25 replies to this topic

[richarda]

Hi

It's about time I overhauled my front forks. I'm sure there's wear in the bushes which is giving me a slight wobble in the steering at motorway speeds.

I'm assuming I need a pair of each of the following:
Top bushes
Bottom bushes
Oil seals

Are there any other bits I should replace? (apart from dust seals - which are ok, fork springs - which are relatively new and oil, of course)

And, although I've done a forum search, I've not found any write ups on how to do the overhaul. Can someone post a link if there is a posting lurking somewhere.

Many thanks

Richard

[dapleb]

Yup sounds about reet, though you mayhaps should include new copper washers for the borrum of the ferk leg. There is a method of ferk removal what will save yer bushes (else they will be destroyed on removal) but if you think they are boogered anyway it wont matter non.

Enjoy yer pickled onion water adventure.

[Studley Ramrod]

Might be worth making sure you buy yamaha seals as one or 2 peeps have had new aftermarket seals leaking after a month.

I did mine, bushes and seals, following the Haynes and it was a bit of a challenge pulling stantions out, but not too difficult that I wouldn't do it again.

Oh yeah, if you look at the parts files the bushes are called metal slide 1 and metal slide 2

[ChrisG]

Hardest bit is getting the bolt out of the bottom, an air wrench or electric impact driver is whay you need, though I think Dapleb managed with a modified broomhandle down the end of the fork to stop the cartridge turning. Be carefull how you hold the fork in place while you turn it too, there's quite a few sets of forks out there with broken mudguard mounts where people have tried to clamp them.

[dapleb]

Borrum bolt always comes ooot no probs fur me. Its gettin the billy badger bacon thats oi find a burger. Normally pop down to nosheets and borrow their air.

[richarda]

Thanks Guys for the replies.

About the bottom bolt. Could I not loosen it with the forks in situ (wheel removed)? ie what turns with the bolt that prevents it from coming undone? I've done this trick before on forks from other bikes. Is there a knack for doing it up again?

Thanks

Richard

[steveearwig]

I'd think you'd need a fair bit of pressure on it to stop it spinning, the cartridge inside just turns round & round. No idea what I'm doing wrong that Dapleb does right, I even tried an air wrench. In the end I made up a tool out of a bit of 22mm copper pipe with a brass fitting soldered on the end, I filed it so it has just two flats outside, looks like a big hex socket with 4 of the flats removed (I think I need to photo and measure this...)

Btw guys, how the feck do I get the copper washers out the bottom? Mine are just in there and don't want to come out, no matter how much I frown at them.

[richarda]

Ummm.. one of the reasons for me wanting to do this is that I've got a 'big' trip on at the end of November to Metz in France. As I mentioned, at motorway speeds I get a slight shake on the handlebars and I think I've eliminated everything apart from worn bushes so far. I dont think I would feel comfortable doing the trip with the shake as it is. I really need the overhaul to be straighforward as possible as the bike is my daily ride and so cannot afford for it to be off the road for any longer than I can help it. It seems to me that the real obstacle are these bottom bolts. If I could loosen them somehow before proceeding with the overhaul it would give me some confidence that the job could be done fairly swiftly, otherwise I've got to seriously consider putting up with the shake until after the trip. Unfortunately I'm not blessed with any kind of fabrication tools, eg welder etc, nor the skills. However, not many tasks in the past have beaten me. I guess I'm up against having the correct tools for the job vs luck vs a bit of technical savie. If anyone can help with the latter I would be grateful.

Rgds

Richard

[steveearwig]

I guess the first thing you need to do then is work out if you actually need to do this. Get the front off of the ground and try pushing the forks backwards and forwards (probably better without the front wheel), I *think* movement should be just noticeable to be ok (I'm sure the experts will have something to say...).

Btw I got my bike of a fairly large chap and I used to get some wobbling at high speeds. Having never had a bike where you could change any of the suspension settings before I never thought of it but the first time I changed the fork seals I put everything back to standard and the wobble disappeared (when I say wobble I mean it started to act like a fish over a ton)

[ChrisG]

Btw guys, how the feck do I get the copper washers out the bottom? Mine are just in there and don't want to come out, no matter how much I frown at them.

Wasn't a problem for me, the buggers weren't in there in the first place!

[dapleb]

Btw guys, how the feck do I get the copper washers out the bottom? Mine are just in there and don't want to come out, no matter how much I frown at them.

Think I posted a piccy of this at some point. In good light with fork bottom up, look through the side (where the axle goes) you will be able to see the joint atwix furk and washer. I just use a tiny pick to hoike it aaat.

[dapleb]

Hmm not convinced this is gonna fix yer vobble but if yar happy you have eliminated obvious stuff loike tyres/balance/bearings etc etc?

Oi wouldnt count undoing the borrum bolt as a precursor that the worst is over!!! The internals are what will spin with the bolt so with them under a little load might help a bit whilst on the bike (thought you may end up with pickled onion water everywhere), or tek em of and tourniquet.

When did you last change the furk oil? Check the furk oil level?

Anudder thang you will need if ya decide to blitz the furks is zummat to drive the new seal on with, a piece of PVC poipe or alike.

[richarda]

Things I've changed/done so far to eliminate the wobble are:

New fork springs
New fork oil
New head bearings
New front wheel bearings
Good condition 2nd hand rear shock
Removed swing arm and regreased/checked all bearings
New front tyre/balanced
Adjusted front/rear suspension settings
Tried riding with/without luggage/topbox

So, not much more left, hence the fork overhaul.

Richard

[Studley Ramrod]

Borrum bolt always comes ooot no probs fur me. Its gettin the billy badger bacon thats oi find a burger. Normally pop down to nosheets and borrow their air.

nosheets

I just put a hex socket in me drill an spun the bolts lemon squeezee. Did the same when putting em back in, had to press down on the forkalerios at the same time. Took me a short day to do both forks, and I were a fork bush virgin at the time

Oh yeah, I could tell the bushes were worn from feeling the play in the forks, could just hear them thudding too, with the wheels off.
Didn't get a wobblyon when they were worn tho

Silly really but have ya got enough air in the tyre ?

[hammerman]

I'd think you'd need a fair bit of pressure on it to stop it spinning, the cartridge inside just turns round & round. No idea what I'm doing wrong that Dapleb does right, I even tried an air wrench. In the end I made up a tool out of a bit of 22mm copper pipe with a brass fitting soldered on the end, I filed it so it has just two flats outside, looks like a big hex socket with 4 of the flats removed (I think I need to photo and measure this...)

Btw guys, how the feck do I get the copper washers out the bottom? Mine are just in there and don't want to come out, no matter how much I frown at them.

Got mine out by screwing a large e-z out into the washer, then pulling it out, the O/D of the washer is slightly smaller than the hole in the bottom of the fork leg, so if you are careful you won't damage the fork.

[SteveK]

Have you checked that the forks are both inline, looking from above. A recent post on here asked how to re-align them, slacken yokes, hold wheel between legs and yank on the bars, tighten yokes. Also check that the rear wheel is in line with the centre line of the bike, wear on either side of the sprocket will indicate this issue.

Good luck
Steve

Edited by SteveK, 06 October 2010 - 04:38 pm.

[richarda]

I've checked all of those good things. Have decided to do the forks anyway - bits are on order. As I'll have everything apart at the front I'll double check when putting it all back together that things line up ok.

Thanks

Richard

[steveearwig]

I'd think you'd need a fair bit of pressure on it to stop it spinning, the cartridge inside just turns round & round. No idea what I'm doing wrong that Dapleb does right, I even tried an air wrench. In the end I made up a tool out of a bit of 22mm copper pipe with a brass fitting soldered on the end, I filed it so it has just two flats outside, looks like a big hex socket with 4 of the flats removed (I think I need to photo and measure this...)

I finally remembered this while I was at home just now. So, for those of you without the magic touch:


The top of the damper, across the flats it's 26mm (dammit, I should have measured not across the flats

The tool I threw together:

22mm copper pipe with a fitting to take it to 1" steel soldered on with the gas cooker 'cos I was too lazy to break out the blowtorch. Just about anything would do, even a compression fitting because it doesn't need to be anything special, all you're doing is stopping the damper spinning. I left about 18" of copper pipe to grab on to.

[dapleb]

Ingenious...just be careful not to scratch oubt!

If you want NAF measurement oi can go do it.

[steveearwig]

Copper's softer than steel, which I think is what the damper rod's made of, so it shouldn't damage it. Hopefully...

I was thinking not across the flats might conceivably be a useful measurement but the maximum outside measurement should be easy 'cos it's the inside of the slider, innit.