Trail and Track?

[MNScrambler]

If someone wanted to use a CRF450R for both riding on trails and MX tracks, what are the most important things to consider. I know you'd need a new silencer with a spark arrestor. Hand guards would be nice along with a skid plate. What about preventing overheating on trails? Can you add an overflow bottle or do anything else to help this? How about gearing recomendations?

 

[Ol'89r]

What about preventing overheating on trails? Can you add an overflow bottle or do anything else to help this? How about gearing recomendations?

The overflow bottle from a CRF450X will work on the R model. Radiator guards will protect your radiators and the gearing should be lowered if you ride tight singletrack type of trails. The CRF450R has a very high first gear and does not like tight trails. The Recluse clutch makes it much more trail friendly with the stock gearing.

Aside from the skid plate and hand guards that you already mentioned, a rear disk sharks tooth will keep your disc from getting damaged.

Just my $ .02

 

[PeteN]

I ride my CRF450R mostly on trails and sometimes on the track. I have a PMB SA endcap, handguards, skidplate, shark fin, Rekluse clutch and rear handbrake (best mods!), Clarke 3.3g tank, GPR damper, Works rad braces, O-ring chain, and it works great for fast trail riding. I also use stock gearing.

 

[MNScrambler]

How big of a job is it to add the "X" overflow bottle to an "R"? And is it nessesary? Is there anything else you would need to do in order to keep from overheating?

 

[PeteN]

The "R" already has an overflow bottle built right in, the front frame down tube! Just drill a small hole and plumb the overflow tube into the bottom of the down tube with a little fitting, then drill another near the top for a new overflow tube. There is a small hole in the back near the valve cover that needs to be plugged with JB Weld, but that it. It works great and I lose no coolant, even on the tight trails!

 

[MNScrambler]

That sounds like a good idea. If someone wanted to rig up an identical cooling system as a CRF450X, what would it cost for the overflow tank and any other parts needed for the job? Is it pretty straight forward, or are there any tricks to doing this?

 

[MNScrambler]

When you ad the "X" overflow tank to an "R", does it act just like a catch bottle, or will it actually draw coolant back out and into the radiators once it cools down? Also, will this actually keep the bike from overheating, or just serve as a way to keep from loosing coolant that would otherwise spill on the ground?

 

[mox69]

I assume if you use the radiator cap off of the X model and a bottle off of the X model it will suck excess coolant back in after it spills out.

As long as the tube that overflows the coolant in the bottle is submerged in the coolant, it will suck it back in.


I'm not really sure I would want coolant sitting inside my aluminum frame...but I guess its safe enough for the aluminum engine.


It will help overheating in the sense that if you overheat slightly you wont loose that coolant, it will be pulled back into the system. If you experience a major overheat, it probably wont help (but once it cools back down you can hop back on instead of walking the bike home / pouring your camelbak into the radiator).

 

[PeteN]

There is no difference in the radiator caps, they both vent at a pre-set pressure and allow free flow back in. If the overflow tube is full of air, the radiator will suck in air as it cools, if it's full of coolant, it will suck in coolant. Using an overflow bottle doesn't really increase cooling capacity, it just keeps you from losing any coolant. I've had no problem with using my frame downtube as an overflow bottle and never heard of any. The guys who use the main frame spars for aux fuel tanks are the ones who scare me! ;)