Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Fivespeed302]

Did it increase the range vs stock bearing?

If that's directed at me, it doesn't seem so, or at least not enough to be immediately obvious. I've only commuted on it twice now, and it's doing exactly what it's always done.

I've seen a thousand of those "wheel spins forever on ceramic bearing" videos, and I suspect they're all comparing a greased, sealed metal bearing with an open, ungreased ceramic bearing. Both the grease and the seal add some friction, but it's not worth talking about, and you'd be crazy to ever run a bearing (even a ceramic bearing) ungreased. I don't think the "it spins forever" test is very representative of the bearing's performance under real-world load.

Like this guy?  (I love AvE's videos, BTW)

[Lipo423]

Mmm...I would not suggest you to get ceramic bearings, the price difference will not pay off

I have no experience having them installed on motorbikes, but I have a wide nice experience in bicycles (I clarify the words to avoid confusion). They are suitable for reducing drag and improve life in "soft applications" I guess you know what I mean...as soon as you get the rough word in the middle of the conversation you will destroy them same way -or faster- than regular steel bearings (this is my experience -I own 7 bicycles-)

For people like us (99% do not race with the bikes, or can afford to replace them on regular bases), get SKF new bearings with the suitable required type/model (a bearing shop will tell you what to go for), and you should be ok.

I have not checked Zero wheel bearings but I bet you one beer they are not top notch 

[MrDude_1]

Mmm...I would not suggest you to get ceramic bearings, the price difference will not pay off

I have no experience having them installed on motorbikes, but I have a wide nice experience in bicycles (I clarify the words to avoid confusion). They are suitable for reducing drag and improve life in "soft applications" I guess you know what I mean...as soon as you get the rough word in the middle of the conversation you will destroy them same way -or faster- than regular steel bearings (this is my experience -I own 7 bicycles-)

For people like us (99% do not race with the bikes, or can afford to replace them on regular bases), get SKF new bearings with the suitable required type/model (a bearing shop will tell you what to go for), and you should be ok.

I have not checked Zero wheel bearings but I bet you one beer they are not top notch 

just for clarity.... the ceramic bearings on bicycles are undersized for minimal friction and to make them "as efficient as possible" at the expense of being weak to the point that a couple curb jumps would trash them.... but they're intended for bikes where a couple curb jumps would demand a new rim, tire and possibly new frame.

In the case of motorcycles, they're still strong enough.... however as soon as trash gets in there, they will destroy themselves.. so axle/bearing seals are critical, and they're no good at off-road applications, double so if watercrossing is expected
.

[Doug S]

When I found out the bearings had failed on my bike, I needed to decide what I wanted to do, and fast, so the bike wouldn't sit in the shop forever. I did a lot of reading on ceramic bearings in one evening, and found out there's very little scientific information and a bazillion opinions on ceramic bearings. We do know they're harder than steel bearings; that's quantifiable. It's also clear they're a lot more expensive. It also seems pretty undeniable that they're more brittle than steel, but I haven't seen any hard numbers showing that to be true, and I also don't pretend to know what's "tough enough" for a bearing to survive impacts without shattering or dimpling the races.

I've heard that "they'll wear longer", which seems plausible; they are harder, so it seems like wear particles might break off less frequently. But I've also heard they "don't last as long", which might be due to premature shattering, dimpling, or it may just be because people run them dry, without grease -- they're usually used by high-performance types that want them for their lighter weight and perceived lower friction.

So I decided I'd try them. If they do last longer, I may well never have to replace them again (I got 24,000 miles out of the original set). If it doesn't work, I'll just go back to steel, and I'll just have to get them replaced once in a while.

In a way this isn't a valid experiment, though, since in addition to going with ceramic, I'm pretty sure I upgraded them spec-wise too. The ones I chose are ABEC 5, C3 fit, and have Grade 5 balls, which is a pretty high-precision bearing, so it's probably not fair to compare to the originals (which I assume are mid-grade at best). Even the upgraded bearings are still cheaper than having another set put in down the road, however.

[Lipo423]

Doug,

What is your experience so far with the ceramic bearings?
I'm just curious...

[Doug S]

Doug,

What is your experience so far with the ceramic bearings?
I'm just curious...

So far, so good. I didn't record the mileage when I replaced them, but based on the date it was probably 3,000 miles ago. The rear end is still smooth as silk. And I'm a big guy (300 pounds), so I'm a pretty tough load for bearings.

[Killroy]

There are probably better gains switching the belt for a chain.

[Doug S]

I'm not concerned about efficiency gains. I'm concerned with the life of the bearings.

[DynoMutt]

How would they survive crappy roads with lots of pot holes?

I wouldn't want one shattering under me because of a pot hole impact.

[Doug S]

I've banged across plenty of potholes, and like I said, I'm a good bearing load tester. No problems so far.

[Doug S]

Update: I'm over 30,000 on the clock now, so at least 6,000 on the new bearings. Not a single problem so far.

[Fivespeed302]

Update: I'm over 30,000 on the clock now, so at least 6,000 on the new bearings. Not a single problem so far.

That's great to hear.  I'm about to hit 14,000 on my bike (original bearings).  I'd be closer to 16-17,000 if I hadn't had my initial 3 visits to the dealer for the well known on board charger failures and then the time it was in the shop after some old lady ran it over in a parking lot.  I got it almost exactly two years ago.

[BrianTRice@gmail.com]

I filled in a section of the manual to accommodate this success report:
http://zeromanual.com/index.php/Unofficial_Service_Manual#Rear_Bearings

[Doug S]

Update: The experiment is over. I was riding home from work a couple of days ago and a heavy-duty giant plastic bag wrapped itself around the right side of my rear axle. By the time I could get off the freeway and even attempt to clear it, it was too late. The axle was moving around in the frame and it was clear the bearing(s) had been destroyed.

At this point, I'm considering taking Terry's advice and having the shop install a 2015 (or later) wheel on the bike. The larger bearings really appeal to me at the moment.

I've got almost 41,000 miles on the bike now, so the new (ceramic) bearings lasted almost as long as the originals, and weren't giving any hint of a problem until they were murdered by the debris I picked up. Also, for whatever reason, the price of the ceramic bearings I bought has tripled since I bought them, and if I'm going to have to spend $300 on just new bearings, I'm going to at least check out the price of a new wheel.

[Perseverius]

But having the bearings in my motor fail around 10k miles points out a serious flaw in their design for long term use ... at least in a motor with exposed internals and with 10 kN higher tension above stock

So while the bearings were subject to near constant axial forces they didn't experience sudden jolts a wheel would experience. That said ... if they were such a bad idea for wheels then they wouldn't be able to sell them nearly as much as most motorcyclist are cheap bastards who flinch when they have to replace a 0.10$ part

I'm in the sad position where my motor bearings seem to have worn out. There are 2 reasons for me to suspect this. Firstly there is a slight noise coming from the motor and secondly I'm able to slightly move the pulley up and down by hand. Plus the motor doesn't feel as punchy as it used to. My local Zero dealer have proven themselves to be a bunch of scamsters, so I'm left to my own devices. Is there anywhere that I can find more motor info? Is it even possible to replace the bearings yourself, or do I need to find electric motor specialists?
This is all I have so far: http://motenergy.com/mepmbrmo.html