front fork geometry 1960 650

thomthom · Post by **thomthom** » Sun Nov 18, 2007 10:30 pm

I can now see that my bike (1960 Matchless 650 De Luxe) has been dropped on to it's nearside. The front brake lever has been ground down. There is a scar on the timing case from the fixing screw aft of the cylinder down to the "M" emblem. The font crash bar has scuff marks concurrent with being dropped. The front wheel is not correct for the year and model.

Now that I have removed the front mudguard, I can see that it has been worn away on the near side in way of the recess for the front fork cover tube slide. The forks do not appear bent and from the days when I did ride it I don't recall any handling problems. What should be the approx clearance between the fork slider and the mudguard when the fork springs are compressed.

I am fairly sure that the bike was attached to a chair at some time in it's life. Is the only difference between forks of each application the spring rating.

Biscuit · Post by **Biscuit** » Sun Nov 18, 2007 10:43 pm

The only difference is indeed the spring rating.

The holes in the mudguard are elongated and it is possible to bias the 'guard to the centre position as the bolts are tightened.

Won't do any harm to reiterate this - On the nearside there must be studs for the mudguard stay and bolts on the offside. The brake stay should fit between the mudguard and the slider.

Sometime ago Spriddler dropped his bike whilst admiring the South Downs, and bent the frame. he can probably tell you more.Edited by - Biscuit on 18 Nov 2007 10:45:35 PM

SPRIDDLER · Post by **SPRIDDLER** » Mon Nov 19, 2007 12:00 am

quote:
Sometime ago Spriddler dropped his bike whilst admiring the South Downs, and bent the frame. he can probably tell you more.
Just home tonight from a couple of weeks in France -
Hmm, yes there have been several off-road deviations Most recently whilst trying to evict a wasp or bee from inside my visor at about 40mph in a leafy lane on a right-hander.
Cross-eyed and distracted it seems that I must have drifted wide. Apparently the car driver following me had some difficulty pulling me out of the hedge without my co-operation.
Some months after getting the bike back on the road and prior to riding to this year's International I decided to overhaul the front forks because the front end wobbled enough to shimmy my shoulders when I took one hand off the bars to signal; especially when braking or when fully loaded with camping gear.
Also two of the front mudguard stay lugs had been broken off the fork sliders for a year or so, although they were still attached to the stays. I felt however that this was not ideal.
Upon stripping the forks I found to my surprise that both stanchions were deeply and seriously cracked for about 25 - 30% of their circumference at the point where the bottom yoke clamps them. I assume this was as a result of one or more of my involuntary off-road events. Whether replacing the fork bushes and seals etc or the replacement stanchions cured the wobble I cannot be sure but it doesn't wobble as much now.
What the eye doesn't see, the heart....... etc?

itma · Post by **itma** » Mon Nov 19, 2007 9:13 am

did everything in France wobble OK?

SPRIDDLER · Post by **SPRIDDLER** » Mon Nov 19, 2007 11:30 am

quote:
did everything in France wobble OK?

Yes, thank you Ken - and I didn't fall off in the Pyrenees, but had to sin for my supper two days last week helping out 'une madame' on a steep Normandy farmhouse roof, IN THE SNOW.
The lady's husband was a banned from driving alcoholic plumber, so her live-in lover drove for him. He was out a lot.
Sorry, this shouldn't be in the 'Help' section but I can't find the 'Counselling' forum.

Merlin · Post by **Merlin** » Mon Nov 19, 2007 11:43 am

Which job did you take over plumber or lover

SPRIDDLER · Post by **SPRIDDLER** » Mon Nov 19, 2007 1:55 pm

quote:
Which job did you take over plumber or lover

I'd have posted a photo but my link wouldn't work.

(Now leaving this 'Help' thread before I get my wrists slapped).

itma · Post by **itma** » Mon Nov 19, 2007 3:41 pm

just the alcohol part.........

thomthom · Post by **thomthom** » Tue Nov 20, 2007 9:26 am

Biscuit. Thank you for that.

The mudguard stay was secured with bolts on both sides.

The threads (for the mudguard/brake stay, bolts/studs) in the sliders are all damaged. My intention is to repair them with helicoils.

itma · Post by **itma** » Tue Nov 20, 2007 10:02 am

Be very careful with those holes that serve to hold the brake stay, any weakening of the metal around this area will be LETHAL.
As in very dead.
If in doubt take advice.
For my part I would have reservations about the use of helicoils here.