1. Does the part give clear "warning" that failure is imminent (e.g. sound, feel, appearance), or will it just fail suddenly? (This characteristic is often a key design feature of safety-critical equipment)
2. When the part fails (note, different failure modes should be considered separately), what is the range of outcomes? (E.g. drive failure is dangerous if you're crossing the street, not so dangerous at other times; bell failure could occur at the worst possible time, etc). Then on the other hand we have structural failure of the frame and handlebars etc which are almost guaranteed injury.
So if you are riding a bike with lightweight racing components that aren't designed with a "leak-before-break" philosophy, riding in mountainous terrain in a crowded peloton, then yes - pretty much any small deviation from normal could cause a massive pileup. On the other hand, a leisurely commmuter ride on a quiet path has much more tolerance for component failure.
tetraodonpuffer · 1h ago
it still depends what component it is, when I was a teenager I was riding a bike with rim brakes, the bolt holding the front rim brake to the frame broke all of a sudden during very light braking, the caliper rotated and got caught between the spokes and the front fork leading to the front wheel immediately stopping leading to me performing a superman dismount (since then I've ALWAYS worn bike gloves when riding). There had been no signs at all that the bolt was about to fail.
In my experience (many years of riding, quite a few years of bike commuting full time included) most mechanicals on the front wheel mean a fall/crash, but everything else just leads to having to walk home if you don't have the right tools (carrying a couple spare chain links in addition to the typical flat repair stuff and a full set of hex keys lowers the chance you'll have to do so).
eitally · 37m ago
I think this depends a lot on the rider and their level of experience (just like it does with drivers). Modern ICE cars are so quiet (to the point that many cabins feature ANC to help mask engine noise) that you'd never be able to hear a whining belt or misfiring spark plugs, and perhaps not even squeaking brake pads. Bikes are similar but the rider is much more directly connected; even so, many riders are pretty oblivious to how they work or how to fix problems.
kqr · 1h ago
> drive failure is dangerous if you're crossing the street, not so dangerous at other times
As TFA states, it depends on how much you're relying on it to keep balanced.
andrewaylett · 9m ago
Can confirm: my chain snapped cycling along Princes Street, and I couldn't wear trousers for about ten years. Turns out that sliding down the road isn't very good for the skin on your knee.
Most frustratingly: I'd already ordered a replacement, it just hadn't arrived yet.
pentamassiv · 1h ago
Modern bikes allow novel attacks too. I wrote a blog post about how to downgrade the firmware of a Shimano Di2 groupset and doing a replay attack to shift someone elses bike.
this is why if I was a sprinter a the TDF I'd 100% be on a mechanical groupset (assuming the sponsors allowed me to) a missed shift on a sprint means losing 100%
exabrial · 35m ago
One thing to know about torque wrenches: it’s actually more important that they are consistent rather than having absolute accuracy. (for the most part) why is this? If you have four bolts tightening down a handlebar into a stem, using a torque wrench correctly ensures consistent clamping load and avoids creating a stress point.
Whether those four bolts are at 8.86nm or 7nm is not usually a big deal. This is strictly speaking about bicycles, however, not aircraft or rockets :) there are a few bolts where an absolute clamp load on a single fastener is important: controls on a carbon bar. For my experience, though I have seen some bike shop mechanics reef on these (8-12nm) without consequence, even though the manual clearly states 4nm. I would do exactly what the manufacturer says here.
donatj · 1h ago
This undervalues how much it depends on context, how and where you ride. Cycling is varied.
My casual rides to the shop on my beach cruiser in my sleepy little town? Both my wheels could come off and I'd probably be fine. I'm rarely hitting 10mph.
Downhill mountain biking? Yeah, basically everything is important.
Aside, I was expecting an article comparing good software to a bicycle. Every part of good software being important and well maintained.
thorin · 39m ago
Downhill mountain bikers basically expect their bike to be destroyed and train to bail and are dressed for impact. Road cyclists wear no protection other than some thin skimpy lycra and don't fall often but when they do it can be catastrophic.
Scarblac · 1h ago
Yes, this article seems to be about racing bikes.
kqr · 1h ago
Or commuting in locations without good infrastructure (which is almost everywhere). That exposes you to both velocities and traffic that can be seriously harmful.
saidinesh5 · 1h ago
One of the surprising failure i didn't anticipate with bicycles was how little contact the tires made with the road..
Even when the brakes fully work, the tires don't provide enough traction to stop quickly ...
Ever since that last big crash I am way more cautious about all the ways my bicycle can fail me while riding.. the one good thing is there aren't that many parts to worry about with bicycles
kqr · 1h ago
I'm sure you know this but a lot of people don't: if you want to stop quickly, use the front brake while adjusting your weight backward. The rear wheel can skid along a good distance, but if you apply the front brake to the point of wheelie liftofff but no further, that's as fast as you'll stop.
Aside from just laying down and scraping yourself against the rode, which might still be preferable depending on the alternative!
(Gravel or other slippery surface where the front wheel would just skid? You're toast. Ride slowly instead.)
7952 · 29m ago
And tense your arms muscles and hand grip when you brake. A lot of over the handle bar accidents are due to people not being ready to absorb the force of braking.
Also, on uneven ground you can apply a little brake to get a sense of the surface. Feel how the bike responds and moderate accordingly.
analog31 · 51m ago
Moreover, a lot of casual cyclists don't use the front brake at all -- evidenced by the condition of the front and rear break pads on bikes I've worked on. I think that effective use of dual braking is vital to safe riding.
I advise beginners (yes there are a lot of them) to practice making panic stops in a safe place such as an empty parking lot, both going straight and while turning.
mariusor · 18m ago
A panic stop while turning is a sure way to get a face full of asphalt even for seasoned riders. Don't try that please.
WillAdams · 1h ago
The basics are as simple as ABC (Air, Brakes, Crank/Chain/Cassette) and on some newer bikes, a Q (Quick releases):
There is also a certain matter of training --- badly bent a frame when I was young because I wasn't taught how to deal with a brake failure (rainy day and steel rims) --- the answer of course is to put one's foot up on the front wheel:
Of course, the biggest danger could also be addressed by training --- as a part of getting a driver's license, drivers should be taught the "Dutch reach":
and riding a bicycle a mile or two in practice and a use of/review of hand signals should be a part of the road test.
mrob · 1h ago
I think the chain slipping off the cogs is one of the most concerning failure modes because it tends to happen only under heavy acceleration, e.g. to dodge traffic at a busy intersection. Everything can seem fine and then you're stranded without power exactly where you need it most. It's worth regularly checking for wear and correct adjustment.
1. Does the part give clear "warning" that failure is imminent (e.g. sound, feel, appearance), or will it just fail suddenly? (This characteristic is often a key design feature of safety-critical equipment)
2. When the part fails (note, different failure modes should be considered separately), what is the range of outcomes? (E.g. drive failure is dangerous if you're crossing the street, not so dangerous at other times; bell failure could occur at the worst possible time, etc). Then on the other hand we have structural failure of the frame and handlebars etc which are almost guaranteed injury.
So if you are riding a bike with lightweight racing components that aren't designed with a "leak-before-break" philosophy, riding in mountainous terrain in a crowded peloton, then yes - pretty much any small deviation from normal could cause a massive pileup. On the other hand, a leisurely commmuter ride on a quiet path has much more tolerance for component failure.
In my experience (many years of riding, quite a few years of bike commuting full time included) most mechanicals on the front wheel mean a fall/crash, but everything else just leads to having to walk home if you don't have the right tools (carrying a couple spare chain links in addition to the typical flat repair stuff and a full set of hex keys lowers the chance you'll have to do so).
As TFA states, it depends on how much you're relying on it to keep balanced.
Most frustratingly: I'd already ordered a replacement, it just hadn't arrived yet.
https://grell.dev/blog/di2_downgrade https://grell.dev/blog/di2_attack
Whether those four bolts are at 8.86nm or 7nm is not usually a big deal. This is strictly speaking about bicycles, however, not aircraft or rockets :) there are a few bolts where an absolute clamp load on a single fastener is important: controls on a carbon bar. For my experience, though I have seen some bike shop mechanics reef on these (8-12nm) without consequence, even though the manual clearly states 4nm. I would do exactly what the manufacturer says here.
My casual rides to the shop on my beach cruiser in my sleepy little town? Both my wheels could come off and I'd probably be fine. I'm rarely hitting 10mph.
Downhill mountain biking? Yeah, basically everything is important.
Aside, I was expecting an article comparing good software to a bicycle. Every part of good software being important and well maintained.
Even when the brakes fully work, the tires don't provide enough traction to stop quickly ...
Ever since that last big crash I am way more cautious about all the ways my bicycle can fail me while riding.. the one good thing is there aren't that many parts to worry about with bicycles
Aside from just laying down and scraping yourself against the rode, which might still be preferable depending on the alternative!
(Gravel or other slippery surface where the front wheel would just skid? You're toast. Ride slowly instead.)
Also, on uneven ground you can apply a little brake to get a sense of the surface. Feel how the bike responds and moderate accordingly.
I advise beginners (yes there are a lot of them) to practice making panic stops in a safe place such as an empty parking lot, both going straight and while turning.
https://bikenewportri.org/abc-safetycheck/
There is also a certain matter of training --- badly bent a frame when I was young because I wasn't taught how to deal with a brake failure (rainy day and steel rims) --- the answer of course is to put one's foot up on the front wheel:
https://bicycles.stackexchange.com/a/7287/7344
Of course, the biggest danger could also be addressed by training --- as a part of getting a driver's license, drivers should be taught the "Dutch reach":
https://www.theaa.com/driving-advice/safety/dutch-reach?msoc...
and riding a bicycle a mile or two in practice and a use of/review of hand signals should be a part of the road test.