10 replies to this topic

[b40rt]

What is considered the best set up for these forks ?

At present running 220ml of TQF (approx7w)and works OK, but open to suggestions.

I weigh about 13 stones.

The fork caps have a screw at the bottom, presumably to release pressure but seized solid at present, don't remember them having this, is it a modification ?

Thanks

Ross

[schweizmeister]

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[schweizmeister]

I was watching your forks yesterday after we were talking and the rebound looked a little slow and 'lazy'. It might be worth fitting new springs.

[b40rt]

schweizmeister, on 11 July 2011 - 06:59 PM, said:

I was watching your forks yesterday after we were talking and the rebound looked a little slow and 'lazy'. It might be worth fitting new springs.

Thanks Brian

Will try and get a pair.

Ross

[woody]

I have no idea whether ATF is suitable for forks or not but I would only use proper fork oil in them.

220 is probably the maximum you'd want, I usually start with 200cc of 10w and take it from there, adding another 10 if they feel like they are close to bottoming or topping but 200 usually is enough for me - but obviously all forks differ in their behaviour, even when they are identical in terms of components.

You could try WES progressive springs which you can get through BVM. At least you will know they are new and have not sagged, then it is just a case of playing with preload. A friend has some in his 240 Fantic and the forks are very good.

Or you could fit Magical front fork springs. No need to buy the caps with adjustable preload or the internal spacers as well, they are nice to have, not essential. You can make your own spacers.

With the WES or Magicals you would have new springs which would eliminate the springs from any performance issues.

[b40rt]

Thanks Woody, have sent an inquiry to BVM.

The springs have certainly lost a bit of life as it required little effort to put the caps back on.

There is a spacer fitted of approx 50mm in each leg,from memory I think that was standard ?(plus a 2p piece in one of them!)

Do you know anything about a pressure release screw in the bottom of the allan key recess ?

Thanks

Ross

Edited by B40RT, 11 July 2011 - 10:02 PM.

[woody]

B40RT, on 11 July 2011 - 10:01 PM, said:

Do you know anything about a pressure release screw in the bottom of the allan key recess ?

Thanks

Ross

Not really as they differ from fork to fork. They are either a screw that you undo to bleed pressure build up in the forks. Or, they are a valve which is supposed to do that for you and let air, but not oil, out through a pin hole in the fork cap - in my experience this latter type, usually on Betor forks (Ossa, Bultaco) either block up or let oil out as well giving you an oil jet wash in the face every time the forks compress until finally they are empty. I always block the hole off and can't say that I've ever had a problem with forks pressurising.

[b40rt]

Woody, on 12 July 2011 - 12:32 AM, said:

Not really as they differ from fork to fork. They are either a screw that you undo to bleed pressure build up in the forks. Or, they are a valve which is supposed to do that for you and let air, but not oil, out through a pin hole in the fork cap - in my experience this latter type, usually on Betor forks (Ossa, Bultaco) either block up or let oil out as well giving you an oil jet wash in the face every time the forks compress until finally they are empty. I always block the hole off and can't say that I've ever had a problem with forks pressurising.

Thanks Woody

The forks on my Aprilia do pressurize, to the extent that they will continue to leak sitting on a stand.

Not a problem with the Marzocci's I have to agree.

Ross

[b40rt]

I got a new pair of fork springs from In Motion Bultaco as no one else seemed able to supply, and they were half the price.
Tried them with 200ml of oil but although much better, were topping out occasionally. Went back to 220 and cant fault them.
Surprised just how much better they are.
Thanks for the help / suggestions.

Ross

[reginald]

Hi Ross any idea of the spring rates for those?
I have betor forks on both my TL320s and one pair has those little hex screws in the caps. The others have nothing.

I run straight atf oil but only cause of convenience of supply. Was going to try 5wt because as a C grader we don't big hits and the more supple the boingers the easier is to get grip I reckon.

Edited by Reginald, 10 September 2011 - 01:28 AM.

[b40rt]

Hi Reginald
In Motion could give you the rate I'm sure, your tall so them being to hard would'nt be a problem.
The springs are not specific to Marzzocci I don't think, just 35mm forks.
I'm also using ATF for the same reason, and according to a chart I saw should equate to approx 7wt,
though ambient temp must place a part so you should be fine, I find them very supple.


Ross

[reginald]

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[reginald]

Cool thanks. I might stick to the ATF.