Mason ISO2 2025
Archive model 2025. Probably no longer sold new. I only have the frame geometry, not the build.
I’m buying or selling this bike ↓
Geometry ?
Mason ISO2 geometry for model year 2025. Model years are approximate: manufacturers rarely say exactly when the geometry changed.
| Size | 42cm | 46cm | 50cm | 54cm | 58cm |
|---|---|---|---|---|---|
| Stack | 606 | 614.4 | 623.8 | 633.1 | 654.5 |
| Reach | 366.6 | 375.7 | 379.4 | 384 | 397.4 |
| Head angle | 69° | 69° | 69° | 69° | 70° |
| Head tube | 100 | 110 | 120 | 130 | 150 |
| Seat angle | 74° | 74° | 74° | 74° | 74° |
| Top tube (effective) | 542.7 | 554.1 | 560.5 | 567.6 | 587 |
| Seat tube (c-t) | 420 | 460 | 500 | 540 | 580 |
| Chainstay | 445 | 445 | 445 | 445 | 445 |
| Wheelbase | 1062.1 | 1075 | 1082.3 | 1090.2 | 1101.3 |
| BB drop | 76 | 75 | 75 | 75 | 73 |
Geometry source: bikepacking.com (magazine test, not the manufacturer)
Same geometry as Mason ISO 2 (2026).
Bike from a listing
Buying this bike second-hand? Enter the size, stem and spacers actually on the bike to see whether it fits you.
Selling it? Fill in the details and paste the link into your listing. Buyers will see where the bars end up, based on what you enter.
How do I measure it?
Cover + spacers: measure from the top of the head tube to the underside of the stem. That’s the headset cover plus any spacers. Length and angle are usually printed on the stem (−6° is typical, with the stem pointing down). Bar reach is on the bar manufacturer’s website. If you can’t find it, leave it at 75 mm. Spacers above the stem show how much higher the stem could still go. Leave that blank and I’ll assume it can’t go any higher.
Is it an integrated cockpit, a one-piece bar and stem? Then the stem may not be swappable. Check with the seller.
Do you ride it? Enter it as your position.