Delta Clutch

Malossi Delta Clutch Review


The Malossi Delta Clutch is fully adjustable. The springs are on serrated plates that can be moved between 3 positions. It also has additional “mass” plates that can be adjusted between 3 positions. Besides that, there are the typical 3-4 springs rates available (white, yellow, blue, red). Adding more spring provides a higher stall speed before they react. By adjusting in additional mass (read: shoe weight) the shoes hook up tighter. Also, the clutch has a better, thicker, non asbestos shoe material than stock with lots of metal in them.


After jettting the new Dellorto 21mm carb to the new Zen 65 pipe and other mods, I began to work on fine tuning my drive train. I’ve had the Malossi Delta Clutch for a while but haven’t bothered to tune it with all of the other engine performance parts/setups in transition. Adding the 16” rear wheel to raise the final drive ratio also played a large part on the final clutch/drive line set up. With all of that is squared away and with my observation cover in place, I was able to see what was happening under the cover while riding (Whoooo, watch out for that car door opening!).

My initial impression of my current setup was it seemed that the clutch/drive line just wasn’t hooking up as good as it should be. I run a Koso variator and had previously tried a variety of weights and settled on 36g (6x6g). I bought a Polini variator spring set (2-large center springs) and tried the blue one first (15% stiffer) with lighter 30g. roller setup (3-6g, 3-4g). The RPM at take off was way too high, it didn’t hook up well and was worse than with the stock center spring. I pulled it out and put in the white spring (7%) and I immediately felt a big difference. I went back to the original 36g setup and it felt better yet. I went back to the blue spring with the 36g and it was even better. I decided to do some clutch adjustments and set the spring rate one notch tighter and moved the adjustable mass blocks all the way out. I also noted that the shoes weren’t making full contact and dressed off the high spots with an extra fine grit on my belt sander. I could tell the clutch hooked up faster and observing the variator under running conditions I could see I had a smooth opening transition all the way through the power band w/ no bog or flat spots. The clutch came with white springs and I still want to experiment with some new yellow clutch springs (next stiffer) to see how they react at a higher RPM, but it is pretty close now to optimal for my set up. I just need to put some drive time on the new clutch shoes to get them to seat better and get full contact.


The center spring ensures that the belt isn’t slipping and holds it back from shifting out of the lower drive range too soon, keeping the optimal gear ratio throughout the total acceleration range. The variator/weights let the engine reach the optimal power band so it doesn’t bog down and get stuck there while transitioning to the higher drive ratio. The heavier shoes ensure that they hook up firmly and the smaller clutch springs let the clutch stall out until a bit higher RPM to keep it in the correct power band. It all works together and if you change one thing, it can effect other areas. Different weight riders/bikes and riding conditions will effect these things too. The idea is to find the “happy medium” that works for you, and without these tuning options, it’s harder to do, but not impossible. For me, I get off on the tuning aspect of getting the most out of my bike.


Overall impression is that the clutch is great for persons who are looking to fine tune their bike to their particular riding style (flats, traffic, hills) and performance setup, or for the weekend warriors/racers. It’s a bit pricey, but for me, it was well worth the $30 extra cost to know what works and what doesn’t, as opposed to thinking I was getting all I could out of what I had from the stock, or Delta Fly (non adjustable) clutch.