wr250x on a trackday

I did one last week, besides the bike being geared totally wrong and having to ride the rev limiter for a good 3-4 seconds per lap, it did pretty well. I went out with sport bikes and got destroyed on the straights, gained it all back on the brakes and corner speed. I was able to keep up no problem, until the brakes started to fade and I couldn't trail brake into corners anymore. The poor lil bike got a heck of a workout though, the cooling system was barely keeping up despite it being just a warm day, brakes faded and the lever turned spongy after about the 5th lap. I had the engine on full boil the entire time, the empty light came on after just 40 miles.



Edit: more video
https://www.youtube.com/watch?v=sEoU2WSqt-c

Twowheeled: Perhaps a subtle limitation (or advantage) between a street tard vs a track tard ? ...or correctable with set-up and mods ?

Sweet....I am surprised you were not required to at least remove your mirrors. I can see they are taped...but they simply unscrew.

And if you removed those mickey mouse ears you might have gained 1 or 2 mph's down the straight.

What track were you on?

I am surprised to hear you had problems with cooling. I assume you had to run straight water in the radiator, but that still should not be that much of a problem.

Perhaps an after-market front fender would help? That stock gigantic mud flap on the front does not help.
Future mod that might help would be to cut the front fender and perhaps even cut some holes in the rear of the fender to allow more air to meet the radiator.

If you haven't done it yet, remove the black plastic duct behind the radiator, below the fan. :)

twowheeled wrote:

brakes faded and the lever turned spongy after about the 5th lap.

steel braided brake lines will fix that problem.

Scraping pegs with the liter bikes is fun. I've had mine out on the big road track here. On all the tight corners I was passing them all. On the fast corners I was an obstacle because I didn't have the acceleration to get up to speed. On the straights, well, there long here so I could have read a book. It handles really well, much easier than a sport bike. The trick is to get down and keep enough weight on that light front wheel.

I've found that I can run 15-20 minute sessions on the big track without a problem. I can also run similar sessions on the tighter cart track here without a problem. When I had brake fade it was because I was sharing my bike with someone and it was probably run at a 90% duty cycle all night. A couple of times I had to actually pull into the pits to give it a rest to get the brakes back.

Brake fade happens if the brake fluid or the pads get too hot through too much use with not enough cooling time. Ensuring your brake fluid is fresh and has no water in it is important. Changing to a higher temperature brake fluid should help. Changing to a different set of pads may help as some are more prone to fading when hot than others. Changing brake lines will, under all conditions, enhance the feel of the brake lever, but it will not effect fade due to pads or fluid.

I've taken mine to the kart track. I think everyone should have that much fun.

Our trackday requirements are pretty low, I've done a few track nights where I didn't even tape anything on the street bike. "just don't crash" is how my buddy who runs the track nights put it. This is also one of the few times I rode the bike to the track, so I didn't have tools or really want to start pulling stuff off.

I was running coolant, completely stock bike. I should have known the brakes would fade, I'm just so used to my old race bike with race pads, fresh dot 4 fluid each weekend, stainless lines, and brembo master. I was amazed at how much later I could brake vs my sv650. I would start braking where my old turn in points used to be, barely needed to do any straight line braking at all, the bike LOVED trail braking. Steepened the geometry of that soft front fork, and put some more weight on that front tire as well.

I'll be back there in a few weeks and have a go at running without mirrors/front fender and see if that helps the aerodynamics at all. Might also try going up or down a tooth on the front sprocket, as I spent the entire infield of the track in between gears. I wasn't brave enough to pull the airbox cover off, the way I was riding it probably would have burned a hole in the piston.

The track is stratotech park in Canada, it's a large kart track, big enough to race bikes and cars to lap on.

engine ice and a brake fluid with a high boiling point like motul 5.1, boils over 500 F dry, may solve your problems.
worked for me anyway, I also put ferodo hh pads and stainless lines.
i have never had overheating or brake fade become an issue.

I run engine ice in mine also since any track I've been on requires it, or waterwetter. I've found it to work great and never have issues with engine heat while on the track, probably never run more than 15 minutes at a time though.

bike will def be switched to water wetter and distilled water later on if I do more track with it, same with brake fluid. The only issue now is that the bike sits outside overnight and temps are still hovering around freezing , so I didn't make the switch to water in the cooling system yet.

^^^ That's the nice thing about Engine Ice, IMO. It is an anti-freeze. It just does not contain ethylene glycol, which is the stuff that track day organizers dislike. It is polypropylene based (for those scoring at home).

WRoldman wrote:

^^^ That's the nice thing about Engine Ice, IMO. It is an anti-freeze. It just does not contain ethylene glycol, which is the stuff that track day organizers dislike. It is polypropylene based (for those scoring at home).

yep... that's what i run in my track bike.

Right on, sweet pics! I'd kill to have mine out at Stratotech one of these days, problem is that it's in too many pieces in the garage right now

Pete wrote:

Right on, sweet pics! I'd kill to have mine out at Stratotech one of these days, problem is that it's in too many pieces in the garage right now

Hey Pete, welcome aboard. Where are you? Edmonton by chance?

Yeppers! I've been on thumpertalk/supermoto junkie, just never got around to posting on here yet

wanted to share some video with you guys, the camera is a gopro HD, still trying to figure out the mounting as you can tell. This one caught a great deal of my butt.
https://www.youtube.com/watch?v=01vhUbucISE

nice video, thanks for posting

Nice video! I checked out your "Go Big" vid also. That trail is freakin insane!

Well, I'm new to the WR250X, but I've taken another "non-optimum choice to a track day (my 1200GS) and I also caught 'em in the curves to a very large degree (though my cylinder heads prevented truly being awesome).

The WR's just too gutless run with the big boys on an open track. Gotta get them on a tighter track, or a tighter road, to really spank em.

Yep, just a lil gutless and only so much I could make up with corner speed/brakes. I did fiddle a little more with tire pressure and it seemed to help, but what this tard really needs is a healthy dose of power or a much more talented rider!!

here's the latest video:

https://www.youtube.com/watch?v=sEoU2WSqt-c

Check out that knee drag!