Fork Spring pondering

discussions specific to the 907IE
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paso750
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model: 750 Paso
year: 1987
Location: southern Germany

Re: Fork Spring pondering

Post by paso750 »

WP 907ie
http://www.world-of-suspension.de/shop/ ... E.-92#tab1

In the Wilbers file you posted there`re also fork springs for the 906 (p.9)
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ducinthebay
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model: 750 Sport
year: 1990
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Re: Fork Spring pondering

Post by ducinthebay »

And a reply from Wirth.

Hi Phil,

we have a type of springs for this M1R Marzocchi fork. It's our set 6085,
which is 31,5 mm in diameter, 470 mm in length and have a starting spring
rate of 7,3 N/mm, progressively climbing up to 10 N/mm.

Does that help?

MfG
WIRTH-Federn

Olaf E. Wirth

Osterdiecksfeld 23
D-21274 Undeloh
Tel. +49-(0)4189-811020
Fax +49-(0)4189-811040
E-Mail: info@wirth-federn.de
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.
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ducinthebay
paso grand pooh-bah
Posts: 1323
Joined: Sat Sep 03, 2005 12:00 am
model: 750 Sport
year: 1990
Location: SF Bay Area

Re: Fork Spring pondering

Post by ducinthebay »

After my lap through the fork spring countryside, i settled on a set from Race Tech.
Image
The set came with
- 2 springs to the weight I ordered ( one is longer than the other)
- 4 washers that they insist go on either side of the aluminum spacer.
- A length of 1.250 aluminum tubing to make spacers
- A handful of stickers.

The springs do NOT have a taper at the bottom, so they don't sit on top of the damper rods like the old ones. I had to add some big fat washers on top of the damping rods for the springs to sit on. The washers came off a rear axle, so they were small diameter OD with 17mm ID.

Here you can see the length difference between the 907 springs and the Race Tech springs. The 907 springs are the shorter ones.
Image

I cut the spacers 10mm above the extended fork tubes for about 18mm of compression.
One of the reasons I went with the Race Tech springs was the length. They were in-between the 907 length and the 750 springs. I am using a set of 907 sliders and 750 tubes. These forks are going on my 750 Sport, with a set of 851 triple clamps. Stay tuned how well they work.

Cheers, Phil
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.
User avatar
paso750
paso grand pooh-bah
Posts: 5558
Joined: Sun Jul 18, 2004 12:00 am
model: 750 Paso
year: 1987
Location: southern Germany

Re: Fork Spring pondering

Post by paso750 »

( one is longer than the other)
It just seems to be about 10mm but why is that?
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ducinthebay
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Posts: 1323
Joined: Sat Sep 03, 2005 12:00 am
model: 750 Sport
year: 1990
Location: SF Bay Area

Re: Fork Spring pondering

Post by ducinthebay »

Stock springs are left and right, and are not the same length either. I cut spacers to accommodate, and marked them left and right, as they are now a few mm different to. Of course, who ever takes them apart in some future time, will hopefully be wise enough to look at what they have before doing something silly.

Certainly not a plug and play option, as many of the other spring sources seem to be. But they offer a wide range of spring rates, high performance springs which are lighter and offer a bit more air space than the stock springs, and they were longer than the 907 springs, which is one thing I wanted because I am going with the longer travel of the 750 top out springs.

Phil
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.
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