Well...I'm pissed,just not sure at what. Been riding and wrenching on my new ride the last week getting it dialed. Swapped the handlebars out today and double checked all bolts that were used. Everything was good and away I went. Just did a quick Aliso run (trying to get suspension dialed) Up/down 5 oaks everything was good...up cholla down stairstep even better...gave a quick once over and everything seemed in order. Went back up stair to leave via lynx and trouble hit. About 1/3 down the trail at at speed clocking 33mph(only know this as I looked down in horror) to see/feel my freshly tightened bars dropping down,brings my levers up and no where for me to grab. Flipped over slammed my face,got a fractured cheekbone and a bunch of scrapes that remind me of texas chainsaw movies. point is that was in the top 3 most painfull crashes I have endured and to top it off,freakin just riding down a flat trail. fyi,it was a thom. stem,which was properly torqued and never been a problem in the past. Anyone have any simlar problems?
Did you torque them in sequence? If you tightened the top and then the bottom, you were in for disaster. You have to tighten them in a cross pattern so they snug evenly.:?:
i did a quick run day before yesterday and yes i noticed my bars where a little loose as well and as i was tightening them i notice that the bottom set was loose again so i had to start over ,it reminded me of the way i tune my drums,the tighten the accross technique! details details......
This happened on Lynx? Holycow-man! How do you hit 33 mph on a trail like this? :bang: Any broken or bent bolts on the stem? Stripped?
that sucks!!!!!! I have had that happen in a quick parking lot ride, not easy to keep control when that happens. What make/model bars were you running?
Man thats scary. Ive only had that happen on cheaper bmx stems...the handle bars put way more stress on the stem clamping.
Hey Guys, Went through all possibilities...yes I tightened in sequence and torqued as supposed to be(been building bikes for a long time) and then double checked everything. That's why this came as such a suprise. bwolmarans - running a Thomsan elite 4x(6 months old and only removed/installed the faceplate bolts twice) w/Transition Tbar30's (1 week old) moment8 - If you start at the top of the little up and over hill(bench at top) youcan carry a lot more speed into the trail and maintain(at least for me)
a co worker and riding partner of mine had his stem, neck bolts go loose on him pre running at southridge a few years ago. his bars came loose in his hands while cruzing down a hill. cost him a broken arm, some surgery, and months off the bike. i try to check my bolts for proper torque as often as i can remember. why dont things ever come apart on the slow climbs?
There could be many causes for this accident. If you haven't messed with the parts since the accident it might be possible to show them to a mechanical engineer or good bike mechanic for clues, although the accident could have removed the evidence. Since the failure happened so soon after assembling the thing there is a good chance that things weren't fully seated and as soon as one of the parts adjusted itself you lost all of the bolt tension. Kind of a freak unlikely thing to happen. Tightening the screws to the proper torque is only part of the issue. If the threads are damaged or crossthreaded you will gets lots of torque but no holding force. (I doubt this was the case here, I'm just saying that using a torque wrench doesn't quarantee everything is secure.)
I have a Thomson stem. I installed it, went out riding, went down a steep ass hill, and then the bars flipped down like back towards me, then down and i faceplanted pretty bad. Not having a torque wrench, I just used my multi-tool and wrenched each bolt like a drumhead but turning it as hard as I can. Is turning each bolt as hard as you can enough torque??? It hasnt happened since.
The bolts have to be tightened in cross fashion evenly. When you are done tightening the face clamp look at the gap between the face plate and stem at both the top and bottom bolts, this gap should be the same for top and bottom, if not then loosen and try again.
I do not have a wrench either and I turn each screw as hard as I can, but I have broken a couple of screws. When it is time to swap parts, loosen the screws is such a pain. I will get one soon.:-k
i personally never had that problem with a stem. but i did have a seatpost get loose but that was while climbing. seems like you tightened the way youre supposed to....I SMELL SABOTAGE...get well soon nevertheless
