SwtBadger

What is reasonable lifespan of higher end bike components?


Ultegra 6800 rear shifter and right crank failed within the last week, in addition to two punctures.

I expect a crank to have essentially an infinite lifespan and the rear shifter lasted less than 2000 miles as it already failed once.

Replaced the whole crankset, as was in the middle of vacation and it was quicker that way - Competitive Cyclist was able to send it in 2 days to my away address so Kudos to them.

Returning to the question;

For cassettes, chains, front rings those items will need to be replaced but I'm guessing 8-10k or more depending on conditions and lubrication. Cables - no idea. Derailers, shifters, bottom brackets, brakes (expads), cranks expecting very long lifetimes.

Thoughts or experience?

topflightpro

Cables, housing, and bar tape: About once a year. (When you see the cable strands peeking out the ends of the housing, that's often a sign the housing is worn out.)
Chain: ~2000 miles
Cassette: ~8000-10,000 miles
Chainrings: ~50,000
BB: ~It depends. Outboard, pressfit, BB30 are all different, then ceramic vs. steel... I've gone as little as 6 months on ceramic BB30 bearings to more than 10 years on steel BB30 or GXP.
Shifters and derailleurs: If you don't crash on them or have a cable snap in them, they should last decades. You may need to replace pulley wheels, if they break.
Brake Pads: It depends - weather conditions are a large factor.
Cranks: Decades.

Drew Eckhardt 

Modern shifters have parts which fail due to fatigue. I shift like I have ADHD and got 24,000 miles out of my first right Campagnolo ergo lever before the rear ratchet spring failed. Other shifters have plastic internals that wear out.

Drew Eckhardt 

It varies radically with component and rider.

I get about 4500 miles out of Campagnolo 8/9/10 speed chains at which point I replace them due to sluggish shifts to my big ring because of excessive flexibility from side wear although they've only elongated 1/32" over a foot. OTOH, I had an off brand chain elongate 1/8" in only 2000 miles including some time in wet Washington state.

Heavier cyclists pushing big gears get half that.

I get 5+ chains out of each cassette, and expect to replace my current 25,000 mile old part with the next chain.

People who shift less and favor a few cogs get half that.

1,000 - 20,000 miles for rear shift cables.

I shift like I have ADHD and got 4,500 miles out of rear shift cables until switching to new levers having a 90 degree internal guide for hoods level with bar tops plus under tape routing which cut that in half to 2,000 miles from the extra flexing. The next batch of cables dropped it to 1,000.

I've heard of people who shift less and manage 10,000 - 20,000.

My front shift housing developed increased friction after 13,000 miles - this is the normal failure mode with modern housing where going around bends the cable wears into the lining which pinches it.

The rest of the cables and housings last almost indefinitely, although most people replace housings and cables at the same time.

I got 24,000 miles out of my first right Campagnolo ultrashift lever before a ratchet spring failed due to fatigue.

My last bottom bracket (FSA SLK Light external bearing) made it 15,000 miles.

79pmooney

Aluminum cranksets break. All of them. It is just a matter of time (and design and manufacturing details and in-use abuse and how hard it is ridden. Good ones go a few decades. Some were famous for rather short lifespans. I have ridden one that broke across the pedal threads and witnessed two others (from immediately behind) from the same failure. Campagnolo NRs tended to broke across the threads. (The two I witnessed.) Probably because the threads were cut, rather than rolled. The many Suginos cranksets I've ridden have been retired from wear from toestraps and winter boots, damage to the chainring bolt holes (user error), hard crashes and the like. Never actually broke one. Never broke a Shimano either, They just go into spare parts boxes as I find other cranksets that set up to lower Q-factors. Never broke the old "erector set" TA"s either despite them be far less massive than almost anything else out there.

For real longevity, I'd stick to the Japanese brands because they are likely to be the best for rolled threads, good design and attention to manufacturing details. With aluminum. those detail often matter far more than the easy stuff, like alloy used, weight, stiffness ... Cranks see many repetitions of sometimes rather large forces. Get the details wrong, tiny cracks start and sooner or later, they break.

If you never want to see a broken crank - replace them before they break or use steel cranks.

Ben

DrIsotope

If either of my Rotor 3D cranks ever fail mechanically, I will be genuinely shocked. And I've broken or outright worn out pretty much every part of a bicycle.

MoAlpha

I broke two Record crank arms BITD and not from strength or weight. If I remember correctly, both showed evidence of crevice corrosion at the fracture face.

noodle soup

I'd love to see a photo of the broken parts, and an explanation of how they failed.

Jack Tone 

I don't remember ever wearing out a part, except chains, because I have too much fun upgrading. I did snap a pedal axle once when sprinting that led to a crash. It was an old Mavic clipless pedal.

MSchott

I don’t ride as much as most here but the only components I’ve born out in 25 years of riding are chainrings, brake pads, chains and cables. This was on a bike with an 8 speed full Ultegra group. Can’t yet speak to the components on my new ride. So far 700 miles with nothing replaced.

Dan333SP

I have 5700 levers, and the cable routing design means that the rear shift cable will start to fray and then snap after maybe 3,000 miles of regular shifting usage. To prevent having to pull cable strands out of the lever body with tweezers, I just replace the rear shift cable every 3-4 months. Housings last me about a year, brake pads maybe 6 months, same for chains (riding 5-6k miles a year on mostly dry roads). Cassette is maybe once every year for me, but I swap them around based on gearing needs so it's hard to say how many miles I get out of each one.

I've never replaced the BB bearings on my bike, they've got over 30,000 miles on them. Conversely, my headset bearings have required replacement about once a year as they rust and start seizing with the slightest bit of moisture.

Crank and chainrings are original, so over 30k miles on them. My 5700 levers are feeling very worn and the internals are probably a bit rusty and gunked up, but they still function fine with new cables. Same for the FD/RD. The caliper brakes I use tend to lose return spring tension after a few years, so I'm on my 3rd set of APEX caliper brakes.

DrIsotope

I must have had some kind of blessed 5700 levers, because I used the same rear shift cable for over 10,000 miles. Then I moved on to 6700 (which was supposed to have the same problem) and I think changed that cable once, when I changed the color of the cable housing.

Same story for housing-- 10k on my Jagwire Elite Link, and the housing for the single shift cable on my 1X bike (Jagwire LEX-SL) has been on there since day one, 15k+ miles.

Kimmo 

It seems that Shimano didn't get the design of the four arm crank right on the first try - I've heard of a few failures, from 105 to Dura-Ace. The crank was redesigned for the next generation.

noodle soup

I've seen a few photos of those cranksets that have failed, but think about how many of them are in use. I've never seen one that failed(in person).

FTR, Shimano redesigns their crankset in every generation.

Kimmo 

I read the crank was redesigned in response to fractures. They were all breaking where the near spider arms meet the crank arm, so that area was basically swallowed by the huge new right arm.

downhillmaster

Cables once a year?
Seriously?
How many miles are we talking here?

MoAlpha

Holy crap! I have this crankset. Fortunately, I'm weak and light, but I'm going to inspect it regularly.

noodle soup

So do hundreds of thousands of other people. When 5800/6800/9000 cranksets fail, this is what it looks like. It just doesn't happen that often.

Kimmo 

Yeah, I'd still prefer the 9000 to any other four arm crankset, and just cross my fingers I wouldn't be one of the very unlucky ones.

But I reckon that bonded construction is a bit suss. Shimano gets the side-eye from me on that.

topflightpro

How often are you changing them?

DrIsotope

All four cables on my R3 now have 7,751 miles on them (Jagwire Elite Link + all Ultegra 6800 components.) Partly because shifting and braking still feels fine, and partly because it's internally routed and I don't wanna mess with it again.

TimothyH

Assuming 5000 miles/year, proactive replacement every 2500 miles isn't uncommon.

I replace the inners 2x/year and the outers with new bar tape every winter(ish).


-Tim-

noodle soup

I was getting 10k miles out of shift cables on DA9000 levers, but AZ is pretty flat, and you don't need to shift as often as in other areas.

drewguy

Interesting question - replace cables proactively? Unlike other components that for the most part don't suffer catastrophic failure (a snapped chain aside) and instead just wear past a point of acceptable performance, seems like for cables it may be a good idea just to replace every so often? Or just let them break and figure out how to ride home on a semi-fixie?

noodle soup

Let them snap, and then deal with the PITA of removing the cable end from the shift lever.

It's much easier to remove the cable while it's still intact.