Stock clutch vs double pulley. Opinions, pros/cons

Hello! So, I am gearing up to start a build thread and doing a little research as I strip down to frames. I would love to hear your opinions on stock clutch vs two pulley racing style clutches. What are you using? Any pros and cons would be great. Also any design ideas for racing clutches such as: distance between clutch pulleys, spring arrangement, and how and where to attach linkage for smooth clutching... if that exists. From what I have read on Fearless fronts design, he says it's instant hard grab and no easing the clutch. Is this pretty standard or can smooth engagement of a racing clutch be achieved? If not, has the hard engage been problematic for anyone?
For these (murray) tractors I will be using 5" pulleys for front and rear for a 1-to-1 ratio, Doc-locked, and are intended for trail riding.

Love to hear any input because I am new and have no benchmark to compare these methods. Thanks everyone!

That is a very good question.  Some run a FearlessFront style double pulley.  I have one on one of my tractors.  I also have a murray that came with a double pulley up by the engine.  Some may call the double pulley overkill and just one more pulley to go bad.  I personally am at a loss.  As for any technical data about placement and distances, I think the modified ATLT is pretty much a guess and go community.  About the most technical of the group is @Mister_Studabaker, but he has a drive shaft and no belt.

My Amf has a double pulley clutch and it’s nice and progressive. It’s all about your linkage ratios. I just drilled a series of holes in my linkage arms as close as possible so I had lots of options, and played with it till the full travel of the clutch pedal resulted in the right amount of clutch movement. I was able to go from a sort of on off switch of a clutch to a nice progressive clutch just playing with the holes

The closer the pulleys are the tighter it will hold the belt when engaged

Thank you all for responding, this is exactly what I was hoping for... it's possible lol. I'm looking maximum control of the clutch.

Thanks @MightyRaze, I have watched every video i could find on double clutches and no one goes beyond basic theory. I am also familiar with Mister Studabaker's work, and your right... he's a fantastic fabricator. I am hoping to get some feedback on how everyone has done theirs, what worked, and what didn't. I love to discuss things at the technical level because I think that way, but I don't discredit the trial and error method. It's how we learn, and I'm thankful to those who have and share their trials and errors. That's what I like best about this forum, acceptance of all skill levels. I'm a beginner, made my first weld last week. Put a pulley on a weld hub, looks awful lol. We share what we know so we can grow  

Thanks CraftsmanQuad19, the closer the pulleys are together, the more surface area in contact with the belt, therefore tighter hold on the belt. I will add this to the list.

@Creepycrawler, you have an AMF? I want one! Man, I bought a wheelhorse c-125 because I saw what wheelhorses were capable of in your vids, Crazy Carl too. Future build though. Great idea drilling multiple holes ahead of time. Makes for quicker adjustment and fine tuning too. Having read your response, I think I remember you posting that same info before. Stupid short term hazes out once-in-a-while lol. So may I ask about your double pulley clutches? Is the pivot centered on the center line between the pulleys or offset to the side of the pulley armature? Is the linkage arm at the pivot, or about what distance from pivot?

I get it, it's a lever... the further from the pivot, the more leverage or "pull" a linkage or spring will have. But I'm driving myself crazy on where to start. Should the linkage leverage be maximized with the linkage arm placed near the pulley or if the linkage arm is near the pivot you get more control at the expense of leverage? Basically, will i have a hard time depressing the clutch pedal if the linkage arm is at the pivot?

I've ran both single and double pulley clutches and it never made a huge difference. The Murray single pulley clutch doesn't let the belt get a lot of surface area on the pulley but it's actually a pretty good concept. They can work if tuned right, but they just aren't what I like. I used a double pulley clutch on the Mountain Murray, thinking it would fix a bunch of problems. Instead it just created a bunch of problems. It wasn't worth the hassle if you ask me. Constantly throwing the belt and it was a pain to get back on, bad fitment, hard to get the right pulleys. I had to add an idler pulley up front, add belt guides on the rear pulley, I finished the build around November and I think I finally got it tuned last month. Just not worth the hassle if you ask me. Of course, I didn't build the clutch, Murray did, so I can't say anything about a homemade one. The way I saw it, it was easier to put the belt on the single pulley than the double pulley when it threw it. I'm gonna look into building a nice smooth clutch on the new build that won't throw the belt. But for now, I'm still a stock clutch guy.

There's my 2 cents.

Thank you @Murraymountain! Your 2 cents is a valued commodity, as are all the opinions. Everyones 2 cents together adds up to make a lot of cents (sense lol.) I am researching alternatives because one of the 3 murrays I have has had a pulley swap and locker already done. Plastic stock clutch pulley gets very hot on a short test drive. It's starting to melt a bit, but I think its the wrong size belt. It's loose with the tensioner maxed out. I think the slippage is causing the extra friction on top of the added rotational speed of the pulley swap. Or is this just normal and those plastic pulleys need occasional replacing?

Yes you normally have to replace them. But I'd just replace it with a steel flat idler from TSC. I can guarantee that it won't melt...


(man I haven't used an emoji in forever)

I have the steel replacement pulley... it was that or the double clutch lol. I cant get the spacer into the new pulley bearing so i was looking into the racing clutch. So my options were:
1) continue cursing at the spacer as I try to press it without a press lol
2) cut off stub on stock clutch and weld in a bolt
3) custom clutch

PS- I'm proud to be the recipient of a thumbs up emoji, thank you lol! And... I have the same moto that describes why I do off the wall stuff... "because we can"

I have 2 plastic clutch idlers on my craftsman and I haven’t had a problem with them.

CraftsmanQuad19 wrote:

I have 2 plastic clutch idlers on my craftsman and I haven’t had a problem with them.

I have 2 on the Mountain Murray as well and haven't had much of a problem with them. It's the single pulley clutches though. Those are the ones that melt them real fast.

Just a reminder to never assume! Measure first... I pressed it and cracked it. Man you should have seen it pop out when I went to press it back out. Lol, I was prepared for it at least. Hmm...

Yep, I tried that once. Just cracked it.

TSC also sells the reducer for about $2 and some change. Don't remember the dimensions but it looks like a spline.

Thanks Murraymountain! I went right down to TSC and found one left in stock! I had high hopes as my local store is usually out of stock on every item you go in for. Once home, I easily pressed the adapter in with a 1/2" shaft bolt and nut. Just put the bolt through both and cranked the nut until it was in. I think I will run the factory clutch for now and play with custom clutches later. This will give me some experience to benchmark any future changes. Thanks everyone!

For me the motivation to do a double pulley clutch is usually found from the stock clutch being in an inconvenient location. Craftsmans have this problem as their clutch pulley is right up in the front next to the drive pulley, making anything bigger than a 5 or 6" pulley just about unusable with the stock clutch. If I'm having belt slip i usually need to downshift anyway. The only time I use high gears in water is when i screw around on flooded roads.

https://www.ebay.com/itm/Craftsman-GT6000-Clutch-Arm-Assembly-161590-532173438-532139123-131494-139123/124234871872?hash=item1cecf9b440:g:A6sAAOSwih5e898L

I have used these clutches on a couple builds now, including the AMF, they are easy to find, they already have a nice shoulder bolt based pivot and have built in belt guards so it saves you a ton of work. they are the factory clutch on gt6000 craftsman garden tractors. They seem to work very well. Id say the biggest advantage to a double pulley clutch is the fact that they can take up way more slack than a normal single pulley clutch. so you can run a slightly longer belt or just have a stronger engagement of a worn out belt. my wheel horse has a single pulley system and it makes a huge difference on the clutch engagement depending on how worn the belt it. where the amf doesnt seem to mind a worn belt as much

RichieRichOverdrive, that is the kind of info I was hoping for. Very informative. This helps me understand for what applications a double clutch would be best suited. Thank you for your help.

Creepycrawler, Also full of good info. That link is a great example (pictures) and I see why that clutch assembly would be a good performer and definitely a time saver. That clutch assembly goes in mental inventory lol. Thanks for the link and all your help.

I'll be the first to admit that I tend to overthink things, but an informed decision is always best. Thanks for all the educational info guys, it's very much appreciated!

Here’s my setup, much better than stock and Didn’t require any welding at all