Clutching on the cheap

[turbo800]

Cranked out a few shims on the lathe today for some testing...

Few different sizes to mix and match:
2- 1mm
2- 2mm
2- 3mm
1- 4mm

 

[cannondale27]

Still waiting for somebody to fire one off and check the engagement speed. Last I heard the MTX was engaging at around 6k, hope that changed.

It says 3900 rpm engagement. Still has that pink spring though.

 

[cannondale27]

Here are all the specs for mtx
.

 

[stingray719]

Here are all the specs for mtx
.View attachment 99539

Interesting, Ulmer said (unless I read it wrong) the MTX was coming with a Blue-Brown-Blue spring. Makes more sense with the GGG and 14.5 rollers, with the middle "green" showing a lower engagement than the "white" middle identifier. The green-green-green shown in your pic is very similar to the green-white-green we put in our cheap kit. I may have to try a GGG with a shim just for fun. This should be interesting!

BBB is 50 - 116 at 98.4mm length

GGG is 40 - 131 at 87.9mm length
GWG is 45 - 136 at 89.8 length

 

[cannondale27]

How do our rollers compare? Can't believe they are running that secondary spring. Do they not ever hold it tight? You know just because casting numbers are same doesn't mean they don't have machining differences. Only way I would be sure would be to measure. Heck you might not even need the shim in your clutch kit anymore. I believe the pocket is machined. At factory they could just machine less or more.

 

[stingray719]

How do our rollers compare? Can't believe they are running that secondary spring. Do they not ever hold it tight? You know just because casting numbers are same doesn't mean they don't have machining differences. Only way I would be sure would be to measure. Heck you might not even need the shim in your clutch kit anymore. I believe the pocket is machined. At factory they could just machine less or more.

Parts fiche shows 8FG-17624-20 in your and my XTX also. Chart below (that I stole from another thread on TY) says ours is 15.6mm. Larger rollers quicker backshift and less belt pressure.

 

[cannondale27]

Thanks. Sure hope the river here is safe this year. Awesome place for testing all these things. Last year it froze nice and then broke up for a week before freezing again leaving big chunks under snow. Was very dangerous if you got off the 1 sled wide path. It's a five minute ride on sled from my house. Well broken in and can't wait to keep it pinned for miles if needed. For me my goal is to get all the performance I have now with a 8jp size belt so I can avoid any machining of the clutches. If my old srx could easily hit 110mph there which it did and more many times with no clutch machining this sled ought to be able to hit 100 or more and have clutches that look as clean as with 8dn. If not can always go back to 8dn.

 

[stingray719]

Thanks. Sure hope the river here is safe this year. Awesome place for testing all these things. Last year it froze nice and then broke up for a week before freezing again leaving big chunks under snow. Was very dangerous if you got off the 1 sled wide path. It's a five minute ride on sled from my house. Well broken in and can't wait to keep it pinned for miles if needed. For me my goal is to get all the performance I have now with a 8jp size belt so I can avoid any machining of the clutches. If my old srx could easily hit 110mph there which it did and more many times with no clutch machining this sled ought to be able to hit 100 or more and have clutches that look as clean as with 8dn. If not can always go back to 8dn.

8DN does not require any clutch machining to work, just 3 washers to change belt deflection. I have an experiment I am doing with Terry to maybe find a cheap and easy solution to the spring bind issue....more to follow after testing.

 

[NOS-PRO]

I am hoping the river is better this year also Cannondale. Plus, I hope the trail is superb by me like it was last year as it is awesome to have my test track 200 feet away from my driveway. 1 nice thing is the groomer will make a turn around for me so I have a fresh track now Timer will be setup on certain days if anyone wants to do testing. (The trail is on my friends property so we can park the sleds, sit and bs....but just need to be courteous to the other trail riders). If needed, my house is right there also

 

[cannondale27]

Can't wait Nos.

Got the new secondary spring from Ulmer. Hope that takes care of binding.

 

[Kerrdog569]

I am hoping the river is better this year also Cannondale. Plus, I hope the trail is superb by me like it was last year as it is awesome to have my test track 200 feet away from my driveway. 1 nice thing is the groomer will make a turn around for me so I have a fresh track now Timer will be setup on certain days if anyone wants to do testing. (The trail is on my friends property so we can park the sleds, sit and bs....but just need to be courteous to the other trail riders). If needed, my house is right there also

I wish I lived closer

 

[Kerrdog569]

8DN does not require any clutch machining to work, just 3 washers to change belt deflection. I have an experiment I am doing with Terry to maybe find a cheap and easy solution to the spring bind issue....more to follow after testing.

I couldn't get the belt deflection I wanted even with 3 washers,the clutch sheaves were almost touching and the belt was still sitting down or almost even with the top of the secondary,could be my belts on the long side of spec too but I sent my clutch for machining anyways to fix both issues,coil bind and belt deflection

 

[stingray719]

I couldn't get the belt deflection I wanted even with 3 washers,the clutch sheaves were almost touching and the belt was still sitting down or almost even with the top of the secondary,could be my belts on the long side of spec too but I sent my clutch for machining anyways to fix both issues,coil bind and belt deflection

You added 3 more everyday variety washers to the original 3 washers and still couldn't get enough? Very odd.

 

[RTX]

You added 3 more everyday variety washers to the original 3 washers and still couldn't get enough? Very odd.

Dont think you can add much more than 3 washers under that bolt.
I think 3-4 washers has the clutch sheaves hit each other.
If i remember right, to get my belt riding at the correct height in the secondary i had to pull out all 3 bolts.

 

[Kerrdog569]

You added 3 more everyday variety washers to the original 3 washers and still couldn't get enough? Very odd.

I got the same washers from my dealer and had three stacked on each bolt so the sheaves were almost touching then I started the sled and ran it then checked the deflection plus how high the belt was riding and it was flush with the top of the secondary and seemed too loose,now on my other brands of sleds I've always ran my belt deflection as tight as possible without the sled wanting to creep ahead,if I grabbed the secondary I could spin the belt around the primary really easy,so it's too loose IMO