broke a stem bolt; replace bolt or buy new
05-20-07, 09:48 PM
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broke a stem bolt; replace bolt or buy new
I have a nice DEDA Newton stem that I broke a bolt on. My friend was able to remove the broken piece and retap/clean up the threads. Should I trust this stem after that? Should I just get a new bolt? Where can I get a 6/4-titanium bolt for the steer tube clamp part?
(I know...get a torque wrench)
(I know...get a torque wrench)
05-21-07, 07:19 AM
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If the LBS can't fix it up then contact the manufacturer or seek out a fastener specialty store.
05-21-07, 07:50 AM
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Also, carefully inspect your steerer tube. Enough torque to break the bolt, (even a Ti bolt) could crush the steerer tube.
05-21-07, 08:15 AM
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Originally Posted by Relayer
I know...get a torque wrench
05-21-07, 08:53 AM
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Originally Posted by twobikes
Make your own torque wrench inexpensively from a fisheman's scale with a dial indicator and a steel bar. A five pound pull along a ten inch bar is 50 inch pounds. If the bar is a piece of 1/4 or 3/8 inch pipe, just slip one leg of the "L" shaped hex wrench into the open end of the pipe. Check the accuracy of the scale by weighing something of a known value. Meat from the grocery store is stamped with the exact weight of the package. Adjust the ten inches between the wrench and the point where the scale attaches accordingly.
05-21-07, 03:52 PM
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Originally Posted by Psimet2001
...or get a torque wrench.
05-21-07, 04:05 PM
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Originally Posted by twobikes
Making your own will cost about $5. Buying a new beam type will cost a minimum of about $40. I get a lot of satisfaction from using my homemade torque wrench. But, it is your call.
I'm not really knocking it, and lord knows I have had to use a home-made torque wrench before - like when external BB cups came out and you couldn't get your hands on a tool that had a socket drive on it - only a wrench. Measure the wrench, add known weight, and violas and fiddles - you have your torque.
To the OP - I wouldn't have a problem reusing the stem as long as the individual who removed the broken half of the screw did a good job. Not sure I would re-chase those threads though. If it is a 4 bolt face plate then no worries. If it is a 2 then I would be looking at it hard before re-using it.
Enough torque to break the fastener - even ti - is enough to damage the threads. Chasing them with a tap will probably just end up cutting them the rest of the way out. You'll end up with little ridges with about 10% engagement.
If the bolt had a fault or inclusion that caused the failure prematurely then the threads are probably just fine and I would trust the stem.
Worse case scenario you pull a Hincapie that puts you in a very bad place - although you could still steer by the stem if you needed to...
05-21-07, 04:16 PM
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Originally Posted by Psimet2001
...or get a torque wrench.
05-21-07, 06:09 PM
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i wouldn't trust it...the alloys deda uses are too soft and strip easily, at least from from experience....id toss the stem and get an easton or thompson stem instead...
05-21-07, 09:30 PM
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Aluminium Crusader :-)
I don't trust ti bolts. they're not worth it just to save a few grams
I've read of two guys busting the ti bolts on their Cinelli Soloido stems.
I've read of two guys busting the ti bolts on their Cinelli Soloido stems.
05-22-07, 07:54 AM
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Originally Posted by Psimet2001
...in materials...and $50-$100 of your own time.
I considered buying a commercial torque wrench, but knew I would use it only occasionally. I do not like paying $40 for a tool I use infrequently, unless there is no other way. Further, a commercial torque wrench would have required buying a set of hex bits for a 1/4 or 3/8 inch socket wrench. My homemade version allows me to use regular "L" shaped hex wrenches I already have.
05-22-07, 08:03 AM
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Originally Posted by twobikes
Your job must pay better than mine.
I considered buying a commercial torque wrench, but knew I would use it only occasionally. I do not like paying $40 for a tool I use infrequently, unless there is no other way. Further, a commercial torque wrench would have required buying a set of hex bits for a 1/4 or 3/8 inch socket wrench. My homemade version allows me to use regular "L" shaped hex wrenches I already have.
I considered buying a commercial torque wrench, but knew I would use it only occasionally. I do not like paying $40 for a tool I use infrequently, unless there is no other way. Further, a commercial torque wrench would have required buying a set of hex bits for a 1/4 or 3/8 inch socket wrench. My homemade version allows me to use regular "L" shaped hex wrenches I already have.
Apparently many of you aren't familiar with oppotunity cost.
05-22-07, 08:07 AM
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Actually, there is precendent here. OCP rules dictate that if there is an opportunity to replace a failed part, even if said part can be repaired to serviceable condition, it must be replaced with an item that costs at least half again as much as the original part. The only way around this is to get a waiver from the Grand High Pooba and he's on vacation.
Also, you must have a torque wrench in your toolbox so that you can tell everyone at Starbucks that your new stem is torqued to precisely 40Nm, just as the manufacturer recommended.
Also, you must have a torque wrench in your toolbox so that you can tell everyone at Starbucks that your new stem is torqued to precisely 40Nm, just as the manufacturer recommended.
