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How to fix shifter guide that broke off downtube
#1
On my first ride after my bike was moved in a house move, the downtube guide for my shifter broke off of the downtube. I believe the bolt that held it in was cracked; although a significant amount of the bolt is still there.

The cable is attached to 14-year old Shimano 105 brake lever shifters.

The shifter guide (is there a better name) does fit back onto the downtube, but it needs something to attach it to the downtube

Can I just superglue it back on? Or is there a better way to fix this? I'm not sure if I would need to remove the guide in the future (which would be prevented by gluing it).

Do I need to take it to a shop?

[attachment=2973]
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#2
I guess superglue might work, though Nigel could probably suggest something professional (depending on frame material etc) as there is the little spike and the main force is perpendicular to this spike (tangential to the frame tube). So the glue just keeps it from falling off and the pip actually has to counteract (balance) the forces when shifting.
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#3
The frame is made of aluminum.
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#4
I would like to see the other side as it is also. Is the pin in the downtube loose? can you remove it? and could it be possible to rivit it back on?
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
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#5
Also there is this alternative... http://www.amazon.com/SunRace-6-Speed-Clamp-on-Downtube-Shifters/dp/B0025UJXLK/ . Not exactly the same thing but nice for a temporary repair, until you get this fixed. Aluminum alloy tubing hmmm.
Good maintenance to your Bike, can make it like the wheels are, true and smooth!
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#6
The guide was glued on when the bike was manufactured so it's likely the glue just aged out (I can see the residual glue in the photo). The repair is easy. Just follow the exact procedure I described (writing as "Voyage") elsewhere in this forum:

http://forums.bicycletutor.com/thread-1013.html

As an aside, the repair I did (down tube shift lever mount) still holds two years later. The Technium leads an energetic semi-retirement, 500 miles per year, remains beautiful and is my favorite old sport/recreation bike.
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#7
I too would like to see the other side of holder.

However JB Weld is one of the best epoxies out there. It has been used to fix engine cracks and holes on motorcycles, etc.

Use the slow drying one. Lightly send both frame and holder first and clean with alcohol or other cleaner.

BTW once dry JB weld can be machined , sanded , shaped etc.
Never Give Up!!!
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#8
Thanks for all the advice! I already ordered some of the JB weld from Amazon.

Here are some more pictures.

When I touched the screw that went into the frame it actually rotated. This surprised me, as I thought it was attached to the frame. So it might be possible to remove the screw from the bike and replace it with a longer one. Except I have no idea where to get such an unusual screw. I'm worried that if I do unscrew it, whatever it is attached to might either slip down the downtube or that I'd be unable to screw it back in.

I don't plan to convert this bike to add downtube shifters at any point (as it has brake-lever shifters). I think that's the only reason I would need to take this guide off, right?
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#9
OK that photo helps. It looks like the cable guide was screwed into the frame and the bolt broke.

Unscrew the allen head bolt from the holder and the broken piece from frame go to a hardware store and find matching bolt.Do not over tighten.
Never Give Up!!!
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#10
I found this for you to look at, it may help
http://www.bikeforums.net/showthread.php/729717-HillRider-s-Klein-Stage-Comp-Fix-for-Shifter-Boss-Bolt-Stripping
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
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