JAVA CL Carbon 20inch 451 18 Speed Disc Mini Velo Bike

The Java CL Carbon 20 inch 451 is a small-wheel bike (mini velo) with an internally routed carbon aero frame, a carbon aero fork, Shimano Sora front and rear derailleurs for 18 speeds, Shimano MT-200 hydraulic disc brakes and 451 wheels. It pairs 20-inch wheels with a carbon frame and double-chainring gearing, for riders who mostly ride in town and on cycle tracks and like the look of a mini velo.

Key Facts

• Category: 20-inch (ETRTO 451) carbon mini velo, flat bar, 2 x 9 for 18 speeds, hydraulic disc brakes
• Brand: Java (Shenzhen ChuangXinWei Bicycle Co., mainland China)
• Standout feature: internally routed carbon aero frame with a carbon aero fork
• Key numbers: Shimano Sora FD-R3000 front and RD-R3000 rear derailleurs; Shimano SL-M2010 Rapidfire shifters; DECAF 34/50T 170 mm hollow crankset; 12–28T cassette; Shimano MT-200 hydraulic discs; CST 20 x 1-1/8 (451) tyres
• Best for: riders about 150–180 cm tall who mostly ride in town and on cycle tracks and want a carbon mini velo; if you need to fold the bike, choose a folding bike instead

The Problem It Solves

If you want a small-wheel bike without compromising on frame or gearing, the Java CL is one option: a carbon aero frame with internal routing for a clean look; Shimano Sora front and rear derailleurs with a 34/50T double for 18 speeds, giving suitable gears for the flat and for hills; and Shimano MT-200 hydraulic disc brakes. Its 451 wheels are slightly larger than standard 20-inch 406 wheels, and Jollymap's review notes that 451 rolls better and reaches higher top speeds.

Who It Suits

• Good fit: riders about 150–180 cm tall who like a flat-bar position; anyone riding mostly in town or on cycle tracks who wants a carbon frame; fans of the mini velo look.
• Maybe not: the CL is a mini velo, not a folding bike. If you need to fold it for storage or public transport, consider the 451-wheel JAVA Fit 20inch 451 18 Speed Disc Folding Bike or Java NEO Carbon 20 inch 451 105 Di2 Folding Road Bike. For drop bars and more gears, there is also the JAVA CL Carbon 20inch 451 22 Speed Disc Drop Bar Mini Velo Bike.

Key Features

Carbon aero frame with internal routing

The frame is a carbon aero design with internal routing for a clean look; the fork is a carbon aero fork too, and the seatpost is a flat aluminium aero post with a laser-engraved finish.

Shimano Sora 2 x 9 for 18 speeds

A Shimano Sora FD-R3000 front derailleur and RD-R3000 rear derailleur work with Shimano SL-M2010 Rapidfire flat-bar shifters, a DECAF 34/50T 170 mm hollow crankset and a 12–28T cassette. Use the 34T ring for climbs and the 50T ring for cruising on the flat.

Shimano MT-200 hydraulic disc brakes

Braking is by Shimano MT-200 hydraulic discs. Jollymap's review notes that hydraulic discs feel lighter and more linear than traditional cable-actuated discs or V-brakes, giving strong braking with a light pull of the lever.

451 wheels

DECA aluminium rims run on aluminium bearing hubs with CST 20 x 1-1/8 (451) tyres. Both 451 and 406 are called 20-inch, but 451 is slightly larger, and the tyres are not interchangeable.

Java 451-Wheel Models Compared

The table compares three Java bikes on 451 wheels:

Comparison sources: each model's Jollymap product page and Jollymap review articles. "—" means no reliable figure is available.

Jollymap Recommends

The Java CL comes in one size, and Jollymap's spec sheet lists a suitable rider height of 150–180 cm. If you are near either end of that range, or unsure whether the riding position suits you, chat with us or message our Jollymap Facebook page before ordering, with your height and inseam. When you buy replacement tyres, remember to choose 451 size (stock is 20 x 1-1/8).

Specifications

Brand	Java
Colours	Black Grey, Black Red
Frame	Carbon aero frame, internal routing
Fork	Carbon aero fork
Seatpost	Flat aluminium seatpost, laser engraved
Shifters	SHIMANO SL-M2010 Rapidfire
Front derailleur	SHIMANO SORA FD-R3000
Rear derailleur	SHIMANO SORA RD-R3000
Cassette	CS-R5009 12-28T
Crankset	DECAF 34/50T x 170L hollow crankset
Brakes	SHIMANO MT-200 hydraulic disc
Rims	DECA aluminium
Hubs	Aluminium bearing hubs
Tyres	CST 20" x 1-1/8 (451)
Rider height	150–180 cm

Specification source: Jollymap product data, matching the 2020 Java CL Carbon 18-speed flat-bar 451 specification published by a Hong Kong bike shop (Java's official website no longer lists this model).

*Components and parts may vary between production batches. Enquiries are welcome.

FAQ

Is the Java CL a folding bike?

No. The Java CL is a 20-inch 451 mini velo, listed in our shop as an urban bike. If you need a bike that folds, consider the JAVA Fit 20inch 451 18 Speed Disc Folding Bike, which uses the same 451 wheel size.

Is there a drop-bar Java CL?

Yes. Our shop also lists the JAVA CL Carbon 20inch 451 22 Speed Disc Drop Bar Mini Velo Bike, a drop-bar 22-speed version; this page is the flat-bar 18-speed version.

What tyres does the Java CL use? Can I fit ordinary 20-inch tyres?

It comes with CST 20 x 1-1/8 (451) tyres. Many 20-inch folding bikes use 406 size, which is not interchangeable with 451, so buy 451 tyres when replacing them.

How many frame sizes does the Java CL come in, and what height does it suit?

One size, and Jollymap's spec sheet lists a suitable rider height of 150–180 cm. If you are near either end of the range, contact us before ordering.

Are the Java CL's brakes safe?

Yes. The Java CL uses Shimano MT-200 hydraulic disc brakes. Jollymap's review notes that hydraulic discs feel lighter and more linear than traditional cable-actuated discs or V-brakes, giving strong braking with a light pull of the lever, which adds a margin of safety on Hong Kong's long descents and in sudden traffic situations.

What is the difference between 451 and 406 wheels?

451 is slightly larger in diameter than 406. Both are called 20-inch, and Jollymap's review notes that 451 rolls better and reaches higher top speeds, but the tyres are not interchangeable.

How does the Java CL differ from the Java Fit?

Mainly in frame and purpose. The Java CL is a carbon aero mini velo with Shimano Sora shifting and MT-200 hydraulic discs; the Java Fit is an aluminium folding bike with DECAF shifting and C STAR disc brakes, weighing about 10.5 kg. Both use 451 wheels and 2 x 9 for 18 speeds.

Where can I buy the Java CL in Hong Kong?

It is available from the Jollymap online shop and store. To check colours or specification, chat with us or message our Jollymap Facebook page before ordering.

Specifications and components follow the manufacturer's latest release and may change without notice. If in doubt, please contact us to confirm before ordering.

Last updated: October 2026