Bicycle Mechanics - stripped stem bolt solution

What do you guys think of this fix for a stripped stem bolt (stripped threads) vs retapping the hole?
http://www.emhart.com/products/helicoil/standard.asp
I don't think retapping will work for my stem, unless I enlargen the bolt head area also...the helicoil method would use the same size bolt.

The biggest downside is buying the tools, but if done properly the repair will be stronger than the original and you will be able to use the original bolts.

my auto mechanic has the tools, and offered to do the fix. Just wanted some opinions here first, so far it looks pretty good.

What do you guys think of this fix for a stripped stem bolt (stripped threads) vs retapping the hole?[QUOTE]



There is no retapping the hole in conventional stems. What you're retapping is the metal wedge anchor the stem bolt threads into, which is separate from the stem. Thats why the bolt is so long. But yeah, you could retap the wedge anchor and screw in the heli-coil. But once you got that far with it, would'nt it be easier to just replace the wedge?


just my thoughts :D

[QUOTE]



There is no retapping the hole in conventional stems. What you're retapping is the metal wedge anchor the stem bolt threads into, which is separate from the stem. Thats why the bolt is so long. But yeah, you could retap the wedge anchor and screw in the heli-coil. But once you got that far with it, would'nt it be easier to just replace the wedge?


just my thoughts :D


You are assuming he stripped the wedge on a quill-type stem; I assumed he meant one of the bar clamp bolt holes.

Maybe we should ask for clarification before we go any further?

I'm sorry, I should have clarified - it's the stem clamp bolt hole that is stripped, and the stem is an OS threadless. The clamp is 2 bolt.

I wonder if there is enough metal around the stripped hole to allow drilling and tapping it oversize for a helicoil. A lot of the threadless stems I'm familiar with don't have a lot of "meat" around the bolt holes.

If the bolt isn't threaded into a "blind" hole but the stripped hole is drilled all the way through you could drill out the hole to a clearance size for the bolt (usually 5 mm so a 7/32" drill bit will work) and then use a longer bolt and nut.

I'm sorry, I should have clarified - it's the stem clamp bolt hole that is stripped, and the stem is an OS threadless. The clamp is 2 bolt.


I guess I'm a bit old school. When someone says "stem bolt hole" I'm thinking old quill stem that uses the long bolt. But yeah, the heli-coil would sure enough work on your stripped handlebar clamp. It would greatly increase the clamping strength over the threaded aluminum. In fact, if you do one hole, then do the other holes too.

my local bike store was concerned that the steel sleeve of the helicoil would still strip out of the aluminum clamp hole, being so small...