magicpie55

Hello ..I searched ..there is probably an answer to this here but I couldn't find it ..Sorry ..
Looking to upgrade the rear wheel on my bike .. Change from a Freewheel Hub to a Freehub wheel .. The ones I see have 4 bearings ..2 in the hub and 2 in the Freehub .. Question is ..Does the weight of the bike ride on all 4 ? Or just the 2 Hub Bearings ?

I have taken an Electra Townie and turned it into an Electric Bike with a front hub motor .. I am Heavy 220 lbs ..The bike is heavy ..I put ebike tires on it .and the ball and cone setup was fried when I took it apart ..The cones were badly pitted ..
However ..even these 1/4 balls are bigger than the ones in the sealed bearings .. What I have read says the sealed bearings are better ..just trying to understand how when their smaller ..If it runs on all 4 bearings that would be good ?? I read where the load is pushed more to the outer part of the hub with a freehub over a freewheel ..
Hope someone can set me straight about all this .. Thanks for any advice you can give ...Don

Bill Kapaun

Were "fried" bearings ever serviced?
The higher speeds from Ebikes put a much higher load (think heat too) than just poking around the path.
Low end hubs such as a Shimano FH-RM30 have an oxide coating on the cones instead of being polished. I've pitted those even when I was servicing them. I would think those would be quickly expendable in Ebike use.

magicpie55

Thanks For the Reply ... The cup and cone Bearings did go for 2 years of 50 miles a week riding .. I was changing the Freewheel and chain when I noticed they were rough ... Hard time finding cones for this hub ..Finally got them from the dealer .."Duh" .. I was an auto/truck mechanic in a previous life . used to mostly Tapered Roller bearings .. The cones I got weren't polished .. I took the wheel off a month later to put a solid axle in and the cones were pitted again ..Just 1 though ... Freewheel side??? ..
I ride 8-9 mph for exercise . I am Handicapped and cannot stand or walk for very long ..But can ride this bike for Hours ..
So the Question is .. Does the weight of the bike go on all 4 bearings or just the 2 in the hub of a freehub system ? Thanks for any help I can get .. Always trying to learn ...Don

magicpie55

The cones I got from the Electra Dealer weren't Polished .. When I replaced them the 2nd time I used some used polished ones from a Deore Hub ..

canopus 

They make the wheel go round & round ()...

icemilkcoffee 

For a traditional Shimano type hub, the weight of the bike is supported by the 2 hub/axle bearings See top picture:


But Campagnolo cassette hubs and a lot of the newer cassette hubs are more like the freewheel hub in the above picture. The weight supporting bearing on the drive side is inboard. And the freehub is not rigidly attached to the hub body. The freehub body floats on the axle.

Bill Kapaun

You want to make sure the races are in the correct place.
Here's the cone I was referring to in my above post. You can see how rough it is-
https://www.sjscycles.co.uk/hub-spar...03000/?geoc=US

magicpie55

Thanks for the Reply .. I am not going with a shimano ball and cone hub ..Rather the Sealed bearing type ..Says there are 2 in the hub and 2 in the freehub part .. I am wondering if they all support the weight of the bike or do the 2 in the freehub part work only for it ?

Andrew R Stewart 

The rider's weight is supported by the bearings that span the hubshell to the axle. The bearings in the freewheel or freehub body (of any bearing type) only support the drive forces.

The hub cutaways really show how the axle bearings are loaded differently WRT each other, by their placement along the axle, how far from the axle's center they are. Andy

magicpie55

Thanks ... That was what I wanted to know .. So those 2 little bearings support more weight than the 1/4 ball and cone system .. The hubs I'm looking at use 6000 series bearings ..

Andrew R Stewart 

No, the two bearings support the same amount of weight as the loose balled type do, given the same rider and bike weight. What you might be trying to say is that when a weight supporting bearing is moved along the axle the amount it shares with the other bearing changes. Leverage is at play. But the total the two see is still the same, just that the bearing that is closer to the axle/frame's centerline will carry more then the other that's closer to the axle end.

Think about picking up and holding a wood 2x4 that's 8' long. It's easier to hold it evenly in both hands, about 3' each side will stick out beyond the 2' center section (assuming that your hands are 2' apart). Both hands are doing about the same amount of weight bearing. Now move one hand toward the 2x4's center about 1' and the other hand towards the end the same foot. Now that 2x4 is held off center and the hand that's closer to the center has more weight but the other hand closer to the end carries less weight. The total weight, of the 2x4, hasn't changed just how each hand is being used has changed.

The primary reason to have a Shimano like freehub's axle bearing locations is to reduce the bending stress that an uneven bearing placement places on the axle. Freewheeled axles are known for bending, and breaking, at the RH side's bearing cone edge due to more leverage being focused there. Yes there's some bearing life possible improvements too but most all bearing failures are due to preload, maintenance, and lube contamination, not too much weight placed on them. How to seal off the outside world from the bearing's insides is vastly more important to bearing life then where that bearing is located. Interestingly a freewheel RH bearing has a better "seal" that that of the LH side if only because the RH one is further from that outside wheel (being tucked inside/past the freewheel). Andy

magicpie55

Thank You Andrew for the explanation .. I screwed up the Question .. I didn't mean to say the sealed bearings need to hold more weight ...
What I meant to ask was ....Do these smaller 6000 series sealed bearings hold more weight than the 1/4 ball and cone system ??
I could maybe understand if all 4 in the hub were supporting the bike ..but 2 and the balls inside are 3/32 I think .. Both of these bearings have a very thin contact point with ball bearings ...I am used to Roller Taper Bearings form my mechanic days ..
The ball and cone system is simple and easy to adjust/service .. I just wonder if the sealed bearings will hold the weight of the ebike better ..

magicpie55

This is the one I am thinking about .. Just the rear wheel the front is a hub motor that came with a strong wheel ..
This hub has 4 sealed roller bearings ... I can get this rim with a Deore freehub for 1/3 the cost of the"Clydesdale " From Velocity ...I don't mind paying more if I will get a stronger hub .. If the sealed bearings aren't any stronger than the cone and ball system I might as well stay with it ..

Velocity - CliffHanger 26" Rim Brake Clydesdale Wheelset

davidad

The load is carried by the hub's bearings. The advantage of the shimano design is that the drive side is supported by an outboard cup and cone. Cassette or Freewheel Hubs by Jobst Brandt (sheldonbrown.com)

magicpie55

This one is way less $$$ is it the same quality as a Velocity Clydesdale ??

https://www.universalcycles.com/shop...&category=6780

bikemike73 

Another thread with GREAT info !!!!

Will make a note of this !!

Thank you !!!

magicpie55

I have a Deore freehub from an old mountain bike I had .. I see how the bearings are held ..1-2 inches further outboard on the sprocket side .. The Clydesdale with 4 bearings total is supposto be a stronger wheel to hold more weight .. That's what I'm trying to sort out .. Thanks for the Help ..

https://www.sheldonbrown.com/k7.html

magicpie55

I have used the cones from this hub after the stock ones pitted for the second time .

70sSanO

This is a great source for Shimano cones and dimensions, especially for mix-n-match.

https://wheelsmfg.com/products/hub-parts/all-cones.html

The charts will give the hub to cone compatibility.

John

magicpie55

Thanks for the reply .. That's just what my stock ones and the replacements Electra Gave me look like .. Here's a pic of one that went 150? miles .. The originals went 2 years who knows how long they were pitted and rough .. The second time I rebuilt it I used Cones from a Deore Hub I happened to have ..

magicpie55

Andrew R Stewart 

Well if the question is bearing loads, and not the specific bicycle application, my understandings will get thin fast. But here's what I learned decades ago. The load potential of a ball bearing is proportional to the size of the balls with a geometric relationship and the load WRT the number of balls is a linear increase. Doubling the size of the balls increases the load by a factor of 4. Doubling the count of balls (but the size remains the same) gets you a 2x load increase.

One challenge that bike component designers have suffered with for decades is the dimensional limits of what will fit a bike. Sometimes these limits are restricted by what other components control and still be compatible. Rear hubs have to fit some sort of cog or pulley for the drive (excluding shaft drives) attaching to the shell. For a multi cog set (freewheel, cassette) that fits within the rear drop out spread and for the spoke bracing angles to remain sane this means that the drive side bearing diameter is limited by the cog's IDs (and by the cog carrier's material thickness needs). Freewheel hubs got around this by placing all the smallest cogs outboard of the RH side bearing, the larger cogs sit more over the RH bearing (and for that matter they sit over the freewheel body's inner balls too). Freehubs that don't have a stepped driver (the part with the spline) and have the RH bearing far outboard (like Shimano does) have that bearing size limited by that smallest cog size.

Now go back to the load capacity VS the bearing size. Were the bearing size not limited by other constraints one would use many large balls to gain load capacity by both increasing size and count. But that's not what is really being done because other factors are at play. As mentioned, the bearing has to fit inside the component. And as the size of the inner shafts (axles, spindles, steerers) have increased (so less dense materials can be used to drop weight but need larger diameters to maintain stiffness/strength) the available space to house a bearing is less and less. This is one reason why oversized BB shells are liked by designers. To reduce the bearing ODs the ball size is decreased... And with most cartridge bearings the ball counts are not significantly different from the older cup and cone designs, with hubs sometimes even less a ball count (due to bearing manufacturing and assembly issues).

Then why do sealed cartridge bearings rule these days when they have basic shortcomings in load capacity? Because, as I mentioned in a previous post, bearing load being exceeded is not the usual failure cause on a bike. With improvements in bearing surfaces finishes, ball and race materials, preload control and sealing modern cartridge bearings do address/improve the usual paths to failure. Plus they allow a manufacturer to outsource bearings parts more readily. Plus when used in a freehub body and when the ratchet is not within the freehub body (but at the shell FHB interface) the manufacturing of that hub is less involved in general. In many cases the axle diameter can also be increased (and thus countering the axle bending nature of bearing offsets from the centerline that threaded axle freewheelled hubs suffer with).

The consumer is always looking for the next better thing. Claims of "sealed bearings" (we could debate what is a "seal"), less maintenance, precision manufacturing, smoother rolling (see preload control) are easy hooks to buy into. What's not generally advertised is the real engineering and changed maintenance the cartridge bearings bring to the table. I've serviced cartridge bearing components since the late 1970s and can say that they are no different in how they follow the laws of physics. They just have "qualities" that are different and can be taken advantage of but still suffer from all the same in use issues that cup and cone designs do. Andy

davidad

The 6000 series bearings re more than adequate for our uses. They are designed for high-speed electric motors. A friend who has older Trek wheels with Taiwanese hubs that use 6000 series bearings have held up and I don't think we had to replace them. I guessing that they have over 20k miles on them.

magicpie55

Thank you Very Much .. I read this ten times and learned a Lot ..
You Said something about "Application" It's a Electra Townie I converted to an ebike with a front hub motor ..I am handicapped and can only stand/walk 15-20 minutes without stopping .. I can however sit and ride for hours and ride at least 40 minutes each day .. Set the "cruise control" for 7-8 mph and petal up to 9-10 mph .. Also heavy 220 but loosing from the bike rides ...40 pounds this year ..
I upgraded to wider ebike tires after the 2nd pinch flat and now the 2.20 tire seems big for the 19mm wide rim ..Looking at the Velocity Cliffhanger Rim and trying to decide between the Deore ball and cone Hub or Velocity's sealed bearing hub ..uses 4 bearings 2 in the hub 2 in the freehub ..
Which would you Choose ??Or maybe I'm totally off Base here ? Thanks for the Help ...

Andrew R Stewart 

I have friends and had customers with both hubs and I can't say one was vastly better than the other. The Velocity hubs with two riders (out of maybe a half dozen total) seemed to wear their bearings at a faster rate than I thought was usual and the bearings for one were less common in the bike world suppliers. But they are easy to remove and replace so for me no big deal (and the hubs that wore through bearings might be a tolerance issue that increased their preload?) Shimano Deore hubs are pretty much the standard for many touring bikes and work well even if they are heavy (can't believe I said that) and spark little sizzle in most riders. Perhaps that aspect, they are a very common and have minimal negatives show them to be the better choice. Andy (who can debate either way)