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New bolts: titanium of Aluminium?

8K views 16 replies 10 participants last post by  pat1098 
#1 ·
Gents, just after some opinions. I'm doing some off season maintenance and have decided to change out a few bolts. Looking at subframe, footpeg and other misc. bolts.

Question is, should I go for Aluminium or Titanium fasteners? Pros and cons of either?

Cost is not a big factor, as I will be changing them a few at a time and not everything I see.

Cheers
Grumbly
 
#2 ·
The two bolts you speak of rearsets and subframe are both load baring bolts. (do not use Alu bolts) My rule of thumb is if the bolt is a 6 mm or bigger I will go with TI because if the weight exchange alone. (unless this is a true race bike then go wild) TI is also stronger and able to stretch and flex more without braking.

Jay
 
#4 · (Edited)
Substituting aluminum and titanium for steel fasteners requires an understanding of material strength properties, safety factors, galvanic corrosion, appropriate anti-seize material selection and the use of protective coatings. If you make a mistake, you risk catastrophic failure of a safety-related connection and/or a serious corrosion problem caused by dissimilar materials. This is not a simple subject and there's much to learn — so I suggest you start here:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900009424.pdf

In particular — not all grades of steel have the same strength, and not all grades of titanium have a yield and tensile strength greater than steel. When possible, buy bolts that have a specific application, e.g., for use for brake rotors. If you’re not sure of the quality or source, my advice is not to use them in critical connections.
 
#6 ·
I have replaced almost every fastener, spacer and washer on my bikes, as many on here would be aware.

Essentially, aluminium bolts should only be used to secure plastic parts, like fairings and belt covers. Places where there is minimal load on the fastener.

Parts like subframe bolts, or anything requiring strength, should be replaced in titanium. And yes, as Shazaam rightly points out, many of the titanium fasteners available now are coming out of China, and may not be of supreme quality.

But then, neither are many of the steel fasteners that come out on our bikes.

Titanium weighs roughly 60% of steel's weight, whereas aluminium is only about 30%. So of course there are greater savings by fitting aluminium, and they are also cheaper than titanium.

But they do not have the tensile strength of titanium or steel, so use judiciously. OK for fairings and side-panels, mudguards/huggers, belt and sprocket covers, number plate etc.

But stay with steel or titanium for anything that needs strength, or to be done up with much tension.

Safety first!
 
#7 ·
Thanks guys. Basically you all reinforced what I was thinking. Shazaam, I am in engineering so am aware of a lot of these issues, but also gathering extra information. I have found a couple of suppliers from the UK and Aust, so hopefully quality won't be an issue.

And pat, as always, I thank you for your wise words :)
 
#8 ·
I have 98% of the entire ProBolt Titanium (Gold) on my 1098S and some ProBolt Natural titanium on my 1199S.

Go with Titanium (as recommend several times in the thread).

I favor ProBolt over every other brand, it is more expensive than most - however that British Titanium is very high quality.

What is not mentioned and is critical to know, is that with Titanium you *HAVE* to use "anti-seize" rather than "loctite" and never ever mix the two compounds together.
 
#9 ·
I have spent thousands with ProBolt, and am about to spend a bit more.

But I'm not sure about your comment regarding "British titanium is very high quality".

Yes, they are a British firm, but I've never heard them claim to use British material..

But I've never had a quality issue with titanium components from either ProBolt (UK), Poggipollini (Italy) or TPO (Texas).

I now have some Ti crankcase bolts coming from Tuning Pedals in Germany, and Graceo in Cheshire UK.

I will report on these (when they arrive) in my Pat's Engine Overhaul thread, which has currently stalled while I wait for Ducati to MAKE another 1098 piston..

:mad:
 
#11 ·
Can I ask who the Aussie supplier of titanium bolts is?

Always happy to spend my money here if possible.

I didn't think ProBolt's prices were too bad actually, although their prices have been creeping up.

But they have a good range. I guess there are costs involved with stocking so many varieties.
 
#12 ·
Just an ebay seller mate, very poor range but the bolts look ok.
So long as the bolts are made using the right grade of ti and threads are within tolerance then even the stuff out of China is ok. So many over here use chinese made bolts ( I used to work in quality control and still am in engineering).
ProBolt's range is awesome and I will admit I'll probably grab the ally ones from them.
 
#14 ·
I buy titanium bolts from a UK seller who bulk buys from a Chinese manufacturer which also supplies Pro Bolt. Apparently Pro Bolt purchase natural titanium bolts from the Chinese manufacturer then finish them to their own colours and polish. As far as I can tell the better quality bolts have roll formed threads, whereas the cheaper options have cut threads. The bolts I get from UK are identical in dimension and machining characteristics to the pro bolt offerings, just not finished to such a high visual standard.
 
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#15 ·
^ who is your supplier? I too have spent mucho dinero with ProBolt. Btw, aluminum bolts are good for a few installations, then begin to wear beyond my specification. Ti stuff is good for the long run if you have the where-with-all.......just sayin
 
#16 ·
This threads leads me to a question Grumbly. When it comes to caliper bolts for example, it's not as much the tensile strength rather the shear strength, since the force is transverse to the bolt's axis, I would think?

In this case, where some aluminum can run a shear strength in the 70,000+ range, would it be more if the bolt could withstand the constant of force, resulting in a weaker bolt over time, where as the Ti will maintain it's integrity?

I'm just wondering, with some of the types of aluminum out there that are very strong(say 7075-T6), and when in conjunction with radial brakes which reduce the amount of force per bolt, why it's not being done yet? It' doesn't necessarily have to be specific to calipers, but they were on my mind when reading the thread.

Pat, I'm sure you have experience with this type of thing too, so I am open ears.
 
#17 ·
Yes Brian - I considered these issues when starting out on the sickness that lightening my bikes has become.

You are right about the shear force, as opposed to tensile strength. But being brake components, I stuck with titanium.

Mind you, I should confess to fitting the aluminium bolts to the brake pads on my pushbike, which (you'll be staggered to learn) I have also lightened! They have been fine so far..

My conservatism with the lightening process (as in, I have done radical amounts of lightening, but conservatively regarding safety) has resulted in NO FAILURE of any of my lightening measures.

Mind you, I had faith in TPO's assurances to the extent of fitting their Tennalum front axle. This is a scary-light part, but has given no indication of weakness. It is one beautifully made part.

They state that it is actually stronger than either the stock steel item, or even Ti replacements. I hope not to die proving them wrong..

:eek:
 
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