Autoclutch: Love em or hate em?

[Colemanian]

Originally Posted by jgas

Yes, the move to the new type Core seems strange to me when the Z start was so popular and effective. Can we still buy the Z start? Can someone explain the difference, perhaps in terms a dumb Arkie can understand with engineering facts, and also compare real world performance between the Z start and Core? I have read a few posts on this and other sites, but am still not clear on the differences and +/- between the two.

I did notice in this months Dirt Bike mag that several of the Pros in the Tennessee Knock Out used autoclutches. Not currently remembering details of who won, and which auto they used. Anyone know which they used and why? Until recently I have not been reading that many Pros use any autoclutches, but the mags mainly cover WORCS and GNCCs, which are basically easy wide open interstates these days. I raced Loretta Lynns GNCC in 07 and I could have ridden my KLR 650 easily through the entire Sunday long course. I wouldn't have been fast, but would have had no problem finishing. Not much need for any autoclutch there. As we know, a long course Enduro is a different animal, as is all of the "Extreme Enduro" events.

Now that I'm finding that more Pros use Autos in the harder events it makes me a bit more interested in trying one again.

I can give you a vague idea of the mechanical differences.

The z start pro is basically the entire pressure plate system. It is made of two pieces that have ball bearings set in groves that get narrower toward the outsides of the plate. That means the clutch is able to freewheel at idle speeds. As the rpms increase, the ball bearings are forced to the outside by centrifugal force. This takes up the slack in the clutches and away you go. The problem is, at idle the clutch feels very soft, like pinky finger soft, but as the rpms increase the clutch lever gets MUCH firmer. Infact I doubt you could pull the clutch in at wot. The other problem is the clutch becomes more like a light switch, meaning there is no "feel" anymore. You can use it to give the bike a quick rev to get over a log or when you want some wheel spin but you can't manually engage the clutch very well. I didn't have much problem with this because the rekluse gives a very consistent clutch engagement on its own anyway.

The base core is a completely different. It uses an expansion ring that has wedges in it to expand as rpm increases. You simply remove 2 friction plates and 3 steel plates and put the ring in place of these. You install the stock pressure plate with the supplies heavier springs and away you go. The problem is, you have a heavier clutch pull and fewer friction surfaces to take up the wear so you may go through clutch plates faster if you ride hard.

The core exp (only one available for gas gas) is different still. It uses the same expansion ring as the core, but it comes with an inner hub and a billet clutch cover with additional room to run all your friction and steel plates. I'm not sure exactly how, but with this combo you can still have close to the same clutch pull and there is a stock feeling friction point. This is the best of both worlds but it is pricey.

The reason gas gas hasn't developed the z start for our bikes, is they are phasing out that technology. I hope this helps a little. I am no engineer.

[andoman]

Well said.
I believe it is the springs in the Core EXP that give the more consistent feel across the RPM range. It really does feel and act just like a stock clutch regardless of RPM.

[CACTUSREID]

i just went for my 1st ride with the rekluse left hand rear brake installed above my clutch lever on my 11 ec 300 with the core exp installed. I was getting close to taking the exp out and going back to stock, although i love what the rekluse can do, i also hated what it does at the same time. I live/ride in the interior of bc canada in the mountains. missing a hillclimb and suddenly rolling backward possibly off of a rocky climb or sliding backwards with no idea where your going to end up was making me really question whether this clutch was an advantage or just a quick end to my riding days? today just may have been the turning point for keeping the auto clutch,as i was way more confident that i could manage the downsides and still enjoy the advantages of the core exp. I am faster and less tired after a day's riding in the tough snarly stuff than i was without the rekluse. time will tell, as i'm also an old dog trying to learn a new trick!

[andoman]

If I had to choose between the Rekluse and the LHRB it would be a tough call.
The LHRB is so versatile. It shines on long rocky downhills: Shift up a couple of gears so the engine braking isn't a factor and modulate the LHRB and your front brake and you will FLY down really scary stuff.
Use the LHRB as poor mans traction control: A little throttle while modulating he LHRB to maintain traction and there is no snot that you can't get moving on.
When the trail truly becomes a trials course, The LHRB allows a level "creep forward" control that your right foot can never duplicate. Especially when it is the foot that HAS to be on the deck to avoid going down!
As time goes on, you will find yourself using the clutch lever less and less. Eventually you may toss the clutch lever to save the weight and make your bar less cluttered.

[desertgasser300]

Originally Posted by andoman

If I had to choose between the Rekluse and the LHRB it would be a tough call.
The LHRB is so versatile. It shines on long rocky downhills: Shift up a couple of gears so the engine braking isn't a factor and modulate the LHRB and your front brake and you will FLY down really scary stuff.
Use the LHRB as poor mans traction control: A little throttle while modulating he LHRB to maintain traction and there is no snot that you can't get moving on.
When the trail truly becomes a trials course, The LHRB allows a level "creep forward" control that your right foot can never duplicate. Especially when it is the foot that HAS to be on the deck to avoid going down!
As time goes on, you will find yourself using the clutch lever less and less. Eventually you may toss the clutch lever to save the weight and make your bar less cluttered.

Can I ask how you set yours up? Did you buy the kit from Rekluse or make your own?

[andoman]

I ordered the complete Dual LHRB kit from Rekluse.
Consists of:
-LHRB lever/MC
-Hyd line to the rear foot brake
-the "dual" adapter for the foot brake
You'll also need the "Clutch Lever Elimination Kit." This is a short line that goes into the clutch slave to provide a constant static oil supply on the lever side of the slave once the clutch MC and hyd line is removed.
I just looked at the Rekluse website. It looks like they have changed the lever setup from what I have. Their new lever design looks like it better allows for retention of the clutch lever than their old design.