Bicycle Mechanics - Aluminum Bolts on handle bar / stem?

Hello,

Is there any danger in using aluminum bolts on the handle bar / stem clamp? My steel bolts started rusting so I'm trying some anodized aluminum bolts, fits / torque down fine (4.5Nm). Am I asking for trouble later on?

http://photos-e.ak.fbcdn.net/hphotos-ak-snc1/hs020.snc1/4244_80812523787_639968787_1703500_408346_n.jpg

Hello,

Is there any danger in using aluminum bolts on the handle bar / stem clamp? My steel bolts started rusting so I'm trying some anodized aluminum bolts, fits / torque down fine (4.5Nm). Am I asking for trouble later on?


I wouldn't trust aluminum bolts for any "mission critical" application like a bar clamp. You'll won't have any warning about metal fatigue- you could be JRA and have one, then the rest snap off. Depending on your situation, you'd either be walking home or taking an ambulance ride.

FWIW: I installed a aluminum wedge bolt in a Cinelli stem long ago. It worked fine until the head snapped off and hit me in the chin. Fortunately I wasn't going that fast, the wedge kept the stem from turning at first, and I could walk home. I learned my lesson.

Titanium bolts might be better, but I don't have experience with them.

You can buy stainless steel bolts in metric sizes. I think they would be a much safer choice.

I concur with all of the above. Aluminum bolts should not be used for applications where failure can cause a crash and handlebar clamp bolts certainly fit in that catagory.

Ti bolts are pricy but apparently acceptable as there are some OEM's that use them. Stainless steel is definitely the preferred material.

They are scary light when I took the out of the package. That's when it sorta hit me that maybe these aren't exactly what I should be using on the bar clam. Thanks for the comments.

I concur with the recommendations to get steel bolts. That is the most critical application I can think of - my advice: Don't ride it until you've got steel in there. And be sure to grease the bolts first.

Happy Trails!

Hello,

Is there any danger in using aluminum bolts on the handle bar / stem clamp? My steel bolts started rusting so I'm trying some anodized aluminum bolts, fits / torque down fine (4.5Nm). Am I asking for trouble later on?

http://photos-e.ak.fbcdn.net/hphotos-ak-snc1/hs020.snc1/4244_80812523787_639968787_1703500_408346_n.jpg

Idiotic to the extreme.

Uh, do you realize that aluminium has 1/3rd the strength of steel for the same size part (albeit at 1/3rd the weight). To take advantage of aluminium, you have to design the part to use it. An alloy bolt for a stem would most likely need to be 10mm. Then the face-plate and stem has to be designed to take a 10mm bolt.

I hope your health-insurance is paid up, other wise buy some life-insurance pronto!

Nylon bolts would be lighter.

Ti bolts are pricy but apparently acceptable as there are some OEM's that use them.

Ti bolts are a bit so-so. Compared to their size equivalents in steel they will stretch more/easier, which can be an issue in certain applications. For a bar ti bolts are probably borderline OK. It probably won't come off w/o warning, but might allow the bar/stem to rotate easier than expected.


.Stainless steel is definitely the preferred material.

+1 on that. For the price penalty and the weight advantage Ti bolts aren't a particularly hot deal, even in places where they do work.

Ti bolts are a bit so-so. Compared to their size equivalents in steel they will stretch more/easier, which can be an issue in certain applications. For a bar ti bolts are probably borderline OK. It probably won't come off w/o warning, but might allow the bar/stem to rotate easier than expected.
I mentioned Ti bolts since Jeff Wills alluded to them in his posting. I wouldn't use them either. The cost puts them firmly in the "weight weenie" class even if they are structurally adequate.

Ti Bolts yes, Aluminum Bolts no way. Many stem manufacturers spec Ti bolts on their high end stuff. I would only do Ti bolts if it were a 4 bolt bar clamp.

You can buy stainless steel bolts in metric sizes. I think they would be a much safer choice.
+1 this. Stainless bolts would be both cheaper and stronger than either Ti or Aluminum.

Yup, ordered up some stainless bolts. Abt 25 cents each from boltdepot.com. LOL. However, shipping is like $8. :( So I order a bunch more for other stuff in the garage as well.

Sounds like Hewlett~Packard. Something very small will (WILL!) break. You have to get THE BOLT that fits THEIR computer, etc. $6.95 for bolt. $15.88 for shipping.

Stainless steel or brass bolts/screws is the safe choice. Aluminum bolts/screws can work but you would need to assemble them with anti-seize or your aluminum stem and screws will become one piece sooner or later and sudden breakage still could occur...not a very desirable possibility.

You could just keep your old bolts.
When my parts start to show rust I just coat them in 'rust fix' type products (phosphoric acid).
Turns them black and then I never have to worry about them again.

A little counterintuitive, but you can't use a rust treatment like that until After some surface rust has appeared, since the rust itself is converted into a protective coat...

If you use aluminum-bolts on your steerer to prevent rust - or lower weight - I'm sorry. You are waaaaay off the target. There are many ways to slow down oxidation (rust) on your bolts. Such as cleaning them. Oiling them. Even dripping wax on them!

If it's the weight, it might work. You will not be adding weight to the bicycle as you will be in the hospital when & if they fail.

There is no point in this thread from continuing: Steel bolts. Torque-wrench. Or don't apply to work at my shop. Ever.

.... or brass bolts/screws is the safe choice.....

The anti-weight weenie. :roflmao2:

Still, I wouldn't think brass approaches Ti nor steel strength.

If you use aluminum-bolts on your steerer to prevent rust - or lower weight - I'm sorry. You are waaaaay off the target. There are many ways to slow down oxidation (rust) on your bolts. Such as cleaning them. Oiling them. Even dripping wax on them!

If it's the weight, it might work. You will not be adding weight to the bicycle as you will be in the hospital when & if they fail.

There is no point in this thread from continuing: Steel bolts. Torque-wrench. Or don't apply to work at my shop. Ever.

Actually, I didn't really think about weight saving that much (like what? 3 grams?) I should loose 10lb first. lol.

Originally I was thinking of just bling factor w/ the anodized red and also lower maintenance since I don't have to fuzz w/ oiling / painting / cleaning / etc raw steel bolts sux. I'm not even sure why Specialized use them here. I think it's just stupid. They should have used something more weather proof like stainless steel.

But once I picked up these aluminum bolts, I immediately got worried because they were nearly weightless. Hence I posted here to get more info. Apparently Info I get, plus wayyyy more attitude. But hey, this is BF, what else would I expect? hahahahah... cheers!

Sounds like Hewlett~Packard. Something very small will (WILL!) break. You have to get THE BOLT that fits THEIR computer, etc. $6.95 for bolt. $15.88 for shipping.


Hee-hee. I'm glad neither me nor my wife work for HP anymore. She hired on back in the middle of the "tech bubble", while I got a temp job testing software. A few years later and I'm driving computers at a hospital and she's an unemployed software engineer... but very happy to be not working for HP!

Hee-hee. I'm glad neither me nor my wife work for HP anymore. She hired on back in the middle of the "tech bubble", while I got a temp job testing software. A few years later and I'm driving computers at a hospital and she's an unemployed software engineer... but very happy to be not working for HP!

I could tell you a story about the guy who invented the cheap hardware for the then new pocket calculators. And gave it to HP in exchange for a job! :eek:

To the OP - of course you did this for the visual aspect. I made the same bone-headed mistake some years ago! But I'm not saying where o the bike I was looking to do this. :D

Yup, ordered up some stainless bolts. Abt 25 cents each from boltdepot.com. LOL. However, shipping is like $8. :( So I order a bunch more for other stuff in the garage as well.
You could probably pick them up at your local hardware store or boat store for $0.50/each and no shipping.

The strength of brass depends too much on the material condition.

Male aluminum threads won't be as strong as the threads in the stem because the root of the thread is much smaller. Imagine stripping the bolt, or stripping the threads out of the stem. Which way tears more metal? You can't use aluminum bolts and expect them to be as strong just because the stem is aluminum too, even if you know the grade of the aluminum bolts. (What grade are they?)