Isaac Proton Flyweight Frameset.
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?

(Framekit only)

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.

For more info on the Isaac Proton Flyweight Framekit please contact us.

Shipping for all Mainland UK orders is free including bikes and frames. Overseas delivery is worked out differently for each order based on the weight and size. For more info please put something into your basket to see an estimated delivery charge or get in touch.

All in stock items ordered before 2pm will be priority despatched for next day delivery*

We use Royal Mail's 1st Class Recorded delivery service for most orders, so you'll need to be in to sign for your goods. For larger items, we use FedEx Parcel Distribution Service, again you'll need to sign for them.

We will deliver goods to an address other than the credit card address, although we may require further details from you.

*excludes some bikes and bulky items

Please click here to see our returns policy