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  1. #1
    destructionismyobjective
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    aluminum chainring bolts?

    Who has experience with them? Ive heard a few horror stories and ive been told they will be fine as long as I locktite them.

    My ss specific chain ring will be here or is here so im continuing to try to shed weight. Aluminum chainring, losing the bash ring and wanted to go aluminum bolts but wanted to know whos had good/bad experiences with them?

    This is my main trail bike right now so I dont want to be walking it out of the woods from failed chainring bolts but every gram counts on my way to under 20lbs so I would really like to use them.

  2. #2
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    I've used them and haven't had issues. There are more reports of failures compared to steel, though. But I think as long as you're careful and use a torque wrench for proper torque, you're fine.

  3. #3
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    I think they are O.K., especially if you are counting grams. I'm not sure about the locktite though, I've always used oil which allows them to torque down better without risk of rounding the bolts.

  4. #4
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    They will be fine. The only downside of alloy bolts is for if you change your chainrings often. Basically the source of wear and stress on the bolts is the wrench and as long as you are not wrenching often the bolts will be fine. Medium strength thread locker is a good idea.

  5. #5
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    Quote Originally Posted by febikes View Post
    Medium strength thread locker is a good idea.

    Are you sure about that? I have no proof to dispute that claim but it just doesn't seem like a great idea, especially on aluminum bolts. I've never used it on a chainring bolt and have not had any problems with them coming loose.

  6. #6
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    I've had several aluminum chainring bolts crack on me. I pretty much stick to steel at this point. You're saving like 10 grams by switching, but at the cost of piece of mind. If they fail, you're walking to the race timers to report your DNF. Not to mention the fact that if one breaks and falls out, your Aluminum chairing will break or if you're using steel will fold into your chainstay.

  7. #7
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    Quote Originally Posted by J.B. Weld View Post
    Are you sure about that? I have no proof to dispute that claim but it just doesn't seem like a great idea, especially on aluminum bolts. I've never used it on a chainring bolt and have not had any problems with them coming loose.

    A agree. These Aluminum bolts are pretty soft. If you use a thread locker on them, you're putting more stress on them when you remove em. More stress = more likely to fail.

    I've never used thread locker on chainring bolts. I've always used some sort of lubrication - whatever is within arms reach, usually. I believe that the only time I've had them back out was when they've broken. At that point, thread locker isn't going to save you.

  8. #8
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    The bolts will likely be fine without any thread locker but it is not going to hurt. Thread locking compounds are designed to keep threads in place. It will not do any harm and *might* help long term. Anytime you are working with an alloy bolt it is a good idea to have low or medium strength thread locker to help things along. Thread locking compounds were designed for this sort of thing.

  9. #9
    destructionismyobjective
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    Well I dont pull the ol switcheroo with the chainring... I only swap rear cogs. Ive never ran anything but a 32t up front and never plan on changing this one unless it fails. So I dont think a lil threadlock would be a bad thing.

    I think im gona go for it. I wont be racing until sometime next summer so Ill have plenty of time to see if anything will go wrong. 10g is close to 1/2oz so yeah its enough weight that id like to shed. Id go Ti but its like $15 a bolt or something rediculous. Im running out of parts to change to add lightness.

  10. #10
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    Threadlock in itself doesn't do harm and keeps the bolts tight, but the stress is increased when loosening them.

    I just grease the threads (anti-seize paste or MoS2) to prevent the threads from binding and pay attention to the torque. Every once and a while I check that they aren't coming loose, but I've never found them to have done so.

  11. #11
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    If they ever come loose they creak, so its easy to know when to retighten.

  12. #12
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    I used Middleburn alu bots on a middleburn crank and they took very little time to snap. To stop creaking they had to be torqued beyond their strength. Steel for me now.

  13. #13
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    I'm with steel bolts, too ... recent convert when I discovered that the creaking that was making me nuts was coming from the aluminum chainring bolts.

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  14. #14
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    I've snapped a few aluminum chainring bolts. They work fine on geared bikes, but my experience on single speeds is that they can't handle the stress as well as steel bolts. It's a really fine line between "tight enough to not come loose" and SNAP! when it comes to aluminum. (I really wanted those Vuelta red anodized chainring bolts to work since they added some nice bling to the bike, but alas, they did not).

  15. #15
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    I prefer steel chainring bolts myself but the OP said he (she?) was "counting grams" and trying to get under 20 lbs. I know the weight weenie thing isn't for everyone, but in the context of this post I think aluminum bolts are a viable option.

    I really think a lot of problems relating to them stem from the fact that people don't lube the threads. Oil, grease, or anti seize all allow the bolt to turn with less restriction as it tightens then it would when dry, which makes for easier, more accurate torquing and a tighter connection that won't easily loosen. Loctite also works as a lube, but only one time.





    Quote Originally Posted by Thor29 View Post
    I've snapped a few aluminum chainring bolts. They work fine on geared bikes, but my experience on single speeds is that they can't handle the stress as well as steel bolts.

    I always feel a need to contest these claims. One day I may figure out why. Anyway, aluminum bolts can't handle the stress as well as quality steel- period. A crankset being torqued hard doesn't know if it only has one gear or 30, and the chainring bolt will be under the same amount of stress either way.

  16. #16
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    Quote Originally Posted by J.B. Weld View Post
    I prefer steel chainring bolts myself but the OP said he (she?) was "counting grams" and trying to get under 20 lbs. I know the weight weenie thing isn't for everyone, but in the context of this post I think aluminum bolts are a viable option.
    Yes, Aluminum bolts really only make sense in terms of counting grams. Personally I always ride steel bolts but if the OP wants to build an ultra light bike there is nothing wrong with using alloy bolts.

    Quote Originally Posted by J.B. Weld View Post
    I really think a lot of problems relating to them stem from the fact that people don't lube the threads. Oil, grease, or anti seize all allow the bolt to turn with less restriction as it tightens then it would when dry, which makes for easier, more accurate torquing and a tighter connection that won't easily loosen. Loctite also works as a lube, but only one time.
    I personally tend to think of alloy bolts as something that you will only wrench on a few times so loctite makes sense because you won't be taking the bolts on and off a lot. If you need a bolt you can remove and re-install many times then aluminum is not the best choice.

    Quote Originally Posted by J.B. Weld View Post
    I always feel a need to contest these claims. One day I may figure out why. Anyway, aluminum bolts can't handle the stress as well as quality steel- period. A crankset being torqued hard doesn't know if it only has one gear or 30, and the chainring bolt will be under the same amount of stress either way.
    Actually the stress on the drivetrain and the bolts is much higher when running geared bikes with low gears. When you have a geared bike and the rider is in a very low gear like 32/36 or even something silly like 22/36 the mechanical stress on the crank bolts will be much higher then would be possible with 32/18. Basically standing at 22/36 puts all your weight on the drive train and does so with the mechanical leverage associated with the low gear. Standing on the pedals with 32/18 is less stress on the drive train because the gear ratio is lower so the stress on the bolts is a smaller multiple of your body weight.

  17. #17
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    Quote Originally Posted by febikes View Post
    Actually the stress on the drivetrain and the bolts is much higher when running geared bikes with low gears. When you have a geared bike and the rider is in a very low gear like 32/36 or even something silly like 22/36 the mechanical stress on the crank bolts will be much higher then would be possible with 32/18. Basically standing at 22/36 puts all your weight on the drive train and does so with the mechanical leverage associated with the low gear. Standing on the pedals with 32/18 is less stress on the drive train because the gear ratio is lower so the stress on the bolts is a smaller multiple of your body weight.
    Blasphemy!! Everyone knows single speeders destroy aluminum because they are so manly!

  18. #18
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    I have never used a torque wrench on CR bolts and I dont ever plan to. Yeah, I have broken a few alloy bolts in the past, but once you learn your lesson you wont over-torque them.

    Also, the only set of CR bolts that I have ever owned that loosen over time were stainless. I have never has 1 alloy set loosen up!
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  19. #19
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    [QUOTE=J.B. Weld;
    I really think a lot of problems relating to them stem from the fact that people don't lube the threads. Oil, grease, or anti seize all allow the bolt to turn with less restriction as it tightens then it would when dry, which makes for easier, more accurate torquing and a tighter connection that won't easily loosen. Loctite also works as a lube, but only one time.
    .[/QUOTE]

    In my case I tried both grease and antisieze but still no luck.

  20. #20
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    I kind f hate chainring bolts.

    They are hard to work on, with that stupid awkward tool, etc.

    Plus they're not that cheap when you do mess 'em up.

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  21. #21
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    Quote Originally Posted by SlowPokePete View Post
    I kind f hate chainring bolts.

    They are hard to work on, with that stupid awkward tool, etc.

    Plus they're not that cheap when you do mess 'em up.

    SPP
    Not all bolts use that "stupid awkward tool" Many use a 4mm and 5mm allen respectively for the sides.

    My Rotor Crankset came with aluminum bolts, I have used them with no problem, same with the SRAM bolts. I also use loc-tite...almost mandatory IMO.
    I have used titanium bolts and steel with great success too.

    IMO, the "assembly process" is just as important as the quality of the bolt. IE: you have to use thread-lock'er, put the male side of the bolt through so that it contacts the crank spider first, and use proper torque. Otherwise something could fail.
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  22. #22
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    one trick i use all the time now is to use the longer bolts that come with geared cranksets with short singlespeed specific backs/nuts whatever you want to call them.

    the longer bolt puts more threads onto the backing making for a stronger connection. i stated doing it after one too many steel singlspeed specific bolts came loose. i noticed they barely threaded in before being tight. with the longer bolts you get way more thread contact and it seems they are less likely to loosen on you once properly tightened in my experience.

    i always use grease, never threadlock and i may even be mixing alloy bolts with steel backs i think. i am crazy like that. i think the longer bolt makes more difference in the strength of the connection than the material it is made of.

  23. #23
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    Switched to steel bolts after this mishap...not saying it was just the alloy chrinrings bolts, could have been the cheapo chainring, or a bolt I forgot to tighten, but this did require a rescue from my gf, as I had ridden about 8 miles from home to the trailhead, and wasn't about to walk home. IIRC, at least one of the bolts snapped at the head, couldn't find all the pieces in the woods.

  24. #24
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    Quote Originally Posted by Coloradoxj13 View Post
    Switched to steel bolts after this mishap...not saying it was just the alloy chrinrings bolts, could have been the cheapo chainring, or a bolt I forgot to tighten, but this did require a rescue from my gf, as I had ridden about 8 miles from home to the trailhead, and wasn't about to walk home. IIRC, at least one of the bolts snapped at the head, couldn't find all the pieces in the woods.
    I've had that happen to me twice, both due to a bolt coming loose..and its a domino effect from there. The ring bends and stretches from chain torque, the other bolts holes stretch, and chainring bolts break or get sheered off the lip that holds the ring in place.
    It wasn't from using subpar equipment, I had a Renthal AlumiGold Race ring, and Action Tec titanium chainring bolts. The fact that I didn't have loctite on them is the reason it failed.
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  25. #25
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    steel is real

    I also think alloy bolts are to be avoided if you plan to demount/remount chainrings.

    I recently switched my 1x9 chainring from 36 to 32t and when remounting the nc-17 alloy bolts (greased each time), a first one exploded without excessive torque. As I had a steel replacement one I used it but a 2nd alloy bolt exploded again!

    Just need to trust my cranks so now waiting for delivery of new race face steel bolts (my two other rigs are a singlespeed and a fixed gear with chainring steel bolts).
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  26. #26
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    Quote Originally Posted by bitterrider View Post
    Who has experience with them? Ive heard a few horror stories and ive been told they will be fine as long as I locktite them.

    My ss specific chain ring will be here or is here so im continuing to try to shed weight. Aluminum chainring, losing the bash ring and wanted to go aluminum bolts but wanted to know whos had good/bad experiences with them?

    This is my main trail bike right now so I dont want to be walking it out of the woods from failed chainring bolts but every gram counts on my way to under 20lbs so I would really like to use them.
    Run them on all my bikes and never a problem, just don't over-torque them. I put a tiny bit of Park grease on the threads and then tighten with two hex keys.
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  27. #27
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    I just use steel with blue loctite and I properly torque them. One less thing on my mind.

  28. #28
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    CR bolts are a poor place to save weight, IMO. I favor grease over Loctite, though I admit I've never employed the latter.
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  29. #29
    destructionismyobjective
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    well I've put over 100 miles on them so far no issues. Got the bike to 20lbs 14oz. Just got to replace the deore crank with something lighter and I should be in the sub 20lb range.

    Im thinking its just taboo with the material of the chainring bolts. Same thing as when I was told to not run non ust tires tubeless... rode em half the summer and they have been great.

    So If something goes wrong ill let you know. Untill then aluminum chainring bolts get my approval.

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