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Why haven't small wheels caught on?

by Canyon48
Thu, Feb 08, 2018 12:12
39

I've noticed something about most cyclists since I've been cycle commuting across Bristol.

Most cyclists aren't dedicated road cyclists, in fact, they are just trying to get from place to place. I've noticed a surprising amount of people driving to the outskirts of the city before cycling the remaining distance to the centre. I've also noticed a lot of people riding dutch style step through bikes.

I can't work out why small wheels haven't caught on. They are far less cumbersome than 700c, so much easier to put in your car. They are much easier to store (in an office, at home or at cycle racks). Obviously, I've seen a few Bromptons around, but they retail at around £1000 and weigh a silly amount due to the folding.

The only disadvantage I can see is they don't give such a comfortable ride, which could be very easily solved by rubber dampers.

Moulton came up with this design in the 60's, I'm struggling to work out why it hasn't caught on for city commuter cyclists (which make up a surprisingly large portion of cyclists).

I'd certainly find a small wheel bike much easier for when I drive halfway and cycle half way on my commute...

If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.

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39 comments

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kil0ran | 6 years ago
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I regularly ride my partner's eBike (folder, 20" wheels) and I find it utterly terrifying but that's mainly due to my ham-fisted handling skills. Steering damper would help I guess - until you ride a smaller wheeled bike you have no idea how much wrestling a 700c wheel needs.

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hawkinspeter | 6 years ago
2 likes

I suspect it's just to do with the quality of most roads - larger wheels can easily roll over bumps/dips that cause a significant 'bump' on smaller wheels.

I'm not convinced that rubber dampers are an effective solution as they're relatively heavy for a small amount of travel. That's why most suspension forks don't just use a rubber damper. What might work is to keep a small wheel size, but have a much bigger tyre on them. That would also increase weight, but would provide much better cushioning.

Also, I suspect that small wheels are relatively heavy compared with larger wheels as some features can't just be shrunk without compromising strength (e.g. the hub). There's also the economy of scale that makes 700c wheels cheap to produce.

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iandusud | 6 years ago
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I have a Moulton Jubilee amongst my collection of bikes and it is a delight to ride. As a touring bike it is fantastic, it is relatively heavy compared to a stripped down CF road bike but weight isn't everything and the weight is comprable with a touring bike. The small wheels accelerate well and are indestructable. The comfort in unsurpassed and load carrying with the rear rack is fantastic and very stable. I've descended mountains in France fully loaded with camping gear at over 50mph and the bike was as steady as a rock - I couldn't have done that on my previous touring bike with 700c wheels. Also the small wheels with mudguards which wrap well around them makes it a very good bike for wet weather as there is next to no raod spray. It is my bike of choice to jump on for everyday journeys. My weekend warior riding with the club is a stripped down road bike. 

As ever trends in bikes, like cars and motorbikes, are heavily influenced by what goes on in the workd of racing and the UCI put a ban on small wheels on bikes back in the 60s (limiting wheel size to 24" iirc) when Moultons were racing because they had an unfair advantage over traditional designs - how's that for progress. 

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Boatsie | 6 years ago
1 like

Anyone remember the old gyro demonstration? If you hold each axle side with each hand and spin the wheel away from you then by pushing on the left side of the axle, the wheel will tilt left rather than turn right.
Yes, at slow speeds we can turn the handle bars yet at higher speeds, by pushing on the handle bars, rather than the handle bars turning, the bike will lean into the corner.
A larger diameter experiences a larger gyro effect and that to me is a lot safer at higher speeds.
A 20 inch rim is more likely to survive trail punishment, jumps, etc and a 20 inch rim is easier to transport but a 28 inch rim will be a lot kinder at higher speeds associated with road bicycles. MTbs being smack bang in the middle.
With regards to road cycling; smooth through to not so nice yet jumpless roads, 700c seems perfect especially with our tyre advancement and some wider low resistance tyres/frame combinations offering comfort on our fun roads.
Basically... Bigger diameters need less grip than smaller diameters while traveling at speed when cornering is required.

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Canyon48 replied to Boatsie | 6 years ago
1 like

Boatsie wrote:

Anyone remember the old gyro demonstration? If you hold each axle side with each hand and spin the wheel away from you then by pushing on the left side of the axle, the wheel will tilt left rather than turn right. Yes, at slow speeds we can turn the handle bars yet at higher speeds, by pushing on the handle bars, rather than the handle bars turning, the bike will lean into the corner. A larger diameter experiences a larger gyro effect and that to me is a lot safer at higher speeds. A 20 inch rim is more likely to survive trail punishment, jumps, etc and a 20 inch rim is easier to transport but a 28 inch rim will be a lot kinder at higher speeds associated with road bicycles. MTbs being smack bang in the middle. With regards to road cycling; smooth through to not so nice yet jumpless roads, 700c seems perfect especially with our tyre advancement and some wider low resistance tyres/frame combinations offering comfort on our fun roads. Basically... Bigger diameters need less grip than smaller diameters while traveling at speed when cornering is required.

Gyro forces are insignificant in bike handling http://www2.eng.cam.ac.uk/~hemh1/gyrobike.htm

I'm confused why you believe bigger wheels need less grip? Wheel diameter has nothing to do with cornering forces.

So far, the CFD I've done is concurrent with the prevailing opinion that smaller wheels are more aerodynamic anyway. Not only that, smaller wheels give more responsive bike handling.

It seems to me that we are only using 700c because it was the most common size derived from an archaic French system of wheel measurement.

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Boatsie replied to Canyon48 | 6 years ago
1 like
wellsprop wrote:

Boatsie wrote:

Anyone remember the old gyro demonstration? If you hold each axle side with each hand and spin the wheel away from you then by pushing on the left side of the axle, the wheel will tilt left rather than turn right. Yes, at slow speeds we can turn the handle bars yet at higher speeds, by pushing on the handle bars, rather than the handle bars turning, the bike will lean into the corner. A larger diameter experiences a larger gyro effect and that to me is a lot safer at higher speeds. A 20 inch rim is more likely to survive trail punishment, jumps, etc and a 20 inch rim is easier to transport but a 28 inch rim will be a lot kinder at higher speeds associated with road bicycles. MTbs being smack bang in the middle. With regards to road cycling; smooth through to not so nice yet jumpless roads, 700c seems perfect especially with our tyre advancement and some wider low resistance tyres/frame combinations offering comfort on our fun roads. Basically... Bigger diameters need less grip than smaller diameters while traveling at speed when cornering is required.

Gyro forces are insignificant in bike handling http://www2.eng.cam.ac.uk/~hemh1/gyrobike.htm

I'm confused why you believe bigger wheels need less grip? Wheel diameter has nothing to do with cornering forces.

So far, the CFD I've done is concurrent with the prevailing opinion that smaller wheels are more aerodynamic anyway. Not only that, smaller wheels give more responsive bike handling.

It seems to me that we are only using 700c because it was the most common size derived from an archaic French system of wheel measurement.

Different view and possibly a better writer than I. Understanding gyro forces significantly improves cornering and bigger diameter wheels improve such.
Corning is handling, hence whom am I to know whether a Baker is teaching an art class?

How'd aero get recognised? Is it because their closer to ground? The wall behind them doesn't count aye; just a wheel aye.

Less grip, corner at speed, bigger diameter wheel. If too big like pointed out, wind resistance. I like 700c, still way smaller than my wall.
Basic principles, physics.

It is a known force. It might not be named 'gyro' and if such the case I wronged you there.
I ain't pedantic, it is basic physics principles although with support towards smaller wheels one may argue that at the same speeds the wheel speed is greater hence more gyro or whatever the name of that force will translate into movement.
Bigger wheels roll over potholes. Lol.
Thanks with the information that 700c came from the French engineers.
They often intelligent. English used to stick two fingers up with that jester originating from the English /French war as it was more effective to chop two fingers off an English archer than it was to terminate him. The qualified archers would stick 2 fingers up at the French to let them know that they are still qualified archers.
I like 700c wheels, my roads are basically flat/smooth.

Imagine a very smooth road and a road bike using a grass hill skateboard wheel on the front end. Yes, an aerofoil would be easier to manufacture enabling the pushed wind to displace into a slipstream yet the grip required when cornering would be enormous.
I didn't read the entire article, I remember reading something to do with initial steering which too me is important at higher speeds.
My mate commuted 2*30km daily on 20 inch rims. They suit some. Momentum of the wheels tangent using 700c suits most road riders. Besides all that, I haven't neither a wheel or tyre factory and same as you with we use what we get.
Less grip.. I haven't the expertise to explain angular momentum.

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Canyon48 replied to Boatsie | 6 years ago
2 likes

Boatsie wrote:
wellsprop wrote:

Boatsie wrote:

Anyone remember the old gyro demonstration? If you hold each axle side with each hand and spin the wheel away from you then by pushing on the left side of the axle, the wheel will tilt left rather than turn right. Yes, at slow speeds we can turn the handle bars yet at higher speeds, by pushing on the handle bars, rather than the handle bars turning, the bike will lean into the corner. A larger diameter experiences a larger gyro effect and that to me is a lot safer at higher speeds. A 20 inch rim is more likely to survive trail punishment, jumps, etc and a 20 inch rim is easier to transport but a 28 inch rim will be a lot kinder at higher speeds associated with road bicycles. MTbs being smack bang in the middle. With regards to road cycling; smooth through to not so nice yet jumpless roads, 700c seems perfect especially with our tyre advancement and some wider low resistance tyres/frame combinations offering comfort on our fun roads. Basically... Bigger diameters need less grip than smaller diameters while traveling at speed when cornering is required.

Gyro forces are insignificant in bike handling http://www2.eng.cam.ac.uk/~hemh1/gyrobike.htm

I'm confused why you believe bigger wheels need less grip? Wheel diameter has nothing to do with cornering forces.

So far, the CFD I've done is concurrent with the prevailing opinion that smaller wheels are more aerodynamic anyway. Not only that, smaller wheels give more responsive bike handling.

It seems to me that we are only using 700c because it was the most common size derived from an archaic French system of wheel measurement.

Different view and possibly a better writer than I. Understanding gyro forces significantly improves cornering and bigger diameter wheels improve such. Corning is handling, hence whom am I to know whether a Baker is teaching an art class? How'd aero get recognised? Is it because their closer to ground? The wall behind them doesn't count aye; just a wheel aye. Less grip, corner at speed, bigger diameter wheel. If too big like pointed out, wind resistance. I like 700c, still way smaller than my wall. Basic principles, physics. It is a known force. It might not be named 'gyro' and if such the case I wronged you there. I ain't pedantic, it is basic physics principles although with support towards smaller wheels one may argue that at the same speeds the wheel speed is greater hence more gyro or whatever the name of that force will translate into movement. Bigger wheels roll over potholes. Lol. Thanks with the information that 700c came from the French engineers. They often intelligent. English used to stick two fingers up with that jester originating from the English /French war as it was more effective to chop two fingers off an English archer than it was to terminate him. The qualified archers would stick 2 fingers up at the French to let them know that they are still qualified archers. I like 700c wheels, my roads are basically flat/smooth. Imagine a very smooth road and a road bike using a grass hill skateboard wheel on the front end. Yes, an aerofoil would be easier to manufacture enabling the pushed wind to displace into a slipstream yet the grip required when cornering would be enormous. I didn't read the entire article, I remember reading something to do with initial steering which too me is important at higher speeds. My mate commuted 2*30km daily on 20 inch rims. They suit some. Momentum of the wheels tangent using 700c suits most road riders. Besides all that, I haven't neither a wheel or tyre factory and same as you with we use what we get. Less grip.. I haven't the expertise to explain angular momentum.

I'm not quite sure that I follow, to be honest.

Avatar
John Smith | 6 years ago
2 likes

Because most people go in to a shop (generally Halfords) and pick the first bike they like the look of that they can afford. They don’t think about wheel sizes and the like. For manufacturers, where cost is the major factor for the majority of cycle commuters, one wheel size makes it much cheaper, especially where is is the standard wheel size for most bikes. 

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Canyon48 | 6 years ago
0 likes

https://forum.cyclinguk.org/viewtopic.php?t=18319

I think I just found the answer.

Seems a combination of build quality of some small wheeled bikes and the poor performance on bad roads mean small wheeled bikes fell out of favour.

Interestingly, small wheel bikes are in fact very popular in Japan, perhaps not a surprise due to the lack of space!

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