ETX-125 DEC LOCK MODIFICATION Last updated: 12 March 2011

Subject:	ETX125PE Dec lock 'flop' problem.
Sent:	Thursday, March 10, 2011 14:25:24
From:	Brian (msa.co@freeuk.com)
I promised a follow-up on the floppy tube syndrome of my ETX.

Grand news. My engineering company produced the goods.

In essence, they cut off the stub axle where the clutch washer is/was
bonded to the shoulder and replaced it with a stainless steel stub.

They cut straight through the plastic and the steel tube liner, leaving
the steel tube in the right tube adaptor which they drilled from the
tube side to take a through bolt and lock washer.

The stub was exactly the same dimensions as the plastic stub, tapped to
take the Dec lock knob bolt in the outer end and an M5x25mm bolt at the
inner, tube end. This bolt went through the right tube adaptor and into
the end of the new steel stub, both of which I fixed in place with
Loctite on the threads and epoxy on the faces of the shoulder and the
end of the stub and also on the washer and bolt head.

It was very fiddly to get the remaining parts assembled correctly.

First I had to clean and de-grease the lock stop / clutch components and
coat the inner face (tube end) of the previously bonded clutch plate
washer with epoxy.
These were then inserted into the compartment behind the large bearing
which was then pressed in place*.
The right tube adaptor was then inserted through the epoxy'd washer, the
worm wheel and the lock stop plate.
The small, outer, bearing was then slipped in place and the whole lot
tightened down lightly with the Dec knob and assorted washers in place.

It was at this point, as I was tidying up, that I discovered a spare
plastic part lying around; yup, you guessed it, the right fork arm inner
cover plate. Off with the dec knob and out with right tube adaptor,
drift out the large bearing and retrieve the cleaned and epoxy'd parts.
Clean everything and start again, this time making sure the cover was in
place before assembly.

Once (correctly) assembled I left everything to cure for 24 hours.

I have to say, the final result is very satisfying to use. It has the
feel of a quality engineered part about it, almost as if it had been
designed to lock the parts together snugly. My tube has never been so
firmly held.

*Had my large bearing been as sloppy a fit as the small one, I could
have assembled everything prior to insertion but it was a tap in / drift
out fit and I was loathe to ream out the casting to make it a sliding
fit. I think if I was to do this again, I would loosen the fit and
assemble the whole thing out of situ and then just slide it all in. Had
the bonded washer been a lug fit into the plastic, of even into the new
steel axle, then it would have been a lot easier to assemble and it
wouldn't have needed to be epoxy'd in place at all. C'est la vie.

I have included some photo's (usual rubbish quality) to show the stub
axle in place and the locking bolt through the right tube adaptor from
the inside. I would have taken some shots of the axle prior to assembly
but the battery on the camera went down at the wrong moment. It looks
exactly like the original, except that the part of the stub axle from
the shoulder outward is steel instead of plastic; easy to visualise I
guess.

Typically it is now a lovely clear night but I am too tired to take
advantage of the sky, so it's off to bed to dream of my lovely new
clutch action. Ooooohhhhh!

Brian Martindale

Picture 1. View showing the through bolt holding the steel axle


Picture 2. View of the assembled steel axle prior to the small bearing going in


Picture 3. View showing the outer end of the steel stub axle with small bearing in situ


Picture 4. Little Blue back to 'better than original'

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