Stainless bolt replacement advice???

[smudge]

Sup lads, I have just finished painting my engine and tidying up a few bits and pieces on my never ending slabside streetfighter project , I still have to get paint on frame and bodywork and then get ready for assembly, the  engine/ frame and suspension/ cushion lever bolts that came with the bike originally are a bunch of mix n match rusty crap I was planning on replacing them with a2-70 stainless bolts but I'm not sure how they would hold up? Are they strong enough for the engine mounts and  suspension parts? I can make out a number 7 on the bolt heads which I think is equivalent to an 8.8 ? Would I better to use titanium on critical parts? As usual any advise is really appreciated.

[Captain Chaos]

 

[Gixer1460]

Apparently Ti is no better for tensile strength than A2 or A4 stainless! Most of these type of bolts fasteners will be 8.8 steel and a comparible SS which is A4 will be approx 12.5% weaker. I've never had an issue using A4 for the majority of these fixings - only the big long ones did I retain stock steel!

[MeanBean49]

Ditto

Ive used stainless for pretty much most things except main engine bolts, swingarm and wheel spindes and shock and linkage bolts.

[yantosh]

me too 

[smudge]

1 hour ago, Gixer1460 said:

Apparently Ti is no better for tensile strength than A2 or A4 stainless! Most of these type of bolts fasteners will be 8.8 steel and a comparible SS which is A4 will be approx 12.5% weaker. I've never had an issue using A4 for the majority of these fixings - only the big long ones did I retain stock steel!

Thanks for the reply, from what I've looked up grade 5 titanium has tensile strength of 150,000 psi, which I think is a bout the same as 10.9 bolt, a2-70 and a4-70  SS have the same tensile strength (100,000psi) , A4 has better corrosion resistance? This is all info I have got from various websites so I could be totally wrong! I was thinking of using stainless for engine and titanium for cushion lever if I can afford it. Thanks again , all advice appreciated.

[smudge]

30 minutes ago, MeanBean49 said:

Ditto

Ive used stainless for pretty much most things except main engine bolts, swingarm and wheel spindes and shock and linkage bolts.

Thanks all advice appreciated.

 

[smudge]

1 hour ago, Captain Chaos said:

 

Thanks for the link, appreciated.

[smudge]

2 hours ago, MeanBean49 said:

Ditto

Ive used stainless for pretty much most things except main engine bolts, swingarm and wheel spindes and shock and linkage bolts.

Thanks for the advice, this seems to be the consensus, appreciated.

 

[Dezza]

I have used stainless for suspension linkages with no problems, and also for caliper mounts, for which they are widely sold, again with no problems.

[smudge]

3 hours ago, Dezza said:

I have used stainless for suspension linkages with no problems, and also for caliper mounts, for which they are widely sold, again with no problems.

Thanks, again all advice appreciated, do you know what type of stainless? A2-70 ? A4-80, 

[MeanBean49]

6 hours ago, smudge said:

Thanks, again all advice appreciated, do you know what type of stainless? A2-70 ? A4-80, 

Either is fine, A4 is marine grade so is even more corrosion resistant. Depends how your going to use your bike, if its a winter hack and will be out in all weathers and covered in winter salt A4 might be worth the extra cost. If not go with A2

[dupersunc]

14 hours ago, Dezza said:

I have used stainless for suspension linkages with no problems, and also for caliper mounts, for which they are widely sold, again with no problems.

Lots of different grades of stainless. The fancy bolts you but from pro-bolt, race bolt etc aren't made from the same grade as A2 or A4, they'll be at least as strong as a 8.8  bolt.

[Gixer1460]

Maybe true ie. Stainless 410 grade is an option but is not widely available and its rarity probably increases its cost exponentially! Not even ProBolt are likely to use 'Hi Grade' stainless! For the aggro sourcing HT SS - just use a plated steel 8.8 or 10.9 HT bolt.

[smudge]

25 minutes ago, Gixer1460 said:

Maybe true ie. Stainless 410 grade is an option but is not widely available and its rarity probably increases its cost exponentially! Not even ProBolt are likely to use 'Hi Grade' stainless! For the aggro sourcing HT SS - just use a plated steel 8.8 or 10.9 HT bolt.

Hi thanks for the advice, I can't find any one selling high tensile stainless ( heat treated ,martensitic etc ) and to be honest I think your right that the cost would be crazy , I guess it's all a trade off and a compromise between strength and corrosion resistance, I live in Ireland whare it pisses down every other day so so I always try to use stainless if I can ( have most of my dirt bike done and it's paid dividends when it comes to maintaining it) I think I will probably go with a2-70 on frame and engine mounts and grade 5 titanium on the suspension and other more critical bits, either way has to be better than the rusty crap that came out of it? Big thanks to everyone one who has taken the time to offer there advice and experience, this is my first "proper bike build"  so it's all really appreciated, cheers lads.

[Dezza]

After a recent slight modification, I have realised the original swingarm pivot for my Spondon is aluminium alloy. It's coated in what looks like olive green passivate that must actually be hard anodising so not so obvious even though it's weight is a massive clue (doh).

[Gixer1460]

I think the 'olive green passivate' coating is similar to that used extensively on aircraft panels, mainly I think as an anti corrosion measure, cracks being a bad thing at 35,000ft! For a swing arm pivot, its not really loaded as such, just there to hold the bearings and spacers but obviously given its location on a bike, corrosion could be an issue so protection warranted?

[mellow-fellow]

We used to do various things to parts for helicopters, all the aluminium went from us to the platers and was Alochromed, thats greenish/gold coating.
I heard it called alodine, alochrome and something else.

Any fasteners I have to make for my vintage bike I make from 431 stainless.

Use Duralac between stainless and aluminium.

 

 

 

 

[smudge]

6 hours ago, mellow-fellow said:

We used to do various things to parts for helicopters, all the aluminium went from us to the platers and was Alochromed, thats greenish/gold coating.
I heard it called alodine, alochrome and something else.

Any fasteners I have to make for my vintage bike I make from 431 stainless.

Use Duralac between stainless and aluminium.

 

 

 

 

Hi, thanks for the advice , unfortunately I don't have a lathe or the skill to make up fasteners, but if do get any made I'll take your advice and go with the 431, I'm mostly going with grade5 titanium for the engine and suspension bolts except for the two long bolts at the back of the engine which I'm using a2-70 stainless because I couldn't get them in that size in titanium, as regards to using the duralac , do you use it on the the threads ? Do you need it if your using locktight ? All advice appreciated, 

[370steve]

12 hours ago, smudge said:

 going with grade5 titanium for the engine and suspension bolts except for the two long bolts at the back of the engine which I'm using a2-70 stainless because I couldn't get them in that size in titanium, 

you can get them made in Grade5 Ti from Component Engineering

[smudge]

3 hours ago, 370steve said:

you can get them made in Grade5 Ti from Component Engineering

Hi, thanks for the advice, do you have a link for component engineering and if you don't mind me asking how much did they charge? I'll probably chance it with the stainless for now but will definitely upgrade to titanium as soon as I can. Cheers bud, appreciated.

[370steve]

http://www.componentengineering.co.uk/, if i remember correctly they were £90 with postage

[bluedog59]

2 hours ago, 370steve said:

http://www.componentengineering.co.uk/, if i remember correctly they were £90 with postage

Each or the pair ?

[370steve]

1 hour ago, bluedog59 said:

Each or the pair ?

for both 

[bluedog59]

That's actually not a bad price. 

Edited May 26, 2021 by bluedog59
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