Ritchey OCR Wheels

"Greg Sackett" <[email protected]> wrote in message
news:[email protected]...
> I recently purchased a Jamis Aurora for my wife. While replacing a few components, namely the
> brakes, I noticed that the rear wheel didn't appear centered. So I checked it with both my truing
> stand as well as my dishing tool, and sure enough, it is several mm (like 5 or so) off center (rim
> closer to drive side).
>
> This wheel is a Ritchey OCR Comp 700 coupled with a Ritchey ZER System hub (8/9 speed). Because
> this is an off center rim and hub, was the wheel built incorrectly? To fix the problem do I need
> to completely rebuild the wheel with shorter spokes on the non-drive side?
>
> Suggestions?
>
> Greg

Greg,

The OCR aspect of the rim has nothing to do with correct centering. OCR is a design that allows the
drive spokes to have a greater spoke support angle and therefore making the side to side spoke
tension closer to even. If the correct spoke lengths were selected for the build you should be able
to re-dish the wheel to make it properly centered without changing any spokes. You will be able to
tell if you look at the spoke thread engagement at the back end of the nipples. When you are done
re-centering, don't forget to stress relieve the spokes again. I don't want to insult your
intelligence, but make sure you are using the dishing tool correctly, with the gauge resting on the
locknut and the ends resting on the rim. I have seen cases of the gauge resting on the axle end and
others where one end was touching a spoke. David Ornee, Western Springs, IL

Greg Sackett at [email protected] wrote on 3/4/03 6:32 AM:

> I recently purchased a Jamis Aurora for my wife. While replacing a few components, namely the
> brakes, I noticed that the rear wheel didn't appear centered. So I checked it with both my truing
> stand as well as my dishing tool, and sure enough, it is several mm (like 5 or so) off center (rim
> closer to drive side).
>
> This wheel is a Ritchey OCR Comp 700 coupled with a Ritchey ZER System hub (8/9 speed). Because
> this is an off center rim and hub, was the wheel built incorrectly? To fix the problem do I need
> to completely rebuild the wheel with shorter spokes on the non-drive side?

The OCR wheel I have uses the same size spokes for drive and n/d sides. Tension is virtually
identical on both sides. The hub needs to have the correct orientation with respect to the OC rim.
Wheel should be centered.

hope that helps,

-- Jim

"Greg Sackett" <[email protected]> wrote in message
news:[email protected]...
> I recently purchased a Jamis Aurora for my wife. While replacing a few components, namely the
> brakes, I noticed that the rear wheel didn't appear centered. So I checked it with both my truing
> stand as well as my dishing tool, and sure enough, it is several mm (like 5 or so) off center (rim
> closer to drive side).
>
> This wheel is a Ritchey OCR Comp 700 coupled with a Ritchey ZER System hub (8/9 speed). Because
> this is an off center rim and hub, was the wheel built incorrectly? To fix the problem do I need
> to completely rebuild the wheel with shorter spokes on the non-drive side?
>
> Suggestions?
>
> Greg

Unfortunately, it's not that unusual for a bike to have the wheel dish off out of the box. As others
have said, make sure you're using the dishing tool properly, with the center gauge/bolt on the
locknut, not the axle end, and the ends resting on the outer edges of the rim. Let the dishing tool
be your benchmark, as it doubles the error and gives you the most accuracy. Whatever the gap is with
the tool, the actual offset is half that much. To fix it, just back off all the spokes a bit on the
side the rim's offset towards and tighten the other side by the same amount. Once it's close, you
can do only one side's spokes to get the rim centered.

Probably a good thing, actually, as OEM Ritchey wheels are known for inadequate build quality. A bit
of attention would likely benefit both wheels and pay dividends in wheel life.

SB SB

Steve Blankenship wrote:

> Let the dishing tool be your benchmark, as it doubles the error and gives you the most accuracy.
> Whatever the gap is with the tool, the actual offset is half that much.

I've always thought of it as 4 times. Twice as you have described and another twice because your
measuring the difference between the locknut to rim distances.

So if you have a feel for how much a 1/4 turn moves a rim when your trueing, it will remove an out
of dish measurment of 4 times that.

--
Andy Morris

AndyAtJinkasDotFreeserve.Co.UK

Love this: Put an end to Outlook Express's messy quotes
http://home.in.tum.de/~jain/software/oe-quotefix/

"Greg Sackett" <[email protected]> wrote in message
news:[email protected]...
> I recently purchased a Jamis Aurora for my wife. While replacing a few components, namely the
> brakes, I noticed that the rear wheel didn't appear centered. So I checked it with both my truing
> stand as well as my dishing tool, and sure enough, it is several mm (like 5 or so) off center (rim
> closer to drive side).
>
> This wheel is a Ritchey OCR Comp 700 coupled with a Ritchey ZER System hub (8/9 speed). Because
> this is an off center rim and hub, was the wheel built incorrectly? To fix the problem do I need
> to completely rebuild the wheel with shorter spokes on the non-drive side?

Disregard any marketing-speak and just center the rim over the locknuts as with all bicycle wheels.

When you drop the wheel into the bicycle or a truing stand and note the place the rim falls,
flipping the wheel over should exactly duplicate the rim's position. ( a wheel cenetring, aka
"dishing", tool shows this more conveniently).

The claimed advantage of modern asymmteric rims is spoke tension that's less differentiated from
left to right. That effect is not significant to spoke length. Overall this design is a good thing.
Ritchey's is a good design. But no improvement to rim design covers for sloppy building, as you
discovered.

You should evaluate the wheel's overall tension and either slack one side or, more likley, tighten
one side, such that the rim is centered over the locknuts. If the nipples "klink" when you turn
them, detension the wheel completely and lubricate the nipples. This will actually save time and
frustration. As you bring it back to tension, centered, ensure it is round and in one plane, stress
relieve the spokes and you're done!
--
Andrew Muzi http://www.yellowjersey.org Open every day since 1 April 1971

greg-<< So I checked it with both my truing stand as well as my dishing tool, and sure enough, it is
several mm (like 5 or so) off center (rim closer to drive side). << Because this is an off center
rim and hub, was the wheel built incorrectly

<< To fix the problem do I need to completely rebuild the wheel with shorter spokes on the
non-drive side?

N-loosen the tension, dish, round, true on the way to proper tension and stress relieve as
well..Many of these wheels are built poorly, along with just about every wheel I see that comes
outta a box, or on a new bike.

But giving these, as well as many wheels, some attention when new, can make for a good,
reliable wheelset.

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

Andy-<< Disregard any marketing-speak and just center the rim over the locknuts as with all
bicycle wheels.

Ya suppose the offset rear rim was built backwards?

Spoke holes should appear on the left side of the rim, with the cogset on the right, when looking at
the wheel.

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

> Andy-<< Disregard any marketing-speak and just center the rim over the locknuts as with all
> bicycle wheels.

"Qui si parla Campagnolo" <[email protected]> wrote in message
news:[email protected]...
> Ya suppose the offset rear rim was built backwards? Spoke holes should appear on the left side of
> the rim, with the cogset on
the
> right, when looking at the wheel.

Maybe a picture would be helpful. http://www.yellowjersey.org/velrim.html (The one at the top) There
should be more rim to the right of the spokes than to the left of them.

--
Andrew Muzi http://www.yellowjersey.org Open every day since 1 April 1971

> Ya suppose the offset rear rim was built backwards?

Pete,

That was the first thing I thought of, but the orientation was fine. I took your advice and
tightened all the spokes (3 or 4 times more on the non-drive side) and it centered up without
any problems.

I appreciate everyone's advice on the topic.

Many thanks!

Greg