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Discussion Starter · #1 · (Edited)
1) I know this is a go-kart facility that allows supermotos...but I'm wondering if they have the typical Moto-race track rules and requirements like safety wires, riding gear requirements, top speed on the straights, etc. for us SuMo riders. Also, are there better days than others to go to IMI?

2) I just got done doing the majority of a conversion to my WR450, but am still stuck with the stock sprockets 14/50 and stock brake components. The set-up seems fine for the street though of course with all the new grip I can see the need for a bigger front rotor and a SS front brake line. But with my stock sprocket and brake set-up, will I still be able to have safe fun at IMI? Of course I would be taking it very easy as it would be my first track experience ever. Regarding gearing, I've read some people gear their bikes lower than stock...? What's up with this? I feel like on the street I definitely would appreciate taller gearing like 15/45 or even 15/40...but on the track I have no idea what is appropriate because I don't know what typical top speeds are at IMI. My WR450 is uncorked, if that matters.
 

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They don't have any tech requirements besides a helmet and shoes... We require minimum tech be done and proper riding gear to race however. You can ride there 364 days a year. The days you should avoid are the obvious days when there is a kart race. Sometime weekends get busy so go early before the kart renters get there. It's $35 for a track day.

Yes most guys run a few less teeth on the rear sprocket, but your fine not. You do need to get an oversized brake rotor for the extra stopping power you need. Epic Motosports in Longmont sells a Warp9 supermoto front brake kits for like $80 I think? That's a rotor and caliper relocator which cost WAY less than any other manufacturer.

Come to IMI on Sunday we are having a race. Hell show up and race beginner class, there is another guy showing up Sunday to race beginner class that has never ridden at a track before either.
 

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Top speed at IMI with your current set up will be less than 80mph, so with your wide ratio gear box and stock gearing your probably won't max out top gear on the long straight.

Brakes do get hot on the track, but you will know when they start to get there as the lever will get spongy before it totally goes away. Expect 4-5 REALLY hard laps before they go soft. But at a beginners pace you will probably get 10+ laps before that happens. Get the big brake kit, SS line and replace the stock brake fluid with Motul 800 dot 4 (it's got a really high boiling point)
 

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Discussion Starter · #4 · (Edited)
I'm definitely going to save up for those essentials before I spend any serious time on the track. I may go to IMI once on a Monday morning just to get acquainted before I do, though, but I want to play it safe and not get addicted until I have the gear to safely do so. The Motul is something I can afford to do tomorrow, though. :bannana:

Since I posted this I bought taller gearing for the street that I will be able to use with the stock chain, 15/48, but I'm still wondering what kind of gearing is optimal when I do hit the track in full force...what's a typical (optimal?) top speed for bigger bore 4-stroke on the IMI asphalt? I have only found one thread that said a speed similar to your take, Thorny. They said a KTM 525 topped out at ~80 MPH at IMI. Then again, no mention of the gearing in this post. :headscrat I know gearing and its effect on the bike, especially in race/track settings, is highly subjective...so I will likely end up gearing it to my preference when I get comfortable at the track...I guess the answer is for me to find out. :hmmm:
 

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:headscrat I know gearing and its effect on the bike, especially in race/track settings, is highly subjective...so I will likely end up gearing it to my preference when I get comfortable at the track...I guess the answer is for me to find out. :hmmm:
For a new racer, Practice has a much more profound and immediate effect on your results than gearing.
 

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For comparison, on my KTM 450 with a 6 speed gear box I ran 13:46 gearing, and never used 6th gear. I'm not sure what the gear ratio's are in a WR, but if you gear your bike too tall you will find yourself using only the throttle, and not the throttle and gear box to accelerate.

Go out there and give it a shot with what you've got, worst case scenario is that you can't go quite fast enough down the back straight. But I'm pretty sure that a stock WR is good for 80-85mph in dirt trim, so with a slightly smaller rear wheel you may top out at 70, but that's perfect for someone without enough brakes to calm it all down at the end of the straight.
 

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Discussion Starter · #7 ·
Thanks for all the replies, guys. The point of me starting this thread was to find out the basics about IMI especially gearing/speeds...I didn't want to head out with useless gearing and I didn't want to assume stock was going to be all that useful.

NOW I know that I will be fine hitting the track with stock sprockets. My first thoughts about IMI/track riding were that I would want to gear taller like for the street. And now I know better! Though I'm still happy I have those those taller sprockets coming for my street-tardventures.

Oh, and from what gearingcommander.com is telling me as far as theoretical top speed/MRPM (BTW that has to be the most useful website that isn't a forum)...

WR450 stock top speed (MPH): 103
add in 150/70R17: 98
add in 15/48: 109

Interesting...obviously these are theoretical and more important, HYPOTHETICAL numbers 'cause you wouldn't catch me dead at 103 on the stock setup (or would you? :rolleyes:) and I can't say for sure but I'm not sure about even wanting to see 109 with these sprockets coming despite the new shoes. :hmmm:
 
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