MPB Collets, anyone using them?

discussions specific to the 907IE
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FrankS

MPB Collets, anyone using them?

Post by FrankS »

There has been some discussion of the use of closer shim collets made by MPB (in Canada) and sold by California Cycleworks in the US.

I got interested after my most recent shim clearance check, which showed three closer shims loose out of tolerance (i.e. more than 0.05 mm loose). The mechanic at Fay Myers in Denver looked at my little keeper wires, which I had tossed into the envelopes with their respective closers, and told me that the wires were crushed, nothing wrong with the shims.

People on the Vicki Smith's mailing list responded to my message, suggesting that the little half circle wires be replaced with MPB collets, which are expensive but long lasting.

Which brings up two questions:

(1) Any other 907 owners using the collets?

(2) Presumably owners of other Paso models would also be interested. Do I have to re-post this message or does the keeper of the site have a way to forward this message to the other groups?
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fasterdammit
paso grand pooh-bah
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Joined: Wed Jan 19, 2005 12:00 am
model: 750 Paso
year: 1988
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Post by fasterdammit »

I'll post - even though A) I'm not a 907 owner and B) I've only installed the collets in my Monster so far. I do have a 750 and the collets will be going in in short order though.

Having done the job myself I can really see the benefit - not so much from a 'prolonging the service period' point of view, but from an engineering point of view. Martin's collets' essentially reduce the tolerance between the shim bucket and the valve to zero. The half rings they replace create some space and ultimately, the opportunity for freeplay; the collets remove that opportunity and tighten the works up completely.

I installed the collets on my '97 Monster 750 at 36k mi; this was the first time I needed to replace a shim, as well. When installing the collets it turned out that the half-rings they replaced had deformed the valve stem over time. I had sand/file the valve stem back into round in order to remove the shim to begin with. Not fun.

Otherwise, there is no difference in the installation process whether it's collets or half-rings - just that everything is a lot more snug with the collets in place.

As to the 18k mi service interval? Well, let's just say I didn't test it on their say-so - I still checked after 6k and sure enough, it's exactly how I left it in there. I may go the remaining 12k before I check again ... maybe not. Depends how retentive I feel. ;) Besides the point; I'm a believer - they'll be going into my Paso in the next month or so.
Just because you're not dead doesn't necessarily mean you're living, either.
1988 Paso 750 #753965
1997 Monster 750
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