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Old 10-01-2009, 01:05 PM
Kevlarr's Avatar
Kevlarr Kevlarr is offline
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Join Date: Jul 2009
Location: Mi
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Default No more broken studs or bolts for me!

Well I broke another stud yesterday, lucky for me it left quite a bit sticking out so I could remove it with vice grips.

Ran to the hardware store to buy some 6mm allen bolts since they don't have any studs long enough and in the tray right next to the bolts were bronze sleeves, a light bulb went off in my head! When you torque the bolts on the front strap it bends around the downtube causing the holes in the strap to get closer together and putting stress on the side of the stud, if only there was something we could put between the block and the strap.... 1/4" bronze sleeve bushings!

They're a little expensive ($2.25 each) and they smoke like a son of a b on the grinder but they worked perfectly! Bought two but I only ended up needing one, just cut it in half.

Best way I found was bolt everything up just not fully torqued, only tight enough to put some pressure on the strap, measure from the block to the strap and subtract about 1/8" cut and install.

I had to grind the right hand bushing on the side a bit to clear the frame but now everything is tight, there is no stress at all on sides of my bolts and if I would have thought of this before I don't think my studs would have ever broken in the 1st place.
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Old 10-01-2009, 02:24 PM
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bairdco bairdco is offline
a guy who makes cool bikes
Join Date: Aug 2009
Location: living the dream in southern california
Posts: 6,258
Default Re: No more broken studs or bolts for me!

i used the bearing spacers out of my old skateboard wheels.

or here's a BMX stem for 25 bucks(see what i'm going for here?):
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Old 10-01-2009, 10:18 PM
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2door 2door is offline
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Default Re: No more broken studs or bolts for me!

Maybe the reason they smoked so bad was that they were 'oilite bushings' in which case they are not solid but actually a crushed bronze material, oil impregnated. If that's the case I'd keep a close eye on them. They'll crumble eventually leaving you with a loose motor mounting. Just a thought.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"
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