1984 WR Forks

[luvwoods]

Hi All,

I'm new to this old '84 WR250. I bought it a few months back but it came with no documentation so I'm at a complete loss on some things. Can anyone offer advice on grade and quantity of fork oil. The fork caps have air fittings so what about air pressures?

Also does anyone have advice on best way to remove a sheared off threaded stud at the bottom of the fork leg which holds the axel cover plate on? One of mine is sheared flush with the fork leg and I'm thinking of using a screw extractor. Any better ideas? Also, will its removal cause the fork oil to drain or is it a blind hole? Lastly, where do I find a new threaded stud??

Thanks, Tom

 

[HodaddyB]

How much do you weigh, and what will be the bike's intended use? These two items are necessary to give advice of any value. Do you happen to know anything about the springs? Have you ridden it yet and have a specific issue? Just curious..........there may be a few issues we can get squared away at once.

Concerning the air valves............I really only ever run 1 atmosphere of pressure even in forks w/ schrader valves. If you pick the right oil weight and level, there's no need to air them up, at least I don't believ it adds any value over the proper weight/height of the oil. But that's me, and I haven't yet had anyone complain after tuning their suspension, and advising to simply use them as bleeds. YMMV

If you have a Harbor Freight nearby, pick up a set of their left hand drill bits. I think they have a 5 piece set for under $10. Drill a pilot hole w/ a standard bit, and then drill into the stud w/ the left hander, slowly. It should grab at some point and back the stud out.

I don't believe I've ever seen an axle pinch stud NOT installed into a blind hole. If it does go through, I'd suspect a prior repair, or a sloppy guy at the factory

 

[luvwoods]

You know, after I clicked the submit button, I thought it would probably have been smart to include the me info, so here it is. I weigh 170 pounds and will use the bike primarily for trails and slower technical woods riding. I like somewhat softer than firmer suspension for that but don't want to bottom when I do wick up the speed. The bike has a newly rebuilt engine which I'm still breaking in so I haven't been able to get any consistent speed up yet but the forks feel a little squishy over moderate bumps. Thanks for the tips on the left-hand drill bits; looking forward to the rest of your input.
Tom
Almost forgot; I have no idea what springs are in them. In fact, have no idea how old the oil is either.......

 

[Picklito]

Great advice from HodaddyB.
Couldn't agree more.

I really like the 40mm fork overall, but one thing Husky consistently did was supply a very soft fork spring with too much preload. At 170 for slower/softer stuff you'll probably be OK, depending on how picky you want to be. I like a firmer spring with less preload but our options are limited to cutting and refinishing the stockers or having custom springs made (I'm looking into this right now, actually, with a local spring maker). This may sound crazy, but I've used ATF for years in these forks. Start about 6.5" from the top with springs out/forks collapsed and see how that goes.

 

[HodaddyB]

I agree w/ Picklito, ATF ought to be a good place to start for weight. 6.5" is also a safe starting point w/ a weight of 170lbs and trail riding. I suspect you'll end up closer to 5.5" if the springs are as soft as Picklito says they are........I can't really say; I'm not too familiar w/ the trends Husky may have followed w/ the spring rates.
Be careful as you begin to preload them, IF you decide to. Perhaps just enough to keep your sag (chassis pitch) even. Adjusting the air bubble will your most convenient and economical way to diddle the compression characteristics if springs are hard to come by. If they aren't too collapsed, I doubt you'll be too far off at your weight. If you start to preload them too much, they'll quickly turn into pogo sticks.
If the bike feels ok, but tends to understeer in corners, try heavier oil like 10wt (ATF is usually ~5wt).
If it tends to oversteer or bottom out, raise your oil level.

Of course, all of this is assuming your rear end is somewhat squared away. Oversteer, and understeer can also be symptoms chassis pitch problems brought on by poor shock adjustment and/or condition.......In fact having said that ( I will shut up soon, really), get your rear sag squared away first, then you can adjust the front preload to suit. FWIW, you're looking for something around 30% of your total rear wheel travel for sag w/ you on the bike.

 

[auto]

broken bolt

The whole trick is drilling the stud dead center.If you start drilling and it's off, STOP. Once you destroy the hole you'll have to find some one who has a milling machine and heli coil the hole. I never had much luck with screw extracters.Some times they work if you use a little heat.

 

[luvwoods]

Thanks for this detailed info; I really appreciate this more than you know. Since I have no idea what's in the forks now, I'll drain them and start with your recommendations as my baseline and work it out from there. It's interesting to know that the springs came soft from the factory because that was my impression within the first 15 minutes of ride time. Once opened up, is there anyway to tell if the springs are original Husqvarna? As for the rear I think I may be okay, sag seems to be about 1/3 of total travel but I haven't actually measured it, just eyeballed.
Tom

 

[luvwoods]

The whole trick is drilling the stud dead center.If you start drilling and it's off, STOP. Once you destroy the hole you'll have to find some one who has a milling machine and heli coil the hole. I never had much luck with screw extracters.Some times they work if you use a little heat.

I'm worried about that to. I'm going to pull the fork off the bike and mount it in a drill press to keep everything straight. I can just picture how bad a hand drill, close to the floor, hole on an angle, will work out for me!

 

[HodaddyB]

I haven't had much luck w/ proper screw extractors either.........but the LH drill bits have saved the day for me many times.

If you have the option of the drill press, rock & roll. And as was mentioned, putting a heat gun on it when you go to back it out may help immensely. But you'll need to get the local temp above 250 to make it worthwhile.

Good luck!

 

[Picklito]

Once opened up, is there anyway to tell if the springs are original Husqvarna?.
Tom

Ya - take them out and roll them across the floor. If they bounce and wiggle like drunken snakes they're original Husky. Seriously - the springs were not made that well. Likely, they're original. Not many guys changed springs "back then."

 

[HodaddyB]

Has anyone tried measuring the I.D. of the fork tube, measuring the length they need, and calling a place like Progressive or Race Tech to see if they have some that size, and what rates might be available. The RT part numbers have to do w/ the diameter of the spring relative to the tube.
Progressive makes all kinds of springs for vintage bikes............bikes w/ forks of a similar dia. to the old MXers

 

[HodaddyB]

I actually just checked out Progressive's site, and while the show springs for a '74 Husky, they don't show any for an '84 Husky. There's gotta be something close enough though.

 

[luvwoods]

Found this while trolling today:

http://www.husqvarna-parts.com/catalog/item/3736872/3413747.htm

Any thoughts?? I see they are temporarily out of stock, hmmmm.

 

[Picklito]

I checked around a little bit...
Race Tech: No.
Mx-Tech: No.
Cannon Racecraft: Sure we can make them... $175/pair.
Progressive 'used to' make them, but I had a set and they were too soft.
ATK sold a set that were pretty good... good luck finding any of those. Out of production for years.
I tried my stock WP 40mm KTM forks... just barely too large O.D. Close, but no cigar.
Need to call Uptite and see what George has.

So I'm talking to a local spring guy. I've got a pair of stock springs there right now and he's taking some data off them. The more we buy the cheaper the price. No details yet, but not $175. I'm gonna guess we can come in around $100, which is about the same as over the counter stuff... if it existed. I'll post a thread once I have info. Glad to see there's some interest.

 

[mattskn]

I checked around a little bit...
Race Tech: No.
Mx-Tech: No.
Cannon Racecraft: Sure we can make them... $175/pair.
Progressive 'used to' make them, but I had a set and they were too soft.
ATK sold a set that were pretty good... good luck finding any of those. Out of production for years.
I tried my stock WP 40mm KTM forks... just barely too large O.D. Close, but no cigar.
Need to call Uptite and see what George has.

So I'm talking to a local spring guy. I've got a pair of stock springs there right now and he's taking some data off them. The more we buy the cheaper the price. No details yet, but not $175. I'm gonna guess we can come in around $100, which is about the same as over the counter stuff... if it existed. I'll post a thread once I have info. Glad to see there's some interest.

Keep us updated on your finding

 

[firecrackerkid]

Picklito,
I too am interested in new springs. As you can see by my avatar pic I would need double the spring weight of Luvwoods . Also I have a pair of WR forks with no springs and a pair of XC forks with springs. The 84 reference list shows the different fork bottoms but the same spring. Does anyone have a wr spring they can measure the total length?
Just saw on another thread cr/xc = 720 MM springs with a .30 Spring rate Thanks HuskyT!
Now anyone have a wr spring to compare?

 

[firecrackerkid]

It appears Racetech now has springs. 500mm long by 30mm diameter.