Fork pinch bolt seized, snapped off...

[DrDonnyBrago]

Hi all,

Doing fork oil, bike is new to me (2004 sv1000s). Fork pinch bolts were all insanely tight and very corroded, three came out, one snapped off. Fork is now off the bike. Plus gas and cutting a slot in the back of the bolt for an impact driver did fuck all, the bolt steel is very soft and there are no signs of it budging. It's just getting more and more chewed up.

As such I think it needs drilling out, or welding to a nut etc etc by someone with a more advanced skillset and toolset than I.

Best place to take it? Garages, engineering firms? What sort of business am I looking for?


I'm in Southampton if anybody can suggest a specific place, otherwise general suggestions would be appreciated.

Cheers,

Donny

https://i.imgur.com/lRoYBQKh.jpg

[recman]

Got any pics?

[J4mes]

if it's stuck stuck fucking stuck I'd be tempted to take it to a machine shop and ask them to drill it out and remove the leftovers from the threads.

I had a threaded insert cut in to a brembo calliper by a machine shop after a garage stripped the original threads beyond repair. I was amazed at how good a job they did.

[Islander]

You also have the option of dissolving the bolt out of the fork bottom by using a strong hot alum solution. Plenty of information on Google and Youtube.

[redeem ouzzer]

If you don’t have a friendly machine shop then second hand yokes are cheap as piss.
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[Riejufixing]

What size bolts? M8? If so, how easily can you find centre? A 6.5mm drill or thereabouts can be put through, and a junior hacksaw with the blade depth reduced if need be used to slit one side of the remains, which should then tap/wiggle out. Don't cut deep into the aluminium, just through the threads!

[Riejufixing]

[kramdra]

Yoke or axle pinch bolts? I assumed axle. If so use alum, if not, yokes are steel so drill it.

Cut the bolt down the yokes/lower leg slot, allowing you to put a tight fitting drilling guide in the other half of the hole. Drill 3mm then 6mm then peel out the remaining thread.

[Pete.]

[DrDonnyBrago]

Hi all, thanks for the suggestions.

It's the fork lower pinch bolt that holds the axle on.

I've added a pic, the steel is made of cheese and isn't budging, I cut a small slot but it got chewed to bits by my impact driver. I'm concerned that putting too much heat into it will knacker o rings etc for the compression adjuster and damper rod.

I'm leaning towards finding someone to drill it out. If I do it I'm sure to veer off rrack and into the fork leg.

How fast does the alum work? Has anyone actually tried it? I'm not sure I understand the chemistry behind the iron reacting but the aluminium not? Passivation of the aluminium?

It's sat in a bath of plusgas whilst I decide how to rectify.

[Islander]

Not sure about the chemistry, but it needs to be as concentrated as you can make it and hot (close to a simmer) for it to work effectively. Obviously, you'll need an aluminium, glass or ceramic container. Some people advocate drilling a hole into the steel part to give a greater surface area to attack as well.

It's an old watchmaker's trick for removing steel screws from a brass component

[recman]

Personally, I'd start by drilling a 2-3mm hole in the bolt about 1cm deep.
Then I'd use the smallest easy out extractor I had but if it didn't budge I'd go to 4mm and use the next size up easy out.
If none of the above works, its not the end of the world.
Heli-coils are your friend.

https://jrtoolsuk.co.uk/stud-screw-extractor-remover-set-easy-out-5pc-3mm-18mm-by-bergen-2588/

[Riejufixing]

I have never tried this (alum process). I will see whether I have a bit of light alloy I can experiment with, but it won't be today! I'd also tend to drilling out (and slitting), or even drilling out and helicoiling.

[fatjames]

I wonder if the bolt is binding due to the gap. Maybe try clamping it together / putting the other bolt back in to bring them together?

Hard to explain what I mean. Highly skilled artist's impression:

https://i.imgur.com/qxRsafh.jpg

[DrDonnyBrago]

[DrDonnyBrago]

So.... I took the cheater's way out and found an old man in a small, swarf filled workshop full of cylinder heads and oily machining equipment.

£20 and an hour later and it is out.

[J4mes]

[DrDonnyBrago]

[Riejufixing]

Good. "How did he do it?".

[recman]

[skatefreak]

Curious here as well...
Had a crash bobbin bolt bend right over & snap almost flush... well and truly stuck in an the engine mount...
Almost had the front wheel off the ground with fancy easy out rod type thingy so eventually figured snapping that in there would make it even worse so hammered it out, drilled clear through and whacked a nut on the end of a longer bolt...

Not saying it's right but does the job

[recman]

[stinkwheel]

My local guy took 45 similarly stuck fork brace bolts out of a set of fork lowers for me using his milling machine. Milled the centres out to the point he could collapse the threads in then ran a tap up the middle.

I really do want to try the hot alum thing myself some time though and that particular part would have loaned itself nicely to it. I've done the opposite by dissolving a stuck alloy seapost out of a steel bike frame with caustic.
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I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Suntan Sid]

Has anyone tried these?:-

https://www.powertoolworld.co.uk/trend-grab-se2-set-grabit-damaged-screw-remover-set-4-pcs?gclid=EAIaIQobChMIlMX0x6TH3AIVDZ3tCh2XNANxEAQYAiABEgKFT_D_BwE

They appear to be a step up from the usual "easyout" extractors.
Self centring bit at one end and extractor at the other.
Assuming you can drill a small pilot hole to start with.

Trend do make good woodworking stuff, so not an unknown brand.
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[Pete.]

The alum trick is one of those things that work better in theory than in practice. If you have an expensive alloy part that absolutely must not suffer any damage at all - such as a complicated part you've machined and snapped a tap off in one of the holes - it's the stuff to use (or sinker EDM).

For a cylinder head or fork lower - drill it out! Dissolving with alum is like trying to get somewhere by hitching a ride on a glacier.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good