Hi all,

So dismantling the front fork to fix a weeping seal, the nut rounds off. Splendid. Means either drilling out with uncertain result or buying a new fork at around £130.

Anyone else been here?

--and do previous year forks fit a '90 16v??

ArbOl wrote:
--and do previous year forks fit a '90 16v??

You'll have to source a 16V fork due to the four piston caliper bolt spacing and the 305mm brake discs and/or the fork tube's larger diametre. But which 'nut' are you referring to specifically? Surely a large pair of grips can be used on the large topnut, or an 'Easy-Out' extractor on any of the smaller 'nuts'? How about a picture...

Hi ArbOl,
Please post questions in the appropriate part of the forum in this case in the Frame, fairing and wheels, start a new post there. Not all of the gurus read the new members section so you miss out on their expertise.
Regards,
K-BIKE

I've just popped it over under the correct heading. I missed that when I replied. All done. Cheers.

Thanks, back in the right room.

Here's the problem- the damper rod allen screw (fig.36):




And here's what it's worth:

http://www.ebay.co.uk/itm/270995031836?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

Just get an appropriately sized "Easy Out" extractor, drill a sufficient hole on the head of the screw, and go to it. It might be easier than you think, if you don't have a lot of mechanical experience.


...But why would you replace the lower leg if the damper rod screw is stuffed? It threads into the fork's internal and is attached to the fork tube's guts.

I reckon you need to step back, then take a closer look as to how it all goes together. The allen head bolt holds the lower fork leg onto the damper rod inside and if this screw, or bolt, (but not 'nut' as you stated earlier) is stripped round the internal area where your allen key goes it only needs to be extracted with the aforementioned 'Easy Out'.

it really does pay to have the right fitting tools ...and know the teqniques to loossen aged metal bits

we often find that a good solid tap on the head of a bolt (by using an extension or whatever ) just makes things soo much easier .... the use of anti sieze durring reassembly is just forward thinking as well .

that seems a good price for a replacement ...new part for sure

but perhaps you can drill the head off ...extract the fork proper ...then unscrew the bolt whilst disasembled and with some shaft still visible ...if in fact so, with vice grips ...or worst case cut a cross cut in the bolt remains with a good hacksaw blade and with a good well fitting screwdriver blade get at the bolt to turn it out .

good luck

With a range of Ezy Outs like this kit, you might not even have to drill the stripped area out any larger. Just insert the tool and as you turn it the 'correct' way it tightens in, bites down on the remaining metal and (hopefully) removes the errant screw. If it won't grab then you drill the stripped area a bit larger and try the next size up.

Usually, the problem is the washer (or seal), part #37, being crushed and creating a lot of pressure on the thread.
If you drill the head, you may find that the screw is only finger tight.
The screw is M8 (8mm) and if you are perfectly centered, a 1/4" hole should clear it.
After that, just continue to drill with a drill fitting your easy out.


Nothing ventured, nothing gained....

CF

That's right, a bit of force and perhaps also a bit of heat applied to the screw might just loosen it sufficiently to save you a whole mess of trouble. We call it 'mechanical advantage'.

Not having to buy an eBay fork leg (however priced) that won't be what you need when you open the parcel is a bonus too. You'll be back to square one.

This is, roughly, what that stubborn screw is threaded into, and it can spin inside the fork leg so it's best to leave the whole she-bang tight in the triple clamps (axle slid through the fork legs too) so you have something larger to brace against when attempting to turn the buggered screw.

Before you go any futher lets establish what is the problem.
Can you say for sure the thread is striped or does the bolt just turn in situ and nothing else comes loose.
If the bolt is tight in the damper cartridge then it can feel as if it is striped but will be turning the cartridge inside the fork tube. There is no thread for that bolt in the alloy of the fork tube it clamps the damper cartridge into the fork tube.
I have often got those bolts to come out by putting a lot of pressure on the cartridge #14 by inserting a broomstick down the fork leg and holding as much pressuer as possible on the cartridge while turning the bolt and it often breaks loose and out it comes. Often an air powered rattle gun will vibrate it enough to break the bond. If not use the rattle gun and the broomstick trick then if that doesnt work drill the head of the bolt using an 8mm drill bit.

good point rick ...they often turn without releasing .

I think you got things mixed a bit here, Rick.

It isn't any cartridge on a -90, the cartridge was used from 08/91.
Early Marzocchi's got the damper assy shown on the left in the drawing.
But the broomstick metod would function on a -90, as you put pressure at
the piston and the piston rod points down.

On models with a cartridge the broomstick metod won`t function, unless you
drill out the center of the broomstick, as the piston rod points to the top...
and is much longer than the cartridge (fixed at the top of the stanchion).

Yeah I used Cartridge for want of a better word but thingy No 14.
I am not functioning very well at the moment my back is giving me a lot of pain and the pills don't work well.

No matter, we've got this bloke's bike fixed and we don't even really know the extent of it...

lol thats true dazza ...

hope he appreciates all the advice .... he could be just screeming in a dark corner ....NOOOOOO !!!

its all good ...good luck !

thanks folks - a dark and subzero corner, out on the kerbside.

I've gone soft and ordered a fork leg from Motorworks, not just super reasonable prices but willing to spend half an hour on the phone discussing in detail.

oh you lucky people with a) warmth and b) a garage

[quote="ArbOl"]thanks folks - a dark and subzero corner, out on the kerbside.

I've gone soft and ordered a fork leg from Motorworks, not just super reasonable prices but willing to spend half an hour on the phone discussing in detail.

oh you lucky people with a) warmth and b) a garage[/quote]



When you get the fork leg off you can try to extract the rounded screw in the comfort of a garage. No sense in throwing away something that is, in all likelihood, quite repairable.

Sorry this is a bit out of date now Ive just been searching for advice on fork oil weights so I hope you got sorted.

Ive dealt with similar fork issues over the years and its actually quite straight forward to drill the head off the allen screw that retains the stanchion/damper rod to the slider. Jap bikes use an M8 allen screw (not sure about BM's) so a nice sharp M9 drill will make short work of the allen head. As you can insert the drill into the head of the allen bolt, no worries about the drill bit wandering, all you need to do is keep the drill as near vertical as you can and stop drilling as soon as the head comes away . Once the head is gone, the stanchion will pull straight out and in every case Ive had, Ive been able to then remove the remaining thread with my fingers.

Incidentally, for siezed bolts Ive started using left hand drill bits instead of eazi-out/extractors. As you have to drill the snapped bolt in any case to insert the eazi-out why not use a L/H drill bit and with a bit of luck......and Im at 10 out of 10 now.......the drill bit bites into the snapped stem bringing it out as it continues to rotate, the heat from the drilling also assists to free the siezed item. Additionally it beats trying to remove a snapped eazi-out!!

Fentible raises a very good point about broken bolt removal if you choose to use an eezyout or whatever flavour of spelling you like, I suggest you buy the best quality tool you can because if it breaks you will really regret buying a cheap one. If the worst happens there are firms that specialise in fixing broken drills and taps using electro machining or spark erosion here is one such with some interesting comments on the risks of extraction http://www.brokentap.com/index.html
Regards,
K-BIKE

I imagine by now OP is either so confident of removing the errant bolt he is breathing easy or the dire warnings have his rectum is cleched so tight he can't breathe!

Themason wrote:I imagine by now OP is either so confident of removing the errant bolt he is breathing easy or the dire warnings have his rectum is cleched so tight he can't breathe!

Im going with super confident...........