Upside Down Front on my 907.

[900streetfighter]

After the dissapointing test ride I left it alone for a while to have a think and re-assess. I had no work today so Ive been taking the forks in and out and having a good look at the situation with the fairing off. It seems Ive got 25mm too much travel. Im surprised the forks bottom out under braking with full preload set on the fork top but it appears they will.
I think I can raise the rad and tilt it back enough to give me clearance by altering the top mount holes and making new brackets for the bottom, so thats my next move. I might have to file a bit of inner fairing to suit.
On the 5 min test ride the bike went round corners ok but the front did feel a bit 'raked out', probably due to the extra 4mm offset. I read in an article on fork swaps recently that a change of more than 2mm would be noticable so I guess that could be it although the bike was cobbled together and has odd tyres so I'm still hopfull it'll be good. If it isnt my back up plan is to use monster yokes which are about 2mm less offset but this will mean using conventional bars as there wont be room for clipons round the fork leg. Also the steering/ign lock wont fit plus loads of other snags. I was hoping to quicken the steering but I've a feeling its going to be even more of a barge.
Right now Im filing 1mm off the top of the clipon clamps so they sit higher on the legs to give me more clearance at the tank. All good fun. Still cant load pics sorry.
Cheers, Keith.

[900streetfighter]

To cure the Rad/Tyre contact problem I've fitted a 120/60 front tyre I had around and thats almost cured it. Ive done about 100 miles and been winding the preload in and out and the max I can use is 2 lines showing, which gives me a reasonable amount of sag and probably about how I'd set it anyway. Ive pushed the rad back as far as it'll go but theres scope to move it up and back further.
It rides really well, better than my 1st impression. I think the lower profile tyre helps a lot to make it a bit more nimble, it might be worth trying 1 on a standard set up.
The new speedo drive now reads +50% so I can do 150mph in 4th now. Its not a problem working out how fast Im going but I'm also putting extra miles on the mileometer, so I'm thinking of trying to get a KPH to MPH converter to fit on the speedo which should almost correct it.
Cheers, Keith.

[paso750]

you chose the incorrect link option in Photobucket. When you move the mouse on a photo uploaded in your Photobucket account a drop down menu will appear showing "Email & IM", "Direct link", "HTML code" and IMG code. You chose HTML code and should have chosen IMG code.

The part marked red is the actual link:
<a href="http://s1119.photobucket.com/albums/k63 ... usd002.jpg" target="_blank"><img src="http://i1119.photobucket.com/albums/k63 ... usd002.jpg" border="0" alt="Photobucket"></a>

Add [/img] at the end and [img] at the front of that link and it will work.
If you copy the IMG code provided by Photobucket it will work w/o having to do anything else.

G.

[higgy]

looks pretty squir·rel·l-y from here

at the very least you need to figure out some sort of brace

[900streetfighter]

Thanks paso750, Im getting the hang of this.

[angelix]

I have the feeling that you need to do some tweaking to the fork... as it Sounds not "right".

what was the donor bike?

you need to take into account the weight of the 907 compared to the donor, i bet there are 15 Kgs if not more.

having said that, you might need a stiffer set of springs or a higher oil level ( or a combination of the two) so, before making any mods, I would try playing with the fork so that it does not bottom down every time four brake hard.

by the way, if you Increase the oil level the result is less travel, in fact the Paso 750 has the level set at 180mm , the 907 is at 160 mm and my guess it is because with a lower level there is a chance that the front wheel touches somewhere

[900streetfighter]

Hi Angelix,
The legs are from a 04 Multistrada, they're the only (showa)legs long enough, 790mm spindle ctr. to top.
I've been using Ian Falloons Ducati Story as a reference, he quotes 907 fork travel at 125mm, 25mm less than other Paso's(also 10mm longer) and 160mm travel for Multi forks. I think the fully loaded weight would be similar, maybe more bias to the front when riding on my bike but the same on the brakes. The Multi's designed to carry a lot of luggage.
Basically when Ducati introduced the 907 with 17" wheels they had the same problem so they got marzocchi to make the forks longer and reduce travel. Thats how I see it anyway. So much for R+D.
Cheers, Keith.

[Mc tool]

Would it be possible to use a pair of smaller moto X tye radiators , one on either side ah lah paso 750 oil coolers .
I have not actually measured anything but I have an arsey feeling that Im going to run into similar radiator / wheel clearance issues with my 17" conv. Id love to stick my ( tweeked ) SS motor in the paso , wouldnt need a radiator

[angelix]

Hi Angelix,
The legs are from a 04 Multistrada, they're the only (showa)legs long enough, 790mm spindle ctr. to top.
I've been using Ian Falloons Ducati Story as a reference, he quotes 907 fork travel at 125mm, 25mm less than other Paso's(also 10mm longer) and 160mm travel for Multi forks. I think the fully loaded weight would be similar, maybe more bias to the front when riding on my bike but the same on the brakes. The Multi's designed to carry a lot of luggage.
Basically when Ducati introduced the 907 with 17" wheels they had the same problem so they got marzocchi to make the forks longer and reduce travel. Thats how I see it anyway. So much for R+D.
Cheers, Keith.

well there you are, there is a 20Kgs difference (189 the multi, 211 the 907) and with the multi's forks you have 35mm more travel

the only way to limit the travel is to ENCREASE the oil level in the fork, this is something you can do on the bike without touching anything else.

[Duc750]

If you increase the oil volume you'll also increase the pressure in the damping circuit which maydo some strange things when you work the fork hard. Can you not use the top out bumper to reduce the travel. I've not ever been in these type of forks but I guess there is one in there?

[900streetfighter]

I want to leave the forks standard, they're designed to travel 160mm and any kind of oil increase or a stop is going to make them work differently but only at the end of the travel with a stop or possibly right through the stroke with oil level. I contacted a few suspension specialists and the only firm willing to do any mods is K Tech, a reputable company, who will make a spacer for the piston, but then I think the forks would bottom out under braking which is no good. USD forks are a lot more complicated than RWU and altering them other than changing oil grades is a no-no for me.
At the moment, with the preload adjusted to 2 lines showing I have no problem. I dont think the forks want to travel much further if I wind the preload out. I'm only a few mm off, which, when I have time, I think can gain by moving the rad up.
Meanwhile I've been clocking up miles (+50% due to the speedo drive) and enjoying the ride, The low profile tyre(120/60) is a tiny bit strange tipped into a tight corner, I might up the pressure from 33psi and see what that does. Apart from that Im really pleased with the way its turned out.
Cheers, Keith.

[Duc750]

Keith, I would suggest K tech would adjust the stop and the spring rate to avoid bottoming out. Incidentally if you have linear springs then a top out bumper change will have no effect on springs - essentially all your doing is upping the preload. The damping circuit is entirely independent of spring rate. The only thing that makes USD more difficult than RWU is gravity and the challenge of preventing oil leaks. If you want something complicated try air springs

[900streetfighter]

K tech want about £200 to turn the spacers and service the forks inc oil, not inc any seals or parts which is reasonable enough, I would ideally like springs to suit my 210 lbs + pillion, but I'm trying to do this on a budget and Ive gone way over. With all the adjustment on these forks I'll get them as good as I can and maybe treat them to a standard overhaul for £100 or so locally. Next job is paint the wheels, when I can stop riding it. : .K

[Duc750]

You might want to try mh racing in corsham if he's still going. Used to be cheaper than most and very good a lot of the ng road racers used to use him

[900streetfighter]

Thanks for that, I'll check them out. K.