Mountain Bike Reviews Forum banner

*critical* components that will fail in time????

1038 Views 10 Replies 7 Participants Last post by  rr
Im a bit concerned about *critical* components that will fail in particular the handle bars and pedals...should i be worried about those? When would you recommend changing them with normal MTB use and 20% downhill stuff (about 50-100 miles/week, 180#)? Mine are stock aluminum, nothing 2 yrs old.

I figured the cranck arms, headset, stem, seem pretty solid and unlikely to break unless in a direct hit from a crash...??

Id hate to have the handle bar or pedal break when ridding....
1 - 11 of 11 Posts
Well what are you riding? What components? When you say downhill, do you mean like Northstar or Plattekill (sp?) downhill or like just riding down a hill? If you give us some more details about your equipment and riding styles maybe people can give you some pointers....
I think that you are worrying needlessly about your bike components failing.

The most critical components that you should be worried about failing are your knees, back, neck, hands and fingers, ankles and body.

The bike components are of secondary importance.. :)

things that break that can spoil yer day

Freehub pawls: Dunno about downhilling, but if you're strong and pedal uphill, pawls can fail, leaving you in freewheel mode in both directions. I've killed probably 6 or 8 hubs and freewheels on tandems, and 3 or 4 on singles. To get home, use something handy -- fence wire, toe straps, big zip ties, etc -- to tie the largest rear cog to as many spokes as you can on the rear wheel, turning it into a multi-speed fixed gear. It may torque the wheel a little, and you probably can't climb steeps, but you can definitely pedal most terrain and get home. You can even shift gears, just don't use the largest 2 or 3 cogs. And don't try to coast. Once cleaned Pritchett Canyon in Moab fixed gearing a tandem this way, pedaled right back into town. I carry a couple nylon toe straps on backcountry rides for this purpose (and for making splints).
Steerer tube: Lots of aluminum steerers out there, their owners probably don't pull their forks to peer at them closely at least annually, and they should. Steel steerers also can break. Both usually fail right around the crown race. Worth a look, a busted steerer can be real nasty.
Quick release skewers: They usually break right at the threads where the R side end piece screws on. Sometimes the levers fail. Steel and ti, they both break. I carry a spare rear on backcountry rides, with a 35mm spacer to adapt it to the front. Saved a buddy probably a good 6 or 8 hours of tough hiking last summer by having one along.
The wimpy little allen bolts in many 2-bolt seatpost clamps. I've broken several, and now carry a spare.
Seatpost bolt: It'll break when you tighten it after adjusting your saddle height far from home. I carry a spare. The tensioning allen screw in aheadset systems can be used as a seat post clamp, as it's doing absolutely nothing once the headset adjustment is locked in by tightening the stem.
Rear shifter cable: It'll break right at the barrel end, not a crisis, you can always one-speed it out, but inconvenient. For some reason I have never broken a front shifter cable.
Stems and bars depend on their construction, design, age, and use/abuse. Save 10 grams at your peril.
See less See more

should have been more precise on my setup...I have deore, LX shimano, and lesser trek 4500 stock components...Ive craked a crank and rear wheel, chainrings on those downhills...but nothing seems from bulC post, i need to check my steerer tube, and seat post along those lines...anything that breaks but does not hurt me is not a big concern....I put the HB, and pedals up there, now probably the steerer tube too...

Gabe, not sure what those trails are, you are talking about...the worst i do, is an unmarked downhill/trail nobody uses (not even hickers becasue its too steep) carvedup by rain, so loose rocks, big roots, solid rocks on the sides, 1-3 ft successive drops...its pretty much slide and hoppe side to side the whole way for 10-20 min...i dont do it more than once a week because if i fall there, im done for..and only if im not too could be an average downhill for the average mtber but, too me, it feels a bit sketchy....

Rainman, i hear you, Im not concerned about the bike per worried what the bike will do to me if i dont worry about it :), thanks though...i may be just making a mountain out of a nothing :)...the thought of my handlebars breaking on those downhills has me a bit cautious :)...
See less See more
When in doubt...

...replace all components every other week.

Shimano recommends this. :rolleyes:

Hi there Steve....

steve3 said:
No offense, but pretty much every post ive seen from you is non-sensical..i am not familiar with posters on this forum but you stood out for posting numnerous pointless replies (benign though)...I know you guys get tired of answering trivial questions from newbies...but, hey, what are we to do? :)

hope you dont take this the wrong way, its just a comment...if youd like me to link your various replies in question as proof ill be glad to do it.

Take care.
Well, I have found that LX components are usually pretty durable. In fact, perhaps moreso than the "superior" XTR lineup. Given what you're doing and the bike you're doing on it I would be most worried about fractures in structural components, not your drivetrain.

On a regular basis I would inspect the frame, steerer tube, seatpost, stem, and handlebars for hairline fractures. Actually, add the cranks in there too. Repetitive 3 foot drops are going to put a whole lot of stress on a bike like the Trek 4500 which wasn't necessarily designed for that kind of abuse. I check my bikes out maybe once a month. It only takes a few seconds (except for the steerer tube which takes a little longer). I also check after I did a particularly hard ride, cased a jump, crashed, etc.

Anyway, that's my $0.02...
See less See more

I didn't realize you had over 2000 posts....I have badly mis-represented your posts in general..erratum humanum est (sp?), I just happened to read your recent posts by accident (no spin :) ), where you suggested one should have a seat above the seatpost, and where you wondered why some guys are so thouruoghly whipped by their female counterparts :), than the "everything" reply on which I missed the humor (the nature of posts i guess) bad.

It seems the moral of the story is that no bike parts require change at set time point before failure, no need to worry, and must check regularly a few "critical" parts instead, including crank and steerer tube...Well, at least to avoid "bad" breakdowns if tahts the goal...


btw, Gabe, "stress on a bike like the Trek 4500 which wasn't necessarily designed for that kind of abuse"...I always thought that my Trek 4500, if not light, would at least be more resilient even with that abuse thanks to the extra weight (that bike weighs close to 40#s at 21.5"!) opposed to those higher end, lighter, bikes that seem to have their frame brake more often (as per the posts here, and others that I know have broken their frames...see Jamis for ex.) since they have less material to sustain the repeated stresses and fatigue...

steve3 said:
Please, I would like you to link the posts in question, but I will also request you link posts on the informational side of things to keep it balanced. There is interspersion of both sides there and you only wanting to post links to your case is called "spin".

"Everything" is a meaningful response with a bit of humor added to it. Every component of one's bike is essential and has the potential to strand the rider when you're out on the trails somewhere.
See less See more
It depends

sometimes on certain parts like handle bars and seat posts, the "cheaper" (aluminium) parts will bend a bit and give you warning they're in trouble, whereas the expensive carbon versions will just snap. As you clean your bike after every ride, give the parts a once over, and don't worry too much unless you're going to be 50 miles out in the back country.
Looking back, I can't think of a single part that hasn't failed or worn-out on my bikes. It completely depends on the rider and the terrain. Things like handlebars and pedals should last you awhile (3+ years) unless they are lightweight stuff. Go over your bike and check for problems before you ride, I have a 5-10 min. routine I use to check my bike before every ride and I very rarely have a problem during the ride unless I crash.
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.