ST4 chain gear.

nwerring · Aug 1, 2016

Can any of you tell me what option I have regarding the "large" gear ring on the chain drive? I would like to get a gear ratio as close as possible to a SnowTrac on the SnowMaster I am rebuilding/modifying. So far, the smallest front gear ring I have found is the ST34. By the way, this is a late SnowMaster with internal brakes. I am also changeing the small rear gear ring to the larger 15 tooth gear.
Thank's.

3512b · Aug 1, 2016

Check with Red squirrel, he had some different options
Just don't invite him over! He just mite do it!
I wonder how maney outboards he have to bolt go his van to make the crossing! :clap:

:

redsqwrl · Aug 2, 2016

I made small sprockets to acquire the optional high speed ratio that was available from the factory. I felt my yellow trac master with the high speed ratio was perfect.
first gear was usable for positioning and pulling.
second gear became a starting out gear
third was comfortable driving gear.
fourth was for getting there in good conditions you could really cover some ground.

So I basically went from starting out in third and watching the world go by in fourth....
to
starting out in second driving in third with an extra option above and below those two.

I feel the factory high speed ration is perfect

nwerring · Aug 2, 2016

redsqwrl said:
I made small sprockets to acquire the optional high speed ratio that was available from the factory. I felt my yellow trac master with the high speed ratio was perfect.
first gear was usable for positioning and pulling.
second gear became a starting out gear
third was comfortable driving gear.
fourth was for getting there in good conditions you could really cover some ground.

So I basically went from starting out in third and watching the world go by in fourth....
to
starting out in second driving in third with an extra option above and below those two.

I feel the factory high speed ration is perfect

Sounds exactly like what I'm hoping to do. On my old (1964) SnowTrac I have the 15 tooth small sprocket and the "smallest ST34" on the front sprocket. With a 1600cc, this is perfect. Like you say, start in second and go flying in forth.

Do you by any chance have a photo of your special sprocket setup? And how many tooth is it?

redsqwrl · Aug 8, 2016

Sorry for the delay, I have made many trips this summer and my camera is either in AK, or New York.

My faithful laptop has given me the blue screen of death.

My internet provider of 18 Yrs stopped service while I was travelling.

So, Here is my sprocket solution.
IN view one there should be a 16 tooth sprocket.
Aktiv offered a 11, 12 (standard) and a 15 tooth in the ST4
ST 2002A, 2027,2049
the 11 tooth was an option
the 15 tooth was an option.

On my Snow master I had a ?# (maybe 42) of teeth on the front sprocket. so I had a 16 tooth sprocket made to get the Optional factory ratio of 2.62 to 1
I am getting ready to order metric sprocket blanks and create some more sprockets and i agreed on a manned and unmanned machine rates for the spline cutting.
In view two there should be a top view looking down.
if you want to stay with your large sprockets and get the high speed let me know I can send you these.

Hope this helps,

nwerring · Aug 9, 2016

redsqwrl said:
Sorry for the delay, I have made many trips this summer and my camera is either in AK, or New York.

My faithful laptop has given me the blue screen of death.

My internet provider of 18 Yrs stopped service while I was travelling.

So, Here is my sprocket solution.
IN view one there should be a 16 tooth sprocket.
Aktiv offered a 11, 12 (standard) and a 15 tooth in the ST4
ST 2002A, 2027,2049
the 11 tooth was an option
the 15 tooth was an option.

On my Snow master I had a ?# (maybe 42) of teeth on the front sprocket. so I had a 16 tooth sprocket made to get the Optional factory ratio of 2.62 to 1
I am getting ready to order metric sprocket blanks and create some more sprockets and i agreed on a manned and unmanned machine rates for the spline cutting.
In view two there should be a top view looking down.
if you want to stay with your large sprockets and get the high speed let me know I can send you these.

Hope this helps,

Thank's for your reply. Looks great.
If I could buy a pair of 16tooth sprockets from you, that would be great. They will be perfect with the 1600cc industrial engine I have now, and super with the Ecotec I plan to put in next year.

redsqwrl · Aug 10, 2016

Just a thought here:
I am ordering sprockets soon and I got to thinking, ( nothing good usually comes of that) about what to have made to keep on hand.
Louis' ratio is 2.41 to one. If you want that ratio, I will cut you 17 tooth sprockets. 42/17=2.4 to 1

My in hand 16 tooth sprockets, will put you at 2.62 to 1 ( I feel that it was perfect for the heavier snow master track assemblies )

I am going to cut a pair of 15 T for my subaru powered ST4. 36/15 = 2.4 I feel with the lighter track of the two band and the increase of torque from the motor I will find it worth trying.

I could order some 17 tooth sprockets as well, the shop will be set up to cut my sprockets, so the setup labor could be avoided...... they charge two rates which is nice. manned and unmanned rates are different.

Just a thought. Aktiv never offered 17T so I never went thought to go that big in the past. I pretty sure they would fit.

nwerring · Aug 15, 2016

redsqwrl said:
Just a thought here:
I am ordering sprockets soon and I got to thinking, ( nothing good usually comes of that) about what to have made to keep on hand.
Louis' ratio is 2.41 to one. If you want that ratio, I will cut you 17 tooth sprockets. 42/17=2.4 to 1

My in hand 16 tooth sprockets, will put you at 2.62 to 1 ( I feel that it was perfect for the heavier snow master track assemblies )

I am going to cut a pair of 15 T for my subaru powered ST4. 36/15 = 2.4 I feel with the lighter track of the two band and the increase of torque from the motor I will find it worth trying.

I could order some 17 tooth sprockets as well, the shop will be set up to cut my sprockets, so the setup labor could be avoided...... they charge two rates which is nice. manned and unmanned rates are different.

Just a thought. Aktiv never offered 17T so I never went thought to go that big in the past. I pretty sure they would fit.

Dont you think 17 tooth might be to large... So that the chain will chafe/contact the chassis?.. Would be grate if it worked though. I'd love a set with the 17 tooth if you manage to make it. Otherwise 16 tooth will be perfect.
I found a nice 1975 ST4 today. Price was good so I bought it. It was in great shape until these idiots tried to move it with a forklift through the hardtop.... It's still not to bad though.

redsqwrl · Aug 20, 2016

That is just straight funny. ( lift the cat on thin aluminum)

I will save these 16 sprockets for you. Pm your address.

I ordered 6-15 tooth ISO sprocket blanks, (I will get a pair of 17 and try them here and report back on fitment.)
I know you will be happy with these sprockets on your master.

Mike

P.S. they are shipping from 54913 in the US Pretty sure the USPS ( united states postal service) boxes work for international shipping. I sent two sprockets to alaska recently (very cheap), and that's practically Russia. (intended as humor)

Snowtrac Nome · Aug 20, 2016

up yours mike we vote for the same president. the real difference is in ups rates and we know who is winning the race before we get a chance to vote

Lyndon · Aug 20, 2016

I put an 80 HP, 1776, balanced and blueprinted engine in a trac master and ran the taller gears. 15-34, didn't work that well. You need more torque, like maybe the 90 HP 2 liter VW diesel or something bigger. The weight of the extra track, and the additional snow it throws was too much. It wouldn't keep up with a snow trac with the factory gearing and a stock 55 HP VW 1600. On long hill climbs it just couldn't pull up the hills, especially in unpacked snow. While the snow tracs (2) climbed right along up a logging road around Mt. Ranier Nat. Park, the brand new (newly restored) trac master lagged way behind. It had to down shift to another gear and still couldn't keep up with the snow tracs when they were doing all the work packing the trail.
The stock VW tranny that the Variator is built around can safely handle 100 HP, beyond that you might consider installing some of the upgrades used in dune buggy's that allowed up to about 140 HP.
Factory speeds for a stock snow master/Trac Master is 13.5 MPH with a 53 HP 1600. (13-48). Snow trac was 23 MPH with same engine, 13 or 14 to 36 or 38. Snow conditions will rarely allow you to go this fast. bombardiere B-12's and Hagland Susvy's will do higher speeds, but the conditions that would sustain this kind of speed were usually on frozen lakes and sea ice. coming down out of the mountains in absolutely ideal conditions, like after servicing a radio tower, where no snow mobiles had been, we could achieve 30 for short streches in the Snow Trac & Trac Master. On the Arctic ocean we hit 45 in the B12, but rarely went over 35 in the Haglund. Pretty rough, noisy ride too. Instead of trying to reinvent the wheel, I've always observed that it is best to do the research and try to improve over where some other guy left off. It saves a lot of time, money and headaches.

redsqwrl · Aug 22, 2016

I was thinking he was staying with his larger big sprockets 16-4(X) 16-42 puts him at 2.62 - 1 I felt optional 2.62 final drive was perfect with about the same HP as you.
( and yes the tracks on the master were throwing snow )

16-34 would be quite tall. (2.125 to one) Ill take your word for it. ( torque needed)
15-34 is what the eco tec powered st 4 machine is running (louis)
I get lost in the words sometimes.

nwerring · Aug 30, 2016

redsqwrl said:
That is just straight funny. ( lift the cat on thin aluminum)

I will save these 16 sprockets for you. Pm your address.

PM sent.

JimVT · Aug 30, 2016

it looks like it also dropped. it takes a lot to dent those front fenders.

nwerring · Aug 31, 2016

JimVT said:
it looks like it also dropped. it takes a lot to dent those front fenders.

I was told that the guys trying to move it was going to dump it at the local garbage dump.. Think they lifted, pushed and shoved it around with the forks on the tractor.. They are shipping it down to me next week ? Doesn't look to bad below the cabin/waistline, and the front fenders are quick to replace.

redsqwrl · Aug 31, 2016

nwerring said:
redsqwrl said:

That is just straight funny. ( lift the cat on thin aluminum)

I will save these 16 sprockets for you. Pm your address.

PM sent.

Click to expand...

Yes sir, got it, I think I can fit them in a USPS priority box...

JimVT · Aug 31, 2016

one st4 in yakama that is like mint with all the original stuff has a hole cut in each fender at the same location. it was done so sticks would fly out.
when at high speed he has two columns of snow shooting forward. it is noticeable but not a problem.
jim

ST4 chain gear.

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