Snow Bike Tech Tips
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Calculating Gearing
Playing with the gearing on your snow bike is a vey common modification that a lot of guys do. It's been hard to set a standard for measuring gearing on a snow bike in comparison to the tires or to another snow bike. For me, I do not go off a calculated gear ratio. I measure the track inches of roll out to one revolution of the engine sprocket. This will show you how far you would travel with one revolution of the engine counter shaft sprocket. This does not compare transmission gearing. It is used only to set a standard for gearing snow bikes, so that we can all go off of the same thing when talking shop tech.
How to do this:- Mark a line on a tooth of the engine sprocket and on the engine case that are in line with each other.
- Mark a line on the hifax and on the track that are also in line with each other.
- Rotate the track forward while looking at the engine sprocket. Stop when you get to 1 revolution.
- Measure the distance between the line on the track and the line on the hifax.
For example:
Stock gearing on the ST Mtn. Horse kit using a 2.86 pitch 7 tooth driver with a 13 (engine) -17 (jack shaft) / 17-20 (chain case) = 13-1/8" of track roll-out. - What grease do I use in the bearings?We would recommend any water proof, lithium base, marine or motorsports grade grease. We would not recommend any synthetic grease because the grease that comes pre-packed in the bearings from the manufacture is a lithium base, and some synthetic bases are not compatible with lithium bases, and mixing the two can cause the grease to have a negative reaction and break down. Also, as a side note, it is also very important to make sure that the bearings do not get over greased, which can unnoticeably hydraulic the seals out of place, leading to rapid bearing failure.
- What lube do I use on my chains?Any high quality motorcycle chain lube is acceptable, but our top recommendation would be the Maxima brand chain wax (which can be purchased through many different motorsports dealers). It has excellent lubricating properties, and is very low mess compared to a lot of the other lubes out there.
- How long will my dirt bike engine last with the MH kit installed?With proper maintenance, they should last as long as a normally dirt ridden bike. Although it is harder to spin the track than a wheel, the snow helps by allowing the track to spin like that of a snowmobile. It also depends on how you ride. In addition, because there is no dirt and dust getting into the engine while riding in snow, there is less wear. We have put 1000's of miles on our bikes with no failed engines due to the kit.
- How long will my clutch last with the MH kit installed?We have put 1000's of miles on our bikes with little to no clutch wear. One customer rebuilt a bike with multiple hard seasons of riding and found the clutch showing very little wear.
- How often should I lube and adjust my chains?We highly recommend that you lube and adjust your chains before every ride. This includes taking off the chain case cover to inspect the sprockets and bolts. With proper maintanence, your sprockets and bearings should easily last a season.
- How much does the kit weigh?The frame, suspension and track weigh about 116 lbs. The front spindle and ski weigh 14 lbs. This adds about 60 lbs. to your bike making the typical 450cc race bike weigh in at about 300 lbs. fully fueled.
- What much power do I need?We have found that the 450 race bikes work very well in all situations. A 250cc or 300cc 2-stroke is the minimum we would recommend.
- What accessories do I need?We recommend the following accessories for all riders: Wider foot pregs, handlebar risers, gas can, and cargo bag(s).
- What size gas tank do I need?The stock gas tank along with a tunnel mounted 3.3 gal. gas can is the best combination suitable for any days ride. If you have an extra large gas tank, you can possibly get away with the 1.3 gal. can.
- How well does a Rekluse clutch work with the Mountain Horse? Do I need one?A Rekluse clutch is not needed with the Mountain Horse, however they are a nice feature and hold up quite well.
- Is there any way to lower the bike?By placing a 1/2" shim on the top of the rear suspension slide mechanism and tightening the limiter strap by 1 hole, you can lower the bike by up to 1". See the tuning instructions for further details.
- Is there any way to lower the gearing on my Mountain Horse kit?Yes, it is possible to slightly reduce the gearing by replacing the 17 tooth sprocket in the chain case with a 16 tooth.
- My chain is too tight to get on the kit, what can I do?The chain can be very tight to begin with on some setups. Make sure you have the correct engine sprocket installed on your bike. For most bikes this is a 13 tooth, see chart to make sure. You can try the following procedure to get it installed: 1) remove the upper strut rod bolt, 2) lift the track up, 3) install the chain, 4) re-install the strut rod bolt. Once you have the chain connected, you simply need to spin it a few times and it should loosen up. These chains have a lot of lubrictation in the o-rings and tend to be a about 1/16" shorter than our previous chain.