Hybrid Hub?
 

I recently purchased some old HED carbon wheels and I'm rehabbing the rear hub. I'm not sure who made the hub, but it has a config that I've not seen before. On the non-drive side, there's a cartridge bearing (12x28x8) - no problem getting that replaced. On the drive side, there's a Shimano freehub that is shot - I'm planning on replacing it with an Ultegra FH-6700. All of this got me thinking though, is it okay to have a cartridge on one side of the hub and cone/cup on the other? Once all locked down in the bike, I don't imagine that it'd be a problem, but I'm a little worried about the stress on the cartridge from the axle movement due to the play on the cone/cup when the wheel isn't locked down. Should I stick with the current setup or try to find a cartridge freehub to partner with the other cartridge?

The mixed bearing idea is fine. The "play" in a properly adjusted cup-and-cone bearing is so minimal when the wheel is out of the bike it can't possibly hurt the cartridge and should be zero when it's clamped into the dropouts. Also, when the wheel is out of the bike, there is no load on the axle and unless you pound on it with a hammer you can't do any harm.

Sun Tour did that on some of their better/best hubs for a few years. Roger

Thanks for the replies!

Get one of these and you will be able to properly adjust your hub for preload. http://secure.ultracart.com/cgi-bin/UCEditor

Radial bearings should not have a preload on them and cup and cone bearings need it.

Link doesn't work

The bearing is available at Real World Cycling. It's an Enduro 7001 2RS angular contact bearing. It is adjusted like a cup and cone bearing.

+1, this is the key.

The issue isn't cartridge vs. cup and cone bearing. It's angular vs radial contact.

Angular contact bearings are always used in pairs (the same as a traditional cup/cone system). If you mix a radial with an angular contact bearing you cannot correctly preload the angular bearing (requires tension in the axle) without pulling the radial bearing off center so the balls are running against the sides of the grooves. Doing so will greatly shorten the life of the radial bearing.

Uhhh... Are you sure an Ultegra FH body is even going to mount up to this hub?

Many machined aluminum hubs and carbon wheels from a few years back used Shimano cassette bodies threaded into an aluminum hub shell. Assuming the OP knows what he's looking at, swapping a new body should be easy.

I've encountered minor variations among Shimano cassette bodies when changing 7 to 8/9/10 speed and back, but in general the differences were between road and MTB bodies. I'll assume that the original wheel used a road cassette body, so an Ultegra will work without issue.

If HED changed to an off-brand or proprietary cassette body at some time, all bets are off.

Isn't the "preload" in properly adjusted typical Shimano cup-and-cone bearings so slight that the sideways displacement of the cartridge bearing will be insignificant?

this was the way spinergy made these things. it does not last long in my experience

The problem with mixing radial and angular bearings is Newton's 3rd law. In order to produce the preload on the angular bearing you have to have some thrust (or axial) load. This is normally balanced with a similar angular bearing at the other end. However with a radial bearing there's no way to preload the angular bearing without putting an axial load that it's not designed to handle on the radial bearing.

Simple rule, radial bearings are where there's no meaningful axial load on the axle (or shaft), and angular bearings are for when the baring pair have to take combined axial and radial loads or for when zero axial play is called for. The two don't mix well at all.

I assume (though I've never checked) that in Shimano type hubs with a cartridge bearing on the left, and a cup/cone bearing outside the freehub supporting the right side, that the left bearing is an angular contact type. If not, it will probably fail long before the right side does.

Yes, I understand the theoretical considerations but, realistically, bicycles wheels with radial cartridge bearings do in fact see axial loads every time the bike is leaned over or steered as the force is not taken strictly in line with the center of the tires and hubs. Since they seem to survive adequately, they must have some tolerance for it.

Also, AFAIK, Shimano does not make any cartridge bearing hubs or hubs with mixed bearing types. The OP is asking about a cartridge bearing HED wheel that he wanted to transplant a Shimano (cup-and-cone) freehub body to.

IMO a hybrid hub is the combination; Cassette/IGH http://www.sram.com/sram/urban/family/dd3

Opinion duly noted but that's not the topic in this thread. :p

knock out the other radial contact bearing and replace it with a second angular contact one ,


or the reverse use 2 radial contact bearings and dont go all OCD over a little rim run-out.

:lol:

Yes, deep groove radial bearings can tolerate light axial loads over the short term. I'm talking about what may be described as a locating load, as opposed to a serious thrust load. Electric motors work this way. There's a bit of axial play in the shaft, and depending on the coupling the axle may move back and forth within the limits set by the bearings. But if you don't position the motor so there's nothing steadily pushing or pulling the shaft you'll overload and prematurely wear the bearing out.

Picture a bobsled in a track on the straightaway. I can bounce gently and harmlessly on either wall, but each touch costs it some speed, and if it rubs for a long time the speed loss will be significant.

OTOH angular contact bearings MUST have an axial preload to maintain full diameter contact. Without preload, the inner race moves out to where the cup OD is larger and the cone smaller, so the bearing is no longer supported, and you get what some call axle drop.

BTW- the skf site has informative tech data on things like bearing selection. According to them, their radial bearings can handle light intermittent thrust loads. (I tried to create a link, but the tech sideof the site seems to be down)

I wonder if this entire discussion is moot and the OP's HED wheel already has an annular contact cartridge bearing on the NDS side. I suppose contacting HED would provide the answer.

Yes, it probably does. My point was that the OP had to replace it with a similar one, not a radial bearing.

Thanks for the great discussion!

Here's some of what I know and don't know:
1. The rims are HEDs, but I don't see any markings that show what the hubs are. What's the best way for me to find out?
2. I know a Shimano FH will fit on the rear wheel because that's what I took off. However, I have no idea if knowing if the Shimano FH is OEM or a substitute by previous owner.
3. I know the cartridge bearing on the side opposite the FH are 12x28x8, but I'm not sure if it's radial or angular. The only numbers on the seals are 393r & 65r, neither of which produced anything with a Google search. I ended up getting the dimensions through the use of a micrometer. The bearings appeared radials, but I'll have to take a closer look tonight to see for sure.

The radial/angular discussion really has my head spinning. I'm wondering if I find that there's a radial in there now, if I should just replace it with an angular? Again, I have no idea what the previous owner may have done...right or wrong.

So I guess this goes back to the original question, albeit somewhat different now:
1. Rebuild the hub with cup/cone and angular cartridge on the non-FH side.
2. Rebuild the hub with cup/cone and radial cartridge on the non-FH side.
3. Rebuild the hub with a FH that has a radial cartridge and put a radial cartridge on the non-FH side.

contact HED, ie, the Manufacturer..

Number 1 is safe if you find the existing non-drive side bearing is a radial cartridge.
Number 2 is what you may already have and that's what led to most of the above discussion.
Number 3 isn't practical or even possible if you use a Shimano freehub body as they are all cup-and-cone bearings.

I've got an email out to HED to hopefully ID the hubs. Here's a couple of pics I was able to get - resolution isn't great, but maybe someone can tell from them.

http://bikeforums.net/attachment.php...hmentid=357648http://bikeforums.net/attachment.php...hmentid=357649

If you pulled off a genuine Shimano freehub body with loose ball bearings (which it MUST have if it's a Shimano freehub) then you can put on a different Shimano freehub that also uses loose ball bearings.

If it worked as original equipment why wouldn't it work now?