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I also think it would slip when removing springs. The 4rt clutch is quite grabby compared to other models, Elf and light gear oils emphasise the issue more so. The early ones with the small master cylinder were particularly bad. Setting the lever up correctly is quite important and the dimpled plates really do help, much more progressive and will not slip, ever. The Mitani clutch pack is awesome, starts in 1st gear and is quite a bit lighter…. expensive too, but a good investment. I believe there are titanium springs for these, not sure if they give a different feel or are just purely for weight saving

Hi, I have decided to sell my OSSA tr280i it's in fantastic condition and is keep in my house on display please have a good look at the photos you will not find a better example I'm looking for £2000. ONO

Want to know what will happen after you put lighter pressure plate springs then required in your clutch <- it's going to slip in high gear ranges, same as if you leave 2 of the 6 springs out. Rhetorical question but dimpled steel clutch plates in a wet clutch leaves more space for oil between the plates, do you believe that scenario will make the clutch grab stronger or slip easier 🤔 and with dimpled plates having more oil between the plates and less surface area contacting the friction plates, will that make your clutch feel any lighter to pull at the lever, I think not. Throw in some lighter springs and you have a formula for inducing more clutch slip.

Why do they rub? Do the springs have a smaller inside diameter? Is the plate just slightly thicker with the groove to center the springs.

They give a little more leverage for the shock, it’s hard to explain how it feels, but the shock feels a lot more responsive to rider input. There isn’t much difference when you line them up side by side but it does feel better to ride with. I prefer the feel of the Showa shock compared to the RCV thingy and run with about 7 threads showing below the lock ring. Be careful though as it can be a little more prone to throwing you over the bars until you are used to it. Make sure your bearings and bushes are good. 1mm of play in the linkage turns in to a lot at the rear wheel. Don’t skrimp and buy the all balls kit, Always get the genuine Honda bushes and most importantly the spherical bearing, it’s a world apart from all balls quality

What model tire exactly, is it a tube type tire that you bought? that would account for it, tubeless rims are different profile. ... if it is a tube type tire sell it to somebody that rides an old TY.

I live in the muddy South of England and was persuaded to buy an IRC insread of my usually Michelin. Well it may be very good in the mud but it would be nice if it didn't keep going flat (on my recent TRRS). I moaned about it to my regular riding mates and they said, "Oh yes they deflate all the time" and then they offered various suggestions to keep the air in the tire, sticky rim tapes and inflating to 70 psi were a couple. However my conclusion was that I would never buy another one, no matter how good they are claimed to be. To discover your tire's gone flat halfway through an event is a complete pain especially if you're nowhere near your wheels. And no I don't want to carry a pump with me. As far as I'm concerned they are not fit for purpose on my trials bike, but maybe they work properly on different shaped rims?

The problem you are noting with the Beta 4T throttle response is they fitted the bike with a CV carburetor. Vacuum operated carburetors rob engine intake vacuum pressure to operate the carburetor negatively effecting both the throttle response and the engine performance, in PGM-Fi fuel systems 100% of the engine vacuum pressure is dedicated to intake of air & fuel, Fi does not exhibit the throttle lag and occasional misfires inherent to the CV carbs normal operation.

Are HP and torque numbers available for the standard Beta 300 4t, maybe with rpm numbers? I have one of those too. In a tight section, the Montesa feels much more powerful so I need to use very little throttle. I thought it was overall more powerful. However, the other day I took it to some open trails with good size hills. There it feels similar to the Beta. I wonder if there is a real power difference or if the fuel injection just makes it more responsive.

Hello friends. I’ve become the owner of a wrecked 1987 BETA TR34, which is now running again, although it still needs quite a few things to be fully finished. In any case, it’s already rideable, but I have a problem with the clutch. According to the available parts catalogues, it seems that at some point in the past someone replaced the clutch basket with a 1989 model, because mine is an open-type basket, while the catalogue shows that it should be closed around the perimeter (and based on posts I’ve read here on the forum, the closed one should actually be better than the original type). The problem is that the clutch slips at higher RPM. I would like to ask if anyone has the specifications or measurements of the pressure springs in the clutch basket, and if you could share them. Mine seem visually a bit tired, and after measuring them they’re about 36 mm long — but I haven’t found any information anywhere about what the correct length should be when they are in good condition. The friction plates are in nice shape (around 3.6 mm if I remember correctly) and the steel plates also look OK — around 2 mm thick, not warped or discolored from overheating. Thank you very much for any clarification. Martin Gáborko

Yes that normal trashy clutch sound in neutral the 5 plate Montesa clutch does not exhibit, the TRS o-ring fail was very early after receipt of the bike, was leaking down from the start. Fortunately I rarely have clutch problems with any of my vehicles, that tractor lube works perfect, you just never even tried it to know better.

That is 'nornal' on a diaphram clutch! The oring should not go bad if you are using mineral oil. Must be that tractor lube!

Yes 2 and experienced a failure in a TRS clutch O-ring already. The clutch is not up to par with HRC Cota 315 or 4RT, I have to keep it engaged or it sounds like a bag of bolts.

You were repying to me, again! LOL The Montesa clutch has never been very good ever. But we all have opinions. You should know better. Don't you ride a TRS now?

any particular reason you made that a reply to my post or is that just a habit 🤔

There is a reason the hrc machines use a different clutch.

The 4RT 301RR makes a pathetic 16.3 HP , 1 HP more than a VERTIGO 125 but the 301RR puts out 15.1 ft/lbs torque , where as the VERTIGO 125 makes 8.8 ft/lbs . With that much torque output of the 301 it may be better leaving it with the stock clutch spring set up. 4RT 260 makes 15.6 HP and 13.4 ft/lbs torque

Personally I think you are trying to improve the best clutch in the industry. Hasn't been mentioned yet but there are 2 types of friction plates in the Cota clutch, 3 corks and 2 paper, the consensus was the paper plate gives the clutch more bite, or absorbs less oil and exhibits less compression, depending how you look at it. Key to making the clutch pull lighter is not to weaken the clutch but to improve your clutch actuator leverage at the levers, the further you hold the lever out from the pivot point the more leverage you have against the hydraulics and the greater your friction range is.

The plate holds the springs straight. They other wise rub on the towers. The springs are much lighter. Available from Webike.

There are springs and plate available which improves the clutch feel. of course it`s only available in Japan.

It is a chamber but will never be an expansion chamber like we found on enduro motorcycles simply because the shape and position is not right.

I managed to rip it out, turns out the baffle tube is titanium just like the outer. Took about 4 hours of hammer, lever bar and brute force. NOT FOR THE FAINT HEARTED! I repacked the silencer while I was at it. Started the bike up in the shed and very crisp note, slightly louder. I'm interested to see what it rides like potentially utilising the expansion chamber shape for the first time ever...!

like you said it works the reverse way, the springs push the plates out to the pressure plate on the end, when operated the pressure plate pushes toward the engine and releases the clutch. I've only ridden a few 4RT's and found the clutch to be of a light action so I would compare yours to others before adjusting the springs. It may be you have another issue

Thanks for the clarification. I was installing some spacers to reduce spring preload. I planned to pop the plates out to see if it had dimpled plates but was surprised that the plates could not just slip out. It is sort of the reverse of every other bike clutch I have ever had apart. I learned something new.