Front Fork Servicing

[mattglavin]

I am about to service my front forks for the first time. The bike is a curvy with 29,000 miles. Are there any tips or things to look out for before I begin.

Thanks

[Viney]

The oil will Stink!!

[mattglavin]

Oh, I'll do outside it fresh air then !!

[fizzwheel]

Undo the fork caps before you take the fork legs off the bike. Otherwise they can be a tad difficult to get undone.

[mattglavin]

Thanks fizzwheel

[Spanner Man]

Afternoon all.

Slightly loosen the top caps before removing the forks. Before touching the allen bolt in the bottom of the slider, give it a couple of sharp taps with a hammer & punch. This will compress the copper washer under the bolt, & hopefully make the bolt a touch easier to remove.
Don't forget to anneal the copper washer before reassembly, by heating it to a dull red & allowing it to cool.

Cheers.

P.S. Be careful, forks are expensive & easily scratched.

[jambo]

With the bike on the ground, get the front wheel nut, brake caliper mounting bolts and handle bar clamps loosened off then just nipped back up. With the top yoke nuts loosened, undo the fork top nuts as the thread is no longer pinched by the top yoke clamps they should move a little easier. Loosen and nip up each bottom yoke nut. Now jack the front end up and you won't have to strain at any bolts while it's in the air.

Take lots of pictures so you remember what order springs, spacers and throttle / clutch control cables go.

Measure the air gap very carefully with a steel rule with the fork leg upright, compressed, with no spring / spacer etc in it. Pump the fork up and down a few times and measure again.

HTH

Jambo

Edit, Damnit, too slow, beaten by the Spanner Man....

You only have to worry about the washers and allen bolts in the base if you're stripping the fork right down. This may be best practice but if you're just renewing the oil you can skip that and let the fork drain upside down for a few minutes and pump it a few times to get the old oil out.

[chazzyb]

Undo the fork caps before you take the fork legs off the bike. Otherwise they can be a tad difficult to get undone.

To add to that, undo the top yoke clamp bolts too, as they compress the stanchion tubes enough to hinder progress. Same goes for reassembly - put the fork top caps in loosely, put forks back into bike, torque up lower pinch bolts, torque fork top caps, then top yoke pinch bolts.

[vzzzbuxt]

as above. make sure you loosen the top caps before undoing the yokes.

id be tempted to look at putting heavier oil in too... like 15w..

[chazzyb]

as above. make sure you loosen the top caps before undoing the yokes.


I recommend slackening the top yoke pinch bolts BEFORE loosening the caps.

[Spanner Man]

Edit, Damnit, too slow, beaten by the Spanner Man....


Pretty quick for an old guy aint I?:D

Cheers.

[thinman]

Okay so I have tried to change the fork oil and come across two problems. Firstly after pumping the fork as suggested to get the last of the old oil out the leg has got stuck at the bottom and I can't move it, HELP!
Secondly the idea that the forks simply drop out is a joke. I ended up having to hammer the top of the fork to get it out and the second one is still stuck, I have not only undone but removed all the bolts I can see, top two and the two on the brace and the one that takes an Allen key. Am I being thick or not?

[jambo]

Each fork will be held by 2 bolts on the bottom yoke clamp, one bolt on the top yoke clamp. The handlebar (clip-on) also has a positioning bolt youing up into the top yoke and one bolt clamping it to the fork leg if you have anb S model. So in total that's 4 clamp bolts per leg, plus a locator bolt to hold the clip-on straight.

I have NEVER had to use tools to force a leg out, be very careful of damaging forks, they are expensive. If it doesn't want to go just trace your hand up the leg, every time you meet something check all the bolts are removed.

If a fork leg locks while pumping just twist it back and forth gently while pulling up, it will free up.


HTH

Jambo

[northwind]

If a fork leg locks while pumping just twist it back and forth gently while pulling up, it will free up.


And it'll take slightly longer and more effort than you expect, instilling total terror that you've destroyed your bike. It always comes with your last desperate effort, it's just one of those things ;)

When you say servicing, what are you actually doing? An oil change is a very good idea, but some of the guys here are talking about seal changes and that's a job I'd personally only do when it's needed, not as preventative medicine on a 30000 miler. An oil change is pretty easy- take off top, turn upside down, comment on terrible smell, put in new oil- but seal changes are much more involved as Spanner Man describes.

[petevtwin650]

If a fork leg locks while pumping just twist it back and forth gently while pulling up, it will free up.


HTH

Jambo

Damnit!

My fork leg jammed on one side too. Ended up buying a new nylon/plastic thingy that sits at the bottom. Luckily I was fully dismantling to install my emulators. Or maybe not so luckily as it seems it frees up anyway.:(

To aid the fork removal I would run some WD40 or similar down the stuck fork leg but be careful you don't get any on the braking surfaces.

[zadar]

that nylon thingy is bottom out cone which swells in oil after time.reason tube gets stock when it slides over it.

[Grinch]

Yep even I managed to get my forks off and service them, though I did have a service manual guiding me at the time. Done 2 sets of forks over short period so I know how to do it almost off by heart now. Lol... even took some pics of the work I was doing -> HERE (http://picasaweb.google.co.uk/sv650r/AnSVRebuild) <--

[ELR4ever]

If you only drain the oil and add new oil, then be careful once you get the fork off the bike. Don't mash the tube and the stanchion together, you may have a tough time getting them apart. Turn it upside down and pump it. There is a great how-to on the net somewhere for doing it on an SV650. good luck, p.s. i used 12 Wt oil and love it.

[thinman]

thanks guys, tried twisting and pulling but no good, but i will now try turning it upside down and the wd40 route to see if it gets the bugger out. It's a shame you can't do more by just taking the cap off as that would be so easy! (I guess you could change the spring and the spacer like this). In terms of further suspension adjustment can I change my cap for one that adjusts the space there by making it stiffer or easier? I'm sure i've seen one on a V-strom?

[petevtwin650]

can I change my cap for one that adjusts the space there by making it stiffer or easier? I'm sure i've seen one on a V-strom?

Yes you can. I presume you have a early curvy.

I've done it on mine, about £45 from any Suzuki dealer.

[thinman]

great and how useful are they and what do i ask for? I'm thinking mostly about going from road riding to the track.

[petevtwin650]

You can do the same thing by cutting tube to suit, but this gives you the ability to find the perfect setting rather than using time and effort redoing the tubes.

You'll need the tops, new washers maybe and new washers to go on top of the springs. Might be lucky and find them on ebay or from a breaker.

http://i72.photobucket.com/albums/i184/petevtwin650/orgphoto/forktops.jpg

http://i72.photobucket.com/albums/i184/petevtwin650/orgphoto/forktops1.jpg

[ELR4ever]

And it'll take slightly longer and more effort than you expect, instilling total terror that you've destroyed your bike. It always comes with your last desperate effort, it's just one of those things ;)

When you say servicing, what are you actually doing? An oil change is a very good idea, but some of the guys here are talking about seal changes and that's a job I'd personally only do when it's needed, not as preventative medicine on a 30000 miler. An oil change is pretty easy- take off top, turn upside down, comment on terrible smell, put in new oil- but seal changes are much more involved as Spanner Man describes.

I actually had to hold the fork tube in my hand (clean the grease and oil off my slippery mitts first) then hammer the end of the fork stanchion (lower half of fork) with a drift (soft but stiff metal) until it broke free. I was freakin' too, but, it should be okay once you get them separated. If you can, get a piece of wood, put on the edge of the stanchion (near where the fork seals are just inside) and give it a couple of serious blows. You have to be holding the tube pretty securely. Good luck. EDIT: Best if you have two people trying this.

[Spanner Man]

I actually had to hold the fork tube in my hand (clean the grease and oil off my slippery mitts first) then hammer the end of the fork stanchion (lower half of fork) with a drift (soft but stiff metal) until it broke free. I was freakin' too, but, it should be okay once you get them separated. If you can, get a piece of wood, put on the edge of the stanchion (near where the fork seals are just inside) and give it a couple of serious blows. You have to be holding the tube pretty securely. Good luck. EDIT: Best if you have two people trying this.


Afternoon all.

Bit of a drastic way to separate the forks I think. If you have a vice & lots of padding available to hold the stanchion (upper half), you then jerk the slider downwards to dislodge the top bush & the oil seal.
If you have no vice available it's better to install the forks without the spring fitted onto the bike, & with an assistant holding the bike steady, jerk the slider off. (MATRON):D

Upon reassembly it helps to lightly grease the inside if the slider where the bush & the seal sit, & to lightly oil the outside of the bush & the seal, before attempting to install either of them.

Don't be tempted to use an old screwdriver or steel punch to install the top bush, as you almost could easily scratch the stanchion. I use a thin copper drift to install the top bush, but a suitable drift can be fashioned from a piece of 15mm copper tube, with the end flattened & then filed to an appropriate shape.

You can use the old seal to drive the new seal into place, using a soft drift. Remember to cut out the centre of the old seal, so it wont foul the centre of the new one.
When installing the bush or the seal always tap gently around the circumference, this will ensure it goes in as squarely as possible reducing the likelyhood of a jam.

The last tip in my 'handy hints for fork overhauls':D is to give the stanchion a good rub down with fine wet & dry & lots of silicone lubricant before reassembly. You can use WD40 or similar. Even a good looking stanchion will have minute nicks & high spots on it, which will start to wear the seal straight away. Don't use anything coarser than 1200 grade paper, & don't apply any finger pressure.

Cheers.

[northwind]

I'm not sure how good an idea WD40 would be, with the solvents etc... if you put the axle through the fork leg and stand on it, and bolt the top yoke onto the upper fork, you can put much more force on it- it ought to pull apart...

I fitted the fork caps, but to be honest it's money for not much, it does make setting the preload far easier but it's nothing you can't do without, and once it's set you'll not often want to change it. It's a labour saving device more than anything else.

[zadar]

In terms of further suspension adjustment can I change my cap for one that adjusts the space there by making it stiffer or easier
it does not make it stiffer.