Clutch slip

[florence]

After suffering the dreaded clutch slip I have at last got round to addressing the problem.  My bike needed an oil change and I had a day off work, so I thought I would just go for it.

Having drained the oil, and removed the oil filter, I then undid all the fasteners feeling really pleased that I had used Allen screws when I built the bike all those years ago.  I found taking off the footrests made life easier and was quick to do. Kick starter off, then, with finger in oil filler hole and a small tap with a mallet, despite being undisturbed since 1995, the cover popped off easily.  Worth noting, there is a crevice between the crankcase and the clutch cover which collects road grit, I wish I had noticed before it was deposited on the sprocket but with careful work using oil and a paint brush, I was able to clean up to my satisfaction.  The annoying part of removing gasket residue came next, gentle and careful use of a flat metal scraper worked well and no damage or marks to the gasket surface. 

I replaced the clutch plates with EBC CK1135 and controversially opted for EBC heavy duty springs as I gambled that a heavier clutch was worth the risk to avoid having to strip down once again.

Now, the next day, it is all back together and I have to say the results are extraordinary, it feels like a different bike.  Despite using the heavy duty springs, the feel from the lever is excellent, feels 'springy' and not heavy at all.  Happy to hold in in traffic and most importantly of all, no slip whatsoever, crisp take off and when changing down and opening up the throttle, such as when overtaking, instant power right through the power band.

I thought I would share this because it has been a fault I have just been putting up with for many years and I was surprised how easy it was to do and also not terribly expensive.  My bike is transformed.

[Johnwebley]

Always worthwhile draining the oil when working on the clutch,

I once tried it by putting the bike on the side stand,

Not a good idea,

You get a much better gasket seal if it is dry,

But one learns from experience

Sent from my SM-A546E using Tapatalk

[Oddjob]

Did you check the basket for back and too play, the damper rubbers incorporated in the basket can get hard and cause a slight judder as the bike takes off and it also makes a noise at tickover. The 500 for some reason doesn't suffer from damper rubber problems half as much as the 550, which is odd considering they use an almost identical setup and the same rubbers.

[florence]

that is a good shout and no, I did not check that.  I didn't notice any excessive back and forth play but wasn't particularly looking for it.  Luckily, it seems to be in good condition and no juddering.  Feels like I could probably do a 'wheelie', were I that way inclined, which of course I am not.  ( I did do one once by accident on my CX500, I was in a hurry, quite frightening).

[Robert W]

Stock clutches were notoriously poor and slipped soon after. I have Barnett clutches in both my CB500's and heavy duty springs. Yet with the added horsepower from Yoshimura big bore kits and performance cams, I preload the springs with 2mm thick washers drilled out to match the inner spring diameter. 1/4" washers are just about match the OD of the springs.

The Barnett clutches work great but the plates stick together over night. You have to kick the engine over with the clutch pulled in several times to free up the clutch before riding off. It's a real pain when it's a hot day.

[Oddjob]

I raced the engine that ended up doing over 267,000 miles (not kms) in all that time it never slipped, never got the plates stuck together and was never replaced, even the springs were original. I wasn’t exactly hanging about for most of those miles. It’s now done more since then, however the engine felt very tired the last time I rode it and was replaced by a 550 engine whilst the 500 engine got some attention. It might have to have it’s first rebore this time 😀😀

The engine was regularly disassembled and new chains were often fitted along with rings and any bearings that I felt were getting a little worn. They really are pretty bullet proof.