Clutching 101

[rbell14]

Why do so many people use an aftermarket clutch? I assume it provides some increased performance in speed and acceleration. Does it improve the engagement too?

Are there concerns in how the belt wears or other parts associated with an aftermarket clutch?

Just wonder what drives everyone to modify for those who have a stock clutch still.

 

[rbell14]

clutch

Man - 64 people reviewed and nobody can provide some intput on pro/con of adding an aftermarket clutch?

Help please....

 

[1975FA]

Why do so many people use an aftermarket clutch? I assume it provides some increased performance in speed and acceleration. Does it improve the engagement too?

Are there concerns in how the belt wears or other parts associated with an aftermarket clutch?

Just wonder what drives everyone to modify for those who have a stock clutch still.

A few things that come to mind are smoother clutch engagment at a slightly lower rpm. Better use on the camshaft power band. Better fuel economy because the clutch starts driving at a lower rpm. There will be more top end. I'm sure there are a lot more pro's behond these.

 

[yox185]

Clutching is the single upgrade that every snowmobile, regardless of make or model, can benefit from. It might not be for everyone, some people just figure it's good enough. If you're the type of person who likes to get the most out his or her machines then its a must do. That being said there are some trade offs that you will have to except, ie. if you clutch for top end you will lose down low and vice versa. The manufacturers try to please the average person and therefore clutch the sleds in sort of a vanilla way. Not to much in any direction but decent everywhere. Kind of like, in the days before knock sensors, they would de-tune the motors. They had to assume that some dope was going to take gas from his lawnmower, that's been in his back yard for four years, and dump it in his new sled. The rest of us where then forced to re-jet the carbs and install different exhaust systems to get the sled where it should have been from the factory. Clutching is the same to a lesser extent. Most modern day factory setups are pretty close but there is always something left on the table.

 

[rbell14]

So for example if I had the Ulmer stage I clutch I think, based on dyno data I'd experience the following:
- smoother engagement and lower rpm engagement
- quicker from corner to corner and top end speed vs. stock sled set up
- less HP required to go faster throughout the range
- maybe slight improvement to fuel consumption
- top end over 100MPH while stock is low 90's MPH

Any other differneces? Are there modification for rider weight, track height, or riding style or do you just install the kit as provided?

Here is there graph.

http://ulmerracing.com/

 

[yox185]

You will tell him your weight and style and he will give you direction. I highly recommend the Ulmer kit, I have it in my XTX and its spot on. I think you're taking more from the graph than whats actually there. Without getting into a whole lot of back and forth I'll tell you what that kit did for my sled. Engagement is actually a bit higher than stock so maybe a bit harsher as well, but definitely not unacceptable. Corner to corner is the biggest improvement, which is what I was looking for. Top end is maybe a little higher, but I really don't remember the stock. If you're looking for a plug-and-play kit you found it.

 

[cjjeeper]

look around too

If you are still looking as I am you might want to check out Schmitt Bros kit too. I have heard great things on that kit as well from members here.

 

[Filks]

I've been on the fence about what to do with regards to clutching so I'm intrigued by this as well. Perhaps another question to ask would be the advantage/disadvantage of using an aftermarket setup (Ulmer/SB/etc) vs. stock bits available from Yamaha that I see people chatting about on here (14.5 rollers and springs). Clutch kits aren't exactly inexpensive so what provides the best bang for the buck - regardless of clutching for specific application ie. speed, low engagement, etc.

 

[yox185]

I've been on the fence about what to do with regards to clutching so I'm intrigued by this as well. Perhaps another question to ask would be the advantage/disadvantage of using an aftermarket setup (Ulmer/SB/etc) vs. stock bits available from Yamaha that I see people chatting about on here (14.5 rollers and springs). Clutch kits aren't exactly inexpensive so what provides the best bang for the buck - regardless of clutching for specific application ie. speed, low engagement, etc.

Excellent point. I can't speak to the adjusting stock clutching because I've never done it. The best part of the aftermarket stuff is adjustability. With stock weights you will need to drill out rivets and install rivets. Aftermarket is remove screw add screw. For me it comes down to time and patience to test and retest. Plus with the aftermarket stuff most of the leg work is done for you.

 

[Dodge Ram]

clutching

I have the SB stage 2 kit. Put it in in the summer and rode with it 2 x so far here in Michigan. Love it! I can acutally back it up or didtch bang at low speeds. Before I had to back up at 80MPH once the stock clutches engaged. It engages at a much lower RPM but the speed is still there up top. Worth every penny.

 

[judger101]

clutching is something that is specific to each person, sled, and riding situations. Depending on where you ride and your riding style there are a ton of differences that you can play with in your clutching to achieve what you want to do.

 

[Nytro Nork]

When i bought my Nytro a couple years ago it came with a hauck kit. Being fairly new to snowmobiling i had no idea on how to install it so it just sat on the shelf in the garage I also figured it wouldnt make that much difference to my sled anyway. I found a sticky on here last week of how to install the ulmer kit. I watched the vid twice and decided to give it a try installing it myself. Lets just say im kicking myself in the hoop for not doing this 2 yrs ago. Not only did it make my sled pull like a Mofo but it was a joke to install and only took a few minutes. It was set up to run at 8600 - 8800 Rpm's and its right on.

 

[iwillwait4u]

Re: look around too

If you are still looking as I am you might want to check out Schmitt Bros kit too. I have heard great things on that kit as well from members here.

I have the simple schmidt bros comfort clutch. It lowers engagement to 2800 and hits hard on the mid range with top speed 99mph. I think this make gas stations stops and reverse much better with lower engagement.

Brian

 

[nauti1]

X2 on the SB comfort kit, nice smooth engagement, excellent mid range pull,and decent top end. Simple install and you can actually back up with out trenching and load it up into trailer safely.