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Yeti365
2/24/2019 6:48pm
2/24/2019 6:48pm
Edited Date/Time
2/26/2019 8:47pm
There are countless discussions on if it's it's worth it or not. I'm not here for that.
In terms of using ti axles in aluminum swingarms with a steel nut, ti bolts going into engine areas, shock and subframe mounting points, engine mounts, swingarm pivot.
What issues with flex or corrosion/seizure arise and how to prevent them? Coating, special lube, etc.?
Something I'm really starting to get curious in but the bike gets stripped to the frame every 25-30 hours, not every ride.
Lay me towards your experienced insight. I'm ready.
In terms of using ti axles in aluminum swingarms with a steel nut, ti bolts going into engine areas, shock and subframe mounting points, engine mounts, swingarm pivot.
What issues with flex or corrosion/seizure arise and how to prevent them? Coating, special lube, etc.?
Something I'm really starting to get curious in but the bike gets stripped to the frame every 25-30 hours, not every ride.
Lay me towards your experienced insight. I'm ready.
I guess I'm asking this from more of a POV on preventative maintenance perspective.
Just curious if anyone has had issues with a dissimilar metal condition/corrosion or seizures and best way to prevent it, or just treat it like any other bolt.
I don't think you could convince me to do all the fasteners on a bike in Ti.
The Shop
Plastics, motor kit, motor mounts for for it.
Second i see prices from 89 euro to 450 dollar for the same axle. It always says gr5 ti but so far i can't find anything on the web how it's holding up after a season. Third what i could find is that steel is with stress or something its harder then ti. Or i did read it wrong.
So why are you not gonna try be the ginny pig for the ones what are thinking about those axles etc but are to scared to try it like me
But to be honest i'm staying away from the axles etc etc not gonna put my life in danger for a couple of grams win
http://store.mettec.com/
Fun fact, Titanium is actually heavier than AL from a density standpoint. However, it's strength characteristics allow for it to be implemented in a way that makes it lighter than any other metal. You can run thinner walls on TI and still come out with a higher safety factor and less weight.
As far as axles, pivots, linkage bolts, etc., I only have those things on a bike I never ride so I can’t tell you how they feel. A former pro mechanic told me he had riders who had snapped ti axles and would refuse to run them.
Strength:
In most all cases, titanium will be as strong or stronger than the steel it's replacing. There are certainly steel alloys and heat treatments that are stronger than grade 5, but it's unlikely they're being used on a stock bike anywhere.
Fatigue Life:
This is a minor concern. Depending on the design stresses, titanium will fail from fatigue earlier than steel will. But for most riders it won't be a concern. Unless you're riding A LOT and keep the titanium parts for a long time, you probably won't have any fatigue issues.
Hardness:
Again, in most cases, titanium will be similar in hardness to the stock steel it's replacing, so wear isn't a huge concern.
Corrosion:
Titanium is very inert and will not corrode unless in an extreme environment not found on a dirt bike. It will, however, accelerate galvanic corrosion of the material around it (aluminum, steel, etc.). This can be negated with adequate lube/anti-seize and/or coatings such as TiN and DLC.
Assembly/Seizing/Torque:
This is a big issue for titanium. You can't treat it like steel, you have to be much more careful. It likes to gall, particularly with itself (e.g. nut and bolt are titanium). The solution is to use a lot of anti-seize as others have mentioned. But when using anti-seize, the tightening torque changes substantially. The anti-sieze acts as a lubricant and for the same torque as a dry steel bolt, you'll end up with much higher bolt tension. That's bad. You'll need to account for that, and in general, reduce your torque by ~20%.
We have a handy torque spreadsheet available here if you'd like to play with some numbers:
https://luxonmx.com/resources/luxon-bolt-torque-calculator.xlsx
Stiffness:
This one will likely cause some argument... Large chunks of titanium replacing steel in the primary load-paths will flex more and MAY be noticeable to the rider. The vast majority of people won't know the difference unless they're told it's different (and there lies the problem, the placebo effect is strong). So picky riders and those that notice subtle changes may pick up on more flex from swingarm pivot bolts and axles. No one is picking up on the difference between titanium triple clamp bolt stiffness vs. steel. Again, the placebo effect is STRONG.
Summary:
Titanium replacement parts will be just fine for the vast majority of people so long as you understand the increased maintenance requirements (torque and anti-seize).
And finally, to address this:
Fun fact, Titanium is actually heavier than AL from a density standpoint. However, it's strength characteristics allow for it to be implemented in a way that makes it lighter than any other metal. You can run thinner walls on TI and still come out with a higher safety factor and less weight.
That's not typically true, it's highly dependent on the manufacturing process, alloys selected, and design criteria. The stiffness to weight ratios are nearly identical for most structural metals - steel, titanium, aluminum, magnesium, etc. And strength to weight ratios can be pretty close as well when selecting appropriate alloys. What this means is that for the same weight, a lower density material will be thicker. While this has minimal effect on tension and compresive stiffness/strength, it has an enormous effect on bending stiffness/strength. The lower density material being thicker (for the same weight) will almost always be stronger and stiffer. Additionally, depending on the manufacturing method, you are stuck with material that isn't optimal. For example, a machine part can not have sharp inside corners because an end-mill has a finite radius. And it needs to be stiff enough to cut the material. This results in a radius on the inside corners of parts that doens't "need" to be there for strength/stiffness, but does for manufacturing. So that material is "wasted" weight and it follows that a less dense material will be better suit that situation. Now if we're talking about 3D printed titanium or something, then that is less of a concern, but the bending stiffness point still applies.
So, for example, a steel titanium triple clamp will be less stiff and weaker than a titanium one. This works on down the line - ti will be weaker and less stiff than aluminum. Aluminum will be less stiff and weaker than magnesium. Magnesium, even AZ31B, is a special case, as it's a lot weaker than aluminum so it's not a good choice here typically. Plus there's the corrosion and manufacturing issues to be concerned with. This is why you primarily only see triple clamps made of aluminum.
Titanium shines in places where you're space limited, and bolts/axles are a great example. You can't replace a solid titanium bolt with aluminum and have it be stronger, there wasn't room to add any material. Similar for an axle, since you can't go to a larger diameter, you can only add material in the middle where it's not very effective in bending. (there's a whole thread here somewhere about aluminum axles and why that's not a good idea).
LANOX Lanolin Lubricant is a heavy duty, anti-moisture, anti-corrosion lubricant made with a high grade oil and lanolin base, with specialised chemical compounds. LANOX Is created with Lanolin, a natural wax found in animal wool, especially the wool from sheep, commonly referred as ‘WOOL FAT’ or ‘WOOL GREASE’.
Lanolin has widespread uses, ranging from cosmetics, soaps and medical products to rust proofing and lubrication. Lanolin has been used in skin care and cosmetics as far back as 700BC, but in the late nineteenth century it was refined at a new level, giving us lanolin with an extremely high quality. Although we make INOX, a quality anti-corrosion lubricant, there are areas where a lanolin based anti-corrosion lubricant like LANOX is sometimes better suited for the application at hand.
LANOX MX4 has ideal applications in the Marine industry. It designed to stop electrolysis between different metals and prevent oxidation and rust from forming on the surface. The lanolin base helps to prolong the protection between applications, as it is a natural anti-corrosion compound that is not soluble in water and leaves a protective film behind.
Really my serious considerations were towards axles, steering stem, possible the swingarm pivot. Everything else I was curious about.
Pit Row
It wouldn't be cheap I know, but figured it couldn't hurt to ask on a passing thought.
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