Bad Hub? [wheel building question]



L

L.Jamieson

Guest
Howdy,
I'm building a new set of Rhino Lites(27mm) and XT hubs (FH-M752 rear &
HB-M751 front) and I'm having problems getting the rear trued-up
properly. I've tried both rims on the front hub w/ no problems, but on
the rear hub it's impossible to get either rim true without having tight
and loose spokes. I'm guessing that it has to be a bad rear hub.

Any advice would be great,
Thanks

BTW: I'm careful about not mixing up the different length spokes on the
rear.
 
"L.Jamieson" <[email protected]> wrote in message
news:[email protected]...
> Howdy,
> I'm building a new set of Rhino Lites(27mm) and XT hubs (FH-M752 rear &
> HB-M751 front) and I'm having problems getting the rear trued-up
> properly. I've tried both rims on the front hub w/ no problems, but on
> the rear hub it's impossible to get either rim true without having tight
> and loose spokes. I'm guessing that it has to be a bad rear hub.


Virtually impossible that you have a bad hub. I've laced 4 Rhyno
Lite/Deore hub wheels and I haven't had problems.

It's possible that you probably screwed down all the nipples at first, and
thus the later nipples you screwed down gained high tension within a few
turns. This will put the wheel both radially and laterally out of true.
Try unscrewing all the nipples, and then screwing them in 5 or 6 turns on
each nipple, no matter if the wheel seems to get more tension on it (this is
because the spokes are pulling against each other as you screw them in). Go
around and tighten the spokes all around, not paying attention to how tight
they feel. Once they begin to acquire final tension, worry about truing it
at that point. It should be relatively close and shoudl only need a couple
turns on a few points on the wheel.

It takes a few wheelbuild attempts to get good at it.

--
Phil, Squid-in-Training
 
"L.Jamieson" <[email protected]> wrote in message
news:[email protected]...
> Howdy,
> I'm building a new set of Rhino Lites(27mm) and XT hubs (FH-M752 rear &
> HB-M751 front) and I'm having problems getting the rear trued-up
> properly. I've tried both rims on the front hub w/ no problems, but on
> the rear hub it's impossible to get either rim true without having tight
> and loose spokes. I'm guessing that it has to be a bad rear hub.
>
> Any advice would be great,
> Thanks
>
> BTW: I'm careful about not mixing up the different length spokes on the
> rear.
>


Wheels with dish are a bit more tricky to bring up to tension. I start
where each nipple is showing 1-2 spoke threads. Then go around giving each
a half turn until there is a little tension on all of them. I then bring
the drive side spokes up to about 80% of the tension I want then tighten the
non-drive side to bring the rim over to center. This action usually brings
the drive side close to 100% tension.

Mike
 
L.Jamieson wrote:
> Howdy,
> I'm building a new set of Rhino Lites(27mm) and XT hubs (FH-M752 rear &
> HB-M751 front) and I'm having problems getting the rear trued-up
> properly. I've tried both rims on the front hub w/ no problems, but on
> the rear hub it's impossible to get either rim true without having tight
> and loose spokes. I'm guessing that it has to be a bad rear hub.
>
> Any advice would be great,
> Thanks
>
> BTW: I'm careful about not mixing up the different length spokes on the
> rear.
>

The only way the hub would be bad is if spoke holes are cracking and
deforming. You would've noticed this. :)
If Phil's suggestions didn't do it for you, you may have a lacing
problem I encountered early in my wheel building career (such as it is).
If you poke a spoke through a hole on one side of the hub toward the
holes on the other you'll see that, if the spoke is parallel to the
axle, it will touch the opposite flange between two holes, rather than
going straight through. In other words, the holes are offset between
the two flanges.
OK, hope that made sense.
Now, if you lace the wheel correctly, the spoke pattern on the drive
side will be offset at the rim by one spoke hole clockwise (for example)
compared to the static (non-drive) spokes. If you look at the hub, the
drive spokes are offset clockwise from the static spokes as well.
If the same spokes that are offset clockwise at the rim are offset
*counterclockwise* at the hub(which is what I did), things will be
really AFU. Its hard to do, but I managed.
To see how to do it right:
http://www.sheldonbrown.com/wheelbuild.html#lacing
for good diagrams
Another problem is if you lace to a spoke hole in the rim that's offset
to the "wrong" side.
Hope this helps.

Shawn
 
"L.Jamieson" <[email protected]> wrote in message
news:[email protected]...
> Howdy,
> I'm building a new set of Rhino Lites(27mm) and XT hubs (FH-M752 rear &
> HB-M751 front) and I'm having problems getting the rear trued-up
> properly. I've tried both rims on the front hub w/ no problems, but on
> the rear hub it's impossible to get either rim true without having tight
> and loose spokes. I'm guessing that it has to be a bad rear hub.
>
> Any advice would be great,
> Thanks
>
> BTW: I'm careful about not mixing up the different length spokes on the
> rear.



Lateral? Vertical? How close are you trying to get it?


http://www.sheldonbrown.com/wheelbuild.html#initial

--
DTW .../\.../\.../\...

I've spent most of my money on mountain biking and windsurfing.
The rest I've just wasted.
 
"ZeeExSixAre" <[email protected]> wrote in message
news:[email protected]...
> "L.Jamieson" <[email protected]> wrote in message
> news:[email protected]...
> > Howdy,
> > I'm building a new set of Rhino Lites(27mm) and XT hubs (FH-M752 rear &
> > HB-M751 front) and I'm having problems getting the rear trued-up
> > properly. I've tried both rims on the front hub w/ no problems, but on
> > the rear hub it's impossible to get either rim true without having tight
> > and loose spokes. I'm guessing that it has to be a bad rear hub.

>
> Virtually impossible that you have a bad hub. I've laced 4 Rhyno
> Lite/Deore hub wheels and I haven't had problems.
>
> It's possible that you probably screwed down all the nipples at first, and
> thus the later nipples you screwed down gained high tension within a few
> turns. This will put the wheel both radially and laterally out of true.
> Try unscrewing all the nipples, and then screwing them in 5 or 6 turns on
> each nipple, no matter if the wheel seems to get more tension on it (this

is
> because the spokes are pulling against each other as you screw them in).

Go
> around and tighten the spokes all around, not paying attention to how

tight
> they feel. Once they begin to acquire final tension, worry about truing

it
> at that point. It should be relatively close and shoudl only need a

couple
> turns on a few points on the wheel.
>
> It takes a few wheelbuild attempts to get good at it.


Sounds to me like he's done this before Phil.


Shaun aRe