Easton EC90 SL Aero Carbon Forks
Sunday, 19th March 2006
We have had a pair of the full carbon (including dropouts!) Easton EC90 SL Carbon Aero forks on test over the last few months, and it has to be said they are hugely impressive.
We have swapped the standard issue forks on an 04 Composite Giant TCR with the Easton EC90 SL Carbon Aero forks and the immediate effect was astounding!
Easton is a company with a great deal of expertise in the use of carbon fibre, not just in the cycle industry, but also in other sports such as ice hockey, baseball and archery. Easton has a large research programme which invests heavily in new technologies, such as Easton's CNT Technology. The result is all the better for us as consumers.
Easton make a range of forks, a pair for Cyclo-Cross, a straight and a curved pair for the road, and a full aero pair on test here.
The aero forks are full carbon and very light as a result. They are also made with minute attention to detail. Starting at the top, the steerer is full carbon and made as part of the fork, so there are no joins at the crown - this is where many earlier forks used to fail and is a point of enormous stress. The steerer has been designed using RAD (Relief -Area Design) to avoid excessive stress being put onto the fork when clamping up the stem too tightly. The result is a small flat on the back of the steerer tube.
The drilling for the front calliper is not a drilling at all, but a moulded hole to again increase strength. Even though this is more difficult to produce, it is this attention to detail that sets the EC90 SL Aero Carbon Forks apart from many other forks out there.
The composition of the Carbon in the fork has literally a minute attention to detail as well - it uses CNT (Carbon Nanotube Technology) which puts further particles, or nanotubes, into the resin of the fork, between the carbon fibre to further enhance the strength.
The blades of the fork give an extremely narrow frontal area, although they are deep to cut through the air. They are, however, not just straight from top to bottom, but shaped to slice through the air while giving a degree of comfort too. Finally, the dropouts are again manufactured with the rest of the fork to avoid any bonding and increase strength while reducing weight. They are carbon and have so far resisted any wear and actually feel harder when tightening the quick release on the front wheel, over the more common alloy dropout.
The final innovation is not the fork itself, but the way Easton have addressed the need for a stearer bung. They have completely done away with the need for a Star-Fangled nut or other similiar compersion sytem to take out the slack of the headset.
Easton, instead, have a washer that expands between the stem and the top of the headset and pushes the two apart. We found this to work well with all Easton components, however, you do need to tighten the stem very tight to avoid slipage. With other stem combos, there was a noticable amount of slipage after a 100km ride which causes the headset to rattle.
The ride of the forks is the real reason why we ever need to change them, barring accident. So how did they feel? In a word - outstanding The Easton forks were light, very responsive and comfortable, particularly considering they are straight bladed. We were also impressed with the ride in cross winds. They felt as easy to control as a regular road fork and did not present any problems with steering or stability. On long twisting descents, the lateral stiffness of the forks also inspired great confidence in breaking and cornering, allowing you to carry even more speed through the turns.
In conclusion, if I needed to replace forks, or had the opportunity to specify forks on a new bike, these would be at the top of our list. Easton has really made an outstanding product, packed with technology and at not an unreasonable price for top end after market forks.
- Uncut Weight 370 grams
- Size 650C and 700C (1' and 1-1/8" threadless carbon steerer)
- 43 mm fork rake
- Material Hi-modulus CNT carbon monocoque, Single lay-up design with EMC
- Relief-Area Design (RAD) steerer (protects against clamping damage)
- Compression-molded carbon drop outs
- Superior fatigue life
- Superior impact strength
- Superior stiffness
- Limited 5-year warranty
- Price - £290
RAD - Relief Area Design
CNT - Carbon Nanotube Technology
EMC - Easton Matrix Composite