Proton FW
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I am Isaac Proton Flyweight, the top model of Isaac’s high-end bicycles. My specialty is doing the impossible. My ultralight design allows professionals to rely on me for ultimate performance. Together, we push the envelope in terms of racing bike performance. Together, we aim for the impossible.
In terms of shape, I'm closest to the Isaac Proton, whose spiritual father I am. The use of the very latest carbon-based technology enables me to compete with the very best in the world. I'm always at the head of the pack, particularly on hilly tracks. What distinguishes me is the composition of my tubing and my cable guides, which run around the outside to save weight. This minimises my weight even further without any impact on my optimal stiffness.
Although my frame tubes are identical in shape to those of the Isaac Proton, they definitely differ in terms of composition. My tube set is made of thin but extremely strong 1K carbon fibres. My nickname, Flyweight, says it all. I'm the ultralight top model from Isaac. I am Isaac Proton Flyweight: can you handle me?
Proton FW
(Framekit only)
General
Frame sizes: 50, 52, 54, 56, 58 and 60
Weave: 1K Monocoque
Frame
Weight: From 885 till 1025 gr
Stiffness Head Tube: 115 N/mm **
Stiffness BB: 150-160 N/mm **
Fork
Fork Weight: 360 gr *
Fork Stiffness Lateral: 50 N/mm **
Weave: 1K Monocoque
Steerer: 1K Monocoque 1"1/8 - 1"1/2
Crown: 1K Monocoque 1"1/8 - 1"1/2
Legs: 1K Monocoque
Dropouts: Alloy
Seat Post
Weave: ISAAC-SP03 350X31.6 Off set Black 1K
Frame Technical Specifications
BB Shell Hybrid: Integrated Shimano Press Fit
Headset Cups: 1"1/8 - 1"1/2
Seat Post Insert: 31,6 mm
Dropouts: One piece
Derailleur hanger: replaceable
Seat post Clamp: Isaac-106 alloy black anodised
Cable Stopper Shifter: External
Cable Stopper Brake: External
Headset: Isaac CF 1"1/8 - 1.5
* Target weight
** Target Stiffness
| Dimension | size 50 | size 52 | size 54 | size 56 | size 58 | size 60 | |
| A | seat tube total lenght | 480 | 520 | 540 | 560 | 580 | 600,1 |
| A2 | seat tube joint | 439,9 | 470,6 | 494,9 | 513,3 | 519,8 | 542,1 |
| B | top tube lenght | 510 | 525,2 | 545,2 | 557,9 | 570 | 595 |
| C | seat tube angle | 75° | 74.5° | 74° | 74° | 73.5° | 73.5° |
| D | head tube | 124 | 144 | 160 | 176,5 | 189 | 214 |
| E | head tube angle | 71° | 72.5° | 73° | 73° | 73.5° | 73.5° |
| F | BB drop | 75 | 70 | 70 | 70 | 70 | 65 |
| G | BB to front wheel | 604,2 | 577,8 | 588,9 | 601,8 | 603,2 | 603,2 |
| H | chain stay | 406 | 406 | 406 | 406 | 406 | 406 |
| I | wheel base | 972,5 | 973,5 | 984,6 | 997,6 | 1000 | 1027,3 |
| J | fork rare | 43 | 43 | 43 | 43 | 43 | 43 |
| K | standover height | 746,7 | 769,9 | 787,7 | 797,2 | 825 | 849,2 |
| L | standover height offset | 122,9 | 132,5 | 142,4 | 147,9 | 158,3 | 164 |
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