Page 2 of 2

Time Will Tell

Posted: Wed Jun 02, 2010 10:19 am
by Wheelman-111
Greetings:

These clutches act a lot like a drum brake, operating in "reverse". Instead of the drum spinning and the shoes applying stopping forces, it is the shoes that spin, and they apply accelerative rotating force to the drum upon contact.

Drum brakes and these clutches both have a sort of "self-lockiing" feature, or not, depending on the location of the fixed pivot point. If the shoe on a brake or a clutch pivots from the end Away from the direction of rotation, then the spinning drum tries to drive the shoe further outward upon contact, thus exponentially increasing the friction and the clutch "locks on" in engagement. Drum brake systems featuring a Double Leading Shoe - Two cams - were developed to take advantage of this phenomenon, though not found on our scooters. Single leading shoe - single brake cam - brakes found on our scooters have only one shoe that uses this extra force, while the other does not. The "leading shoe" often wears faster than the passive one.

Back to these clutches: If the clutch shoe pivots from the other end - closest to the direction of rotation - it just drags passively and uses centrifugal force alone to maintain contact. This obviously can lead to more slippage. I suspect the respective clutch designs of the single-reduction Spree and SB models are different from the Variated, double-reduction models whose clutches spin in the opposite direction. If the shoes are symmetric in the radial plane, it might be possible to flip them over and install them in the opposite direction to regain that self-locking feature. If not, I agree that the greater slippage might lead to a very hot drum and rapid "clutch fade". As was said, time will tell, but a geared-up kitted Spree could sure use a bigger, better clutch to deal with the extra power and tall launch ratio. This is a great idea if it works.

Re: in regaurds to the clutch swap

Posted: Wed Jun 02, 2010 3:12 pm
by Spreetard
Only time will tell. I used a half worn cheap china clutch, but 400 miles has not made it look worse. The questionable aspects of this mod are the reason i do not fully endorse it yet. The clutch definatly would grab better the other way. With normal gearing I thought it would wheelie, but no such luck. :cry: I'll try flipping the clutch pucks when it's not so nice out, but i just wanna ride it as-is for awhile.

Gentlemen, the ball is in your court. Glad you like my discovery.

I would add that the 86/87 case is better for this mod due to the extra reinforcement. An 84/85 case with a cut cover may be prone to breakage, as it lacks the lattucework of internal reinforcement later added by honda-san. I think the cover is more structural on the early models.

Re: in regaurds to the clutch swap

Posted: Wed Jun 02, 2010 4:45 pm
by odinxxix
it was suggested earlier in this thread that one could ghange the springs, so that lead me to PM AE86guy. he told me that he got springs for the variated AF05E and had to heat them and re bend the hook as they were a tad longer then the spree springs. worth a shot? i think so. then you could get like a 2k grab spring. the variated af05e is the aero se50? but if its the same as the elite clutch then there you have it right?

Re: in regaurds to the clutch swap

Posted: Wed Jun 02, 2010 6:19 pm
by Wheelman-111
Greetings:

I have personally noted one significant difference between my stock '87 Aero clutch and the one that adorned my 2001 Elite. The Aero "shoes" were each over 140 grams, if memory serves, while the Elite's were closer to 100. I'm not sure what year it was when the switch to the lighter assembly occurred, but 1994 would be my guess.

probably as a result of its heavier shoes, the Aero's springs were considerably stiffer than the Elite's. I dont' remember gauging them, but installed on the Elite clutch they resulted in a considerable increase in engagement RPM. Might be a good choice for Spree applications if they can be shortened as described. A little torch and some needle-nosed pliers...

Re: in regaurds to the clutch swap

Posted: Wed Jun 02, 2010 9:35 pm
by mopar4u
can someone provide a link to these clutch springs you are talking about heating up and bending?

Re: in regaurds to the clutch swap

Posted: Thu Jun 03, 2010 12:27 am
by bakaracer
mopar4u wrote:can someone provide a link to these clutch springs you are talking about heating up and bending?
use stock yamaha jog springs.there shorter.

Re: in regaurds to the clutch swap

Posted: Thu Jun 03, 2010 12:31 am
by Trafficjamz
If some one sends me jog springs, I wil try to put them in a spree clutch.

Re: in regaurds to the clutch swap

Posted: Fri Jun 04, 2010 7:01 am
by mopar4u
bakaracer wrote:
mopar4u wrote:can someone provide a link to these clutch springs you are talking about heating up and bending?
use stock yamaha jog springs.there shorter.

Will 1k jog springs work? Those are cheap on eBay

Re: in regaurds to the clutch swap

Posted: Fri Jun 04, 2010 11:36 am
by Trafficjamz
mopar4u wrote:
bakaracer wrote:
mopar4u wrote:can someone provide a link to these clutch springs you are talking about heating up and bending?
use stock yamaha jog springs.there shorter.

Will 1k jog springs work? Those are cheap on eBay
no one knows for sure. Any jog springs would be worth a try.