jppe

I was piddling with one of my bikes and noticed the handlebars needed straightening. I thought it was strange that it had gotten out of alignment. As I was loosening the stem bolts on the steerer tube and retightening them I noticed something that didn’t look right. If you look at the top bolt in the picture you can see where the metal has broken apart both above and below the bolt head on the stem itself.

I’m sure glad I spotted it! The bottom bolt probably would have sheered at the worst time leaving the bike steerless?!?! I bet the bracket might have fatigued when I bounced off the asphalt and another rider ran over my front wheel over a year ago.

I guess it’s always a good idea to go over your bikes at least annually to make sure they are still snug and to look for potential issues!!

skidder

Just got back from a 18 mile ride on my single speed. It has bolt-on wheels so those get a quick check every time I go out on it. Other than that its just 'bounce' the day's chosen bike and see if anything sounds loose (besides the RD and chain) before heading out. All the bikes get cleaned and lubed regularly, that's the best time to look for loose and worn-out stuff.

Curious, but do you have a picture of the front end of your bike, up where the headset/stem/ and handlebars come together and the break occurred?. It'd be interesting to see the whole thing (and why there are two stem bolts in the original post's picture). I see some carbon fiber in the picture, but still confused as to how its set up.

indyfabz

This thread just screams for a walk down memory lane:

https://www.bikeforums.net/road-cycl...-temper-4.html

Unfortunately, it appears that the baby bike bolts on the back of a milk carton image is no longer available. Funniest thing I have ever seen on BF.

jppe

I can add another photo of the whole setup. Basically the photo shown above are the upper and lower bolts that attach the stem to the steerer tube. The carbon above the stem bolts that you mentioned are the spacers around the steerer tube.

dicktill

@jppe: Good save! Glad you didn't meet with the asphalt again.

DrIsotope

Top bolt, 4 threads exposed, bottom bolt, maybe one and a half. Next time, #torquewrench

canklecat

Yup. I check every critical component pretty often. Especially with carbon fiber and titanium. Weird stuff happens when steel, aluminum, titanium and carbon fiber are in proximity.

Earlier this year I bought an early '90s carbon fiber bike. Had the original Ibis titanium stem. Before taking a test ride I decided to change the angle of the handlebar upward just a smidge to put the hoods and drops in the same position as my Ironman. Good thing because the single clamp bolt for the handlebar snapped -- head came loose from the threaded body.

I was able to remove the headless bolt without drilling and tapping. Checked it and the head, both were darkened and discolored. I'm guessing some kinda bizarre interaction between the various materials, or from sweat or electrolyte drink dribbles.

I replaced it with a new stainless bolt. And now I check every critical bolt pretty often on every bike, at least once a week, just to be sure it's snug (but not overtightened -- I got a mini torque wrench just for cockpits on carbon bikes).

And now I look for stems with multiple bolts. The newer threadless stems with two bolt clamps for the steerer and four for the handlebar aren't as svelte as the lovely little Ibis stem, but there's more safety margin if a single bolt goes bad. If I use the Ibis titanium stem again I'll coat the clamping surfaces and bolts with that anti-corrosion goo.

However, this '93 Trek 5900 spent part of its life as a TT/tri-bike, and it's likely the problem was due to rider sweat or dribbled electrolytes from a bar-mounted water bottle seeping into the crevices unnoticed. Might not have been just galvanic corrosion but the protective goo from Park and Permatex should help.

And I check mountings for racks on my hybrid and errand bikes. Loctite helps but with heavy loads and rough roads I've still had a bolt loosen on rear racks. I think part of the problem was the cheap batch of stainless bolts I bought. I suppose I got what I paid for with 500 mixed bolts for less than $10. They're very rust resistant but soft and tend to gall, deform and bend easily.

jppe

I completely agree with torquing the bolts. In this case what you’ve observed on the exposed threads is actually what tipped me off on there being an issue. The fact the clamps on the top bolt closed completely together had me taking a second look. Neither the upper nor lower clamp should completely close, there should always be a small gap between the two sides.....at least for this sized stem and steerer tube. When the top bolt tightened too easily and the two sides clamped together my reaction was “huh, that’s really peculiar”. When I looked closer I noticed the breakage.

New stem should be in soon. I ordered one with a touch more rise to assist with the aging process!!!

bpcyclist

I check all the bolts and tighten when required maybe four times a year or so. It is well worth it, as I have definitely found some that were loose. Most recently, the downtube bottle cage bolts were both loose and rattling like mad. Nice to have a silent bike again. That said, I have also unfortunately found the opposite at times on bikes--bolts that were tightened way tighter than called for. I always thought mfrs. usually used torque wrenches on these builds, but I guess not all the time. I dunno, I just know sometimes, they're insanely tight. Too tight.

TakingMyTime

I'm always tinkering with one thing or another on my bikes. Having it up on a bike stand makes the inspection easier and more comfortable. I'd say that after about 4-5 rides I'll break out the wrenches and go over the bike in order to make sure everything is snug. Also, when cleaning your bike you should take that opportunity to inspect other parts that might not get your attention the first time around.

FiftySix

That's an interesting break. I'm more accustomed to seeing threads in aluminum alloy strip due to over torque before a breakage occurs.

Speaking of this, I have a creak developing in the front end of my Norco. I'm going to have to do some investigating as I can't replicate it while the bike isn't moving.

berner

I keep my bike fairly clean which I find easier than doing a major cleaning more infrequently. This process itself allows checking for possible problems. Once I found a broken spoke that got replaced with with a spare.

CyclingBK

I just got into cycling in August and thought it would be a good idea to go over the bike once a week and check all was tight.
I noticed 2 screws that seemed not tight and was about to tighten them but *fortunately I posted a pic of the screws on the Mechanics thread and some nice posters pointed out that these were the front derailleur adjustment screws and not to touch them ; )

02Giant 

As part of a normal day before riding, no. When riding, I am paying attention to the sound and feel of the bike. When cleaning, I will give it a look over, check cables, & pluck the spokes to confirm no issues.
I use a torque wrench on everything possible when I assemble my bikes. I don't have fasteners come loose. I don't feel the need to randomly or regularly add additional torque to a properly tightened fastener.

TheDudeIsHere

Yup, check fairly often. A quick glance will show if something looks out of place. I also check my tires and rims often. Not wanting to take a dive over a bad rim or tire on any road.

BookFinder 

I don’t follow a rigid schedule. The best I can say is that I do a visual check routinely and a wrench in hand touch and tweak check periodically.

rydabent

Living in the snow belt, every Feb I do a complete check overhaul and lube of my bike and trike. That means that I check every single bolt and screw on the machine. The reward is virtually trouble free cycling in the summer time.

And as another stated when I ride I pay attention to the sound and feel of the bike that might indicate anything loose. Pretty much noise indictes something is wrong.

jppe

Here are some additional photos of the Al Easton stem with the broken fitting. It was completely separated were the bolt slides through the hole.

The new stem I installed has more rise. I was thinking that since I’m a little older it might be nice to be a little more upright so we’ll see. I was fine with the other setup but will experiment to see. There are enough spacers on the steerer tube where I can lower the bars if needed. The steerer tube could also be cut a little shorter but I’ve used it that way for a long time.

Hopefully I can get in a longer ride on it tomorrow.




Picture shows a clean break in the alloy.

Another view.

The bike with the new stem.

New stem.....a lot more rise than I’ve used before.

mr_bill

After every run I disassemble, then reassemble. Oh wait, that’s top fuel.

Obviously, too little of a good thing can be very bad, but too much of a good thing is also very bad.

So periodic maintenance which includes inspecting? Yes. Loosening and re-torquing EVERY bolt? No.

-mr. bill

OldsCOOL

I remember that one with a grin, wow almost 10 years ago!

Here is another gem:

https://www.bikeforums.net/bicycle-m...heel-fire.html

bpcyclist

Spectacular.

smudgy

Bolts! don't leave home without 'em.

smudgy

You picked a fine time to leave me loose wheel!! 2 more posts!

Hondo Gravel

I check my nuts all the time .. Seriously though I go through the bikes thoroughly often and at times find loose bolts. I have a decent torque wrench for carbon fiber parts and the crank. Metal to metal I just go by feel.

OldsCOOL

Welcome!