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Old 12-16-07, 06:11 AM   #1
Nitram
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Stripped Threads

Hi all, I've managed to strip 2 threads, where the rear rack attaches to the frame (to much swapping between the rear rack and my surfboard rack, and not enough attention to the task)

Whats some solutions.....

My first thought was to drill the hole out for a bigger bolt.....but could that weaken the frame (substantially)?

I'll take it to my LBS in the new year, but i thought i'd get some ideas here first

Cheers,
Marty

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Old 12-16-07, 07:32 AM   #2
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photos would help.. it depends on where it is exactly on the frame - there are usually four mounts on a bike which hold a rack.
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Old 12-16-07, 08:28 AM   #3
J T CUNNINGHAM
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May I suggest 'threaded inserts'?

They are similar to 'pop rivets', only instead of breaking off the mandrel, the threads within allow

the use of a machine screw or bolt. 'Pop rivet', and 'Rivnut', tools are disimilar so that a small

'kit', for each would be the way to go.


Regards,
J T
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Old 12-16-07, 08:38 AM   #4
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Is your rack threaded? Reverse the bolt if you have enough clearance for the chain.
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Old 12-16-07, 09:17 AM   #5
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Quote:
Originally Posted by J T CUNNINGHAM View Post
May I suggest 'threaded inserts'?

They are similar to 'pop rivets', only instead of breaking off the mandrel, the threads within allow

the use of a machine screw or bolt. 'Pop rivet', and 'Rivnut', tools are disimilar so that a small

'kit', for each would be the way to go.


Regards,
J T
The problem with "Helicoils", "Rivnuts" and similar inserts is that they require an even bigger installation hole than drilling and tapping the current dropout hole one size larger. Dropouts are almost universally threaded M5x.8 and the next size up would be M6x1.0. If the eyelet doesn't have enough metal for an M6 hole, it certainly won't have enough to take an insert.

I agree, try reversing the bolt in the current hole and use a nut on the outside. A button head or pan head bolt will minimize the thickness on the inner face of the dropout.
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Old 12-16-07, 09:46 AM   #6
J T CUNNINGHAM
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Yup!

Regards,
J T
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