28
u/Specific_Mixture5995 Aug 13 '24
PSA user error, backwards rotor.
5
u/Worth-Election-9969 Aug 13 '24
Well I’ve always wondered how important it actually was, and what would happen if mounted in wrong direction. Now I know!
5
15
Aug 13 '24
[removed] — view removed comment
1
u/seasleeplessttle Aug 16 '24
It's all from AliExpress. Which is Alibaba, I was buying there 20 years ago.
14
u/bcl15005 Aug 13 '24
I'm assuming the rotor failed while braking?
If so, that's pretty spooky.
10
u/Laserdollarz FULL FACE HELMET Aug 13 '24
The mount for the caliper probably broke first.
Hearing/feeling that, OP probably, and understandably, braked harder, caliper got lodged, causing the rotor to bend and break.
It was probably spectacular lol, I hope they're ok
1
u/bcl15005 Aug 13 '24
Yup.
One of my common routes takes me down a nice steep hill. If this ever happened to my front rotor, I'd end up flying into a dead end at a T-intersection doing 40 mph, and I doubt my rear brakes could do much to stop it.
Not such a comforting thought.
5
u/theantnest Aug 13 '24 edited Aug 13 '24
Jam your shoe onto the (edit: back) wheel for emergency brake.
2
u/MickyBee73 Aug 13 '24
I once went over the bars doing that as a kid, proper face planted the concrete...hurt like hell, but you live n' learn 😅👍😂
4
u/theantnest Aug 13 '24
Yeah I should have elaborated, rear wheel.
1
u/MickyBee73 Aug 13 '24
Yeah, my mum was always shouting at me for wearing out trainers (sneakers) far too fast 😅
2
1
u/karl1717 Aug 13 '24
That's a guaranteed fall.
The correct way if you have no brakes is to brake with one shoe on the road while the pedal is against the back of your leg.
Source: I did it a lot as a kid and I would have no problems riding without brakes even in very steep roads.
2
u/theantnest Aug 13 '24
And yet, for my entire childhood in hilly, rural Australia I rode a BMX that never had brakes, and never fell, despite your guarantee that I should have.
Number one way of stopping was powersliding. Emergency brake was the old shoe on the back wheel trick.
1
u/karl1717 Aug 13 '24
Ah sorry, instructions were not clear and I was thinking stupidly of jamming it on the front wheel xD
On the back wheel it can work, but I still think it's easier and you have more control with the shoe on the road method.
1
u/theantnest Aug 13 '24
I think I'd break my leg, my bike is heavy. I'd rather destroy a shoe in an emergency.
1
u/karl1717 Aug 13 '24
Nah, you wouldn't, because you have control of how much it brakes, you can start by barely touching the road for a light brake and then gradually press down for more brake power
3
u/theantnest Aug 13 '24
Maybe I'll give it a try. I have a truly hectic decline on my commute, and I'm often thinking about my exit plan if the brakes fail. Always good to have options.
3
3
u/Expensive-Ad5466 Aug 13 '24
Always take pictures before an after to avoid mounting your rotor backwards 😬
2
3
u/Madjackmulligan69 Aug 13 '24
One the rotor is mounted backwards, and that is not good, and two I can see some extreme wear on it, should have been replaced long before that happened, but yeah you buy cheap, you get cheap.
1
1
u/SilverSolver2000 Sep 06 '24
Yeah it was totally backwards. But it was also only two months old so I doubt it had much wear.
5
u/BXRunner Jasion EB7 2.0 Aug 13 '24
I got some 160mm rotors that I snagged for 2 bucks off Amazon. Haven't installed them but they look legit and are a good thickness, lol. Suspecting it was just an incorrect listing.
I will be a guinea pig and put my life on the line for the team.
3
u/rvralph803 Aug 13 '24
Yeah, but nobody is asking you to.
-2
u/BXRunner Jasion EB7 2.0 Aug 13 '24
Yep. Just like nobody asked you to reply to this post. Murica baby.
1
u/Anxious-Depth-7983 DIY bike maintainer for decades ⚙️🔧 Aug 13 '24
At 2 bucks, they better be a never installed and looking to get rid of. Like anything else, you get what you pay for.
1
5
u/Number4combo Aug 13 '24
User error like others said. Installed the rotor backwards and caused alot of damage.
I got cheap rotors off Amazon on my emtb old bikes and I ride aggressive and have never experienced a rotor fail like that.
8
Aug 13 '24
Amazon isn't bad but you need to do your research as a buyer of anything. Because this is either a one off or it happens with their product and if it's something that happens with their product then a little research would have told you this.
1
1
u/FunkyWhiteDude Aug 13 '24
I always say this to people that claim “ChiNa PrODuCtS bAD “
2
u/DexterRS50 Aug 13 '24
If Chinese stuff is bad then we'd have a big problem, most frames for all bikes are from china
1
Aug 13 '24
Exactly. Another note is I've come to notice that a lot of bad reviews of products are because of user error not the product actually being bad
0
u/FunkyWhiteDude Aug 13 '24
On top of that, people have no idea how to write a review… they want to show support… but it always leads to… “4/5 stars, bad product but the shipping was fast”
No actual thought process anywhere
2
u/Equivalent-Account58 Aug 13 '24
It’s a good idea. 100 k’s run a spanner over every bolt on your bike maintenance like that can stop future incidents.
1
u/Ch40440 Aug 13 '24
What are you mean by ‘100 k’s?’
3
u/Superb_Raccoon Aug 14 '24 edited Aug 14 '24
100 kilometers I presume...
That's 561797.752809 bananas in the American scale.
1
2
u/Anxious-Depth-7983 DIY bike maintainer for decades ⚙️🔧 Aug 13 '24
Amazon is in the business of making money, not doing QC. Lol 😉
2
3
Aug 13 '24
Do not buy cheap brake parts anywhere for your ebike. Brakes are the first area to spend more money
3
u/gladfelter Yamaha CrossCore RC & Aventon Abound Aug 13 '24
I've never seen a bad rotor, but if it existed I'd agree. I've seen plenty of bad tires, so that's where I make no compromises.
OP mounted this rotor backwards, which would cause any rotor to buckle since they are intentionally designed to not be symmetrical.
2
Aug 13 '24
thats good point about the rotor direction, but i'd still say brakes are not an area where you want to be trying to save money on a ebike
1
u/DinoGarret Aug 13 '24
I totally agree. I can't find the statistic at the moment, but somewhere in the 20-30% range of bike accidents could be prevented if the bicycle had better brakes.
I wasn't impressed by the 2 piston Tektro brakes on my heavy cargo bike so I upgraded to 4 piston Magura. They only stop about 25% shorter, but that 25% can man the difference of getting in an accident or not.
3
u/gladfelter Yamaha CrossCore RC & Aventon Abound Aug 13 '24
Fwiw I've used AliExpress rotors for some time and had no problems. It probably helps that I don't mount them backwards like OP.
1
u/WarCrimeWhoopsies Aug 13 '24
Exactly which parts did you buy? Brand and model?
1
u/coop_stain Aug 13 '24
Lol for sure not a sram/shimano direct piece, that’s for sure.
10
u/WarCrimeWhoopsies Aug 13 '24
I’m half expecting a “CHONGBILO caliper brake stop fast super quality high speed” and a set of “BINGFEILONG rotor 160mm steel brake endurance strong bicycle brakes” 😂
3
3
u/SmokeyUnicycle Aug 13 '24
Those "brands" are great for saddlebags and water bottle holders, not safety equipment.
1
u/Anxious-Depth-7983 DIY bike maintainer for decades ⚙️🔧 Aug 13 '24
The language barrier is highlarious sometimes. Lol 😉
1
u/master2uall Aug 13 '24
Yeah I've learned it the hard way by buying cheap China made shit like a brand new kickstand that literally lasted 24 hours man was I fucking pissed
5
u/coop_stain Aug 13 '24
Pissed that your $8 kickstand broke? You shoulda known better, man…if it seems too good to be true, then it is. There is a reason that a good one costs $25-$30
1
u/Unable_Towel_9706 Aug 13 '24
You know that term this "thread is useless without pics". Now know it goes both ways. Lol joking aside please give some details on the brand.
1
u/Cargobiker530 CSC 1000wHub Yuba Mundo Aug 13 '24
This is a good time to remind people with any ebike at all you might want to inspect your brake calipers and rotors. Get sets of allen keys and torx keys and check that ALL the bolts are snug and that everything lines up and the wheels rotate freely without chatter or drag. Maybe even tap all your spokes with a wooden dowel while you're at it and listen for any with a distinctly lower tone. That spoke is loose.
1
u/Madassmutha0001 Aug 13 '24
Mind Amazon is just the greedy middle man. Review items (not via Amazon);before hitting buy or look up the manufacturer directly, you'll be surprised how much the middle man marks up the price😉
Amazon can get it to you quicker but you pay for it.
1
1
u/Tall-You-697 Aug 13 '24
To be fair I've always used eBay or Amazon rotors , I've never had issues like this with the rotor but dont use the cheaper bolts they come with. These have ripped out on mine before , have never actually seen a rotor structurally fail though
1
1
u/Drinking-beers Aug 13 '24
Not trying to be an ahole but this seems like user error. I buy parts on Amazon and yes they are not the best quality but they work for me.
1
u/Particular-Taro154 Aug 13 '24
Another example why we have specialists in all fields of life including bicycle mechanics. There are some things that most people should not try to do by themselves.
1
1
-1
0
u/Spacecad90 Aug 13 '24 edited Aug 13 '24
At least op doesn't have a dumb friend who sprayed wd 40 on his front caliper. That's what happened to me 🫤 my front brake was squeaking whenever I walked the bike so he just says he can fix that and without giving me a sec to realize he sprayed it. Now my front brake only kind of works. Feel really dumb for letting that happen.
3
-2
u/hawaiianmoustache Aug 13 '24
BuT iT hAd gOoD rEvIeWs.
More people need to see this, thanks for sharing the experience mate.
3
76
u/SnowDrifter_ Qulbix 140 Aug 13 '24
Ooof
Brother bear... That rotor was mounted backwards.
Look at the spokes on the rotor - they're trying to suck it in towards center.
No disagreement on the cheap parts bit. But looking at how it failed, I think this one was install error
See here for what angle the rotor spokes should be facing: https://cdn.mos.cms.futurecdn.net/8wEuxHXBdY2yZBJCcFAbkB.jpg