...according to this, the wheel can handle up to 5000N (about 500kg)?!
...maybe we could lower that by using some asymmetric rims (protected by a patent, obviously) and just weaving the spokes together on one side...
We're talking 500 kg of static load. If you're cruising at 22 miles/h (V=10m/s), you've got a mass of m=100kp. Now, hit an obstacle so hard that you stop the wheel over a distance of 10cm (S=0.1m) and calculate the force yourself. Acceleration is a=(VxX)/(2xS), and Force F=mxa In the real world, you aren't stopping a bike in that tiny distance; you'll likely slam into some aluminum and slow down by, say, 3m/s, which gives you an acceleration of 90m/s². Multiply that by a 100kp mass and there's your 9000kpm/sxs. It's massive, but luckily it's just a momentary spike.
briskbison41 said:Where are you even getting that from? Give me some actual definitions here, because there’s basically zero load on those upper spokes...
A spoked wheel works for a train, not for pressure. All the weight transfers to the hub through those top spokes since the whole thing is essentially hanging from the rim. That's why the wheel is so light yet incredibly strong. If you try to apply pressure directly to a spoke, it'll just bend without a second thought.
casualharbor9 said:... I said 450 lbs just as a rough guess. I think that’s about where the load hits when you're slamming your full weight into an obstacle at full speed... I could easily be wrong about the math here...
You're way off. Dynamic loads are massive compared to that, and they aren't distributed evenly across all the spokes and nipples. The top spokes and the ones on the rear wheel near the hub take the brunt of it because of the torsional stress on the hub itself.
briskbison41 said:I usually ride pretty mellow, nothing too aggressive (whatever that means to some people). The only reasons I see for a full overhaul are bearing cracks, flushing the brake fluid (if they're hydraulic), swapping out springs, and changing fork oil (if those start cracking too). You also have to true the wheels when they get wobbly—though honestly, you should just tighten everything more often regardless of how many turns are on it, because things loosen up and that's what causes the wobble in the first place. Then there's the risk of cracks appearing in the frame, forks, handlebars, etc. Those are all standard issues when riding through the woods. Basically, if you're doing DownHill or FreeRide...
Out of all that, I’d regularly swap the fork and brake oil, and handle the rest as needed if stuff actually starts snapping.
Some guy in the thread below had his wheel axle snap. What happens if a thru-axle bolt snaps while you're hitting a sharp descent in the middle of the forest? Who's actually checking and replacing that stuff on a regular basis?
briskbison41 said:Yeah, pretty much. Until some deity decides to start shaking things up on it, it's fine 😁 And if—and I'm biting my tongue here to avoid jinxing myself—if it actually does happen, then I'll deal with whatever mess occurs and head to the shop (assuming it's a real issue, because you can still fix certain things yourself with a basic toolkit).
The whole point is to THINK. I was considering getting a checkup over at Panch Ville, but that blasphemous crack caught up with me first. Anyway, I mostly ride on asphalt, ranging from moderate to a bit aggressive. It makes me wonder what kind of abuse vehicles actually take when they're flying down a forest trail. Are the parts beefed up enough for long-term heavy use, or are you looking at a total overhaul every month? Seeing a buddy's relatively new Ali Bic snap on him made me seriously skeptical about aluminum.
The 60xx series Al alloys are basically corrosion-resistant—they have moderate mechanical properties, but they hold up great against rust. On the other hand, you've got the 70xx series, which are zinc-alloyed. They’re incredibly strong, but they're also super sensitive to impurities, so you can't just go machining them with tools used for something else. Welding always weakens the material structure, except when you're dealing with CrMo steel, which is exactly why it's the go-to for high-end bikes and aircraft. I just put a new fork on my cruiser, hoping it'll last me another 17 years. It's a little prone to rust, but whatever. Functionality comes first. My old one snapped at the fork leg about an inch from the weld (where the vertical tube meets the two holding the wheel), right through the hole they drill for mounting the fender. I could tell a total havarija was coming a couple of days before it happened, but I just didn't catch the warning signs. So, listen up everyone: if you feel like your ride is acting weird—creaking, pulling, rattling, shaking, etc.—you need to do a thorough inspection immediately. No excuses.
17 years on this steel. Aluminum ages way faster and just snaps. Carbon fiber? That stuff fails without any warning, no plastic deformation or signs beforehand to let you know it's coming. The welds on the fork are especially sensitive. Honestly, maybe they should start using old-school railroad methods—just tapping the frame every now and then and listening closely. A section with a crack should sound dull... X-rays and ultrasound aren't exactly accessible for the average person.
silentpanther15 said:Quite a bit. I have to be careful since I tend to drive like a maniac...
Right now, I'm not just unhappy with the tires (they've seen better days and are begging for replacements), but also the worn-out brake pads, especially the front ones (which definitely need replacing soon). Everything else is still at a 5.
Are you sure about that? My cousin's three-year-old mountain bike had a seat post snap right under them. Talk about an unwelcome surprise.
John Thompson872 said:Which fork are we even talking about here?
I honestly don't know enough about the specific parts to say... which is why when you buy a bike, they hit you with all those heavy-duty warnings. Ride like this, don't ride like that, watch out for this, make sure you maintain it this way or that way... it's endless...😬
Just a standard rigid fork, whatever stock part they slapped on the frame at the factory.
For a few days now, I’ve had this nagging feeling that my headset was getting loose. Every time I hit the brakes, I could feel a slight wobble in the bearing. My bike isn't exactly a showroom model—it’s 17 years old—but I’ve kept it in "good" shape. All the vital components have been regularly serviced, lubed, and pampered. Everything, that is, except for the fork. So, yesterday, I’m cruising down Grushko Street. The fork felt even looser than it did the day before. I’m riding past the botanical gardens, and as I pass under the overpass, I take a massive jolt, like I just slammed my rim straight into a curb. After that, the bike was handling like a drunkard. Once I realized what was happening, I pedaled home like my life depended on it... barely made it. As soon as I got it into the garage, I lifted the bike up and the wheel and part of the fork just... fell right off. If that had happened on Grushko near Chase Bank, they would've been scraping me off the pavement with a shovel. So, tell me, how much do you actually trust the critical parts of the machines you rely on to keep your head attached to your shoulders?
I remember a day just like this one. Back in the late seventies, we were playing at some college music festival at a student union center. The bassist from Boeing showed up with this beat-up Fender that had a warped neck, and those guys would've been totally screwed if we hadn't lent them a truss rod. Later on, we headed over toward them, somewhere south of the stadium near the new Branimirov... For that era, they were playing some really weird music.
It’s worth it—just fix it up. My wheel dates back to 1993. For real, I keep it meticulously maintained; I swap out the axles, bearings, spokes, and chains. I'm already on my third drivetrain. Nothing fundamental about bike standards or dimensions has changed in the last century, so you won't run into any issues finding parts.
Jesse Williams2 said:Look, I get that riding a bike through Washington, D.C. is a blast... but here in Savannah, biking through town is a total nightmare... the terrain is just... it's flat, then there's a slope, then more climbing... and don't even get me started on bike lanes... THERE ARE NONE!!!
What hills are you even talking about in Savannah? Every single day when I ride to work, that last mile and a half feels like a massive climb, a legit hill. And let's be real, bike lanes in Washington, D.C. are pretty rare too, so I spend basically my whole ride stuck on the road dodging arrogant drivers. It’s definitely not perfect, but it's a rush.
Jesse Williams2 said:For those of you who own a car or a motorcycle, tell me—how can you even think about riding a bike when you have a vehicle?...
How could I not ride two wheels when I’m faster than a car and can park wherever the hell I want? I just tie my bike right in front of the corner store, in a parking lot, or wherever makes sense. Honestly, nothing beats cruising past the local high school football field while everyone else is stuck in gridlock, dealing with people trying to strip parts off Mubarak's car and others... I used to have a motorcycle, too. What a nightmare. You end up freezing even in the middle of summer, stepping off the bike feeling stiff as a board. On a bicycle, you actually move around and stay warm. Plus, commuting to and from work is basically built-in exercise, so there's no need to waste time at some boring gym...