Mtn top xfr 126

[z987k]

So I finally got stuck going up a hill today with mine. Trenched hard into some sugar under a slab. Hadn't gotten stuck on an uphill line yet this season that wasn't kind of stupid to try in the first place.

 

[eric82930]

I'd like to see/try the optional skinny ski

Anyone try one yet? Spring is the time to test it.

 

[byeatts]

Norsepeak, were all the mtn tops the 3.25 track? I have report from buddy that the 3.25 is very playful and great in deep but requires more power. Both bikes 450 sx, 129fr yeti could pull a gear higher than mtn top with 3.25. Any thoughts on that? Did the 3.25 require more power yet perform better?

I have the MT 3.25 /126 track on the yeti and it out climbs a 600 sled , and with belt drive it does not pull the power down at all compared to the 2.6 yeti track , Its the track seperating the kits which has the best flex for powder than anything out there. interesting on a digital scale the 3.25 is only juan pound over the 2.6 yeti track due to the 3.5 spacing . I also developed an Air shox adding 11 inch rear suspension with electronics to lock it out from a bar switch, This was necessary since the 3.25 will not keep the skis down, The track is a game changer Alan did a remarkable job in design. A track with perfect flex allows the snow to roll off each paddle compacting the snow and lifting the skid without loading the engine , Ive seen no RPM change switching to this track and i run very tall gearing however i do run a BB full race motor . this track will be the new standard.

 

[eric82930]

I just got juan this year too. Just the track and drivers to replace my yeti 137 2.5". Not the maxtrac but the cmx camso version. I did loose a ton of speed and had to gear down mainly because the 137 would float much better and get on top to pull the next gear. They climb about the same but mt top just goes slower but is WAY WAY more quick turning so I can sometimes take lines that will let it climb higher than the 137 just because it can turn around obstacles faster. I had to drop one tooth on the counter shaft and fifth gear is still strugging on the road but well worth the upgrade. Part of the nimble feel is going to a skinny rail which was a custom hack job for my bike. With the 137 I never had to lock the rear shock to get it to float but now I do. Less ground speed and the shorter track does make it more sensitive to chassis balance. I still ride a lot in may and june so I would never pick this track if I only had one bike but I have three (the other two are riot 120s) and this one is the best for January by a big margin. I've ridden the mtop kits as well and the scissor suspension is dreamy but in deep powder not necessary. If your on a budget, I would just find a way to fit that rubber under what you got and you'll be going places. They sell the drivers that fit the yeti and timber sled shafts now.

 

[byeatts]

good info . sounds like my bike is not a good baseline . I actually gear way up and my 1st gear spins track at 32 MPH, this engine pulls this track hard from a dead stop in deep powder, this gearing makes my 1 st same as most other 2nd gears providing a true overdrive in 5th going 55 mph on trail. Guess i didn't relize how much HP this new motor is making but its really strong however it has everyyhing done and 97MM bore.. Perhaps i re -think adding the 3.25 track to stock bikes. cant beat 3.25 in the deep however i prefer the SS 137 for kniff edge handling and faster speed on less deep days.

 

[eric82930]

Yes big hp will help turn a 3.25 but there is still some advantage without it. I don't think it would be wise choice on my 250sx tough. We ride at 10k feet everything feels a bit wheezy but I rode it around my house at 7k below zero air temp and had some real power to throw those paddles around.

 

[dooman92]

byeatts, what year yeti and what mods to accomplish the 3.25. interesting. I have been happy with my yetis. With my limited experience thus far I think I would prefer my 22 yeti to the MTN top in all but the 2-3 feet fresh we are currently riding. I've pushed snow going up hill with the new 3.25. impressive in the deep. more vibration than the yeti also. did you notice any additional vibration with your conversion. I feel it mostly in foot pegs

 

[byeatts]

I have zero vibration it rolls same as all the yetis we built. the Avid drivers roll flawlessly,My motor is the real deal , Head porting by Beta race dept, High RPM rev cam, 97mm BB high comp piston, RP exhaust, custom mapping, airforce intake, Far stronger than the CR 500 we built.It does not feel any of the effects in reguards to track speed others have mentioned. the 3.25 isnt as precise handling as my favotite SS 137 with 2.6 . but it climbs like a sled and wheelies all day long, its wildly to ride takes more energy since its soo lively but in every ride we look for terrain that looks unridable to climb soo it suits our riding style well. still dialing in the suspension to keep ski down and playfull at the same time , The lockout switch has made this obtainable. for spring snow i may toss on the SS137 skid only takes 30 min., so i agree its a powder tool probably not for everyone. also the 3.25 track weighs in at only juan pound more than the 2.6 yeti 129 track on digital scale .

 

[eric82930]

Mine vibrates in the pegs too. If you look at the avid drivers there is no round wheel like the normal drivers. They are shaped like a pentastar. Some weird changing radius technology going on but they will never skip.

 

[dooman92]

byeatts, what year yeti did you put the 3.25 on. My impression is that it would not fit in my 22 yeti tunnel. Are the avid drivers needed to make it fit? Is the yeti skid the same rail spacing as MTN top? Regarding the vibration, I'm thinking the cf tunnel might absorb more vibration than the aluminum.

 

[byeatts]

byeatts, what year yeti did you put the 3.25 on. My impression is that it would not fit in my 22 yeti tunnel. Are the avid drivers needed to make it fit? Is the yeti skid the same rail spacing as MTN top? Regarding the vibration, I'm thinking the cf tunnel might absorb more vibration than the aluminum.

It will drop right in any 2020 and newer tunnel , kit has new rotor, master cylinder , slave cylinder ,break cover, side bearing , Avid drivers and track, There is Zero vibration, remember the drivers need timed and installed correctly , Pressing drivers on wrong or too far causes out of allignment and is what causes vibration.It can cause vibration on the side clips hitting the teeth if not centered properly. Im contemplating cutting juan down to 10 inch wide and running in a 129 SS tunnel. The SS has knife edge handling so could be interesting however i need to study clearances for the new brake system since that axle is 2 inchs shorter . 3.25 has same narrow rail spacing as yeti. the 3.25 is more than double the traction value over the 2.6 yeti, other kits cannot follow even staying in my tracks on climbs .Its really that good '

 

[snowbikethings]

Mine vibrates in the pegs too. If you look at the avid drivers there is no round wheel like the normal drivers. They are shaped like a pentastar. Some weird changing radius technology going on but they will never skip.

Mine too, my drivers are perfectly aligned and timed right of course. I thought my motor was blown, I think it's ice buildup sticking in the tunnel causing rubbing. Maybe????

 

[snowbikethings]

Mine too, my drivers are perfectly aligned and timed right of course. I thought my motor was blown, I think it's ice buildup sticking in the tunnel causing rubbing. Maybe????

Also not impressed with the hokey brake lever that you can't even put close to the correct position for people used to mx levers. Not to mention you can't middle finger brake. I would expect more considering the price.

 

[snowbikethings]

good info . sounds like my bike is not a good baseline . I actually gear way up and my 1st gear spins track at 32 MPH, this engine pulls this track hard from a dead stop in deep powder, this gearing makes my 1 st same as most other 2nd gears providing a true overdrive in 5th going 55 mph on trail. Guess i didn't relize how much HP this new motor is making but its really strong however it has everyyhing done and 97MM bore.. Perhaps i re -think adding the 3.25 track to stock bikes. cant beat 3.25 in the deep however i prefer the SS 137 for kniff edge handling and faster speed on less deep days.

Yes tall gearing works on big bores and high horsepower motors making lots of low end power. Tall gearing and making the motor work was my strategy with the 2.6 track, it really really required you to work the motor or just you kind of spin the snow if that makes any sense.

 

[byeatts]

Mine too, my drivers are perfectly aligned and timed right of course. I thought my motor was blown, I think it's ice buildup sticking in the tunnel causing rubbing. Maybe????

Take a close look at the track clips, theres a tab on the inside on every other clip that will contact the side of the driver if not pressed on perfectly, Mine seriously has Zero vibration ,none at all even at 55 mph down the trail, We have used the Avid design drivers for 33 years and none have had any vibration other than one that was contactiong that mentioned side clip , after moving the driver it was resolved , These are the same drivers and track used by Mt Top and they also spin smoothly. Somethig is cleary wrong with install , Also the plastic chain slider that mounts to the tunnel has 2 bolts, If ewe look from the front of tunnel ewe can see the one paddle contacts the backing nut inside the tunnel , I grind that down nearly smooth. its always best to put axle into track before installing to measure the clearance from those slid clips. if too tight the left will hit [ they are offset}and as track rotates the right will hit causing oscillation vibration, clearly there is an install issue.

 

[snowbikethings]

Take a close look at the track clips, theres a tab on the inside on every other clip that will contact the side of the driver if not pressed on perfectly, Mine seriously has Zero vibration ,none at all even at 55 mph down the trail, We have used the Avid design drivers for 33 years and none have had any vibration other than one that was contactiong that mentioned side clip , after moving the driver it was resolved , These are the same drivers and track used by Mt Top and they also spin smoothly. Somethig is cleary wrong with install , Also the plastic chain slider that mounts to the tunnel has 2 bolts, If ewe look from the front of tunnel ewe can see the one paddle contacts the backing nut inside the tunnel , I grind that down nearly smooth. its always best to put axle into track before installing to measure the clearance from those slid clips. if too tight the left will hit [ they are offset}and as track rotates the right will hit causing oscillation vibration, clearly there is an install issue.

Thank you kindly!

 

[snowbikethings]

Take a close look at the track clips, theres a tab on the inside on every other clip that will contact the side of the driver if not pressed on perfectly, Mine seriously has Zero vibration ,none at all even at 55 mph down the trail, We have used the Avid design drivers for 33 years and none have had any vibration other than one that was contactiong that mentioned side clip , after moving the driver it was resolved , These are the same drivers and track used by Mt Top and they also spin smoothly. Somethig is cleary wrong with install , Also the plastic chain slider that mounts to the tunnel has 2 bolts, If ewe look from the front of tunnel ewe can see the one paddle contacts the backing nut inside the tunnel , I grind that down nearly smooth. its always best to put axle into track before installing to measure the clearance from those slid clips. if too tight the left will hit [ they are offset}and as track rotates the right will hit causing oscillation vibration, clearly there is an install issue.

Do you have a way I could contact you re: some other questions. Thanks!

 

[byeatts]

Do you have a way I could contact you re: some other questions. Thanks!

Mod Shop 509 703 2266

 

[byeatts]

Heres the thing , every other window clip has a 90 degree inbound tab, Juan on the left and in next window Juan on the right ,so as the driver rotates it will hit a tab on the left and then a tab on the right causing the track to shift left /right , when ewe set up the drivers and set axle/drivers into track it can fit fine however there needs to be additional .030 clearance so the track wont deflect right /left and rolls smooth without contact on either side , Many have made this error and is what typically causes vibration assuming the drivers are timmed correctly.