CRF450R Endurance Test - Dirt Rider Magazine

For 2011, Dirt Rider teamed up with bike-building expert Jay Clark to create a project bike made for the 2011 HYR endurance race series at Glen Helen in Southern California. The HYR endurance race series consist of three races: the 6-hour race that took place on March 13th, the 12-hour race that just passed on June 25th and the 24-hour race that is set for October 8th and 9th of 2011.

The 12-hour race was a great event; there were a couple hundred riders that came to compete and all the sponsors were present showing their support. The race started at 7:40am and ran through 7:40pm making it an epic day of racing. The start was lined up in rows by class and began with the usual procedure- both hands on the helmet with the bike off until we were signaled by the wave of the green flag. The course was similar to that of the 6-hour race, except for some tight creek sections that were really technical and not open to passing, and there were also some rough sections that had a mixture of sand and powder dust. Adding excitement to the course layout were some huge tree trunks that were laid out at one section of the track making it hard to complete, especially half way though the race. The average lap time was 25 minutes long and was full of pure fun and adrenaline but also consisted of passing through an overgrown shaded creek with running water, passing through huge aqueduct pipes that were lined up like tunnels, huge up hills and long, steep down-hills and single track trails full of bushes and rocks. If you are an overall rider that likes all kinds of extreme riding, the HYR endurance race series is an event you need to take a shot at.Going back to our race set up, Jay got his hands on a 2011 Honda CRF 450R from Honda and made some modifications to it for our series race. For the first round of the series, the 6-hour race, we rode the bike pretty much stock, except for the pipe and header, the added 3.5 gallon tank and the re-enforced tire setup to prevent flats. For the second round, the 12-hour race, Jay added some modifications to the 450R that made some great improvements needed to the endurance racing project bike. Our team consisted of a four-man lineup: Alfredo Contreras, Travis Mcrae, Bryan Thompson and myself, Juan Diego Saffon.

Starting off with suspension, Race Tech took care of valving that allowed the bike to be dialed in with great precision. At first the bike felt a bit stiff but a few laps into the race the springs set in and made it a smooth ride. Some changes were made to the clickers throughout the race, making it stiffer on compression and slowing down the rebound, which helped the bike gain stability and control towards the end of the day. One of our riders was 15 lbs heavier that the rest of us but the suspension still felt good for him and had no problem supporting his aggressive riding style.

In the engine department, no major changes were made. The flywheel was modified with a Hinson steel clutch basket to help prevent stalls and the cams were altered with a Stage II cam so it would make the powerband gain strength in its mid to high-end power-band. A custom air filter cover was created by Jay and made to fit on top of the Twin Air filter, allowing cover replacement without removing the main air filter. An FMF Factory 4.1 RCT pipe with a Ti Powerbomb header was added to clean out the power on the CRF450R, resulting in fully sustained power control that was appreciated by every rider on the team. On the rear, we ran a TCR laced up 18 inch wheel to increase tire mass with a 956 Dunlop and on the front we ran a MX51 Dunlop tire that were both equipped with heavy duty tubes that were covered with cut out stock tubes to increase layer protection and avoid flats. Our slick graphics were done by Decalworks and our bars were stock Renthal along with Renthal sprockets 47-13 gearing that were pulled by a gold Renthal O-ring chain. The Renthal hand guards added to the bike were a feature that quickly became appreciated by our entire team.

For brakes, Jay added an oversize front Moto-Master 270mm rotor and a stock size rear wave disc that allowed some excellent power braking when needed. Our clutch was not only modified with a Hinson steel clutch basket but a complete Hinson clutch kit with a Hinson clutch plate cover was added for maximum durability and softer clutch feel. Radiator hoses were switched out for some red CV4 silicone hoses that help with max coolant flow and heat reduction.

Riding the project 2011 Honda CRF 450R was quite impressive. This bike not only looked good but it rode excellently, combining well balanced stability and superb power delivery. At first, when you mounted the bike, you could immediately notice the oversized gas tank that gives it a beefier feel. After the first lap, it was easy to adapt to the bike and you could feel how the Race Tech suspension gave the bike more support through mid-stroke travel. Choppy corners, rocks, sand, over jumping sections, slick and dry terrain, concrete surface and fast bumpy down-hills were mastered by the Race Tech suspension. Headshake was reduced by efficient spring and shock travel and the front stock head stabilizer was modified by Race Tech for improved reaction control that worked to perfection.

As for power, you can feel how the add-on FMF full system and the cam modification gave the bike the right amount of response needed. The bike went from the stock hard hitting powerband, to a tamed down muscle machine that was there to back you up with power when needed. The 13-47 gearing we ran, also helped smooth out the powerband and made the bike quite fast through long straight-aways. We will do more testing with gearing before the 24-hour race to see if maybe a 13-48 gearing ratio is a better choice for single-track sections. As you increase power and speed on the bike, you need greater than stock braking power to be able to control the red beast. The front oversize rotor added gave the CRF450R the perfect amount of stopping power needed. All the modifications made to our race bike performed as expected; one of our side plates popped out from place, but was quickly fixed during a pit stop. At the very end, the Renthal hand guards were ripped off and the plastics were all scratched up from the thick trail bushes. After 33 laps, our race bike crossed the checkered finish line and was still running strong. Our team celebrated with a successful completion of the 12-hour endurance race and we are now looking forward to racing the final 24 hour race of the HYR endurance series for 2011.

Key Details Improvements

  • Goal of this project was to improve on the bike from the 6-hour race.

  • Added a Hot Cam Stage two cam for more mid/top end power

  • Injectioneering did their throttle body mods to prevent flameout and also provide better overall performance.

  • Hinson Steel clutch basket was added for a heavier flywheel feel and greater clutch durability.

  • Added two 18" rims on stock hubs that TCR laced up.

  • Race Tech modified the suspension for the GP conditions-

  • Dunlop 952 rear tire and MX51 front last very well-- Used heavy tubes and double tubed the front and rear to help prevent flats (cut the stock one and put the heavy tube inside).

### Parts:
Hot Cams||515-402-8200
Stage II cam|$199.95
FMF Racing||310-631-4363
Full system with Ti Megabomb header and RCT muffler
Formed Silicone Coolant hoses in red
Hinson Clutch Components||909-946-2942
Single Spring Inner Hub/Pressure Plate Kit
Steel Billet Clutch Basket
Throttle Body Modifications|$225.00
Works Connection||800-895-8292
Elite Perch|$139.95
Front billet brake cover|$27.50
Rear billet brake cover|$24.95
Radiator Braces
Full coverage skid plate
Factory II Stand|$99.95
Big bar mounts
997 Twin walls
Kevlar Grips
Front and rear chain wheels 13/47
O-Ring Chain
Hand Shields
270mm oversize front disk kit and stock rear size with wave/flame
Custom Seat Cover
DeCal Works||815-784-4000
Custom T-8 kit
Custom T-8 backgrounds
Air Filter
Custom foam
TCR Wheels||209 368-9800
Lacing of 18" rim to stuck hub
Dunlop Tire||800-845-8378
MX51 front tire 80/100-21
D952 rear tire 120/90-18
Oil and all grease/lubricants
Race Tech||951 279 6655
2011 Honda CRF450R
170lbs, Off-road (INT)
FRSP 444648 - FORK SPRING, .48KG/MM RATE|$114.99
FPCS 02 - CHECK SPRING|$2.29 X 2 = $4.58
USF05 - ULTRA SLICK FORK FLUID, 5 WT|$14.99 X 2 = $29.98
SRSP 652654 - SHOCK SPRING, 5.4KG/MM RATE|$114.99
US1 - ULTRA SLICK FLUID, 2.5-5WT|$14.99