The joys of 20” / small wheel bikes

[NickJP]

Last year I purchased a Stijn Peg Road from the designer (a Belgian who lives in Taiwan and works in the bike industry there). It came with 451 wheels, but the largest 451 tyre size that would fit under the fork crown was about 33mm, which I felt was too narrow to give adequate insulation from the rather bumpy roads we have around here. As it uses disc brakes, I built some 406 wheels, which not only means a greater selection of available tyres, but I was able to fit 1.75" (47mm) BMX racing slicks, which gives a considerably nicer ride over indifferent road surfaces.

Here's the bike in its original incarnation with 451 wheels.

And I bought a second one for my wife that I setup with flat bars.

[tatanab]

Early 70s Dawes Kingpin folder. Paid £30 for it about 10 years ago. Larger rear sprocket to lower the gearing (now 65" top gear), uprated braking. Then, last year I built new wheels in 451 so that I could fit aluminium rims to improve the braking (excuse really because I just wanted to tinker) consigning the old steel 500A wheels (in the picture) to the back of the shed. Only used around town, and even then very seldom.

Early 80s Ken Rogers unisex utility trike. Bought about 12 years ago in a hell of a state. Replaced all parts with aluminium and put into club rider's trim versus granny to the shops. It is actually a bit lighter than the Kingpin and rides very well. Again, done to satisfy an urge to tinker and very seldom used. Used an A head adaptor, a long one, to clear the slots in the fork column to avoid breakages mentioned elsewhere in this thread. Forks are Raleigh 20, so Raleigh threaded. I replaced the headset with a 1" threadless, just keeping the two threaded nuts at the top. I have a very stout carrier for the rear which can take an enormous folding wire basket, the combination weighs almost as much as the trike itself I reckon.

[rjb]

Toe clips and straps. A good idea for a shopper. I've got some 1/2 clips on one of mine.

[Carlton green]

Toe clips and straps. A good idea for a shopper. I've got some 1/2 clips on one of mine.

Probably a case of whatever works for: the individual concerned, their style of riding, and their intended routes. Both my three speed bikes are purely utility (rather than sports) bikes and I use plain flat pedals on them - they might not be the best ‘answer’ but they suit me. In the distant past I’ve used half clips on other bikes and found them a plus for more serious riding, a useful halfway option, but full clips and loose straps were even better for longer on road journeys with infrequent need to stop for hazards and road junctions.

Half clips, an example: https://www.zefal.com/en/toe-clips-and- ... ps-45.html

[pjclinch]

IIRC Russ did LeJog on a small wheel bike, a customised one but still small wheel

This isn't particularly remarkable as if the wheel size is properly considered in the overall design there's nothing particularly limiting about smaller wheels on the road.
When Alex Moulton released his first bikes he had John Woodburn attempt (and succeed in breaking) the Cardiff to London record, effectively a 160 mile TT, to show that small wheels were not a problem with performance. Moulton AMs have been used in the Race Across America, again not something for an intrinsically limited bike.

and he used small wheelers as that was what he could get into his flat (which had limited access and storage).

One particular point, from Russ’s comments, comes to mind and that is the effect of wheelbase. Small wheelers often have a short wheel base but when that’s increased then so does ride quality. My own Raleigh Compact has short chainstays which put the (necessarily sprung) saddle nearly over the rear axle, full length chain stays would help make for a comfier ride.

Maybe, but they would also make it less compact, so that limited access and storage thing mentioned above... In other words, whether that's a Bug or a Feature is part of the overall design goal. Longer wheelbase would also make the handling less responsive (or, seen from another perspective, less "twitchy").
You choose, you lose...

Pete.

[rjb]

Not disimilar to my sporty Kingpin with 451 wheels.

Kinpin

[drossall]

This is fun.

[hamster]

We may care to recall that there's at least one study out there that identifies the best size of wheel for competition use - and that it's about 20". Not that we all compete, of course, but it's interesting to know. (Having read it, years ago, I failed to book-mark it)
We also recall, wryly, that around the time smaller wheeled cycles emerged and enjoyed success in competition, the uci, bowing to pressure from sundry industry heavyweights, banned the use of wheels under a certain size, citing the fact, interestingly, that as far as they could see, their use gave the employing team & individuals an unfair advantage!

Much of the advantage was aerodynamic, not from the wheels themselves, but that the following riders' bodies could be closer behind, giving an overall better aero shape for the bunch. This was the same idea on the track in the 1984 LA Olympics with small front wheels. Laughably this was then adopted on individual TT bikes as a fashion. Right idea, wrong application!

[drossall]

There's a video of Moultons in a team TT on the track.

[Slowroad]

My vintage (1999) Brompton on our recent tour in the West Midlands. For various reasons it is becoming my bke of choice for touring

[james-o]

Can anyone point me towards any good reading on small wheel bikes - the technical points eg aerodynamics, handling / cornering of a smaller wheel etc?

Much of this will be covered by general bike tech where the maths adjusts for smaller wheels. I've a reasonable understanding of what's going on there, I have a good grasp of bike geometry and handling, but certainly not at the Vittore Cossalter level. Just interested in any studies or articles that might add to my understanding of the experience of riding a Bike Friday currently (it's a brilliant ride that is outperforming any expecations I had).

[cyclist]

I used 20" BMX which I used for short commutes it was a plush ride due to the tyre width, but it was tiring in longer distances.

I cycled many miles on a 20" folding bike for a hybrid commute. It was nimble, manoeuvrable, a bit on the twitchy side, but it was stable and easy to mount and dismount. It was my my go to bike for short and hybrid commutes.

I changed the chainring to get a bigger one, but still it was generally a tad slower than my other commuter bike and a lot slower than my road bike.

I would still consider getting one but it's not at the top of my list.

[rjb]

check out Hadlands blog for bedtime reading.
https://hadland.wordpress.com/category/small-wheelers/

[colin54]

I watched this short film (17min) today- about a daughter and her 87 year old dad revisiting places in Herefordshire, where the family had visited years before. They were both on Brompton's (his hired).
They used buses to avoid the worst of the busy A roads.
They visited some lovely Norman/ Knights Templar churches along the way.
What a nice thing to be able to do and record.
https://www.youtube.com/watch?v=h-_Dsq03XP0

[Boyonabike]

I once had a Brompton on loan through work which I hated riding as it felt so unsteady and I couldn't carry much. But I could take it on the train in the rush hour and even on the tram so it had its uses.

Recently I picked up an Ecosmo 20 inch wheel folder off Amazon. The quality control left a little to be desired (frame locking nuts too loose and tyres that looked like they were made of cling film) but at around £270 and 9kg I couldn't complain. Seems to be the same aluminium frame as commonly used in other branded bikes at far higher prices. A bit of tightening up of loose nuts, a new pair of Marathon tyres (which practically doubled the weight of the bike) and it's actually not all that bad at all for rides of a few miles. Even has a useable pannier rack. Plus it fits in the boot of the car. Amazing how much better a couple of inches feels to ride, and for a fraction of the cost of the Brompton.