Jan Janssen Sonic (2026)
Good to know: Configurable build
Configurable build (at least partly: the cockpit or bar width, for example). The stock build below is only one of the options.
Geometry ?
Jan Janssen Sonic 2026 geometry in sizes S–XL: stack 548–596 mm, reach 377–391 mm, head angle 72–73°.
| S | M | L | XL | |
|---|---|---|---|---|
| Stack | 548 mm | 555 mm | 577 mm | 596 mm |
| Reach | 377 mm | 381 mm | 387 mm | 391 mm |
| Head angle | 72° | 73° | 73° | 73° |
| Seat angle | 73.7° | 73.7° | 73.7° | 73.5° |
| Seat tube (c-t) | 490 mm | 506 mm | 540 mm | 570 mm |
| Head tube | 142 mm | 155 mm | 179 mm | 190 mm |
| Wheelbase | 977 mm | 980 mm | 983 mm | 992 mm |
Source: janjanssen.nl, checked 13 Nov 2026 · bar position: worked out from published data
Stock build
I don’t have the build for each size yet.
Frames with similar geometry
Stack and reach within 12 mm of size S (stack 548 / reach 377 mm).
Stack and reach within 12 mm of size M (stack 555 / reach 381 mm).
Stack and reach within 12 mm of size L (stack 577 / reach 387 mm).
Stack and reach within 12 mm of size XL (stack 596 / reach 391 mm).
Spotted a mistake or a missing build? Let me know.
Are you the manufacturer, or do you sell this bike? I’m missing 6 values for this model’s stem and bars. Add them