clutch plates and steels

[mgentz]

When you get new steels are they dull/shiny metal or are they colored? I ask because my plates are black and blue...burnt...some bikes can come this way...but I am unsure about the 250.

[Motofool]

The discs are made of steel, so steel is their color.

If they are blue, they have been red hot (form sustained skid or overload) at some point of their life within the clutch.

If so, they may be deformed, impairing the proper functioning of the clutch.

[mgentz]

Yea...I figured. I have some that were heat treated for strength before but I forgot this is a 250.

[Racer x]

Some people use a scotch bright and scrub clutch steels when they are new. Don't know why. Also I have seen people soak the plates in ATF before installing. And I don't know why. But I do know if your plates are blue they are trashed.

[mgentz]

Seen some odd things myself.

What plates and steels do you recommend? I will need a stronger clutch.

[Racer x]

I have had good luck with Barnett and hear good things about EBC

[Motofool]

Originally Posted by mgentz

Yea...I figured. I have some that were heat treated for strength before but I forgot this is a 250.

The function of the clutch's discs is to stand friction and to transmit torque in a full bath of warm oil and their flatness is critical (twisted discs don't disengage or engage completely / the clutch drags and skids).

No, for all different bikes that I have worked on, the metal discs are made of low carbon or structural steel (low carbon content / low tensile strength / tempering doesn't improve its strength) that receive no previous tempering and following machining for flattening (tempering introduces deformations (specially for thin plates) that need to be corrected via machining).

The discs of your bike followed the tempered process inside your engine: temperature was increased up to 500~600 F degrees and then cooled down in oil (many times maybe).

That could have been caused for sustained skid or clutching at high rpms' and high torque.

That tempering process may have deformed the discs, without improving their strength.
That high temperature may have weakened your springs (which are made of tempered high carbon-high strength steel).
For the case of the springs, the uncontrolled tempered process inside your engine may have ruined the factory controlled tempered process.

http://en.wikipedia.org/wiki/Tempering#Tempering_colors

A stronger clutch (zero undesired skid at higher torque) with same discs is only achievable with stronger springs.
The only downside is that the control lever requires more manual force.

Heat and high temperatures, that warps metal discs and sometimes reduces the strength of the springs, are the worst (if not the only) enemy of the clutch.

[mgentz]

Yea..I mistyped on my phone. sorry

As for the barnett, are they the ones used on you nitrous bike?

I will need these to handle as mush as possible. I already have strong springs.

[Racer x]

Yes Barnett carbon fiber.

[mgentz]

Originally Posted by Racer x

Yes Barnett carbon fiber.

where does one get that? I searched niche cycles and they list nothing.

[Racer x]

Maybe call them. I found them on E bay. They are rally nice . Tll them racer x recommend them. Hopefully they won't hang up.

[mgentz]

Alright. ..I talked to Barnett and niche cycles. Neither has a carbon fiber clutch. ..just Kevlar.

[mgentz]

also, all of the clutch kits say to not use synthetic oil...did I do my bike an injustice here? Is that why my clutch got toasted without my knowledge?

[tubarney]

They don't make the carbon fibre for the 250. But they make one for the honda crf450r which uses the same plates. Just get 250 steels for the kevlar.

http://www.barnettclutches.com/produ...&clutch_cc=450

With the oil. You will be fine running fully synthetic as long as it is a motorcycle oil. Don't use car oils. EBC recommend an oil with a JASO MA2 rating.

[mgentz]

hmmm. how does the stack height work out? Our inner and outer fibers are different than the three middle ones...

also, can you buy just the 5 required frictions? What sense is it to buy two complete clutch kits...?

[Racer x]

I must have Kevlar and mixed it up . I will check and give you a part number. My new one is still in the bag.

[mgentz]

Originally Posted by Racer x

I must have Kevlar and mixed it up . I will check and give you a part number. My new one is still in the bag.

I think so. Good news here is that I called Barnett and got the CF part number. Niche can work with Barnett/me to get jus the fibers...so I will have a CF kit.

[mgentz]

complete CARBON kit on its way.

FYI, a good way to tell is the Kevlar plates are green the CF are black.

[CZroe]

I've been on the look out for a cheap kit. How much did you pay?

Also, the EBC kits say "friction plates only" and then say that the stack height is exact and perfectly matched. How is that possible without the steel plates?! Are they neglecting to mention that they actually include the plates? I've been looking for a couple years and have yet to see any indication that they do.

[mgentz]

Couple things...

Carbon plates are not cheap. They are Barnett's top of the line plates. When I talekd to the techs, he said that the clutch works better as it gets hotter. Also the holding force (friction) is much greater than their kevlar (or ebc ck clutches). However you need stronger springs and steel plates for the kit to work best...not sure if that was a sales pitch or not but whatever....total price was $105 for the friction and steels. I already hsve strong springs but they can be had for $20 or less.

As for ebc they sell only the frictions and you need to buy oem steels.

To get my "kit" I had to order the individual components from niche cycle. I checked around and their prices were good and included free shipping.

[CZroe]

Originally Posted by mgentz

Couple things...

Carbon plates are not cheap. They are Barnett's top of the line plates. When I talekd to the techs, he said that the clutch works better as it gets hotter. Also the holding force (friction) is much greater than their kevlar (or ebc ck clutches). However you need stronger springs and steel plates for the kit to work best...not sure if that was a sales pitch or not but whatever....total price was $105 for the friction and steels. I already hsve strong springs but they can be had for $20 or less.

As for ebc they sell only the frictions and you need to buy oem steels.

To get my "kit" I had to order the individual components from niche cycle. I checked around and their prices were good and included free shipping.

Is that with some kind of discount? I ask because I think $105 is less than I was quoted for Barnett springs, Kevlar friction plates, and steel plates. How much do you think they'd charge you (me?) for the Kevlar kit with a similar discount?

[mgentz]

They have an ebay add up now for thr kevlar kit. $102 I believe but you csn do a best offer s nd try for less.