1983 WR250 Fork Clunking

I've just had my forks refurbished and had emulators fitted. When weight is taken off the front wheel (wheel leaves ground) a clunk can be felt and at first I thought it was the steering head bearings but now know it is play in the forks at full extension. I bought a pair of Fork Top out washers for the suspension guys to fit but these exact same parts came with the emulator kit and so had already been fitted. Looked at the HVA Factory site and saw that there are also Top Out Springs for EVO bikes with longer springs to suit the WR forks but there is nothing to suit the 1983 bikes.

By the way, these forks have the longer extensions below the axle similar to XC and CR forks rather than the shorter WR for legs but the internals appear to be the shorter travel WR forks.

I don't know the history of this bike so I suppose it could be a wish mash of found parts but previous owners.

Any suggestions about removing this clunking as it is quite disconcerting. Thanks.

enough preload on springs? If I paid for a fork service and it did this I would have them fix it

Hi Joe. Thanks for your reply. The suspension guys aren't offering any recall on the work as they seem to think that there should be a top out spring as well as the top out spacer. The suspension guys aren't real familiar with vintage bikes and are applying what they know of from modern bikes. The parts manual for the 1883 fork does not show a top out spring but there is one from the EVO Husky's. I think that is about 1985 vintage. I just wonder if the Gold Emulators are based on the later fork in which case maybe I do need the Evo Top Out Spring. I don't want to spend $60 freight from HVA Factory on a punt and I don't think there is anywhere else in Australia that I could get these parts, so hoping somebody has had a similar problem in the past.

no spring until later fork years. late 86-87 (depends on where in world you are too as some got before others) the top spring replace the top out washer. One must understand the pre 86-87 husky forks worked opposite of regular forks. on a regular fork the top out spring acts as the check valve but for the rebound stroke. the side holes on the damper rod control compression. On a pre 86-87 husky fork there is no check valve on the dampener rod. the piston ring acts as the check valve as it slides up and down the groove it sits in. on compression stroke it slides down the groove and the oil flows down through the 4 passages in the ring and up the center of the rod. normal fork feed bottom up on compression. on rebound the ring slides up and the oil goes into the side holes in rod and also down the center. you cannot simply add the -86-87 rods. different size anyway


That these guys will not re do is BS. that is a standard....if right away I say you got my stuff valved wrong, they fix free here in USA. Now being what I said before and these forks work almost opposite a traditional vintage fork....that they do not "get it" might be believable.

2 questions
how are emulators sitting on top of damper rod now? (Pictures will help me help you)

with front wheel off ground and forks fully rebound/extended, how much preload on springs with fork caps fully installed?

Joe

Good info Joe.

Faarkthatsfast, Based on another thread topping out sounds common with older 83 forks. Sounds to me like it may be worth changing out the seal washers, #5 in the 83 parts list. It seems that the oil dampening the seal washers provide soften the impact of topping out. Maybe yours are just worn out.

http://www.cafehusky.com/threads/xc430-fork-noise.79416/

If seal washers are not available in your area HVA has them for 15 pounds a pair, whatever that equates to for you.

http://hva-factory.com/frame-fixings/husqvarna-40mm-fork-top-out-washer-151237301-15-12-373-01

Or there is Husqvarna parts in Arizona if dealing with the US is any better.

http://www.husqvarna-parts.com/catalog/item/3736872/4565455.htm

the trick with the cr legs and damper rods is to use a small spring from a honda (valve spring i think) as a top out spring it works and still gives you about 10+ inches and you can ditch those pooh plastic washers. You should not take old forks to new young guys (as you have found)

the 4 inside orifices on the "pooh" plastic washer are controlling the flow of oil on compression. you cannot just ditch them and lose all compression dampening valving. they also act as the check valve for rebound. read above and I explained the pre 86-87 husky forks are not like other forks. I have seen them in machined aluminum as well though and those worked and did not wear

ll look into it...a mate has done just that above joe with great results. im sure he said he turfed the washer

Thanks for the links Crashaholic. I already have the Top Out Washers as I thought that they hadn't been fitted during the fork service. They had and although they were not supplied by HVA but from Emulator company, they are exactly the same. So these new ones were fitted when the emulators were installed which was only a month or so ago.

My complaint about HVA wasn't at all about the incredible service they provide (I get parts to Australia quicker than ordering locally and they are ALWAYS the correct part) but more not wanting to spend $60 on a tiny part in the hope that it might fix the clunking but may not. If it was a lay down misare - the perfect fit, then I'd just order the Evo Fork Top Out Springs. Apparently this won't work either.

Thanks Joe. I sent the great information provided by yourself and Suprize to the suspension guys and they have advised that when they fitted the emulators they had to use an adapter to allow them to sit on top of the damper rods correctly as the damper rods don't have a flat top surface. They also advise that there was 5 to 6mm of preload and they believe any more than this would make the fork too firm and would top out even harder.

So back to the original problem, to alleviate the clucking on top out, I would like to fit a spring. Will the Evo Fork top out spring work and achieve the desired (no clunking) effect.

Alternatively, as Suprize alluded to, is there a spring from another fork that someone has fitted successfully that would achieve a smooth fork action?

I guess the bit I don't understand is, I don't have any of this on the 1983 XC500 or the 1983 TE510 that I own and I would imagine the 4 stroke and the WR 250 would share the same fork components whereas the XC 500 has the longer motocross fork but basically the same design and the action is 'smooth as bro' - (Hi to all you Kiwis!!) on both of these bikes.

Look forward to responses from the Brains Trust and thanks for everyone's help.

i cant remember what spring ol mate used but give mick at bendigo dirt bikes a call, hell know what you need. 03 54479840

Hi Suprize. Wrong number that was an earth moving company. Not to worry.

Suspension guys are going to make a 20mm top out spring from a cut down old fork spring. This will be a perfect outside diameter fit but a little loose on the inside diameter. They also need to make a 5mm collar that will fit over the damper rod so that it doesn't just rattle around in the leg. This is because the top seat is not flat.

I also got an email from Andy at HVA who advised that the emulator is not a worthy upgrade because it has a limited benefit for the cost. Unfortunately, for me, it was too late, and I have gone down this path. Apparently, the better course of action would be to fit the later drilled damper rods from around 1986 vintage fork. Maybe this will be of some help to other Café Husky readers.

Mick from Australia ( the 'go to' guy for info and advice) has successfully fitted Race Tech emulators but he used the larger 42or 43mm emulators (something like those measurements). He then turns down the larger ones so that they are a snug fit in the 40mm fork. Mine are the smaller 38mm ones although my suspension guys aren't concerned about the slop.

Once again, thanks to everyone for all the advice and ideas. Hopefully soon I'll be able to get the TE 510 to start and stop leaking oil...but that's another story.