Bicycle Mechanics - Somebody please HELP!

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brentcmurphy
03-21-05, 12:53 PM
2003 Litespeed Pisgah...one of the bicycle cage rivnuts detached from the interior frame and is now inside the frame down by the crank. The vent holes on this bike are much smaller than the rivnut, so it can't be removed thru the headset or crank. Is there anyway to somehow get it out thru the original hole without damaging the frame? Any good mechanics out there with a solution????
demoncyclist
03-21-05, 12:57 PM
Pull out your seatpost to remove the old rivnut. Then take your bike to a Litespeed Dealer to get a new one installed.
brentcmurphy
03-21-05, 01:01 PM
Can't pass thru the seat post...rivnut broke of off the downtube, not the seat tube!
demoncyclist
03-21-05, 01:04 PM
If it is in the BB shell, you will have to pull it to get it out. Fortunately, cartridge BBs are unaffected by shrapnel outside their cases, so you can ride until you have a chance to get it to a shop.
brentcmurphy
03-21-05, 01:06 PM
Demon...not possible. The vent holes inside the frame are much smaller than the rivnut. This thing is literally loose inside the frame with no way out.
demoncyclist
03-21-05, 01:10 PM
The only possible solution would be if the rivnut is steel. A small magnetic pickup tool could be inserted into the hole, and used to grab the slug as you shake the frame in the proper orientation. I'm pretty sure a magnet won't stick to Ti.
AndrewP
03-21-05, 01:53 PM
If it is rattling inside the frame I would suggest squirting some glue or thick oil in the vent hole so it encapsulates the loose rivnut tail.
Steve Katzman
03-21-05, 04:49 PM
I'd try to open up the vent hole with an appropriately sized drill bit, even if the drill must go in at an angle and produce an oval hole. I had the exact same problem with a friend's Cannondale. Of course aluminum is softer and easier to drill, but it is still possible to do with titanium as long as you have a high-quality, sharp drill bit. This portion of the BB shell is very lightly loaded so it shouldn't be a structural problem. Assuming the riv-nut is steel, you can probably coax it out with a strong magnet.
Demon...not possible. The vent holes inside the frame are much smaller than the rivnut. This thing is literally loose inside the frame with no way out.
I don't understand this part...are you saying the frame tubes are smalller diameter than a nut used inside of them? Aren't the tubes on a Pisgah about an inch or more in dia.?
PJ
I don't understand this part...are you saying the frame tubes are smalller diameter than a nut used inside of them? Aren't the tubes on a Pisgah about an inch or more in dia.?
PJIt's not the tubes. It's how they are joined to the BB shell and HT.There is only a small hole in them for venting gas.
Fill in the tubes with "GREAT STUFF" foam. The expandable foam will encapsulate the rivet.
On the plus side, it will also help dampen vibrations greatly.
Oh god I don't even know if i'm kidding anymore...
http://www.mclendons.com/Merchant2/graphics/10/10855390a.jpg
It's not the tubes. It's how they are joined to the BB shell and HT.There is only a small hole in them for venting gas.
Ok, I guess I see what you mean. I was a little slow this afternoon. Although, every bike I have looked into has a pretty good size connection at the BB.
PJ
Rev.Chuck
03-21-05, 06:59 PM
Glue is the best/simplest solution. Enlarging the vent hole would be difficult because of the shape of the BB and the extreme angle of the drill. It might be possible to do it with a die grinder.
slvoid mentioned the expanding foam. If you go that route use one of the performance foams. These are designed to make monocoque chassis stiffer. Bianchi uses it on their EV-4. Be careful, it makes an awful mess.
Be careful it also doesn't expand into your moving components.
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