How far is the difference between large and small bike wheels? | Testing 8 different bikes from Dahon K3, Brompton, Birdy to road bikes | There's a surprise at the end!

Last updated: 9 October 2026

Are small-wheeled bikes much slower? In our one-push roll test down the same slope, with the same rider and no pedalling or braking, a 700c road bike, the Vaast R/1, rolled 848 metres (848 m on the end-card, 838 m spoken, 839 m on one stopwatch cell) while the 14-inch Dahon K3 and 16-inch K3 Plus managed about 400 metres, roughly half. But an 18-inch Birdy rolled 545 metres, further than a 27.5-inch mountain bike (440 metres), so wheel size is not the whole story.

This English version summarises the first episode of our Cantonese YouTube series "Doing silly things seriously" (uploaded December 2023), which tested eight bikes from a 14-inch folder to a road bike, plus a Hong Kong share bike as a bonus.

How did we test?

Jason started each bike from the same point halfway down a long slope, gave it one push with his foot, then neither pedalled nor braked until it stopped. A bike computer recorded top speed and distance. The same rider rode every bike, but the road has small rises and dips, each bike's tyres, parts and maintenance differ, and each bike had one run, so treat the figures as a rough guide. Where on-screen cards and Jason's spoken figures differ, we give both: for the K3, he said a top speed of about 22 km/h while the on-screen card says 21 km/h.

How far did each bike roll?

The 700c bikes went furthest (701–848 m); the 14- and 16-inch folders stopped at around 400 m. Weights below were taken on a scale in the video, not official figures.

Two figures need a note. For the Vaast R/1, the end-card says 848 m, Jason said 838 m, and one stopwatch cell shows 839 m; the chart's main bar follows the end-card. For the Dahon K3, Jason's spoken top speed was about 22 km/h and the on-screen card says 21 km/h.

Two patterns stand out. Distance broadly rises with wheel size, from about 400 m for 14 and 16 inches to 480–550 m for 18 and 20 inches and over 700 m for 700c. But the mountain bike, with 27.5-inch wheels and wide knobbly tyres, only reached 440 m. After it slowed, Jason suggested the fatter tyres were creating more friction. The lightest bike, the K3, finished seventh.

Do 14-inch and 16-inch folders differ much?

Hardly. The K3 rolled 400 m (spoken top speed about 22 km/h; the on-screen card says 21 km/h) and the K3 Plus 406 m. Jason's take: the slightly bigger wheel does go a little further, but not by much, and the two bikes may also differ in maintenance. A borrowed 2013 Brompton, also 16-inch but on larger 349 rims, rolled 382 m. It is an old bike, so the result says nothing about current models.

Which bikes went furthest, and why?

The Vaast U/1 flat-bar bike hit the highest speed of the day, 32 km/h, and rolled 701 m . The Vaast R/1 road bike with carbon wheels topped out around 30 km/h but kept rolling furthest of all: 848 m on the end-card, 838 m spoken, 839 m on one stopwatch cell. Jason thought its more aerodynamic frame and lower riding position may have helped. The bonus LocoBike share bike, the heaviest at around 15–16 kg, slowed quickly and stopped at 300 m.

What does this mean when choosing a folding bike?

Jason's summary: the method is not very scientific, but it shows real differences between wheel sizes, and each bike's design and upkeep also matter. Our view: if you mainly ride to the MTR and carry the bike up stairs, a 14- or 16-inch folder is lighter and the gap between them is tiny. For long cycle-track rides, an 18- or 20-inch folder or a big-wheeled bike is easier going.

From the test line-up, Jollymap currently sells the Dahon K3 14-inch (7.9 kg without pedals, per Dahon via our product page), the Dahon K3 Plus 16-inch 2nd gen V2 (9.8 kg), the Birdy Standard 3rd gen (10.9 kg without pedals), the Tern Verge D9 and the Vaast R/1 Force AXS (8.3 kg in size S). We do not sell Brompton bikes. Message us on WhatsApp or call 2342 0780 before you buy.

FAQ

Are small-wheeled bikes much slower?

In our roll test the 14-inch Dahon K3 covered 400 m against 848 m (end-card; 838 m spoken) for the 700c Vaast R/1 road bike, about half, but top speeds were closer (K3: spoken about 22 km/h, on-screen card 21 km/h, against about 30 km/h). When you pedal, tyres, gearing and the rider matter just as much.

Birdy or Brompton: which rolled further?

The 18-inch Birdy Standard 3rd gen rolled 545 m and the 16-inch 2013 Brompton 382 m. The bikes differ in age, wheel size and suspension, and each had one run, so take it as a rough comparison.

Should I choose a 14, 16 or 20-inch folding bike?

In this test 14 and 16 inches rolled about the same, and a 20-inch 451 bike went 484 m. Choose 14 or 16 inches if you carry the bike often; choose 20 inches, such as the Dahon K One double chainring, for longer rides.

Further reading

• Dahon K3 Plus 2nd gen vs Mini 349
• Dahon K3 14-inch vs K3 Plus 16-inch (in Chinese)
• Folding bikes at Jollymap

Update log: 9 October 2026. Rechecked every result against the video (added the Birdy's 545 m, corrected the Brompton's speed and weight), added test conditions, a distance chart and results table, an FAQ and quotes from Jason; removed links to sold-out models, linked the Birdy model actually tested, corrected the Vaast R/1 frame to magnesium alloy, and replaced short links with full URLs.

Sources

• Jollymap shop: Dahon K3 14-inch specifications
• Jollymap shop: Birdy Standard 3rd gen specifications
• Jollymap shop: Vaast R/1 Force AXS specifications

Visit the shop

If you would like to see a bike in person, come to the Jollymap store in Kwun Tong: Room H, 4/F, Hoi Yuen Industrial Building, 47 Hoi Yuen Road. Telephone 2342 0780. Monday to Friday 12:00–20:00; Saturday, Sunday and public holidays 11:00–19:00.

Store address, map and opening hours

Colours and stock change. To check what is available now, message us on WhatsApp or call 2342 0780.