USD Front Forks

I soon got tired of the Exup front forks I had first fitted to my FJ. That's not to say they were not an improvement on standard, it's just that despite them being rebuilt by specialists (Maxton), they soon started leaking at the fork seals. A quick trawl through the Exup related web pages soon revealed that this is a common problem. Of course, throwing the whole thing up the road and bending them, also had an input in me deciding to replace them with USD's. Since fitting these, I have found them to be excellent . Though heavier than pre USD's by about 6lb, they give a superb feel to the bike. With benefit of hindsight, I wouldn't have bothered with the first transplant at all.

I considered a number of different forks, but decided to go for early FZR1000 Exup RU's. This was primarily because I could use most of my front running gear (wheel, discs, calipers etc) so the cost was kept 'sensible'. Also I knew this mod had been done before to good effect and was relatively easy to do. RU forks come in two flavours 1991 and 1992-95. The later forks were similar to YZF750, come standard with six-pot calipers and had a larger diameter wheel spindle. Early wheels won't fit later forks or vice versa, without much complication. Later RU forks also have a different top yoke (I believe) so you may have make some adjustments for this.

CLICK FOR FULL SIZE PICTURE. 

1. Relieve frame to clear forks.

2. Modified top yoke.

3. Ignition installed in top yoke.

4. Neat, but not cheap!

5.Make yourself one of these!

6. Note access to  preload adjusters.

7. Near completion.

8. Can't wait to  take her for a spin!

First up, pull those old forks! No need to remove the fairing. The frame has to be ground slightly to achieve clearance (see Pic 1). It's just a matter of a few millimetres. I did this with my 'all singing, all dancing' power file. A small angle grinder would be equally as good. Next up, put your gleaming new USD forks in the hole you just took your old one's out of. It's as simple as that, the head race bearings are exactly the same. You can re-use your front brake calipers, but not the discs (which are now 320mm). Speedo drive's the same, so that's easy too. You'll need to pack the brake line splitter out by a couple of millimetres, where it bolts to the bottom yoke (triple), I used a couple of washers.

Next bit of fun is the top yoke (triple). Here some decisions have to be made. The USD forks do not give the option of attaching the handlebars directly to the fork legs ( a-la standard FJ), so an alternative way needs to be found. Probably the easiest is to buy a handlebar conversion kit, like in Pic 4 (available from M&P) . They are expensive, but solve a number of problems. To retain your original FJ ignition switch though, you will still have to modify the yoke, in a similar way to that shown in Pic's 2&3. An unexplored route would be to forget modifying the yoke and get an Exup switch! Haven't tried it myself and I'm not sure if you would retain the use of the steering lock.

Personally, I don't like the conventional bar conversion kits. They don't look, well 'FJ'. So I've designed an adaptor plate, to allow the use of the standard FJ bars. Please note -

THIS MODIFICATION WAS DESIGNED BY MYSELF FOR USE ON MY OWN PERSONAL MACHINE, I IN NO WAY DECLARE IT SAFE OR RECOMMEND IT TO ANYONE. YOU MUST SATISFY YOURSELF WHETHER YOU WOULD LIKE TO DESIGN AND MAKE ONE SIMILAR FOR YOUR MACHINE !

Gulp! Sounds good doesn't it. But seriously, all mods should only be carried out by someone able and confident to do so. If that isn't you, best consult a competent mechanic/engineer.

I shaped a plate in 0.25" steel plate to match the top yoke, to this was welded two lugs. The handlebars then clamp on in the usual way (see Pic 5,6&7). The plate is attached to the top yoke by two 12mm high tensile stainless steel bolts, with the usual set screws fixing the angle of the bars.

I finished the whole lot off with a modified FZR600 front mudguard (that's what the fella told me), which in my opinion looks better than the standard RU item.

 

Hope I don't bend these!

All worth while!

Getting there!

The latest from the Hacker stable !!

Looks very neat !!

 

RETURN TO MAIN PAGE