the same but the carbones are much faster at speed... aerodynamics play a big role. If you were acceleting from about 10 MPH then the lighter wheels would be better, but at race speeds... 20+ MPH the aero wheels will be faster...

steveknight

aerodynamics play a very small roll in wheels. your body is a far bigger issue.

phinney

!!!!!

Anyway, heavier wheels usually save $$$.

53-11_alltheway

There is no advantage to heavier wheels, but I wouldn't get too worried about the weight distrubution of a wheel either.

I'd take a heavy at the rim 1500 gram wheelset over a light at the rim 1500 wheelset anyday if it was more aero.

As far acceleration goes if I am holding 20mph or climbing at 9 mph I'm not doing much accelerating. Any wheel inrertia effect that is coming into play while climbing is being balanced out by the heavier rim slowing downing less in between pulses. *this is a tiny effect* (see above heavier rim doesn't mean heavier wheelset so total amount of weight I am lugging up hill is the same)

cryogenic

me too... I carry a backpack all the time anyway, so I'd carry around a spare tub and some glue anyday for wheels that awesome.