First ride...

Well, I fell in love with the chance of buying a yellow 1100. I bought it from a dealer without seeing or riding it. The condition is immaculate. It's a 2006 40k.
Being long I took GRiSO ghetto advice and got lower pegs and a corban seat and have a great seating position!

I had read about riding in town environments and that the bike was best suited for open road, first thing I noticed was how high the gearing is and clutch slip is needed starting, but what I didn't expect was knocking at low speeds, seemed to come from gearbox end, I would be very interested to hear if this is characteristic of the GRiSO or I may need to repair/replace something.

Bernie

What year is it? And when you say ‘Knocking’ do you mean that as you release the clutch in a ‘Low acceleration’ manoeuvre you get a sort of ‘Clacking’ noise and slightly jerky movement from the drive train?

Yea, its a 2006 model, well the first maneuver releasing the clutch ( slipping it ) goes ok, its accelerating after that, and if revs drop just after at a low speed (in first gear)it clacks jerks, makes quite some noise in the drive chain.

It sounds like the face cam shock absorber issue that affected some of the early 1100’s. Do a search for ‘Face cam’ and see what it turns up. If nothing I’ll explain in the morning. It’s 1.30 AM here and I’ve just been woken up by thunder….grrrrrrrrr!

Hi Pete,

Thanks for the tip. I've been searching and haven't found anything yet. I hope the thunder lets you get back to a good night's sleep!

OK, I’m sure I’ve covered this before but here we go again.

Unlike the 1200 8V bikes the 850, 1100 and 1200 models that use the venerable pushrod motor still retain the twin plate clutch that had been used virtually unchanged since the advent of the V7 in 1967.

This set up does not include any form of cush drive or shock absorber in the clutch mechanism itself which means that all shock loadings get delivered ‘Unadulterated’ to the transmission driveline. On earlier models, most of them anyway, there was a rubber cush system incorporated in the rear wheel hub, the CARC series bikes don’t have this, although they do have a two part driveshaft with a bonded rubber *Sleeve* between the inner and outer parts that is supposed to offer some form of shock absorption.

All the earlier four and five speed gearboxes though also used a shock absorber on the input shaft of the gearbox and this was carried over to the ‘Nuovo Six Speed’ used on the CARC models. The way this works is shown below.

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Part#8 is the primary drive gear and this incorporates two of the ramps of the cush mechanism. Facing it is part # 10 which is the collar with the other two ramps that interlock with those on the primary gear.

Part # 10 is preloaded by, on the old four and five speed boxes up until about ‘95 a dirty great fuck-off coil spring but as power and shock loadings increased these became fracture prone with catastrophic results. So, instead of the spring the factory changed to a stack of opposed Bellville washers that performed the same function, or were meant to, these are parts # 13 in the diagram.

Now those washers are only meant to deform under quite heavy load and what causes them to do so is the two cam faces on 8 & 10 sliding up each other as a shock loading is applied and then, when the loading is removed they slide back down and the stored energy is dumped back into the driveline *Softening’ the shock.

When the two cam faces are ‘At rest’ as it were there are three very thin wavy washers, parts # 11, that are supposed to impose a slight preload on the cam faces to stop them rattling. All clear as mud?

Anyway, the problem was that in those very early ‘Nuovo Six Speed’ boxes either the wavy washers were omitted or for whatever reason the Bellville washer tower collapsed, I honestly can’t remember now, it was a l-o-n-g time ago, but the result was that when pulling away from a standstill or at light throttle openings the face cams would work under much lighter than originally designed loadings leading to the jerky power delivery and, in some extreme cases a lot of clatter at idle.

The *Fix* was/is to insert the wavy washers if they aren’t there or add a few more to increase the preload on the washer stack. I’ve done this several times with mixed results. On a couple of bikes it cured it completely. On a couple of others it cured it but after a while the problem returned!

The factory claimed at the time that it wasn’t important and there was no risk to owners if it wasn’t addressed. I’m very ambivalent about that because if the washer tower collapses far enough the collets that retain the end plate to keep everything in place could jump ship, (Parts # 15.) and once they are floating around free in the gearbox all hell can break out in very short order! I’ve taken apart old five speeders where the spring had broken and this had occurred. It wasn’t pretty and resulted in a rear wheel lock-up at speed with the expected results and hospital stay!

Unfortunately installing the wavy washers, or adding more, is a gearbox out job so it’s fairly time consuming and expensive as well as requiring the gearbox splitting tools if you wish to do it without damage to the cases.

Before the pearl-clutching begins by 2007 they seemed to have got the issue sorted and because the 1200 8V’s use a different clutch system with a cush built in to the friction plate the face cam shock absorber was deleted. Strangely it reappeared in the Cali 1400’s but I think that is because they don’t have the rubber cush in their driveshaft.

Anyway, that probably isn’t what you wanted to hear, sorry, but it’s the most likely cause of your problem.

Oh, and the other thing it might be is the bush and/or spherical bearing in the reaction arm of the CARC. See if there is any play in them and check the bolts, especially the one at the front to the frame, are tight.

Wauw Pete, thank you for that! I've got a lot to digest.... but as a first reaction, It sounds like the face cams.

Damn near perfect day here yesterday!

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Dunno why this ended up in this thread? I thought I’d posted it as a new one No matter. It was still a great day for riding. 27*C, low humidity, light wind, no rain. What’s not to like……

Haha, nice sunny pic, we are just heading into winter in NL, but being a Kiwi I'm heading home for the summer.

As Peter mentioned the reaction arm.
Mine did the same really crappy feel.
Arm felt ok, but when I took it off and knocked the centre out if just fell apart.
Check first as the difference is unbelievable.