Lock-up clutches

[Dink]

After opinions on lock-up clutches,for street use.
Which one to use?Why?
Good idea?
Bad idea?
Hints Tips and Tricks?
Application is a heavily Hotted-up Katana Big bore.

Dink

[SOS]

8) Ok Dink for us dummies what are lock-up clutches? 8)

[Dink]

There are two common types.
One is a slider clutch, strictly Drag race only.
The other is a Lock-up, it involves replacing the clutch hat (where the springs sit on GSX clutches) and fitting a spacer to the clutch cover.
It has levers on it that are forced in by centrifugal force, providing extrra clamping pressure to the clutch pack as revs rise,very coomonly used in "street-strip" bikes.
BTW these are the short answers.
Dink

[rosco15]

I'm using the MRE. I like the mtc pressure plate with the buttons installed. I was running without the buttons and the arms dig into the aluminum pretty good. So now I'm running the mre lockup with mtc pressure plate.

[biker66]

I have only good things to say about it after a couple of years on the streets with a lockup.
There's some tinkering if you want to try out the optimal weights on the arms, but it's worth it

As usual, check my site for more info.

[lecroy]

I have never tried one on a street bike, but do drive my bike to and back from the finish line. I am sure we talked about this a few times, so you may want to do a search.

I think it really depends on what your trying to do and what your setup is.

Pro's
You can make them very aggressive, or in my case very lazy.

You should be able to come up with a combination that prevents any slippage.

It may sound good when you bench race with your buds.

Low cost.

Con's
Takes up room.

May be much harder on the pack (depending how you set it up).

Because arm weigt is a function of tire speed and not crank speed, there is only so lite you can go with the spring load.


Remember my 0 - 30 in 1 sec video? Like Ryan said, it launches like a slider it's so soft. This is the result of about 90 pounds of static pressure. Most people will tell you to start around stock, or 200 pounds. With this setup I can pull the clutch in with my little finger and hold it. I have seen guys with door springs stuck on the arm to help overcome cable drag.

http://dickey.intell-a-sys.com/movies/clutch1.wmv

The ones I use are not very tuneable. You can play with the static and dynamic weight by changing the springs and their preload plus the weight of the arms. These were both made by MRE. You need to have buttons put into the hub if you want it to live for any length of time. Plus, without the buttons, I could see where it would tend to stick. I think you would notice this on a street bike.

I would stear you to MTC. Their snowflake would be a better setup than the MRE parts I have.

http://www.mtceng.com/clutches_lockup.htm

I wrote this stupid program to figure pack pressure.

https://dickey.intell-a-sys.com/turbo/lockup.exe

The program is built using LabView 6.1i. You will need to download the LabView runtime engine in order to run it.

http://dickey.intell-a-sys.com/496p/LVRunTimeEng.msi

http://dickey.intell-a-sys.com/496p/lvanlys.dll

The RDB cover was a good investment in my case. I can pull the entire pack in about 5 minutes now. This is a big deal because I am still trying to find a sweet spot and pull the pack on every run. I should have made something like this 20 years ago.



In my case, its been difficult to balance the power / nose-dive / clutch. This years damage....

[Dink]

Lecroy is it a case of you can buy the buttons to install to the clutch hat? Or do you need to buy a hat as well?
Dink

[lecroy]

MTC Part#
CC506 GS1100 Pressure Plate with buttons

If you have the equipment available, you could make your own setup. I would shy away from it just because of the time. I have not seen anyone offering the buttons. But, I would think they would sell you a set if you really wanted to go this route.

I was going to mention that you are correct ...

"The other is a Lock-up, it involves replacing the clutch hat (where the springs sit on GSX clutches) and fitting a spacer to the clutch cover. "

When you use the stock clutch cover, you need the spacer. However, with the RDB cover, this goes away. There are a few things about the cover. The oil cap is the smaller (more common) size. In my case I had to adapt the return line with a custom part.



The basket sets in a bit far so you need to stuff a rag between the hub and cover to make sure you don't drop anything when you pull it apart.



For a streetbike, I am not sure why you would want to put a lockup on. My old GS will spin that little tire long before the clutch gives out.

[RifRafRacing]

Lock up Clutch

I agree,unless the bike does more track duty than street.A good set of fibers(EBC kevlar),good condition steel plates(I like to glass bead them),and heavy duty springs,will hold up to more than the rear tire will.The lock up will improve your 60' times at the track,but will be loose on the street when you hop on it at low rpm. Steve

[biker66]

I had slipping problems and sure, HD springs fixed it.
However, the stiff clutch made riding around town an agony, left arm aching at stops. Not a problem at the tracks
Switching to a lockup and standard springs made all the difference, try it !
As I mostly ride on the streets I chose standard springs to avoid slippage at low rpm:s.
If I were to drag race I'd use lighter/fewer springs to get suitable slippage off the start line.

Yes, it's an expensive solution, but like welding the cank I consider it an insurance for the future.
Whatever I decide to do with my engine I know I've got the clutch sorted

[mike J]

I put a lockup on my street bike. I machined lockup unit and made my own buttons for it. Only two noticable differences. One, the clutch is very hard to pull in at speed, the arms keep it locked up. Two, with the spacer and having to move the clutch cable it's harder to get it into neutral with the engine running. The 1150 seems to be very sensitive to cable location. You move it and it dosen't want to go into neutral at idle, not fun for street riding. My two cents. Mike J

[biker66]

I don't have any problems with my lockup.

What kind of power output do you have?
Have you tried removing weights from the arms?

With correct clutch cable adjustment a difficult neutral sounds more like a warped plate...

[marcovandevelde]

I've an MTC lockup on my street-turbo GS1168.

Because the full torque with a VNT turbo comes in at 3500rpm already, I had to fit all the weigth that could be fitted onto the arms, fitted 6 HD springs, an extra steel plate and now it holds the 200 Nm. I can still pull the clutch in at high engine speeds, works very well.

Marco.

[lecroy]

Its about time you joined in!!!!

Now that we have the MTC expert with us (your the only person I know that is using one), I have a VERY simple question for you.

With the MRE clutchs I have the pack pressure is a function of arm weight and RPM so you can not change the overall shape of the curve. You can fine tune how the weight is added by using different combinations of weights on everyother arm, or change the static force, but not the shape.

I am under the impression that the arms on the MTC clutch you have can use a counter balance spring to determine at what RPM the weight starts to add pressure to the pack. I am under the impression that you can purchase different counter balance springs for it. This would allow you to do almost anything you want with tuning. Not quite as complex as the no transmission fuelers, but compared to the MRE, very flexible.

Also, the spacer you are using looks like my MRE spacers. Could you do me a favor and measure the width of it.

Thanks

[rosco15]

THat looks like the 2 stage and not the multi stage. It works the same as our does. I had talked to MTC about the multi stage at the Norwalk Prostar race. I was looking for more adjustability. I've heard if you don't have a data recorder you can forget it. That came from a guy with the multi stage on his busa dragbike.