Oleomatic (Dowty) Forks

[Rod Norris]

I have a 1949 Scott Squirrel with Dowty forks on the front. Not certain how much is completely original as the outer legs have a brass strip rolled around so they are a perfect fit in the bottom yokes. The top yokes are a perfect fit with no “packing” required.
I am aware that a number of people fit springs as the air can escape if you hit a bad pothole and then bottom out. To fit the springs does away with the damping internals and supposedly gives an inferior undamped ride. The main support for the stanchion is a phosphor bronze bush about 1.5″ long at the bottom of the outer cover. I intend to fit another bush about 6″ further up to support the stanchion more adequately. I believe the internal damping can be strengthened to support a short 6″ spring to give assistance to the air and reduce the excess pressure on the air seals.
Further to that turn some alloys covers that replace the present seals to the bush / stanchion tolerance gap.
Has anyone out there considered alterations to this type of fork before or actaully carried out some work. My intention is to create as little as possible visible change whilst making the forks work to their best potential.
I am aware that these forks have come in for considerable criticism. Whislt I believe the construction methods could have been better they were actually many years ahead of their time. My Hayabusa has similar Upside down forks and are the way forward on all modern race bikes. Just proves once again, there’s nothing new.
All comments gratefully received.

[David J Waring]

Hello Rod,
I am not sure why you wish to do this.
My 1947 Flyer has been in the family for over 30 years; a few years ago the forks emptied all the oil during a static period one winter on the garage floor . As a “temporary” remedy I put thicker oil in the forks expecting to have to fit the set of seals we bought years ago from the Panther Club (the first source of new seals) – but the seals are still on the shelf , with no leaks !
David.

[Jan Buchwald]

Hello
My Brum has the brass strip too, the forks come from a ’50 Squirrel
JB

[dave bushell]

Hi Rod
The Scott forks are not upside down forks-they are the right way up!
It’s all the modern bikes that have got their forks upside down!!
Dave

[Rod Norris]

The latest racing forks are known as USD (upside down forks). It is the stanchion that moves and the slider is static in the yokes. For many years modern (by comarison with most Scotts) have had their stanchions clamped in the forks but over the last 4 or 5 years they have been turned upside down as it reduces unsprung weight.
My previous comment was meant to show that these “great ideas” had been thought of and implemented many years ago, although not necessarily perfected. The “normal” forks where the stanchion is clamped in the yokes are easier to manufacture and seal whilst USD forks always have gravity fighting against them and wanting to leak. The Scott Oleomatic or modern USD fork is technically superior to the regular telescopic fork used generally for the past 40 or so years.
So the upside down comment is not a slur, but a compliment, sorry if I did not make that clear in my first posting.

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