touring wheels upgrade

[pwa]

Surely on a bike, like any vehicle, you are either accelerating or decelerating most of the time and rarely at a constant velocity? So wheel weight will affect you all the time.

However, I think this is quite an irrelevant fact as toughness/reliability are more significant for tourers.

If you're accelerating and decelerating a bit all the time it will cancel out. The only real difference is when accelerating hard.

I agree it's all but irrelevant for touring, but it is good to get the facts straight IMO

So it makes no difference what wheels and tyres weigh? Imagine an extreme example, with wheels made as a solid disc of steel and each weighing as much as a man. Are we to believe that such wheels would be as easy to propel as normal cycle wheels? On flat terrain with junctions. Because if the answer is "No", weight does matter to some extent. Where I live we have lots of junctions to deal with on an average five mile trek, and some require slowing down, then building up speed again. In between are bends and other reasons to slow and quicken the pace. Momentum is often lost through braking, so the theoretical plus of a heavy wheel is not realised in practice. If one's journey consisted of a ten mile straight line with no interruptions, the heavier wheel might perform well, but on a route with lots of quickening and slowing I would expect a lighter wheel to perform better.

[roubaixtuesday]

Surely on a bike, like any vehicle, you are either accelerating or decelerating most of the time and rarely at a constant velocity? So wheel weight will affect you all the time.

However, I think this is quite an irrelevant fact as toughness/reliability are more significant for tourers.

If you're accelerating and decelerating a bit all the time it will cancel out. The only real difference is when accelerating hard.

I agree it's all but irrelevant for touring, but it is good to get the facts straight IMO

So it makes no difference what wheels and tyres weigh? Imagine an extreme example, with wheels made as a solid disc of steel and each weighing as much as a man. Are we to believe that such wheels would be as easy to propel as normal cycle wheels? On flat terrain with junctions. Because if the answer is "No", weight does matter to some extent.

Sorry, you've lost me.

Per posts above, the physics dictates that mass at the rim of a wheel takes twice the effort to accelerate than mass on a frame. At steady pace, whether flat or on a hill, the mass has the same effect regardless of location.

[pwa]

If you're accelerating and decelerating a bit all the time it will cancel out. The only real difference is when accelerating hard.

I agree it's all but irrelevant for touring, but it is good to get the facts straight IMO

So it makes no difference what wheels and tyres weigh? Imagine an extreme example, with wheels made as a solid disc of steel and each weighing as much as a man. Are we to believe that such wheels would be as easy to propel as normal cycle wheels? On flat terrain with junctions. Because if the answer is "No", weight does matter to some extent.

Sorry, you've lost me.

Per posts above, the physics dictates that mass at the rim of a wheel takes twice the effort to accelerate than mass on a frame. At steady pace, whether flat or on a hill, the mass has the same effect regardless of location.

My feeling is that the wheel weight thing matters on a route with lots of acceleration points, and not on routes where momentum can be held for long stretches. Does that make sense?

(Edit. It makes sense to me, but I am tired and I have downed a bottle of Old Peculier )

[roubaixtuesday]

So it makes no difference what wheels and tyres weigh? Imagine an extreme example, with wheels made as a solid disc of steel and each weighing as much as a man. Are we to believe that such wheels would be as easy to propel as normal cycle wheels? On flat terrain with junctions. Because if the answer is "No", weight does matter to some extent.

Sorry, you've lost me.

Per posts above, the physics dictates that mass at the rim of a wheel takes twice the effort to accelerate than mass on a frame. At steady pace, whether flat or on a hill, the mass has the same effect regardless of location.

My feeling is that the wheel weight thing matters on a route with lots of acceleration points, and not on routes where momentum can be held for long stretches. Does that make sense?

(Edit. It makes sense to me, but I am tired and I have downed a bottle of Old Peculier )

Yes, I think that's exactly what the physics shows.

Not had any OP for a long time, I shall have to rectify that!

[Jdsk]

...
I agree it's all but irrelevant for touring, but it is good to get the facts straight IMO

Yes, it's worth getting the physics right first. And the language, including distinguishing between mass, weight and the relevant moment for rotation. Then it's possible to be sure that everyone is talking about the same things.

The size of effect may not be particularly important in particular settings. And if it isn't the physics will explain why.

Jonathan

PS: I also suspect that there are some pre-Newtonian concepts of momentum lurking in the undergrowth.

[531colin]

It’s also important to hold on to some idea of the magnitude of the effect of extra weight at the rim.
An extra half kilo at the rim of both of your wheels might make 1% difference but only when accelerating; at least that’s what we said on the previous page.
…accelerating bike and rider, not just spinning the wheels in air.

[roubaixtuesday]

It’s also important to hold on to some idea of the magnitude of the effect of extra weight at the rim.
An extra half kilo at the rim of both of your wheels might make 1% difference but only when accelerating; at least that’s what we said on the previous page.
…accelerating bike and rider, not just spinning the wheels in air.

Absolutely, and the physics helps this; rather than a vague "probably insignificant" or somesuch we can quantify it as you just have.

A kg extra probably does make a difference to "feel" of a lightweight bike, though of course such a bike will almost certainly already have lightweight rims and tyres. If you have such a bike and are considering eg carbon saddle and pedals, or even lighter rims and tyres, it helps understand where to get best bang for buck.

It probably would make a significant difference in a track sprint.

But for touring, where IMO hills when laden are the hard part, it makes no more difference at all compared to weight on the frame.

[pwa]

It’s also important to hold on to some idea of the magnitude of the effect of extra weight at the rim.
An extra half kilo at the rim of both of your wheels might make 1% difference but only when accelerating; at least that’s what we said on the previous page.
…accelerating bike and rider, not just spinning the wheels in air.

Absolutely, and the physics helps this; rather than a vague "probably insignificant" or somesuch we can quantify it as you just have.

A kg extra probably does make a difference to "feel" of a lightweight bike, though of course such a bike will almost certainly already have lightweight rims and tyres. If you have such a bike and are considering eg carbon saddle and pedals, or even lighter rims and tyres, it helps understand where to get best bang for buck.

It probably would make a significant difference in a track sprint.

But for touring, where IMO hills when laden are the hard part, it makes no more difference at all compared to weight on the frame.

How many of us have a bike reserved for loaded touring and nothing else? I have a proper "tourer", designed for that purpose, but most of its miles have been lightly laden recreational miles, for which it is also perfectly suited. I knew that was how I was going to use that bike before I put it together. Mostly day rides, but with the capacity for four pannier touring once in a while. So for me, and I suspect for most purchasers of a "tourer", how the bike rides with minimal baggage is just as important as how it behaves with four panniers. Possibly more important. For that reason I avoid riding an unnecessarily heavy lump. It just wouldn't be fun.

[Mtb tourer]

Most people buy a tourer for going from A to B to C etc. not day runs.
Why buy a full on tourer if it's not used for the job its been designed for?
For us a touring bike with no luggage just does not feel right.
Touring wheels have a hard life, I prefer something that's capable of taking knocks. Lightweight is way down the list of what's needed.

[pwa]

Most people buy a tourer for going from A to B to C etc. not day runs.
Why buy a full on tourer if it's not used for the job its been designed for?
For us a touring bike with no luggage just does not feel right.

A tourer, put together with lightish components, actually ticks several boxes. I commuted on tourers for 17 years. I have toured on them, with two or four panniers. And I do multi-surface day rides on my current version, using it a bit like a gravel bike. I took one on a tour of Provence, then on a day off touring took the front rack and mudguards off and went up Mont Ventoux, for which the wide gear range was perfect. Unlike most gravel bikes my current tourer will, if I choose, take four panniers and a bit more without faffing about strapping stuff to the top tube. I think it makes a really multi-purpose bike rather than a niche machine good for one thing only. If you can only have one bike, a tourer is a strong contender.

I agree with you that wheels, first and foremost, have to be strong enough for the job. My own are 36 spoke with middleweight rims and tyres voluminous enough to prevent the rims getting a dent. But I don't go for the strongest, heaviest rims because I just haven't found that I need them. It is a case of finding that happy medium that does the job without unnecessary weight.

[roubaixtuesday]

It’s also important to hold on to some idea of the magnitude of the effect of extra weight at the rim.
An extra half kilo at the rim of both of your wheels might make 1% difference but only when accelerating; at least that’s what we said on the previous page.
…accelerating bike and rider, not just spinning the wheels in air.

Absolutely, and the physics helps this; rather than a vague "probably insignificant" or somesuch we can quantify it as you just have.

A kg extra probably does make a difference to "feel" of a lightweight bike, though of course such a bike will almost certainly already have lightweight rims and tyres. If you have such a bike and are considering eg carbon saddle and pedals, or even lighter rims and tyres, it helps understand where to get best bang for buck.

It probably would make a significant difference in a track sprint.

But for touring, where IMO hills when laden are the hard part, it makes no more difference at all compared to weight on the frame.

How many of us have a bike reserved for loaded touring and nothing else? I have a proper "tourer", designed for that purpose, but most of its miles have been lightly laden recreational miles, for which it is also perfectly suited. I knew that was how I was going to use that bike before I put it together. Mostly day rides, but with the capacity for four pannier touring once in a while. So for me, and I suspect for most purchasers of a "tourer", how the bike rides with minimal baggage is just as important as how it behaves with four panniers. Possibly more important. For that reason I avoid riding an unnecessarily heavy lump. It just wouldn't be fun.

I definitely agree re handling without luggage being important.

I have a nice light "Sunday best" bike which isn't capable of taking racks or guards, and on which I'd regard light, relatively flimsy rims and tyres as worthwhile.

I've also a commuter/ light tourer where I have relatively heavy, puncture resistant tyres.

Both are, though, I think, at 25 and 28mm considerably lighter than the tyres many seem to favour for touring, 40mm plus.

[pwa]

I think it is also worth saying that the wheels that are adequately robust for me, on a tour, would be overbuilt and unnecessarily heavy for my wife, who is much lighter than me. She rides on 32 spokes without breakages, whereas I'd be wondering if 32 is enough for my weight. I use 36 instead. User weight is a big consideration.

[Mtb tourer]

I think that touring wheels cover everything from credit card, to the back of beyond loaded up.
Some of us are smooth roads and other prefer a mix of every surface. We will never agree on what's correct

[pwa]

I think that touring wheels cover everything from credit card, to the back of beyond loaded up.
Some of us are smooth roads and other prefer a mix of every surface. We will never agree on what's correct

It's always a compromise anyway. We want reliability, but we don't want more weight than is necessary to get that. My own goal in speccing a wheelset for a tourer is to have wheels that will be reliable beneath my body mass on anything up to slightly bumpy tracks, with a bit of care. And more or less bombproof on roads. I'm fairly conservative in that, but shy away from having very heavy rims that I just don't need. I haven't ever had a damaged touring rim, and the last spoke I broke was around 1994, in Umbria. I'm a big heavy lump, myself, so why light riders get very heavy duty wheels is a mystery to me.

[rareposter]

FWIW, I think 36H wheels are a hangover from the days when rims were all 17mm wide, rim braked, shallow section and the extra spokes were the only way to improve strength.

I've done events in Belgium across the Flanders cobbles on my road bike with 24h carbon rims (averaging 40kph) with no issues at all, my current MTB has 28h alloy rims and it sees impacts and speeds way in excess of what an average tourer would get. OK, the tyres are considerably larger too but wheels now - with disc brakes, thru axles, triangular cross sections etc - are way stronger and more durable than any of the old narrow rim stuff of yesteryear in spite of the oft-mentioned (and IMO wildly overhyped) concerns about dishing.