touring wheels upgrade

[Nearholmer]

Wheel damage, as opposed to very long-term wear-out, is the result of the sudden transfer of kinetic energy, so actually speed makes a greater difference than mass, since kinetic energy is proportional to mass, but proportional to velocity squared.

Be kind to your wheels: cycle slowly.

Another key factor must be tyre and tyre-pressure choices, because they affect energy transfer and dissipation.

[pwa]

I used to snap spokes on most tours, and it was a real pain. But it stopped when I began getting wheels from specialist wheel builders who knew their trade. That, I think. is the key.

My damaged wheel rims were flimsy Open Pros (too fragile for me to rely on for touring), and the tyres I had that day were (I later concluded) under-inflated 25mm, which simply bottomed out on a road irregularity. A bigger tyre, or more air pressure, would have avoided that issue.

As for the suggestion of always cycling slowly, Nah! One of my top memories of tours in the past is of overtaking slow moving vehicles whilst travelling down an Alpine descent at close to 50mph, with four panniers on my bike. Wonderful! It doesn't get better than that. I'll wait for you at the bottom.

[rareposter]

I was a bit disappointed going into bike shops I just get a lot of scepticism and directed to 36 spoke and bombproof rims however times I said what I actually wanted to do with them.

Depends a bit on the shop - if you go to one of the more longstanding / traditional type shops, they'll hear the word "touring" and immediately go "oh yes, you need 36 spokes and this and that" while probably also telling you that you need a steel frame and a triple chainset.

But also, shops need a degree of safety built in - they don't want to sell you a superlight set of wheels if you're going to bring them back a month later saying "you sold me these saying they'd cope with touring but they're all broken".

Modern rims (which are generally a fair chunk wider than older style rims) are a lot stronger, stiffer and (believe it or not) lighter so it's perfectly possible to get a stiff, reasonably light but strong wheel with 28 or 32 spokes and have no issues at all.

[ANTONISH]

I used to snap spokes on most tours, and it was a real pain. But it stopped when I began getting wheels from specialist wheel builders who knew their trade. That, I think. is the key.

My damaged wheel rims were flimsy Open Pros (too fragile for me to rely on for touring), and the tyres I had that day were (I later concluded) under-inflated 25mm, which simply bottomed out on a road irregularity. A bigger tyre, or more air pressure, would have avoided that issue.

As for the suggestion of always cycling slowly, Nah! One of my top memories of tours in the past is of overtaking slow moving vehicles whilst travelling down an Alpine descent at close to 50mph, with four panniers on my bike. Wonderful! It doesn't get better than that. I'll wait for you at the bottom.

If you get to the bottom of course - I prefer to descend at a moderate pace.
I've used "open pros" for years and haven't had any problems using them for touring.
No broken spokes (I build my own wheels so maybe that helps).
I will concede that the wall thickness is less than ideal and lately I've moved to a heavier rim - not that it matters I'm getting old and the mileage is dwindling.

[pwa]

I used to snap spokes on most tours, and it was a real pain. But it stopped when I began getting wheels from specialist wheel builders who knew their trade. That, I think. is the key.

My damaged wheel rims were flimsy Open Pros (too fragile for me to rely on for touring), and the tyres I had that day were (I later concluded) under-inflated 25mm, which simply bottomed out on a road irregularity. A bigger tyre, or more air pressure, would have avoided that issue.

As for the suggestion of always cycling slowly, Nah! One of my top memories of tours in the past is of overtaking slow moving vehicles whilst travelling down an Alpine descent at close to 50mph, with four panniers on my bike. Wonderful! It doesn't get better than that. I'll wait for you at the bottom.

If you get to the bottom of course - I prefer to descend at a moderate pace.
I've used "open pros" for years and haven't had any problems using them for touring.
No broken spokes (I build my own wheels so maybe that helps).
I will concede that the wall thickness is less than ideal and lately I've moved to a heavier rim - not that it matters I'm getting old and the mileage is dwindling.

This is the road where I probably reached my highest ever speed for fully loaded touring.
https://www.google.com/maps/@46.6262983 ... ?entry=ttu
Good tarmac, wide, no sudden tight bends, beautiful for high speed descending. I sat up occasionally to bring the speed down before actually braking for bends. The wheels had a relatively easy time. And after the very slow ascent of the other side of the pass. from Italy, I deserved a bit of lovely, cooling speed.

But the quality of the wheel build is vital to avoid spoke breakages. I don't think I had any go on that particular tour, which also took in the Albula and Stelvio Passes.

[531colin]

Has anybody mentioned asymmetric rims? This is a bit of a “free lunch” where you get increased durability for no extra weight. The rim spoke holes are offset in order to make the spoke tension of the left and right sides of the back wheel more nearly equal. (Edit....by making the "bracing" angle more nearly equal, in case that wasn't obvious)

Talking of free lunches, it’s a myth that weight saving in the wheels is better than weight saving anywhere else. Do a “ thought experiment “. Imagine having a car wheel and a bike wheel set up on stands so you can swing them round with your hand: the bike wheel spins so much easier than the car wheel. The elephant in this particular room is that on the road in order to accelerate the wheel, you have to accelerate rider, bike and luggage, not the wheel on its own.

[pwa]

Didn't Francesco Moser break the World Hour record on a bike with intentionally heavier wheels than normal, to benefit form a supposed flywheel effect? But nobody who took that record later on followed his example. Why didn't they? Was the heavy wheel ploy banned or did it just not work?

I do like the nippy feel of light wheels when I'm in situations with lots of small accelerations, but I think that is something you feel on an unladen bike, and not so much on a bike loaded up with camping gear. But few of us keep our touring bikes just for loaded use.

[Thehairs1970]

Just looked up Moser’s bike

https://steel-vintage.com/pages/frances ... le-auction

I can’t imagine that rear wheel was light! The rules around the hour record are, apparently, very obtuse and change on a whim, so I’m amazed this got through.

However, I can’t see this catching on while touring, there’s no room for a rear rack.

[simonhill]

Talking of free lunches, it’s a myth that weight saving in the wheels is better than weight saving anywhere else. Do a “ thought experiment “. Imagine having a car wheel and a bike wheel set up on stands so you can swing them round with your hand: the bike wheel spins so much easier than the car wheel. The elephant in this particular room is that on the road in order to accelerate the wheel, you have to accelerate rider, bike and luggage, not the wheel on its own.

Is this heresy?

I don't know, I have just been following group think.

Will I be wasting my money on a new set of lighter wheels.

[Angstrom]

Talking of free lunches, it’s a myth that weight saving in the wheels is better than weight saving anywhere else. Do a “ thought experiment “. Imagine having a car wheel and a bike wheel set up on stands so you can swing them round with your hand: the bike wheel spins so much easier than the car wheel. The elephant in this particular room is that on the road in order to accelerate the wheel, you have to accelerate rider, bike and luggage, not the wheel on its own.

I might not have understood everything, but I'm far from convinced by this "demonstration".
1) True, acceleration on the horizontal plane requires energy based on the total weight of bike, wheels, rider and gear.
2) In order to get that horizontal displacement, wheels must rotate. Therefore, additional kinetic energy must be used just to get those wheels spinning (rotational energy).

IMHO, those 2 movements (horizontal one + rotational ones) add up. Considering a constant total mass, the horizontal displacement will not be impacted by lighter wheels (and heavier "other stuff"), but the kinetic energy required to get the wheels spinning will be higher to get the heavier wheels spinning.

[pwa]

I think the idea is that the flywheel effect nullifies the initial disadvantage of getting heavier wheels up to speed.

But out on the road, and being fully aware of this theory, I have always felt that my lighter wheeled bike gets me around a hilly circuit with a bit less effort. And the all-up weight I push around the circuit (Me+bike) isn't much different. And when you look at the wheels professional race teams use, nobody is rushing towards more weight on wheels, even though it is an area where more strength could be useful. So my suspicion is that there is some real advantage to having less weight in the rims and tyres, though it may be only on steeper climbs where repeated and rhythmic pulses of acceleration occur.

[Angstrom]

I think the idea is that the flywheel effect nullifies the initial disadvantage of getting heavier wheels up to speed.

Thank you. I understand.
But not sure I agree.
If I rephrase what I understood, the flywheel effect "nullifying the initial disadvantage" would mean that a heavier rim/wheel would require more energy to get spinning initially but not over the course of the ride, when this "stored" energy being "reused" later.

Well, I don't agree with that. Lots of energy possibly "stored" (momentum) will be wasted before it can produce the above-described benefit:
1) every time we brake
2) through various causes of friction
3) by air resistance
4) by other things like suspension loss

Therefore, like in all energy saving matters, "the best way to conserve energy is not to spend it in the first place".
At least that's where my thinking gets me.
But I might be wrong. I took some physics at school, but not much and that was a long time ago.

[Jdsk]

It's a good principle.
...

We're probably at the point in this discussion where rigour in the physics matters if we're going to try and reach agreement...

Stored energy is not the same as momentum. But they're closely connected in the systems under discussion.

The analogy for mass of a translating object is moment of inertia ("second moment" etc) of a rotating object. And that's where mass at the rim is different from mass closer to the axle.

Jonathan

[roubaixtuesday]

Talking of free lunches, it’s a myth that weight saving in the wheels is better than weight saving anywhere else. Do a “ thought experiment “. Imagine having a car wheel and a bike wheel set up on stands so you can swing them round with your hand: the bike wheel spins so much easier than the car wheel. The elephant in this particular room is that on the road in order to accelerate the wheel, you have to accelerate rider, bike and luggage, not the wheel on its own.

I've not checked the relevant physics, but I think it takes twice the force to accelerate a rotating thin cylinder stationary at the point of contact with the ground as it would to accelerate a point mass of equal mass to the cylinder.

But I'd need to check the equations to be sure.

[roubaixtuesday]

It's a good principle.
...

We're probably at the point in this discussion where rigour in the physics matters if we're going to try and reach agreement...

Stored energy is not the same as momentum. But they're closely connected in the systems under discussion.

The analogy for mass of a translating object is momen of inertia ("second moment" etc) of a rotating object. And that's where mass at the rim is different from mass closer to the axle.

Jonathan

We crossed. I agree.