Stainless bolts in aluminium swingarm

[MarkJ]

The RSV has an aluminium swingarm, and the hugger is bolted to it with four small stainless steel allen key bolts (needs a 3mm key). Now being where it is the threads get soaked in water (and salt water in winter) which makes the bolts and swingarm corrode together. Then when you try to get them out you just end up rounding out the small allen key hole.

I managed to get these bolts out last night - but it took me over two hours, and they're all ruined now because I had to either saw a groove in them or hammer a torx head into them.

If i buy some direct replacements the same will happen eventually. I see myself as having two options:

1) Buy some more SS bolts and lube them up with some sort of grease. Apparently copper grease will eventually let the corrosion happen so that's out. I've been told maybe a type of molykote. Any others?
2) Buy some bolts of a different material. I was thinking titanium, would these corrode with the aluminium at all?

[Raffles]

Stainless steel bolts aren't terribly expensive to buy. Rather than trying to find a permanent solution to your problem (which might not be possible) you could always purchase a quantity of extra bolts and discipline yourself to change them every few months before the corrosion gets too severe. Just a thought.
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A good loser will always be a loser.

[SillyMe1]

This guy is great, he has two Ducati's titanium bolts, he custom builds stuff too. If you local or in the Uk I would give him a bell. He will be able ot help I am sure.
That's if you really struggling anyway.

Bikes & Bits

268 Stockport Rd, Ashton-under-Lyne, Tameside OL70NS

0161 339 4231

[Bru]

Avoid copper grease, as it is intended for high-heat applications where the grease may be cooked out, leaving the copper as an anti-seize lubricant. You do not want to lubricate your threads in your application.

Use medium-strength thread lock compound. Loctite 243 or similar. The compound will prevent corrosion. In all the cases I've seen, the corrosion is usually found along the shank of the bolt and at the 'top' of the thread (near the bolt head, closer to 'outside'), if the hole is blind. So, that is the key when applying the threadlock.

[Bezzer]

Near enough all metals react with each other when water is present giving you galvanic/electrolytic reaction that can "weld" them together. Just depends where they are in the table as to how bad it is. Anything that creates a barrier between the metals stops/reduces it so they don't bind. Ti might be a touch better than Stainless but as long as you use at least copper grease or one of the more expensive anti seize compounds you should have no problem .
Where you're using it it doesn't really matter that copper grease would be lubricating the threads, as said it was developed for high heat applications but countless people have used it for donkeys years as a normal anti seize.
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[Teflon-Mike]

Depending on how secure it is, & how heavy, and whether the bolts are M6 or not...... I'd be inclined to look at Plastic M6 Number-Plate screws.
Used to use them on my dirt bike quite a lot of low stress fastenings, as they dont rust up & if they dont want to come out you can cut them easily enough with a pair of wire snips.
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[MarkJ]

Plastic bolts sounds like a good idea actually, hadn't thought of that! There's four M5x16 bolts which should hold fine:
https://aprilia.vladiks.com/forsale/Hugger.jpg
(not my bike)

For reference, you can get a gel called Tefgel which (believe it or not) has teflon in it and is used with steel & aluminium in boat applications which sounds as though it would work well.

Also, apparently titanium is worse for corrosion with aluminium as it's further away on that scale.

[Kickstart]

Hi

Afraid I would use copper grease. Might eventually allow corrosion, but will take so long as to likely be irrelevant.

All the best

Keith
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[neil.]

+1 Copper grease. I have used it all over the bike on various fasteners where Locktite is not specified and never had anything rattle loose with it, ever. In fact, I found it isn't really a good lubricant anyway - tried it on my rear drum brake cam and it went stiff again after a month or so.
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[kestrel]

There are specialist gels and greases available to combat this problem. One i have used before with excellent results is called Tef Gel, made from finely powdered PTFE.

https://www.sailboats.co.uk/ProductInfo.aspx?productid=TG-01

[SoND]

If you are torquing the bolts up be careful because the numbers are maybe given for a dry thread. A greased bolt will turn a little more than a dry bolt under the same force with a greater chance of stripping the thread in the aluminium.
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[Im-a-Ridah]

Also in favour of copper grease, I've got a tub of that and normal grease out back. If you are that worried, just check the greased bolts every year or so

[SoND]

[Walloper]

Don't use copper grease (hee-haw to do with high temperature applications BTW. It is not designed for Hi Temp use AFAIK.)

Copper will react with the stainless for certain so not worth using it.
Dissimilar metals will react galvanically so as suggested preventing water ingress will reduce or eliminate this effect.

Silicone sealant, permatext, hylomar molibdenum grease will work fine.

I had a swing arm chain adjustment eccentric thing on a Triumph bike. Piece of shit was for ever seizing in the swing arm clamp due to galvanic-ism. Was advised by dealer to use copper-slip anti-seize too.

I changed to molycote and solved it.
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[Bezzer]

[dodgydog]

Copper grease, without question, I have used it for years, cars, bikes, everything.




Dog
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[dodgydog]

[Bru]

All I can add, is that in my experience, I have had two sets of bolts come loose which were lubed with copper grease; I had torqued them to the values set in my service manual. Never happens with thread-lock.