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Hi

Just wondering about this. Every single bolt on my bike is Titanium - but for more weight savings im looking at alloy bolts.

Im thinking of:

2 x M6x20mm alloy bolts for rear post mount brake adapter
4 x M6x35mm alloy bolts for brake calipers
4 x M5x15mm for the brake levers


Any input ?
 

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heres where i have alum im 150lbs not a super agressive ride just xc race

water bottle cages
front rear der
brake levers
shifter
stem face plate 4 bolts
chainrings
head set cap when i run a shitty king headset
front rear brakes/ ti the other way
3 ti rotor bolts
ti seat post clamp alum can be ran i had some issues with the seat post slipping so i went ti for extrs tq


i change my bolts every yr or if i think there is other reason to just dont over tighten alum very easy to do..
 

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Do you toss all your old bolts? I hate to beg for your leftovers, but these bolts can add up quick, so if you have a bunch laying around in decent shape, I'd love to buy some off you.
 

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Tiffster said:
Hi

Just wondering about this. Every single bolt on my bike is Titanium - but for more weight savings im looking at alloy bolts.

Im thinking of:

2 x M6x20mm alloy bolts for rear post mount brake adapter
4 x M6x35mm alloy bolts for brake calipers
4 x M5x15mm for the brake levers

Any input ?
I wouldn't use Al for anything for the calipers. I have used Al for pinch and lever bolts, but last time one of my Al lever bolts seized, and it was such a pain to remove that I switched to Ti. I have used Al for my headset bolt but I don't like the way it creaks when I crank it down.

Ti = everywhere but the rotor bolts (to easy to strip heads)
Al = pinch, chainring, headset and lever bolts
St = rotor bolts
 

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Ausable said:
Topfuel98
Alu bolt on the stem face plate?!

Congrats, you have balls :)
At least for now.... :skep:

Race Face has all sorts of warnings about switching the 4x high strength steel bolts on their Deus stems out to Ti because of the torque versus bolt diameter limitations of Ti. That would likely go triple for alloy bolts.
 

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you can see a lot of the blue alum bolts in this pic, i also run an alum bolt for the rear der hanger..


you can just see the blue bolts in the calipers in this pic and the on stem, levers and so on.



i am very up on my maint, I would dif not recomend this for some one that is not or that has someone else working on there bike, that is the biggest reason.. next time your on google check out the tensile strength of 7075 T6 vs Mild steel. Now shear is a diff story..

i have some extras layin around but most of the time i just give them to my buddies for there water bottle cages and stuff, Alum bolts are cheep only like a dollar or two each...
 

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rockyuphill said:
At least for now.... :skep:

Race Face has all sorts of warnings about switching the 4x high strength steel bolts on their Deus stems out to Ti because of the torque versus bolt diameter limitations of Ti. That would likely go triple for alloy bolts.
again this is not something for most people... Alum bolts are not made for everyone, there more or less a one time use bolt in critical areas such as stem, there not made for some joe blow bike shop guy to be made taking them in and out and over tq them.. but if you know what your doin then yes... shimano/raceface/bontrager they all have to manufactur this stuff for a 250lb guy thats goin free riding with it, why do i want that junk on my race bike,

I guess its just like the stem cap, I would like to have a dollar for every time some one told me i couldnt do that...
 

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From Tastynuts.com

ALUMINIUM TECHNICAL SPECIFICATION

MATERIAL SPECIFICATIONS: 7075-T73 high tensile aluminium.

MANUFACTURING PROCESS: Head - cold formed: shank - thread rolling. Chemically brightened and colour anodised to between 8 and 12 microns thick.

ULTIMATE STRENGTH (PSI):

YEILD STRENGTH (PSI): 490-560Mpa (71,000-81,000 PSI); stronger than mild steel.

WEIGHT: 60% lighter than steel; 40% lighter than titanium.

CORROSION: Anodised aluminium is not affected by saltwater, road film or mild acids.

APPLICATIONS: Aluminium is suitable for use in all non-safety critical areas e.g. mudguards, screens, fairings, engine casings, huggers, fuel caps, number plates, lamp units, exhaust cans, heel plates, clutch levers, exhaust manifold brackets, fuel cap surround, air filter plus many more.

SAFETY: Do not use Aluminium in any safety critical areas.

TITANIUM TECHNICAL SPECIFICATION

MATERIAL SPECIFICATIONS: Grade 5 high tensile Titanium

MANUFACTURING PROCESS: Tapered Socket Cap - Forged Head with rolled threads. Flanged Hex Heads - Machined Heads with rolled threads. Other Items - Machined from bar

ULTIMATE STRENGTH (PSI): 120,000 - 160,000.

YEILD STRENGTH (PSI): 115,000 - 145,000

WEIGHT: 42% lighter than steel

CORROSION: Very high resistance to corrosion.

APPLICATIONS: Titanium is suitable for safety critical areas such as: Axle Bolts, Caliper Mount Bolts, Caliper Pinch Bolts etc.

SAFETY:Titanium can be used in safety critical areas - with the nature of these parts it is essential to use the correct torque guide and fit with care. After fittings new bolts (or any new parts) to your motorcycle check all fixings are tight and all parts are secure. Take your motorcycle for a short rest ride - riding with car. Examine your motorcycle after the test ride to ensure all parts are secure.

Warning from Race Face Deus Stem instructions

All bolts used on the Deus XC and Evolve XC stem are DIN grade 10.9 CrMo steel chrome plated. The size is M5X16mm. Do not substitute with inferior lower strength hardware such as DIN grade 8.8 steel, titanium or aluminum. These metals do not have the strength required for this application. Do not use shorter bolt lengths. Full thread engagement is required. If replacement is required, use DIN grade 10.9 M5X16mm only. OEM replacement parts are inexpensive and available from your RaceFace dealer

The DIN grade 8.8 bolts have a tensile strength of 120,000 PSI (equal to SAE Grade 5)

The DIN grade 10.9 bolts have a tensile strength of 150,000 PSI (equal to SAE Grade 8)
 

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of course there going to say that theres a thing called a law suit.. and the avg joe blow dont need to be riding that stuff.. and even most weight wennies on this board dont need to be riding alum but im just saying it can and has been done
 

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4 x 10.9grade bolts is a huge load

Okay this is going to be funny....

To find max load....we need -> sigma = Force/Area -> Force = sigma*Area

Area = 4 x pi x D^2/4 -> pi*D^2 -> pi*(.005m)^2

sigma (150, 000psi) = 1034.2 MPa

Max Force = 81.2 kN or 18,200 lbs.

Huh. Do you really think you're going to exceed the limits of steel? Unless you overtorque the bolts your not going to break those 4 bolts all together. Now, usually one or two are not as well torqued and then only a couple are really resisting the full loading until they stretch and the others can help out. That's why I will always run a 4-bolt handlebar clamp on any serious MTB, but I personally I think Titanium is fine for this application as it has a similar fatigue limit to steel.

Yes, I think Aluminum is a little dangerous here even though you're unlikely to exceed it's tensile limit it does not have an infinite fatigue life. Because you might frequently replace your handlebar or adjust it that means that those Aluminum bolts will eventually fail. It may not be in your lifetime, but they will fail due to fatigue.
 

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rocky you are full of hilariousness today

Fatigue Strength 7075 aluminum 23000 psi
@# of Cycles 5.00e+8
fatigue stength for 6al 4v titanium 60000-100000psi

titanium and steel don't have infinite fatigue lifes the fatigue strength for those materials is just much closer to the yield strength, so as long as you don't load your aluminum bolts up to 23000 psi (which isn't that high) they should never break.

btw what do you guys think of aluminum for brake caliper mounting bolts?
 

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rockyuphill said:
At least for now.... :skep:

Race Face has all sorts of warnings about switching the 4x high strength steel bolts on their Deus stems out to Ti because of the torque versus bolt diameter limitations of Ti. That would likely go triple for alloy bolts.
thats funny considering the deus xc sl comes with ti bolts. . .
 

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Where have you seen a Deus XC SL stem? It's not in the 2009 RF catalog. Even the road stems use the same bolts.

I don't think the bolt stress limits are produced by the static bolt torque alone, I think the concern comes from having the bolts stressed to some significant percentage of their strength under the recommended torque, and then if you add stress through leverage on the bars while riding (or crashing), the combined peak loads may be enough to break a bolt. With the aluminium bolts there won't be any warning, you'd likely just snap the heads off. They're half the tensile strength of Ti or the CrMo grade 8 bolts.
 

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Bolt Sizes

Can anyone tell me where to find specific bolt sizes for parts without measuring them?

XTR Parts
Shifters (attachment bolt- to handlebars)

Deraillers

Thomson Elite Stem

Thomson Elite Post

I live in Korea and I don't have the tools to measure and my local shop hasn't been to helpful. I'd really appreciate your help.
 

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topfuel98 said:
you can see a lot of the blue alum bolts in this pic, i also run an alum bolt for the rear der hanger..


you can just see the blue bolts in the calipers in this pic and the on stem, levers and so on.



i am very up on my maint, I would dif not recomend this for some one that is not or that has someone else working on there bike, that is the biggest reason.. next time your on google check out the tensile strength of 7075 T6 vs Mild steel. Now shear is a diff story..

i have some extras layin around but most of the time i just give them to my buddies for there water bottle cages and stuff, Alum bolts are cheep only like a dollar or two each...
What bar ends are those?
 
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