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How bad is pitting to the front forks?

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skithepowder
Borekit Bruiser



Joined: 27 May 2010
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PostPosted: 14:07 - 03 Sep 2010    Post subject: How bad is pitting to the front forks? Reply with quote

Looking at buying a bike when I see the right one, couple of ads I've seen have mentioned pitting damage to the frot forks or salt damage to them. How bad a thing is this? How does it affect the bike? How do you put it right and roughly how much is it to put it right?

If it has pitting damage to the forks is there anything else that is often associated with it to look out for? Cheers!
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Kickstart
The Oracle



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PostPosted: 14:20 - 03 Sep 2010    Post subject: Reply with quote

Hi

Depends where the pitting is.

If the seals go over the pitted section then it will wreck the seals, resulting in loss of oil (and hence damping).

Fixing it means replacing or rechroming (or bodging it with an epoxy glue).

All the best

Keith
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MarJay
But it's British!



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PostPosted: 14:22 - 03 Sep 2010    Post subject: Re: How bad is pitting to the front forks? Reply with quote

skithepowder wrote:
Looking at buying a bike when I see the right one, couple of ads I've seen have mentioned pitting damage to the frot forks or salt damage to them. How bad a thing is this? How does it affect the bike? How do you put it right and roughly how much is it to put it right?

If it has pitting damage to the forks is there anything else that is often associated with it to look out for? Cheers!


It is bad if the pitting is near the fork seal because when the forks compress the sharp edges on the pits can damage the seals, and can let oil through. It can't be permanently fixed without replacing the entire fork stanchion which are pretty expensive. ABE (AllBikeEngineering) do replacement stanchions.

They can be bodged with araldite and sandpaper but I would rather have a replacement stanchion for my own peace of mind.
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skithepowder
Borekit Bruiser



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PostPosted: 14:39 - 03 Sep 2010    Post subject: Reply with quote

Cool, thanks for the advice, probably a good thing to avoid then if possible! Cheers
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calyx
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PostPosted: 14:57 - 03 Sep 2010    Post subject: Reply with quote

https://cgi.ebay.co.uk/HONDA-CBF500-CBF600-CBF-500-600-FORKS-REFURBISHMENT-/170429903452?pt=UK_Motorcycle_Parts&hash=item27ae69f25c#ht_2846wt_911

have a look at this.
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Teflon-Mike
tl;dr



Joined: 01 Jun 2010
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PostPosted: 15:29 - 03 Sep 2010    Post subject: Reply with quote

calyx wrote:
https://cgi.ebay.co.uk/HONDA-CBF500-CBF600-CBF-500-600-FORKS-REFURBISHMENT-/170429903452?pt=UK_Motorcycle_Parts&hash=item27ae69f25c#ht_2846wt_911
have a look at this.

Read the small print, £100 to basically replace the seals and refill with oil..... NOT exactly a bargain.
Price doesn't include new fork standsions or stansion rechroming, which is whats needed if the forks are pitted.

OP: What bikes are you looking at?

Depends on the bike how easy / expensive reconditioning the forks might be.

Rechroming the fork stansions, ball-park is about £150 +/- £20 depending on who you go to, what fork it is.

Size & shape of fork dont really matter, cost is in the time, labour & specialist kit to do the job.

New forks are often cheaper than a re-chrome, as they dont have to be 'unchromed' before being chromed... IF you can get them.

If you can, depends on the bike, how expensive they are, and whether they are genuine parts or patern replacements.

For something like a CG125, you might find cheap patern
replacements for about £30-£40, more typically about £70ish, for a good one, where a Honda Gen-Spares may be £120 or so.

For other bikes, particularly ones that get crashed a lot, like ZX6's, new fork tubes are likely to be more expensive, but pot luck whether they are more or less expensive than re-chroming.

It NEEDN'T be something to put you off. It isn't NECESSERILY a killer of a fault, especially if the pitting is at the top of the forkl tube away from the swept area of teh fork slider, or above the bottom yoke where its purely cosmetic.

AND if they are pitted, can often be a long time before they need major remedial action; if the pitting is polished out early enough, it wont spread too far too fast, and if slight, and treated, will only mean slightly faster wear of the fork seals, which still wear anyway, and grit and road crud have similarly abrasive effect to slight pitting.

BUT, if they are completely beyond redemption, rebuilding a fork is not usually a terribly onerouse task; and there are places that WILL completely renovate a completely clapped out or bent fork, for between £250 - £500 depending on what it came off and how bad it is to begin with.

Obviousely if we are talking about a £500 YBR125, that is RATHER more significant than if we are looking at a £5,000 Hornet, though.... so back to my original Q, what bike syou looking at?
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Pie-Roe
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PostPosted: 15:35 - 03 Sep 2010    Post subject: Reply with quote

If it's a cheap bike, just fit gators, or neoprene covers on a sports style bike.

I did this with a couple of bikes that needed replacement forks while I was saving for the forks. As far as I'm aware, if you have gators/covers the fork seals are not checked for an mot.

A lot of the pitting on forks is superficial, and a couple of bikes I've bought have been surface rust rather than actual pitting, which cleans up easy.

Pyro
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D O G
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PostPosted: 15:45 - 03 Sep 2010    Post subject: Reply with quote

pyroforlife wrote:
A lot of the pitting on forks is superficial, and a couple of bikes I've bought have been surface rust rather than actual pitting, which cleans up easy.

Pyro


How do you suggest cleaning up the surface rust? I have a little on my bike so would be interested to know.
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27cows
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PostPosted: 18:21 - 03 Sep 2010    Post subject: Reply with quote

The left fork on my old RXS has been pitted for at least five years and doesn't leak oil. So long as there isn't any raised area running through the seals, should be OK, unless it's really extensive.
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skithepowder
Borekit Bruiser



Joined: 27 May 2010
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PostPosted: 21:02 - 03 Sep 2010    Post subject: Reply with quote

Teflon mike, thanks for the reply, very informative... The bikes I'm looking at are sv650s from 99-01 most likely and looking at spending between £1000-£1500, so a £500 job is something I'd rather avoid, but I guess having a good look at the location of the pitting is the most important thing... Thanks for the help guys!
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Teflon-Mike
tl;dr



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PostPosted: 23:15 - 03 Sep 2010    Post subject: Reply with quote

skithepowder wrote:
Teflon mike, thanks for the reply, very informative... The bikes I'm looking at are sv650s from 99-01 most likely and looking at spending between £1000-£1500, so a £500 job is something I'd rather avoid, but I guess having a good look at the location of the pitting is the most important thing... Thanks for the help guys!


Ten year old SV.... well that makes some sense. Suzuki's dont have a great rep for the 'finish' on thier more budget minded models.

Very quick Google; Wemoto, £97.50 a leg, brand new.
So a full fork rebuild with brand new legs, would be about £250 by the time you have bought new stancions, and seals, rebuilt them and chucked some oil in.

Getting the old forks rechromed then might save you £50.

We're not looking at a mega-expensive one, and we are looking at a model where new parts are available off the shelf.

Thats helpful.

Here's what I'd do.

Go look at bikes that you like the look of. Haggle hard, theres plenty around.

Get the tidiest, best running example you can find, BUT hold back about £3-350 of your buy budget.

No, NOT to do the forks with.... 'just in case'.

Polish the foks with solvol, should get rid of any surface marking.

If the seals 'go' or are gone, strip the front end, polish the stansions hard, rebuild with new seals and oil (about £20-30's worth of 'suff') and stick them back together with new gaiters against the dreaded MOT man.

Slight pitting, provided it dont completely chew the seals in no time, is NOT a major problem. Structurally and functionally, the chrome does NOT effect the performance of the suspension, thats controlled by the damping piston & oil in the fork and the bush that it slides on. If they are OK, then the forks OK. all teh chrome does is give a nice smooth surface for the seal to rub on, to keep the oil inside.

As ling as the pitting isn't too deep or extensive, and it shouldn't be on a ten year old bike, then seals shouldn't have too hard a time, provided you keep teh forks polished and free of any rust that will lift the chrome or flake the edges givving a bump or edge to cut the seal.

The pits themselves, when the fork slides over them, will get wiped with oil that will give the seal an easier time, and should keep them from rusting further, provided they are wiped frequently.

If you are worried about it; when you clean the bike, lift the gaiter, polish the chrome, & give it a coat of WD40 or similar moisture repellant. When you do an oil change, loosen the stanscions in the yokes (one leg at a time!) and twist it round a few degrees so that the seal is rubbing on a slightly different area of the leg, to even out any wear.

Reason its an MOT fail, is that there is a clause in the MOT requs which says there must not be any 'visible defect' to the suspension.... some testers WILL fail for fork pitting, some wont, if there are gaiters, they aren't allowed to lift them to check, it gives them the 'get-out' & will let it go.

Back to that £300 'hold-back'?

Its your first bike....... use it fix the thing after your first crash......

Bit of 'luck' that will be one you walk away from......

Bit MORE luck....... forks will be bent, and you can buy new ones, to repair the damage, ANd get nice shinet new chrome!

Basically? dont sweat the small stuff!

Bigger things to worry about buying a bike!
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2wheelsteve
Spanner Monkey



Joined: 05 Feb 2010
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PostPosted: 23:22 - 03 Sep 2010    Post subject: Reply with quote

You can always change the forks !!!! Rolling Eyes
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