Too Tech Suspension Performance and Characteristics Review
2008 CRF250R and CRF450R
SHOCK - similar to analysis below
FORKS - much stiffer than past years. Honda pulled the wheel back 2mm and then overcompensated by preloading the mid speed stack closed. This defeated the purpose of a mid speed valve stack by turning it into a low speed and up stack. For anyone but the most aggressive Pro type rider, this needs correcting.
CRF250R & CRF450R OBSERVATIONS
CR suspension performance has come a long way since the first twin chamber fork and aluminum frame bike in 1997. (Too Tech was really scrambling in 97 to tune the new Twin Chamber forks and develop a suspension that would work with the overly stiff frame.) We were the first company to understand and change the Internal Chamber (IC) springs in 1997. The tuning techniques developed for the stiff 1997 CR chassis are still applicable today (since the fork remains largely unchanged).
Ideal rider weight for the 450F is 160 to 180 pounds while
ideal weight for the 250F is 150 to 170 pounds. Heavier riders will usually feel
their bikes are too soft! This is because the front & rear springs do not
adequately support their body weight. The bike will dive too low in the front
under braking and squat to low in the rear under acceleration. When the
suspension compresses too far under braking and acceleration, there is not
enough travel left to absorb the next bump. So even though the bike feels soft
in most situations, it will become very stiff when it runs out of travel in rough terrain.
CR suspension has used the same valving concepts since 2004, so all the bikes
feel very similar.
The first step to proper bike set up is to install the correct springs. Please visit my "Rear Spring Static Sag" page to check your rear spring rate or give me a call to discuss the optimum front and rear springs for your weight, riding terrain, and rider preferences.
Once the proper springs are installed into your bike, it will then fit the 'ideal rider weight' evaluations discussed below.
CRF 250 Riding
impressions for the ideal rider weight of 150 to 170 pounds.
· Front end rides high in the stroke, won’t dive into a corner, and feels harsh in square edges. Symptoms include jolts to your hands, arms, and shoulders along with difficulty initiating tight turns.
· Rear end deflects when accelerating hard through acceleration bumps. Tends to get knocked off course at high speeds or when slowing in braking bumps. Symptoms include being deflected off course when aiming for a rut or accelerating for a double jump. Trail riders will notice harshness and deflection when hitting rocks or tree roots.
· Because the bike is small and light, many riders are happy with the handling and do not realize how much better the suspension could perform.
· In the rolling bumps, big jumps, and well groomed tracks the bike should feel OK. Problems are accentuated by rough terrain.
The front fork valving is almost identical to the CRF450
except that it uses a 1.9 pressure spring instead of a 2.1.
The excess fork valving causes the front end to resist quick transitions,
resist diving into turns, and provides too much feedback from the terrain -
feels harsh.
Revalving the forks for more compliant action and reducing the pressure
spring rate restores the plushness and promotes front-end turning and more
dive.
The rear shock valving has remained similar year to last year. The stiff high-speed compression damping causes the rear to deflect of sharp bumps. This is most noticeable when accelerating hard through the chop. The rebound remains too fast near the top of the stroke and too slow at the bottom. The bike is either too lively on top or packs at the bottom depending on where the adjuster clicker is set. Too Tech internal revalving includes a new rebound tuning strategy along with extensive adjuster modifications that relieve the high-speed compression kick.
For less aggressive riders in this weight group we recommend a 5.0 rear and .44 front springs. This is because less aggressive riders do not brake or accelerate as hard, so the chassis does not dive or squat enough to promote good handling. Lighter springs restore the correct balance of diving and squatting for this group of riders. I installed “Honda Low” handlebars on my bike to further lower the ride height perception.
Very similar to the 250F except that the problems are amplified due to the increased weight and power. On smooth well groomed tracks the bike is a pleasure, but as the track roughens during the day the bike becomes harder to stay on line and the harshness tires out the rider
· Front end rides high in the stroke and feels harsh in square edges. Tends to get knocked off course when trying to hit a precise line. Rider will tire out quickly. Symptoms include jolts to your hands, arms, and shoulders along with difficulty initiating tight turns.
· Rear end deflects when accelerating hard through acceleration bumps. (This becomes more noticeable after fixing the front end) Symptoms include being deflected off course when aiming for a rut or accelerating for a double jump. Trail riders will notice harshness and deflection when hitting rocks or tree roots. Many riders think their shock is real good, but they do not realize how much the rear is affecting the performance of the bikes front ends.
· In the rolling bumps, big jumps, and well groomed tracks the bike should feel OK. Problems are accentuated by rough terrain.
Situation & Solution
The front fork valving continues to get stiffened each year although the components have been the same since 2003. This excess valving causes the front end to resist quick transitions and resist diving. Revalving the forks for more compliant action and reducing the pressure spring rate restores the plushness and promotes front-end turning and better dive.
The rear shock valving remains similar year to year. The stiff high-speed compression damping causes the rear to deflect off sharp acceleration or high-speed bumps yet may even feel like it wallows and rides low in rolling bumps (it is overly progressive). The rebound remains too fast near the top of the stroke and if you turn the adjuster in to slow it down, the shock packs at full compression. Too Tech revalving includes a new rebound valving along with extensive adjuster modifications and valve stack changes to produce a more linear compression valving rate.
The forks have .46 or.47 kg/mm springs and the shock has a 5.4. For hard charging riders the front spring rates are good for this 160 to 180 pound group. Less aggressive riders may prefer .45 in the front. Many lighter riders get static sag numbers over 1 ˝” which indicates they should move down to a 5.2 or 5.0 rear spring.
Overall, the single most important change I make to the CRF suspension is to reduce the energy required to ride the bike. For a trail rider it means he is less exhausted at the end of the day. To a racer it means he can be as strong the last five minutes of the race as he was the first five minutes.
Please call me to discuss your specific complaints and needs to satisfy your expectations!