52.5cm Kestrel 4000 Vintage American Road Bike Frame

✓ Original vintage frame - built in the 1980s/90s
✓ Super lightweight for the era - only 2.3 kg!
✓ Thoroughly checked over & photographed in detail
✓ Worldwide shipping

The brainchild of composite visionary Brent Trimble, along with former employee's of Trek and Blackburn, Kestrel was launched onto the scene in the late 1980s by Cycle Composites Inc. Beginning with a game-changing monocoque road bike that graced the front cover of magazines and was immediately raced to devestating effect in 1987, followed by the first full suspension carbon MTB (with V Brakes!) in 1988. Through the early adoption of computer aided design and aerodynamics, Kestrel can be credited with creating the genesis of the high-performance carbon road bike that is so prevalent today.

Taking eight years to design, test and prepare for manufacture the 4000 emerged as a fully formed, ready to race super bike in 1987. The first mass-produced carbon monocoque road bike available, it looked like nothing else, and importantly rode like nothing else too. The new technology that went into the building the 4000 resulted in a stiff, comfortable, light, well balanced frame, something of a first for carbon. To top it off it also had a strong aerodynamic benefit with its profiled shape and internal cable routing. As well as the cutting edge technology of the time, renowned bike designer and engineer Keith Bontrager advised on the geometry which pulled together into a phenomenal race bike.

This example of the legendary Kestrel 4000 frame was built in 1990, towards the end of the production run and is spaced for 6 or 7 speed drivetrains at the rear. With the classic Imron white paintwork in great order and very few marks, this rare machine was obviously well looked after and is ready to give many more years of service.

The frame's been carefully checked by one of our mechanics to confirm the alignment's correct and there's no damage to the threads. If there are any minor issues worth noting we will do so in the overview section below. Please take a good look at the detailed photos so you can see the cosmetic condition of the frame before you buy.


Era - 1980s/1990s
Country - American
Frame Material - Carbon Fibre / Aluminium
Weight - 2.345 kg
Stock Code - U-F-R85V


Size Guide* - Small/Medium (Approx 31" Inside Leg)
Seat Tube (ctc) - 52.5 cm
Top Tube (ctc) - 54.5 cm
Head Tube - 120 mm
Chainstay Length - 41 cm
Wheelbase - 98 cm

*This is just a guide, not a guarantee the frame will fit as every rider is different. If you're unsure of your size we'd always recommend trying out a bike with similar frame dimensions first.


Rear Spacing - 128 mm
Front Spacing - 100 mm
Seatpost Diameter - 27.2 mm
Wheel Size - 700c/28"
Brake Fixing - Recessed Allen Key
Front Brake Drop - 45 mm
Rear Brake Drop - 44 mm
Bottom Bracket Thread - English/British/ISO Thread
Headset Thread - Standard ISO (24 TPI - British/Italian)
Headset Stack Height - 40 mm
Fork Crown Race - 26.4 mm (ISO)
Shifter Fittings - Downtube Braze-On
Headtube Internal Diameter - 30.2 mm
Steerer Internal Diameter - 22.2 mm (Standard)


We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.


Seat Tube (ctc) - we measure from the centre of the bottom bracket shell up to the centre line of the top tube to give a consistent measurement regardless of frame design (ctc means centre to centre).

Top Tube (ctc) - this is measured from the centre of the head tube to the centre of the seat tube, along the centre of the top tube.

Chainstay Length - measured from the centre of the bottom bracket shell to the centre point of the rear dropout.

Wheelbase - measured from the centre of the front fork dropout to the centre point of the rear dropout.

Front & Rear Spacing - measured from the inside of one dropout to the other. The dropouts on steel frames can be stretched or squeezed a few mm but it's always best to avoid this if possible, aluminium or carbon frames should never be stretched.

Brake Drop - measured using wheels of the relevant size for the frame, as stated in the technical info section.

Headset Threads - although it's generally recommended to match threaded parts exactly, with headsets you can technically mix and match, unless you have French or the obscure old Raleigh threads, in which case you need to stick to that type.