[Slurry]

I have been thinking about this ever since i first popped my rear hub apart, and anyone who has taken a Pro II apart should (hopefully) be able to visualize what I'm talking apart.

So, the Pro II has 5 bearings in the rear hub. 1 on the non drive side, 1 on the drive side (of the hub shell), and then three in the freehub body. Now since the freehub body is literally just pressed into place inside the hub shell, those three bearings inside the freehub body only support the freehub body, and not the rest of the hub. So, as far as I can tell, its only the two bearings pressed into the hub shell that are supporting all of the load from the wheel (weight, impacts, etc).

I can't see how the freehub body's bearings would help support those loads, as the whole system would just bind up if the hub shell "leaned over" for support from the freehub. To me, it seems no better than an old freewheel rear hub (as far as supporting body weight and dealing with impacts), with the large portion of the axle unsupported. Though In this case, the freehub body's bearings support all the torque from the drive train.

I would also have to assume this is the same for any hub that has the freehub just press into place, opposed to the rigid interface from a bolt-in freehub body (shimano for example).

Now I know this system obviously works, as I've never had any issues and I have never heard of one, and many high end manufacturers use this style system.

So tell me what I'm missing? I feel like there's just something im not understanding here.

 

[deoreo]

In the Hope hub, all of the bearings are supported by the common axle - a very stout system.

In an old separate hub and freewheel combo, the freewheel is not connected to or supported by the hub axle, it's screwed onto the hub shell. So the hub axle lock nuts on the drive side of this system are "far away" from the hub bearing and relatively unsupported, making for a "flexy" assembly.

 

[Slurry]

In the Hope hub, all of the bearings are supported by the common axle - a very stout system.

Yes, all of the bearings are supported by the common axle. The bearings. The hub shell, which holds the spokes, which hold the rim (aka a Wheel) are only supported by the two bearings in the hub shell, afaik, as the freehub and its bearings aren't really connected to the hub shell.

In an old separate hub and freewheel combo, the freewheel is not connected to or supported by the hub axle, it's screwed onto the hub shell. So the hub axle lock nuts on the drive side of this system are "far away" from the hub bearing and relatively unsupported, making for a "flexy" assembly.

Yes, I understand this. I dont know why you typed this.

 

[AZ]

Just like your example of a Shimano hub , 2 bearings are all that are needed to support the hub itself , the axle really only needs to be supported at the ends .

 

[Slurry]

Just like your example of a Shimano hub , 2 bearings are all that are needed to support the hub itself , the axle really only needs to be supported at the ends .

Yes, i agree that two bearings are enough to support the hub, so long as those bearings are near the ends of the axle, like in Shimanos system.

The hope system does have two bearings supporting the "wheel", but those bearings are not at the ends of the axle. they are in fact quite far from the end of the axle, at least on the drive side.

 

[Slurry]

nobody has any thoughts on this?

 

[DSFA]

First, thanks for the diagram! I have one of these hubs but haven't had to mess with it yet.

Ok, as for thoughts on this...
Here's my two cents...basically axle is stout enough to take the load and some of the load is taken by the bearings in the cassette. In the old FW hubs there was air space around the "unsupported" axle so all the bending force was concentrated on the driveside bearing, hence easily bent, especially considering axle size and material used. On the Hope and hubs like it the axle going thru the cassette is supported by the bearings and the fact the axle is 15mm OD instead of hollow 10mm threaded steel.

 

[Slurry]

On the Hope and hubs like it the axle going thru the cassette is supported by the bearings

Yes, the 'axle going through the cassette is supported by the bearings', but what is supporting those bearings? Its the freehub body, which is not attached to the hub shell at all!. I think this system supports the pedaling torque really really well, as you have three bearings that fully support the entire cassette and have a stout driving interface between the freehub body and the hub shell. But, I still am convinced the hubshell itself and the wheel built around it is only supported by the two bearings pressed into it, which are no where near supporting the axle at both its ends.

and the fact the axle is 15mm OD instead of hollow 10mm threaded steel.

I think this has a lot to do with why this system works, but, remember, I acknowledged that this and other similar systems work fine. I'm just trying to figure out if my understanding of the loads on these hubs and whats supporting them is correct.

 

[deoreo]

As DSFA said, the reason the Hope axle does not bend is primarily because it is oversized.

But, when assembled, the drive side hub bearing, and inner freewheel bearing are nearly touching, separated only by a spacer.
The width of the bearings spread some of the load on the axle at the point where the axle would be most prone to bending.

Basically, try to imagine bending an oversized axle right where three cartridge bearings are stacked together...it's going to be pretty stiff

 

[DSFA]

but what is supporting those bearings? Its the freehub body, which is not attached to the hub shell at all!.

Actually the axle is supporting the bearings..which are then supporting the freehub. Not meaning to be a smartarse just trying to get looking at things the same.

I can't see how the freehub body's bearings would help support those loads, as the whole system would just bind up if the hub shell "leaned over" for support from the freehub. To me, it seems no better than an old freewheel rear hub (as far as supporting body weight and dealing with impacts), with the large portion of the axle unsupported. Though In this case, the freehub body's bearings support all the torque from the drive train.

I think since the axle is so oversized compared to the old stuff that it would take a huge hit to side load the freehub to the point of binding.

But, I still am convinced the hubshell itself and the wheel built around it is only supported by the two bearings pressed into it, which are no where near supporting the axle at both its ends.

And you are probably right with this. Again it comes down to quality and design of the axle compared to the old stuff. Think about this... the axle in the Hope is 15mm OD, one on a motorcycle is not much larger, maybe 17 or 19mm, and the bearings are usually a couple of inches or more away from the swingarm. And a moto has ALOT more torque and weight going thru it than what we have on our MTB's.

Maybe since I haven't gotten to go riding due to weather I'll pull my hub apart and scope it out.

 

[DSFA]

Since you have or had your hub apart, a key issue is where the two inner freehub bearings sit. Do they butt against the hub bearing? If they do basically the whole thing sandwiches together so all the bearings share the load.

 

[denjen]

Good topic. I just got a Pro 2 hub and was watching the rebuilt video on the Hope site, I was wondering the same thing, if the free hub is only snapped in and the end caps just push back in then what is holding everything together?

 

[meltingfeather]

Good topic. I just got a Pro 2 hub and was watching the rebuilt video on the Hope site, I was wondering the same thing, if the free hub is only snapped in and the end caps just push back in then what is holding everything together?

the quick release/bolts.
OP-
Look at the axle diameter compared to Shimano and you have your answer. Making that comparison isn't really apples-to-apples; they are two different approaches to the problem.
oh, and not to nitpick, but 'press fit' is not the correct term. a press fit is for fastening (like a steer tube to a fork crown or the ratchet to the hub shell). that's actually what got my attention, because i was interested in what you could be talking about.

 

[denjen]

the quick release/bolts.
OP-
Look at the axle diameter compared to Shimano and you have your answer. Making that comparison isn't really apples-to-apples; they are two different approaches to the problem.
oh, and not to nitpick, but 'press fit' is not the correct term. a press fit is for fastening (like a steer tube to a fork crown or the ratchet to the hub shell). that's actually what got my attention, because i was interested in what you could be talking about.

However it works it works good, I have not heard anyone complainng about stuff popping apart.

 

[Slurry]

well like i said, i agree that the system works, mostly due to the size of the axle. I guess my thinking on the wheel/bearing support is right though.

Sorry if my use of any terminology was incorrect/confusing.