851 Forks?

discussion about the 750 Sport and '89/'90 900SS, which share many mechanicals with the Paso series
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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

851 Forks?

Post by ducinthebay »

Ebay purchase - some rust, but the lowers are in great shape.
Listed as 907 forks, but I'm thinking they are 851, which is great.
New forks pictured on the left with 907 forks on the right. (750 Paso length)
Image

Brake bosses are a tad further from the axle, so I assume 320 rotors. Length of forks is shorter than the set of 750 forks I have built up.
A web search shows the top of the fork sliders is consistent with the 851 forks.

I have a set of 851 triple clamps already, so that all will be going on the 750 Sport this fall.
Interested to see what's inside, and if the damping rods are any different from the Paso parts.

Cheers, Phil
Last edited by ducinthebay on Mon Aug 10, 2015 10:35 pm, edited 1 time in total.
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
MarkST
Posts: 92
Joined: Mon Dec 15, 2014 11:05 am
model: 750 Paso
year: 1987
Location: Sleepy leafy South Birmingham UK

Re: 851 Forks?

Post by MarkST »

ducinthebay wrote:Length of forks is shorter than the set of 750 forks I have built up.
Please expand.
2004 ST4S
2001 ST4
1987 Paso 750
User avatar
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: 851 Forks?

Post by ducinthebay »

750 Paso forks on the Sport currently are 79cm from bottom of slider to top of the fork tube (I assume stock forks)
907 forks are about 81cm (as best I can tell while installed)
the new forks are 77cm overall. I am more convinced they 851 forks.

I have not take them apart yet to see how they made them shorter. One way, of course, is to use shorter tubes. the other way is to put longer top out springs. I will measure the travel as soon as I can get the fork caps off, as they are completely buggered. The travel will definitely tell me if they are 851 forks, as the 851 had much less travel than the Paso or 907.

Stay tuned.

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
MarkST
Posts: 92
Joined: Mon Dec 15, 2014 11:05 am
model: 750 Paso
year: 1987
Location: Sleepy leafy South Birmingham UK

Re: 851 Forks?

Post by MarkST »

Thanks Phil.
I only asked because I have to at some point join a set of ST fork uppers with some 748 fork lowers.
Not exactly the same thing I know, but quite a similar project.
2004 ST4S
2001 ST4
1987 Paso 750
User avatar
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: 851 Forks?

Post by ducinthebay »

Ah, I see. The forks on the right are (were) built up to use on my 750 Sport. They are 750 Paso tubes, on 907 legs, with with Race Tech springs. Now I am considering switching things around and putting the 851 sliders onto the Sport, and using the set of cast iron 320 rotors I have on the shelf, and the black 4 piston calipers.

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.
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