Necessary Snow Bike Mods?

[Camron Presley]

I'm looking to get into the sport of snow biking with my dirt bike but I'm not sure as to what modifications are necessary to have for winter time riding. I live in Alaska where temperatures can range for 30F to bellow zero. I ride a 2015 WR450F in the summer time which has the gytr competition ECU kit on it and larger than normal hand gaurds. I want to put a 129 inch track on my bike and have a few questions on what mods are necessary or recommended for the type of riding I'll be doing.

1. I know a thermostat is necessary but should I have radiator covers on as well?

2. Should I change my gears for a lower gear ratio?

3. Will my stock air box and intake set up be fine if I do nothing or if I just seal off the box (Also if a new filter or air box setup is better which ones would you recommend)?

4. Are pipe wraps good?

5. Not a mod but I've hear a few different opinions on this and am a little confused. How often should the oil be changed out for winter riding?

 

[bighuckpunk]

What I've learned is Q#1 needs multilple replies depending on the outside temperature at the time.
@ 30+ degrees I (ktm450) do not even need a thermostat. @25 -30 I need a thermostat. @ <25 I need a thermostat and a blanket. This is good news 'cause you don't need to modify jack to run at warmer temps. Just put a kit on and go, except Q#3 maybe.
Q#2 I don't think so but I'm no expert.
Q#3 I rented a YZ that had prefilter type material covering the openings to the air box. I don't know what was left inside.
Q#4 I don't know
Q#5 My personal interval is 5 or so hours and I'm easy on my machine. Check after every ride for discoloration.
You will want a temperature gauge, digital or radiator cap if you can see it.
Have fun!

 

[dooman92]

Cameron, I find some method of covering/blocking the rads is necessary. The thermostat is minimally effective with cold radiators. The cold coolant will sink into the engine regardless of thermostat position.
I tried the exhaust wrap but eventually went without, more negatives than positives.
How often you change oil is most dictated by how warm the bike runs. I've put 300 hrs on two different bikes on the snow with out any engine issues. My temps are consistant at 190ish and I changed oil at about 15-18 hrs on the oil. I never had any fuel in oil. If I had a real deep day and temps suffered I changed oil earlier. Some sort of engine and radiator cover is necessary imo.

Regarding the air box, on my 17fx, I removed stock filter and made a cage that I covered with prefilter and mounted on the throttle body concealed in the air box. I found it necessary to prefilter any area where snow can get in include the air intake horns. That system was flawless. I'm not sure if your wr is the same.

i couldn't ride without heated grips or bars so imo necessary mod. Heated bars better but, a bit more work and $$.

 

[tek9tim]

1. I have pieces of thin plastic that I slip in between my radiators and radiator guards that are easy to take in and out, and easy to stow. Help keep temps up nicely. Definitely run a temp gauge that's reads from close to the head.
2. You won't need a lower 1st gear. What you'll run into is the transmission being gappy since it's a WR. You might end up changing out gears to make up for that, but you'll want to ride it first and see where it's at.
3. At least run a filterskin on your stock air setup, check out what other WR owners are doing. I have a Husky, but FWIW I have a C3 intake that's been good.
4. No idea, but you'll at least want a good heat shield to keep from melting any gear.
5. As already mentioned, the warmer you keep your engine the better. Some guys just just change oil every 5 hours and filters every 10-15. It took me a fair chunk of last year to get my temp situation dialed, so I was on the 5 hour drain train. Never any water, just being cautious about fuel dilution.

Coolant heated handlebars are the cat's pajamas. Highly recommend.

 

[sledsuperman]

Great advice from the other responses.
I built my snowbike last year from a stock bike and just added things as I needed them. I started with it in September and spent much of the preseason looking for the right modification in each of the questions you listed. You will have a lot of hours into it but will be glad you took the time in the preseason.
1. Thermostat is necessary.
2. I didn't change any gearing. i know others that have and gone back to the original.
3. Pre-filters are important and keeping the air box open is a must. Snow conditions will dictate what needs to be done. You may run all season with no problems and then have a day that you cant keep snow out. Outerwears or Frogskinz are a good source for what you will need.
4. I didn't use pipe wraps.
5. Watch your engine temps closely and gauge that on whether to change your oil every ride or every 2-3.

I ran the bike for most of the season and ended up managing engine temps just fine until I got into some spring riding. I added a radiator fan kit and it worked very well. I wished I had installed it earlier.

6. Make sure you have your shocks set up right. if you don't stiffen up the front shocks it will seem like the ski is more of a snow plow. AND having the suspension strut is a big difference too.

You will likely love the Snowbike. It's been said that there are two kinds of snow bikers. - ones that are sledders first then convert to snow bikes, and - ones that are dirt bikers that go the snow bike route. I'm Kind of both but after a full season I LOVE it. I was second guessing my change from a sled after the 1st few rides but after I got more experienced with it, it seems more natural and is lots more fun.
At the first of the season I rode my fiend's Alpha and was impressed with the way it handled then rode the snowbike most of the season and rode the Alpha again at the end of the season. It seemed like lots of work and I couldn't get back to my snow bike soon enough.