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 ?
Isaac Boson RS 2027 geometry in sizes XXS–XXL: stack 500–612 mm, reach 366–402 mm, head angle 71.5–73°.
| XXS | XS | S | M | L | XL | XXL | |
|---|---|---|---|---|---|---|---|
| Stack | 500 mm | 512 mm | 525 mm | 546 mm | 568 mm | 590 mm | 612 mm |
| Reach | 366 mm | 370 mm | 375 mm | 381 mm | 388 mm | 395 mm | 402 mm |
| Head angle | 71.5° | 72° | 72.5° | 72.7° | 73° | 73° | 73° |
| Seat angle | 75° | 74.5° | 74° | 74° | 73.5° | 73.5° | – |
| Seat tube (c-t) | 415 mm | 435 mm | 465 mm | 490 mm | 520 mm | 550 mm | 580 mm |
| Head tube | 101 mm | 112 mm | 125 mm | 144.4 mm | 167 mm | 190 mm | 212 mm |
| Top tube (effective) | 500 mm | 512 mm | 526 mm | 537.6 mm | 556 mm | 570 mm | 583.3 mm |
| BB drop | 72 mm | 72 mm | 72 mm | 70 mm | 70 mm | 70 mm | 70 mm |
| Chainstay | 410 mm | 410 mm | 410 mm | 410 mm | 410 mm | 410 mm | 410 mm |
| Wheelbase | 966 mm | 970 mm | 977 mm | 979 mm | 990 mm | 1004 mm | 1017.7 mm |
| Standover | 717.3 mm | 736.6 mm | 757.7 mm | 780.9 mm | 808.7 mm | 832.9 mm | 858.7 mm |
| Fork length | 367 mm | 367 mm | 367 mm | 367 mm | 367 mm | 367 mm | 367 mm |
| Fork offset | 50 mm | 50 mm | 50 mm | 44 mm | 44 mm | 44 mm | 44 mm |
| Stock build by size | |||||||
| Cranks | – | 165 mm | 170 mm | 170 mm | 172.5 mm | 172.5 mm | 172.5 mm |
| Stem | – | 80 mm | 90 mm | 90 mm | 100 mm | 100 mm | 110 mm |
| Stem angle | – | −8° | −8° | −8° | −8° | −8° | −8° |
| Bar width | – | 380 mm | 380 mm | 400 mm | 400 mm | 420 mm | 420 mm |
| Seatpost setback | – | 15 mm | – | – | – | – | 15 mm |
Source: isaac-cycle.com, checked 1 Nov 2026 · bar position: worked out from published data
Stock build
Boson RS Shimano 105 Di2 R7150, DT Swiss wheels €3,499
- Groupset
- Shimano 105 Di2 R7150 2×12
- Shifters
- Shimano 105 ST-R7170
- Cranks
- Shimano 105 FC-R7100 50-34
- Stem
- Isaac aluminium stem (80 mm, −8° on XS)
- Handlebar
- Isaac Airflow III aluminium bar 380
- Seatpost
- Isaac carbon
- Saddle
- Surface Powerbox
- List price
- €3,499 (isaac-cycle.com, 1 Nov 2026)
Source: isaac-cycle.com, checked 1 Nov 2026
Frames with similar geometry
Stack and reach within 12 mm of size XXS (stack 500 / reach 366 mm).
Stack and reach within 12 mm of size XS (stack 512 / reach 370 mm).
Stack and reach within 12 mm of size S (stack 525 / reach 375 mm).
Stack and reach within 12 mm of size M (stack 546 / reach 381 mm).
Stack and reach within 12 mm of size L (stack 568 / reach 388 mm).
Stack and reach within 12 mm of size XL (stack 590 / reach 395 mm).
Stack and reach within 12 mm of size XXL (stack 612 / reach 402 mm).
Spotted a mistake or a missing build? Let me know.
Are you the manufacturer, or do you sell this bike? I’m missing 3 values for this model’s stem and bars. Add them