Supermoto builds

kb228
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Edited Date/Time 6/1/2020 1:18pm
Im almost fully committed to picking up a used kx450 to make a street legal supermoto or dual sport. I have a few questions to anyone who has done it or done it on another brand.

1. How does the bike handle stop lights in the heat? Does it boil over? Do i need radiator fans?

2. How do you prevent people from stealing it if its parked? Did you add a gps or key ignition switch?

3. How does it do at 60-70mph? Can a gearing change make it to where its not screaming in 5th gear?

4. How is motor reliability? Its probably a safe bet that far far less wear is happening on the street vs on a race track.

5. Does the voltage rectifier provide enough power for lights or do you need a battery? Can a battery be installed with a key ignition instead of using the capacitor?
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motoGleamer
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5/28/2020 9:17am
I cannot answer your questions specifically but I was in a similar situation and ended up going with a crf450L as it was a much better option for me in terms of a road legal dirt bike.

The motocross bikes have much higher maintenance needs than an enduro or light dual sport. If you are looking to race supermoto or purely for a bike to use locally, then a motocross bike is probably fine. But if you want susrained highway speeds and safety/security features, I think a motocross bike will be more effort than it's worth. Just my opinion having looked into this in the past. I am very happy with my 450L and would've regretted converting a motocross bike into a streetable bike.
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4DAIVIPAI2K5
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5/28/2020 9:44am Edited Date/Time 5/28/2020 9:46am
I did an 06 CRF 450r. I had no issues with stop lights and such with heat.

I never really parked it anywhere so I can't answer that.

Gearing got me to that speed but she was pretty tapped out, but would pull a wheel in ever gear Smile

I just change the oil, valves never moved on me.

I used a fly wheel stator to power lights. Used a garmin mounted in my cross bar pad for my speedo.


rode a buddies DRZ, Didnt even compare to the fun factor I had on my 450. I left my triumph 675 sit in the garage most rides. I went from putting 17,000-22,000 miles on my 675's to a 1,000 maybe building my sumo.
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CSAR FE
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Tucson, AZ US
5/28/2020 9:49am
kb228 wrote:
Im almost fully committed to picking up a used kx450 to make a street legal supermoto or dual sport. I have a few questions to anyone...
Im almost fully committed to picking up a used kx450 to make a street legal supermoto or dual sport. I have a few questions to anyone who has done it or done it on another brand.

1. How does the bike handle stop lights in the heat? Does it boil over? Do i need radiator fans?

2. How do you prevent people from stealing it if its parked? Did you add a gps or key ignition switch?

3. How does it do at 60-70mph? Can a gearing change make it to where its not screaming in 5th gear?

4. How is motor reliability? Its probably a safe bet that far far less wear is happening on the street vs on a race track.

5. Does the voltage rectifier provide enough power for lights or do you need a battery? Can a battery be installed with a key ignition instead of using the capacitor?
Why not find a first Gen CRF450X for this?
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seth505
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5/28/2020 10:06am
Honestly I don't recommend it. I raced a CRF450 supermoto and can say the following:

1. Yes, I'd add a fan, it will not like sitting and idling in the heat.

2. ?

3. How does it do at 60-70mph? It'll do ok if you change the gearing, I had like 16/45 or something like that. It'll wiggle a lot going 60+ due to the lack of aerodynamics.

4. If you leave it stock it should do ok, unless you are holding for really long trips. People I raced with blew up supermotos a lot. Mine lasted the whole season and I changed the oil/filter every time I rode/raced it.

5. Pretty sure you need modifications to get the output for proper lights/signals.

The Shop

kb228
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5/28/2020 10:24am
seth505 wrote:
Honestly I don't recommend it. I raced a CRF450 supermoto and can say the following: 1. Yes, I'd add a fan, it will not like sitting...
Honestly I don't recommend it. I raced a CRF450 supermoto and can say the following:

1. Yes, I'd add a fan, it will not like sitting and idling in the heat.

2. ?

3. How does it do at 60-70mph? It'll do ok if you change the gearing, I had like 16/45 or something like that. It'll wiggle a lot going 60+ due to the lack of aerodynamics.

4. If you leave it stock it should do ok, unless you are holding for really long trips. People I raced with blew up supermotos a lot. Mine lasted the whole season and I changed the oil/filter every time I rode/raced it.

5. Pretty sure you need modifications to get the output for proper lights/signals.
Good info. Thanks.

I want to keep the engine stock. Longest throttle open ride id ever do is to work which is an 18 mile ride on a state highway at 55-60mph. Other than that it would be hooliganing around on the street or trails if i decide to dual sport it.

Specifically about the battery... kawasaki allows you to hook up a battery to the capacitor connector once you remove the capacitor. This is for powering the system during EFI diagnostic testing. Wondering if its possible to buy a small battery to store in the airbox and run the wires to that capacitor connector. Kawi sells an actual harness to go from a battery to that capacitor. The concern i have is having the battery connected while the bike is running - does it charge and will it overpower the system? Or is it better to simply use the battery and a switch for the lights? Then you can just charge the battery on a battery tender when not riding.
bodean123
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5/28/2020 11:38am Edited Date/Time 5/28/2020 11:39am
Put some wheels on my excf. Done. Flip the axles blocks and you don’t even need to change the chain for gearing.

Fan included, key included, lights, horn, mirrors, battery already done.

I don’t understand why you’d try and go any other way unless.


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kb228
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5/28/2020 11:41am
bodean123 wrote:
Put some wheels on my excf. Done. Flip the axles blocks and you don’t even need to change the chain for gearing. Fan included, key included...
Put some wheels on my excf. Done. Flip the axles blocks and you don’t even need to change the chain for gearing.

Fan included, key included, lights, horn, mirrors, battery already done.

I don’t understand why you’d try and go any other way unless.


The only reason i have the plan that i have is because i never see kawi supermotos. Just want something different. The way you did it is pretty smart though
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HondaMan66
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5/28/2020 11:45am
I second the 1st gen 450X suggestion but I still would not ride it at 55 mph for more than a couple minutes. Seems like asking for trouble. All the fooling with the electronics and wiring sounds like trouble too. Here is a pic of my tagged, titled and insured ‘05 CRF450X. I have put new red fork guards on it recently. I occasionally ride it from my house to the power lines. It’s about 7 miles at about 35 mph. it handles that fine.

CSAR FE
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5/28/2020 11:56am
"I second the 1st gen 450X suggestion but I still would not ride it at 55 mph for more than a couple minutes. Seems like asking for trouble."

Why not? Ever heard of the Baja 1000?
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HondaMan66
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5/28/2020 12:08pm Edited Date/Time 5/28/2020 1:00pm
That’s a good point.
Other folks might want to run ‘em at highway speed for extended periods of time but not me.
-MAVERICK-
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5/28/2020 1:01pm
CSAR FE wrote:
"I second the 1st gen 450X suggestion but I still would not ride it at 55 mph for more than a couple minutes. Seems like asking...
"I second the 1st gen 450X suggestion but I still would not ride it at 55 mph for more than a couple minutes. Seems like asking for trouble."

Why not? Ever heard of the Baja 1000?
Grinning

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LungButter
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5/28/2020 1:26pm
CSAR FE wrote:
"I second the 1st gen 450X suggestion but I still would not ride it at 55 mph for more than a couple minutes. Seems like asking...
"I second the 1st gen 450X suggestion but I still would not ride it at 55 mph for more than a couple minutes. Seems like asking for trouble."

Why not? Ever heard of the Baja 1000?
Or any Desert Race for that matter. A 450x is just fine being held wide open for a LONG time if you have good clean oil in the bike.
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1983YZ125
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5/28/2020 4:22pm Edited Date/Time 5/28/2020 4:22pm
Get a KTM 690 Supermoto or convert Enduro to Supermoto. Prices have come down a good bit in the last couple years for the earlier bikes. No major changes until ~2018 or so.

Good maintenance schedule (3k mile oil changes, 6k mile valve jobs) and enjoy it.
As much as a 450 would be fun on the street, screw the maintenance if you actually plan to ride it.
katooom
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5/28/2020 4:30pm
Understand you want to build a Kawi up, cool.
BUT ....

KTM625SMC. A bit mild for full race, but super easy/fun for tooling around on the street. 0-60 wheelies, stoppies. Run 75mph all day, not so extreme on maintenance. Smile every time I get on it. Mines a 2005.


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skypig
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Caloundra AU
5/28/2020 6:10pm
The WR 6 speed on some KTM models is a game changer for SM

THE CR 5 speed MX gear box means: geared for cruising at 60mph, you’ll be slipping the clutch till 20mph in 1st.
jgmxdad251
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Simi Valley, CA US
5/29/2020 12:41pm
I bought mine already done up. It came with extra wheels And lots of extra parts. The only thing I don’t like so far is the front end wanders when you let off the gas in Sandy conditions (especially downhill). It gives you a real uneasy feeling. Wish I could figure it out.
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rongi#401
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5/29/2020 1:18pm
I would stick with a Honda or ktm, why? They’re the most common street legal moto bike and cops are used to seeing them. So you’ll be less likely to be pulled over
JMX82
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5/29/2020 1:30pm
I have 2008 Husaberg FS650E Supermoto as my street bike. The bike has great motor which is basically the same what Joel Smets rode in open class MXGP's back in late 90's. The bike is great for twisty countryside roads and riding in the city but for longer trips on highways I would choose something else


BroFoSho
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5/29/2020 4:41pm
kb228 wrote:
The only reason i have the plan that i have is because i never see kawi supermotos. Just want something different. The way you did it...
The only reason i have the plan that i have is because i never see kawi supermotos. Just want something different. The way you did it is pretty smart though
There's probably a reason why there aren't a ton of Kawi supermotos...
chuckie108
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Mira Loma, CA US
5/29/2020 5:40pm
I think it's hard to beat 1st gen GRF also as far as bang for your buck. I wanted a street legal dirt bike I could do long rides on. I've done 250 all dirt miles in a day a few times now, and this bike has been perfect for me. I bought the bike for $1600, and I'd guess my total investment is around $4000. My set up is big reinforced rads(Chinese eaby models), 18" rear wheel, Trail Tech stator, IMS big tank, and the real kicker- CRF's only wide ratio gear set(yes, it's even wider than the X model). That's what made it for me. Plus all the other quality dual sport specific parts of course. It also helps I can do all my own labor. Big brake and a SUMO wheelset just may be on the horizon too.

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1983YZ125
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5/29/2020 6:30pm Edited Date/Time 5/29/2020 6:34pm
chuckie108 wrote:
I think it's hard to beat 1st gen GRF also as far as bang for your buck. I wanted a street legal dirt bike I could...
I think it's hard to beat 1st gen GRF also as far as bang for your buck. I wanted a street legal dirt bike I could do long rides on. I've done 250 all dirt miles in a day a few times now, and this bike has been perfect for me. I bought the bike for $1600, and I'd guess my total investment is around $4000. My set up is big reinforced rads(Chinese eaby models), 18" rear wheel, Trail Tech stator, IMS big tank, and the real kicker- CRF's only wide ratio gear set(yes, it's even wider than the X model). That's what made it for me. Plus all the other quality dual sport specific parts of course. It also helps I can do all my own labor. Big brake and a SUMO wheelset just may be on the horizon too.

If you're already $4k into a bike + another $1200 minimum for a wheel/tire set the options for a dedicated street legal supermoto has way better options out there depending on uses. For a mix of uses, definitely a good option.

The KTM LC4 engines are bullet proof and the best option IMO on the market if your'e looking to rack up heavy mileage. Bit heavy if you're looking for dirt duty however. OP, if you do look at these, if you want 100% street, try and find a SMC like in the link below. If you want a mix of uses, get an Enduro and pick up a supermoto wheel set. Easy to convert from the Enduro to SMC than the other way. I believe it's due to the brake set up and clearance issues with the wheel or something, quick search on the forums would net the firm answer.

https://dallas.craigslist.org/ftw/mcy/d/keller-2008-ktm-690-smc-supermo…

FWYT
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5/29/2020 7:13pm
katooom wrote:
Understand you want to build a Kawi up, cool. BUT .... KTM625SMC. A bit mild for full race, but super easy/fun for tooling around on the...
Understand you want to build a Kawi up, cool.
BUT ....

KTM625SMC. A bit mild for full race, but super easy/fun for tooling around on the street. 0-60 wheelies, stoppies. Run 75mph all day, not so extreme on maintenance. Smile every time I get on it. Mines a 2005.


Yes! Mine is an '01 and I frigging love it. Removed the headlight and took it to the kart track today, as a matter of fact!




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AgentOrange
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5/30/2020 5:32am
x3 on the LC4. I miss my '06 625SMC. Got so many comments and likes on it, more than any vehicle I've owned or driven.

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Broughton859
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Philadelphia, PA US
6/1/2020 11:57am
If I was in this sitation, I would go 450L and throw some wheels on it. That or KTM 500. Those should last and be better suited than a 450MX. I currently race a CRF450 for supermoto and it's amazing but I've put a lot of work into it and I still don't think it would be the best for street riding if you're planning on riding it a bunch.

You can always go DRZ. Yes they're pigs but they last for ever and should be cheap unless you live somewhere near 12 o'clock boys. That's probably the way I would go if I wasn't using it to race

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