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PostPosted: Tue Feb 28, 2012 10:45 pm 
Retro Guru

Joined: Mon Jun 02, 2008 2:52 pm
Posts: 347
Safe or not?

Have a set of Monster T, so I'm talking about 4 M5(?) in the main crown/steerer clamp, couple in the upper crown (no load) and then six M4 in the M brace.

I can't see three a side failing the the M brace, upper crown has no load/importance leaving the only risk the lower crown ones would fail and the frame would slide right down the forks. Could be hilarious or could hurt quite a bit :o


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PostPosted: Tue Feb 28, 2012 11:07 pm 
Gold Trader / MacRetro rider
Gold Trader / MacRetro rider
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Joined: Fri Sep 05, 2008 6:36 pm
Posts: 4950
Location: Edinburgh
I think you are asking...........

Will I be safe using my Monster T's with just 2 bolts each side on my lower crown?
(instead of the three they are supposed to have)

Are you??

I think you will be, the three on each side on the lower crown are OVERKILL
two will be ok dude :wink: :wink:

G


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PostPosted: Tue Feb 28, 2012 11:12 pm 
Retro Guru

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Only two bolts per side here but anyway, I just want to replace steel with alu. Obviously less strength but are they strong enough to replace steel..? :D


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PostPosted: Tue Feb 28, 2012 11:12 pm 
Old School Grand Master
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Location: No brakes? Way to commit soldier.
I would never recommend aluminium bolts were used in safety critical areas such as this.

I'm sure an engineer will come along soon to disagree with me though :)


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PostPosted: Tue Feb 28, 2012 11:19 pm 
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Image


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PostPosted: Tue Feb 28, 2012 11:21 pm 
Gold Trader / MacRetro rider
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Ah, sorry I miss-read your post

I wouldnt use aluminiums bolts in a place like that, Definately Steel ones :wink:


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PostPosted: Tue Feb 28, 2012 11:26 pm 
Retro Guru

Joined: Sun Jan 15, 2012 6:00 pm
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Location: bicester
I'd use them but that's me.....
Depends how the bike will be used.!!
Poser bike = of course. :D
Hardcore offroader = do you like your bones in one piece.. :wink:

But don't listen to me as I'm replacing all my bolts on my proflex for gold ally ones :twisted:
Just do it..


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PostPosted: Tue Feb 28, 2012 11:28 pm 
Retro Guru

Joined: Mon Jun 02, 2008 2:52 pm
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Russell wrote:
I would never recommend aluminium bolts were used in safety critical areas such as this.

I'm sure an engineer will come along soon to disagree with me though :)


Yea I know but vanity calls :p

I used SS in my brakes but I think this may be different. There is no shear force, just a straight pull on the clamp across four bolts.

The alu bolts have a tensile strength of 570mpa (ProBolt UK) which is pretty close to steel and it doesn't look like the stock bolts are high tensile steel either.


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PostPosted: Tue Feb 28, 2012 11:31 pm 
Gold Trader / MacRetro rider
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If you aint doing 6ft drop-offs then do it :lol:

(i dont do 6 ft drop offs , but then i'm a shiter!) :lol: :lol:


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PostPosted: Wed Feb 29, 2012 11:04 am 
Old School Grand Master

Joined: Tue Oct 09, 2007 1:55 pm
Posts: 8209
Location: New Forest, UK
The problem isn't the tensile strength, but fatigue. You won't know if one bolt has cracked through, placing all the load on the others - pretty soon that will go too and the thing might be held by only one bolt.

The weight saving is peanuts, the loss of reliability is huge. There are very good reasons why people don't use Alu bolts in regular things. :shock:

They are OK for F1 cars etc which get stripped after every race, not for real life.


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