Roadholder Forks

You could Put a cable tie on the stanchions behind the spring or on the covers as a tell tale and see how much the forks move, you may be supprised, I've fitted later dampers and rods in my forks, and I do at least have damping, but it still feels a bit like a rigid! MY rear shock are was too hard and have no damping either, I'll be investing in some hagons when funds allow.

ideally the forks and rear shocks should work in unison.

i should add that long roadholders don't have any serious damping, the rod at the bottom only really works to stop bottoming.

Dan

My 53 M7 is just the same and it's mostly because the springs front and back are really quite stiff. The bikes are heavy so when you put the brakes on there is quite a weight shift due to inertia to the front this manages to compress the front springs slowly and the oil damping has time to move in the damper tube to accommodate the movement but when you are riding, the front is loaded normally so when you hit a bump or hole this very rapid attempt to compress the fork and move the oil in the damper is resisted much more* and as said above the spring is not loaded so heavily by the bike's weight and simply transmits the jarring impact to the rider..

The rear springs, if they are the original type, are very stiff and on my one hardly move at all. The damping unit in these is valved and only works on the rebound so doesn't contribute to the jarring impacts. It is simply that the rear shocks are so stiffly sprung that road shocks are transmitted at the rear so strongly. The combination of the two creates a firm ride but a stable well handling one. Don't forget that tyres are designed to soak up small bumps and ripples so don't over inflate the pressure. Too high a pressure can also lead to spoke breakages.

Les

* You might wish to try very thin oil but bear in mind the rebound damping will also be reduced...this is OK if the front fork action remains controlled...IE: does not become bouncy on bumps.....Les

I had an issue on my 350 Matchless trials forks. It turned out that, although having rebuilt them myself, the new springs supplied by a reputable dealer were too weak, allowing too much sag, using up too much suspension movement. Easily detected though, and solved with a new set of springs.

Do the forks sag when you sit on? Did you rebuild the forks yourself George? If so, what grade and quantity of oil did you use? If you did not, I would be inclined to drain the oil, measure it, and refill with fresh of the correct grade, 20w I suspect.

My short roadholders were too soft, but were vastly improved by increasing the quantity of oil a little. They also have upgraded damper tubes. I don't know if they are available for the long roadholders, but mine work a treat now.

Ian

Your bike has LONG Roadholders George....

Tyre pressures....Are your tyres Classic Tyres?....if so I would stick with the book. I don't use modern tyres

Les

On tyre pressures ignore the book and go by the manufacturers recommendations, tyre construction is now completely different and needs much higher pressures.

The damper tube in long roadholders isn't a tube it's just a tapered rod, if you remove a leg and Spring, you can feel that there is virtually no damping, it's only the oil that is giving any resistance. As said above there's not much you can do other than alter oil viscosity and volume

but You can easily upgrade the forks that will remain visually the same. You'll need to fit the longer damper tubes (P11?) and commando rods. RGM sell them. If you get aluminium tubes make sure you get steel rods. But they tend to rust so if you choose aluminium rods it's best to put a steel bush in the tube cap to reduce wear. You'll also need the top nuts with a threaded insert for the rods to screw into. You could also fit internal springs if you want, I did but am switching back to external as the internal ones are noisy! But they are progressive

you'll also need the commando stanchions if you go down this route, so prob best to do it when they need a rebuild. I think I did it all for less than £200.

I havent ridden on my newly rebuilt short roadholders to make a comparison yet.

Dan

I agree, but the tube is created by the stanchion tube...the damper "rod" is tapered and surrounded in oil which is squeezed increasingly to flow up the stanchion as the fork is compressed finally creating a hydraulic lock to prevent bottoming....Les

Les that's right but in reality it's only compression damping and then only at the end of the fork movement. Take em off and try it!

if you're only pottering around then the upgrade may not be worth the bother, but if you experience patter when cornering, this will fix it.

Hi Dan....I think there is a modecom of damping both ways but it is slight and equal....you are pumping oil through a restriction which absorbs energy. The taper does create more progressive restriction on the end of the down stroke but midway up the travel the damping is equal in both directions. The later valved units with a proper damper tube work better but even these are not as good supposedly as the Matchless Teledraulic ...I can't remember all the details about these forks off hand and when I have a few minutes will recheck just for my own benefit.

Same tyres as me George...Book says 24lbs front.... 23lb rear !

I tend to put about 25lbs in the rear just to eak out the petrol but I'll try 23lb as well

Yes interesting George...I've just checked the source of my info....it was from the official Norton user Manual for 1955 machines.BUT I now realise this was well out of date as the pressures quoted are for the 21" x 3.0 " front tyre....NOT the 19" x 3.25 tyre that we have..It mentions the 19" tyre in the appendix but not a revised pressure...Certainly 20 PSI does seem low so I'll see if I can find some other info to back that figure up....let you know if I do.

Regarding the London Tourist guide....I spent 10 years working in the City so got to know it really well....The buzzy nature of the city is great fun with a stunning amount of places for entertainment ....and really another world compared to anywhere else in the UK...It's a long crazy story but I moved down to Devon and the change was so massive I thought I had killed myself...this would happen to anyone doing the same I reckon....but it's just a matter of re-tuning one's life and I do love it down in the South West and just being able to breathe clean air and having mostly clear roads to ride on makes it all worthwhile....Les

ATB....Les

I put the max 200cc in all my road holders and use 15W fork oil and it's the best fork action I have known. Took me a lot of years to come to this conclusion. It's what works for you to try anything between 150cc and 200cc.

Warning: Don't exceed 200cc or you may blow your fork seals!

If you are doing it that way George, I would start at 160cc in each leg as 150cc was the recommended and thought by some experts and my experience, to be too little. 200cc is the max without blowing the seals.

Tyre pressures depend on type of tyre and as with weight of oil, it's what works for you. Have fun.

Previously Neil Wyatt wrote:

If you are doing it that way George, I would start at 160cc in each leg as 150cc was the recommended and thought by some experts and my experience, to be too little. 200cc is the max without blowing the seals.

Tyre pressures depend on type of tyre and as with weight of oil, it's what works for you. Have fun.

What my Norton Owners manual says is 7 fluid ounces. This converts to 199 c.c.(as near as dam it).

That's interesting, Charles, my Maintenance/Instruction book (16H, Big 4, 18 and ES2) states 1/4 pint (5 fluid ounces or 140 cc)? So the thinking is between 140 and 200cc! Very strange. There's no date in my book but it cost 2/6d then! From the carb illustrations I would put it at early 50's - say '53/54. George