Finding correct size nut for my swingarm bolt...

[Shay HTFC]

The nut that tightens my swingarm bolt came off recently and I need to buy another. No I am in the bad position of not having a clue how to get a replacement bolt.

My first idea was to get some measurements of the width of the bolt that the nut will go onto, somehow measure the thread etc, but it occurred to me that this could easy go wrong if I get 1mm wrong or so.

Then I thought that maybe I should ride up to screwfix direct tradefloor and just ask someone to come and see (or maybe they have a tool or something?). But it would mean riding without my swingarm bolt secured in place which is a bit worrying (although who knows when it came off in the first place!)

Other than those 2 options, does anyone know what nut goes onto a 1989 CG125 swingarm bolt?


So in essence, which is the best way to find out?

[Pete.]

You measure across the top of the threads for the diameter, so if it's 18mm you'll need a M18 Nut. For the pitch, it's best to measure across 11 thread peaks, that will give you the pitch of 10 threads then divide that number by 10. So if you measure the distance between them and it's 15mm, you would need a M18 x 1.5mm Nut.
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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

[stinkwheel]

You'd most likely need to measure it.

They USUALLY go up in 2mm increments at that size and it's probably 10mm.

But assuming it is, you need to find out what pitch the threads are. It's could be standard or fine pitch.

Best bet is probably to measure it then buy both a standard and fine pitch nut fro that diameter. I suspect you'll probably need a nylok type nut so it doesn't undo again.

If I was a betting man, I'd put my money on a CG125 taking an M10x1.5 nylok nut on there but I could well be proved wrong.

Screwfix may not be able to supply these, you might need to go to a more specialist fastner shop or engineering supply shop.

The best way would be to slide the bolt out and take it with you, a specialist supplier will have a thread guage to measure it with.

If you can't do that, measure the bolt and buy the following:
If it's 10mm: M10x1.5 and M10x1.25
If it's 12mm: M12x1.75 and M12x1.5

See which fits by trying them, don't force them on, the wrong size might go on a turn or so then stick.

Remember there is also the chance that the Japanese are having one of the little jokes they like so much and have fitted a totally obscure thread that is unobtainable or they've used a hex size that is smaller than standard (using an M10 nut with a 14mm hex fitting in a 16mm recess when a standard M10 has a 17mm hex would be a classic Japanese thing to do. So you'd have to buy both a special nut AND a special tool to screw it in with).

I recently had this where they used an M7 nut with a 10mm hex. M7 is FAR from standard and those few places that do them use an 11mm hex .
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Pete.]

M7 is a size for a prop-nut used on some model aircraft engines
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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

[Phil_P]

Off topic, but for StinkWheel.

Could always machine you some M7 nuts with 10mm hex if I could get some some suitable bar (stainless perhaps).
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It is not enough to win, others must fail.
Moto Guzzi 1100 Sport Injection '96

[stinkwheel]

I did get one in the end, thanks for the offers though. Tapped out an M6.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Ichy]

Ask a dealer or just go to a local garage, they are likely to have a box full of nuts.

[Shay HTFC]

Think I'm going to take the bolt with me to a hardware shop in town.
I rang them up and asked if they had nuts and bolts and she just went "YEAAAAAAH", so I guess they do

I take it there is no problem with just sliding the bolt out? It seems pretty long if it goes all the way through! Will it just slide back in easily, or is there loads of hole aligning to do?

Edit: Screwfix didn't have anything, neither did Halfords or 3 hardware stores in town

Will have to try the local MOT garage on Monday. Its an M12 bolt with a thinner than standard thread.

Screwfix were a real help , but unfortunately had nothing with the correct thread.

[stinkwheel]

So it'll be an M12x1.5 otherwise known as M12 fine pitch.

Ask for this when you are calling round.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Shay HTFC]

[hmmmnz]

according to my parts fiche its a 14mm nut
but it could well be wrong
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[Shay HTFC]

[Ichy]

[hmmmnz]

yeah i'd have to agree, the diagrams are for the crazy foriegn ones
must be a 12 have fun is there a bike shop near you, ask if you can go through there box of bolts, every bike shop has one
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[Jamie S]

I have a nut here off a cg swing arm bolt, you can have it for the price of postage if you want mate.

[Odie]

Why didnt you go fucking honda and buy one, the amout of money you have spent on fuel and phone calls you could have got one the next day!

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You are so ugly when you were born the doctor said "I?m gonna drop it, if it falls is a rat, if it flies is a bat."

[stinkwheel]

[Shay HTFC]

[Odie]

grump, is that the best you could come up with, or did some-one have to help you find that as well.
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You are so ugly when you were born the doctor said "I?m gonna drop it, if it falls is a rat, if it flies is a bat."

[Phil_P]

[Shay HTFC]

Used the word grump, because you seem quite grumpy. I'd have used another word if you'd have been more c*nty

[Odie]

i have been known to answer to c*nty
____________________
You are so ugly when you were born the doctor said "I?m gonna drop it, if it falls is a rat, if it flies is a bat."