Maico clutch coil spring conversion.

[firko]

I've had this Wheelsmith coil spring conversion for years and have decided it's time to bite the bullet and give it a try on the new 350 oval engine I'm building. In a nutshell is replaces the Belville stacked washer set up with what should be something easier to set up. The clutch I'm using is a Magnum forged basket with Barnett plates and stock steel plates (Thanks Doug/FlyingDG). Has anybody had any experience with the coil conversion and if so, is there any pitfalls to watch out for? I fitted this spring for a brief time back in the early 90's on my 440 but I couldn't adjust the drag out of it with the cable whereas the usual Belville stacked setup had worked flawlessly. In truth I only ever did a few laps of Nepean with the coil and swapped later that same day so I didn't put much experimentation into it. 
                                                                                         
 
Replace that stack of beveled clutch washers with a single spring! Not only will clutch action be lighter and smoother, but you'll never again have to try to remember which way the stupid washers go together. 

Wheelsmith back when, was the first Maico shop to figure out how to replace the stupid washers with something better and more consistent. We duplicated their design and had new clutch springs manufactured to those specs.

Note that these springs are properly manufactured and heat-treated by an aftermarket motorcycle firm that makes nothing but springs. This isn't some hunk of fork spring hacked off to length.

Because these spring are properly designed, manufactured and heat-treated, they will not sack out quickly as some other versions do.

Easy to install: pull the clutch cover, compress the clutch, remove the beveled washers and install the clutch spring. Reassemble and you're good to go.
 

[Husabergpete]

Firko,

We have just fitted one of these to Marks 1977 AW 250.  With mine I left the original bevel springs in. But Mark bought one so in it went. The instructions said NOT to use the standard tab lock washer that sits over the nut for the clutch. We did as suggested and had not issues. It was raced today at Canberra for the first time. My clutch is slightly lighter to the feel but both work well.

We had 4 AW's at the race meeting today. 3 x 250's and a pair of big ones.

All the best

Pete

[firko]

Cheers Pete.....it'll be a while before this engine gets a spin but I'm going to try some new ideas on it, stuff I'd wanted to do to my squarie but because it was going so well I didn't want to upset the combination. This oval will be a rolling test bed for some ideas Jim McCabe put out there, some of mine and some from Doug Gardner.....I'm glad you had no problem with the coil spring, that's one off the list.

[Brian Watson]

When Gary Jones was out here for the Nats at Broady..we had dinner with him on the Sunday night after the racing... as many would know he works for Hinson....testing stuff....they were at the time "re-inventing" the Belville spring system...he said that they (Hinson) were just going back thru history looking at stuff that has been used before and, applying new technology , they are making items again..

[maico67]

I also fitted 1to my AW 250 , have heard different reports on them , good and bad , however it worked fine , and a whole lot lighter as well !

[KTM47]

I fitted the coil spring to my 490 and had all sorts of trouble with it.  I don't recall getting any instructions about not fitting the locking plate.  That probably was the problem as it felt like the coils were binding up.  I also tried Kevlar clutch plates but it ended up slipping.  As soon as it slips the plates are stuffed.  I ended up getting a complete new sintered bronze clutch kit from VMX Services in Holland.  If anyone know the secrets to making the clutch lighter let me know.

[Husabergpete]

KTM47,

That could have been the issue. We found that when we put my AW together the first time, we put a new tab washer in, bent it down in the 3 spots to stop it spinning, but it was Sitting Up, not sitting down flush so as a result the Bevel Springs were Up about half to one mm from where they should be, resulting in Binding and a major issue in getting the retaining ring into the grooves. Gave up, reviewed and found the issue to be that bent up tab lock washer. Such as simple bit of tin that caused so much stress and swearing.

I could understand when the install on the coil spring said to ditch that tab lock washer - but Lock tight the clutch nut.  One less part in the puzzle too.

Pete

[maico67]

To make your 490 clutch lighter , make sure your cable had no sharp bends , also that it runs freely , and install one of those Moose clutch levers from Socal Maico in the states , mine is as easy as !

[KTM47]

Thanks Brett I've got one of those levers from So Cal haven't fitted it yet. But it didn't worry me on Sunday in the 2nd race I still passed you off the start once I got going.

[maico67]

Bast##d ....... Lol  !!!