Specialized P.1 geometryMTB · 2026 · 1 size (20")
The Specialized P.1 is a mtb bike available in 1 size (20"). Stack ranges from 429 to 429 mm and reach from 310 to 310 mm. Its position sits between racing and endurance.
What size P.1 do I need?
Enter the stack and reach of a bike that fits you well and we will tell you which size is closest and how to set it up.
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Geometry chart by size
Measurements in mm and degrees, as published by Specialized. The ones that matter most for choosing a size are in bold.
| Size | 20" |
|---|---|
| Stack | 429 |
| Reach | 310 |
| Effective top tube | 449 |
| Head tube length | 90 |
| Head angle | 68.5° |
| Chainstay length | 320 |
| Wheelbase | 840 |
| Front centre | 520 |
| BB drop | 5 |
| BB height | 259 |
| Fork length | 380 |
| Fork offset | 40 |
| Trail | 61 |
| Standover | 561 |
| Seat tube (method not stated) | 265 |
| Seat angle (method not stated) | 72.0° |
Source: Specialized official website · data from 11 Nov 2026. Spot a mistake?
Stack and reach of every size
Higher means a taller front end; further right means a longer reach. The blue dot is your search.
Character of each size
Compared with other mtb bikes. Further right means more of that quality.
Bikes with similar geometry (size 20")
The closest size of other mtb models, by stack and reach.
Frequently asked questions
What are the stack and reach of the P.1 in size 20"?
Stack of 429 mm and reach of 310 mm, with an effective top tube of 449 mm and a head angle of 68.5°.
Is the P.1 a racing or an endurance bike?
In between. In size 20" its stack-to-reach ratio is at percentile 51 of mtb bikes: neither very low nor very tall.