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Stripped stem clamp bolt, is this stem garbage now?

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Stripped stem clamp bolt, is this stem garbage now?

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Old 04-23-12 | 10:10 PM
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Stripped stem clamp bolt, is this stem garbage now?

So I finally got the campagnolo ergo levers and on the Mx Leader. Everything was finely tuned, I took it for a 50 mile ride but when I came back home I realized the bars had shifted a little. It was not the first time this happened to these bars and stem so I figure I must not be tightening the clamp enough... bad idea. As it turns out I am stronger than I thought and I stripped the bolt for the clamp, is it toast now?

I got this stem all the way from Belgium from another member and I would hate to think that I can't use it anymore. How would you fix it? Drill and tap to the next bolt size (the bolt was M8)? I also thought maybe I can use a Helicoil to a smaller size bolt so as to not have to drill a lager hole. Has anyone fixed something like this before? Thanks.



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Old 04-23-12 | 10:36 PM
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helicoil is your best chance
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Old 04-24-12 | 05:35 AM
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I think it is all done. a helicoil is a good idea but I an not sure you can get the drill for it in there, let alone the heliciol, without damaging the shoulder that the bolt head rest on.
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Old 04-24-12 | 01:41 PM
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Originally Posted by Bianchigirll
I think it is all done. a helicoil is a good idea but I an not sure you can get the drill for it in there, let alone the heliciol, without damaging the shoulder that the bolt head rest on.
you're right the drill for a helicoil will be larger than the M8, so it will reduce the shoulder for the bolt head. But this job has to be done with drillpress and clamp. if you are careful you'll only reduce the shoulder a small amount and the head will still seat, if it goes too big you'll need an OS washer or spacer and countersink to a slightly wider diameter (which is a drill & mill job). Could be more trouble than the nice panto'd stem is worth...but you decide.
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Old 04-24-12 | 01:51 PM
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I agree that it may be more trouble that it's worth, but could you not drill and tap the existing hole to 10x1? You may have to enlarge the hole for the bolt head as well.
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Old 04-24-12 | 02:14 PM
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Thanks for the replies. I went ahead and bought a new stem only because I need to get back on the bike for training purposes. It will probably be more work than it deserves but I like a challenge. I have never used helicoils before so I will do some research and find out how big the hole has to be for a 7M helicoil. If that doesn't work maybe tap and drill.
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Old 04-24-12 | 07:15 PM
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Originally Posted by elguicho
Thanks for the replies. I went ahead and bought a new stem only because I need to get back on the bike for training purposes. It will probably be more work than it deserves but I like a challenge. I have never used helicoils before so I will do some research and find out how big the hole has to be for a 7M helicoil. If that doesn't work maybe tap and drill.
If I read the chart right the rec'd. size drill for an M7 in aluminum is 7.25mm, if your stripped bolt was M8 it's probably already exceeded that.
The real battle would be finding M7 socket bolts: they may be out there but they're rare.
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Old 04-24-12 | 07:49 PM
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Originally Posted by unworthy1
If I read the chart right the rec'd. size drill for an M7 in aluminum is 7.25mm, if your stripped bolt was M8 it's probably already exceeded that.
The real battle would be finding M7 socket bolts: they may be out there but they're rare.
I was just reading that online, I might be out of luck for the smaller bolt. I'm going to an auto parts store tomorrow to see if they have helicoils there but I think the kit is about $30. I keep thinking I should maybe put the $30 towards a new stem.
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Old 04-24-12 | 08:19 PM
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Originally Posted by ColonelJLloyd
...drill and tap the existing hole to 10x1..
This works - Also note on some of your vintage motorcycle owners the hole was filled in by a welder then redrilled and threaded...
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Old 04-24-12 | 08:45 PM
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drill it sll the way through and put a nice black bolt in from the top, kind of old timey. you could may counter sink the hole at the top and make it less obtrusive? Okay... maybe not.
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Old 04-24-12 | 09:14 PM
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Originally Posted by hueyhoolihan
drill it sll the way through and put a nice black bolt in from the top, kind of old timey. you could may counter sink the hole at the top and make it less obtrusive? Okay... maybe not.
lol i was going to say the same thing.
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Old 04-24-12 | 10:18 PM
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Originally Posted by hueyhoolihan
drill it sll the way through and put a nice black bolt in from the top, kind of old timey. you could may counter sink the hole at the top and make it less obtrusive? Okay... maybe not.
Before I threw it away (or tried filling it with weld since the heat might scorch it bad) I'd really consider that kludge: if you got some nice hardware and countersunk things with precision at least you might have a decent looker and (more important) steel-on-steel threading.
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Old 04-26-12 | 11:49 AM
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OK - I know its late but I found it... Check this out... Even if you don't do it its good to keep in the useles **** file...

Alumi-Weld can be found at Harbor freight - About 8 bucks for 10 rods...

https://www.youtube.com/watch?v=2rH68...eature=related
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Old 04-26-12 | 12:03 PM
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Originally Posted by zandoval
OK - I know its late but I found it... Check this out... Even if you don't do it its good to keep in the useles **** file...

Alumi-Weld can be found at Harbor freight - About 8 bucks for 10 rods...

https://www.youtube.com/watch?v=2rH68...eature=related
Maybe everything works better in Serbo-Croatian...I had rotten luck when I tried some "magic aluminum welding rods" a few years back, the stuff just would not stick to the parent metal. I'm told that the secret to success is to have the metal "sanitary clean": as soon as any corrosion begins you won't get the weld to stick. And corrosion (alumina oxide) starts to form on aluminum the instant it's exposed to air, that's one reason to constantly wire brush the piece before as well as during the process.
Maybe YRMV for the better.

Last edited by unworthy1; 04-26-12 at 08:25 PM. Reason: wrong language!
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Old 04-26-12 | 12:07 PM
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Originally Posted by zandoval
OK - I know its late but I found it... Check this out... Even if you don't do it its good to keep in the useles **** file...

Alumi-Weld can be found at Harbor freight - About 8 bucks for 10 rods...

https://www.youtube.com/watch?v=2rH68...eature=related
thanks. that was a fun watch.
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