'Tard guys - slipper clutches?

[Kitt]

Hey guys... was planning on grabbing a slipper clutch if I saw them cheap, but Heath was saying that they don't necessarily improve longevity of the motor, and a bike without one is no more likely to pop on engine braking.

I know the performance advantages... but for engine health what's the deal?

[lrrs313]

Just speaking from personal experience, but I went a season and a half before I welded the crank in my KTM, three seasons (alright, 2 seasons plus 5 weekends) before I lost a crank bearing. And that's on the supposedly problem-prone 560.

Course, I have a slipper waiting to be installed......

[seth399]

if you do it, do it for performance. Personally I have a full Hinson clutch in my bike so that should prove reliable as well until I get faster/can use a slipper to advantage

[-jro-]

I have a 2005 4-speed RMZ that Jeff Wood beat the bag outta for a full season and I've run around for a few races alright. No slipper and it's held up aeight.

I'm installing a slipper next week mind you, but more for on-track performance advantages. (aka: lower laptimes).

I don't have any hard data either way on if it extends engine life or not. If it takes stress off the drivetrain and gears, one would think that it helps keep those parts in better shape.

Def something to be said for learning to race a motard hard and fast without a slipper thou. Makes you learn to control the slide yourself and act as the slipper does with your clutch hand/finger. Slipper makes it way easier and takes some of the skill out. Also if you learn to ride with a slipper for day one you aren't going to have that 'omg' moment when you drop it in and it helps smooth you out (aka: faster laptimes).

-alex

[seth399]

I have a 2005 4-speed RMZ that Jeff Wood beat the bag outta for a full season and I've run around for a few races alright. No slipper and it's held up aeight.

I'm installing a slipper next week mind you, but more for on-track performance advantages. (aka: lower laptimes).

I don't have any hard data either way on if it extends engine life or not. If it takes stress off the drivetrain and gears, one would think that it helps keep those parts in better shape.

Def something to be said for learning to race a motard hard and fast without a slipper thou. Makes you learn to control the slide yourself and act as the slipper does with your clutch hand/finger. Slipper makes it way easier and takes some of the skill out. Also if you learn to ride with a slipper for day one you aren't going to have that 'omg' moment when you drop it in and it helps smooth you out (aka: faster laptimes).

-alex

omg, jro stole alex's ride!!

[KB]

Heath who? Heath Smith?

KB

[Tricky Mike]

FWIW Motostrano is having an STM blowout. Half price, playa.
http://www.motostrano.net/the-surface/Clutch-Parts_2
Don't see any YZ stuff, though

[Pittenger5]

FWIW Motostrano is having an STM blowout. Half price, playa.
http://www.motostrano.net/the-surface/Clutch-Parts_2
Don't see any YZ stuff, though

I hate you for pointing that out Tricky Mike

[Tricky Mike]

I know... the only thing that saved my wallet was that they don't have one for my '02

[seth399]

ha, damn no crf450 either

[Slyder]

I gots a slipper, just no motard. Though now I am curious about engine longevity and what not.

Aside from not lasting as long as a non slipper clutch, the only bad thing I've heard of is them failing (not slipping)...not something you want when screaming into a turn

[a13x]

I gots a slipper, just no motard. Though now I am curious about engine longevity and what not.

Aside from not lasting as long as a non slipper clutch, the only bad thing I've heard of is them failing (not slipping)...not something you want when screaming into a turn

For what Kitt is asking about comparing a sportbike and motard is fairly futile. A sportbike is designed for use on the street and pavement (high traction). A motard is a dirtbike that's designed for use in the dirt (low traction).

Apples and Oranges.

[xsiliconkid]

For what Kitt is asking about comparing a sportbike and motard is fairly futile. A sportbike is designed for use on the street and pavement (high traction). A motard is a dirtbike that's designed for use in the dirt (low traction).

Apples and Oranges.

along that line...... if you use original KTM supermotard wheels there is no cush drive.... a bit of a shock for the transmission...

[Jim]

i think manny has one on his bike

[R7]

along that line...... if you use original KTM supermotard wheels there is no cush drive.... a bit of a shock for the transmission...

My KTM factory wheels have the cush drive, they are from a 05 450 SMR/SMC/SX
I'm not sure I buy into the fact that no cush drive is that bad for the transmission, seems hit or miss from what I've read with both setups

[clutch]

It’s raining so here is my two cents.

Ever since 01, I have installed a slipper on every bike that has had a slipper manufactured for it.

It’ like that old saying, something like “once you gone ?????, you’ll never go back”

Anyways, here’s a little blurb that talks about slippers and there is mention of the effect on an engine as well.

Back in the mists of time (well, 1998) when we were cooking up our Ducati Supermoto's debut we were trying to find a way to both make the bike easy to ride quick and, especially as it was my pride and joy, keep it reliable and in one piece. We had decided to use 250 riders, these guys like to arrive at corners, mash the gearbox down three gears and power out of the curve, with their two strokes having no engine breaking and virtually immune to mechanical damage over revving this style is very effective.
A four-stroke single, even a desmo, is not going to appreciate such behavior for long. The engine, valves and bearings are going to be hammered by the sudden over revving (the rev limiter doesn't work when the rear wheel is turning over the engine!) and the rear wheel is going to try to lock up, the rear suspension is going to get bounced around too, destroying all pretence of maintaining grip.
Racing is about far more than power; as the MotoGP warriors are discovering right now, well controlled high corner entry speeds are just as important to a quick lap as sheer grunt.
We fitted a Slipper clutch; it gave us a real advantage, our riders could ride the bike exactly as they wanted, it let the bikes suspension work better coming into and through corners and also let the motor take the abuses of race track use without the constant threat of over revving. As a result we picked up victories at both Daytona and Donington, first time out.

Come on spring!

[xsiliconkid]

My KTM factory wheels have the cush drive, they are from a 05 450 SMR/SMC/SX
I'm not sure I buy into the fact that no cush drive is that bad for the transmission, seems hit or miss from what I've read with both setups

WOW, my 06 (same as 07) SMR 560 - no cush drive...
me must be

[Pittenger5]

So should I buy that slipper, or not.

[Awesome]

Hey guys... was planning on grabbing a slipper clutch if I saw them cheap, but Heath was saying that they don't necessarily improve longevity of the motor, and a bike without one is no more likely to pop on engine braking.

I know the performance advantages... but for engine health what's the deal?

Yes it does help.

Ask Heath how many engines he's gone through and how many races he's missed because of a fucked engine.

[R7]

WOW, my 06 (same as 07) SMR 560 - no cush drive...
me must be

I thought mine was no cushdrive as well until someone bought the same wheels as mine that were described as having a cushdrive. I checked mine and sure enough..it had it. I've changed sprockets on mine 2 or 3 times and never knew, it takes a good tug to get them out unlike a sportbike.

As for keeping the Motard motors together, leave the motor stock and change the oil+filter(s) after every race weekend That being said and sense Heath's name was brought up, those are 2 things he was not good at doing

[xsiliconkid]

As for keeping the Motard motors together, leave the motor stock and change the oil+filter(s) after every race weekend That being said and sense Heath's name was brought up, those are 2 things he was not good at doing

YES, and two more things...

1. they are so easy to overfill with oil (creates big back pressure problems and takes out crankcase seals)
Drain oil completely even kick the motor over (minus plug lead) a few times to get it all out - on the KTM's
1000cc of oil if not changing filters
1200cc with filter change - not a drop more
I change oil after every day and filters every second day of use.

2. Crank case breather - make sure it is free flowing... these singles are HUGE air pumps..... if it's restricted - you have crank case seal problems and therefore crank problems - real quick....

[seth399]

^good point, people should hold the killswitch down and kick it over a few times while draining engine oil. Clutch side, if seperate, should be able to fill a little over specs.