Slight Gap in Rim Seam OK?

"Greg" <[email hidden]> wrote in message
news:[email hidden]...

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I recently purchased a New Old Stock (NOS) pair of Matrix Titan

rims.

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I have had great luck with these rims in the past, one pair

having

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lasted 16 years (so far) of normal road usage.

Upon close inspection, I found one of the NOS rims to have a

small gap

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at the rim seam where the two ends of the rim extrusion are

pinned

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together. The gap is slight (0.25 to 0.5 mm at most), but

noticable.

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The rim appears solid in all other respects (no looseness of

the rim

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joint).

I have never seen a gap like this in a standard (sleeved /

pinned) rim

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before. Is this "normal"? Will the compressive forces from

building

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the rim into a wheel close this gap? I don't want to waste the

time

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and money to build up a wheel only to find it is unusable. Any

advice

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would be appreciated.

This is not a problem and used to be SOP. The flash welding,
pinning, machining, anodizing, ceramic-ing, etc. became popular
selling points only in the last 15 or so years. We managed just
fine with out these features (and slight gaps) for decades before
that. -- Jay Beattie.

Greg said:

I recently purchased a New Old Stock (NOS) pair of Matrix Titan rims.
I have had great luck with these rims in the past, one pair having
lasted 16 years (so far) of normal road usage.

Upon close inspection, I found one of the NOS rims to have a small gap
at the rim seam where the two ends of the rim extrusion are pinned
together. The gap is slight (0.25 to 0.5 mm at most), but noticable.
The rim appears solid in all other respects (no looseness of the rim
joint).

I have never seen a gap like this in a standard (sleeved / pinned) rim
before. Is this "normal"? Will the compressive forces from building
the rim into a wheel close this gap? I don't want to waste the time
and money to build up a wheel only to find it is unusable. Any advice
would be appreciated.

Thanks,
Greg

Most pinned rims have a very small gap, but usually ~.05 mm.
Compressive forces from building won't likely cose the gap much.
The way rims are joined it takes more than the compressive forces generated by the spokes.
You could try some of the techniques for "soft rim failure" to close the gap.
I would give that a try before recycling the rim. Partially build the wheel, leaving out spokes nearest the joint. By using leverage carefully applied via the vacant spoke holes, see if you can close the gap. You might want to put some epoxy in the joint to assist holding it in place.
Some rims joining sleeves actually come loose enough that they slide back and forth with wheel rotation and forces of gravity, etc. I have stopped the movement by carefully injecting a small amount of expoxy into the joint area from inside the inner wall.

Greg L64? said:

I recently purchased a New Old Stock (NOS) pair of Matrix Titan
rims. I have had great luck with these rims in the past, one pair
having lasted 16 years (so far) of normal road usage.

Quoted message said:

Upon close inspection, I found one of the NOS rims to have a small
gap at the rim seam where the two ends of the rim extrusion are
pinned together. The gap is slight (0.25 to 0.5 mm at most), but
noticeable. The rim appears solid in all other respects (no
looseness of the rim joint).

Quoted message said:

I have never seen a gap like this in a standard (sleeved / pinned)
rim before. Is this "normal"? Will the compressive forces from
building the rim into a wheel close this gap? I don't want to waste
the time and money to build up a wheel only to find it is unusable.
Any advice would be appreciated.

Yes the gap will close never to be seen again. Of course you could
buy welded, anodized, machined rims for several times the cost if this
is something you worry about, most riders seem to think so these days.
I had rims that I could pull several mm apart before building the
wheel. They all closed and rode well into their sunset years, either
wearing out the braking surfaces or getting bent in a crash.

Jobst Brandt
[email hidden]

greg asks-"<< Upon close inspection, I found one of the NOS rims to have a
small gap
at the rim seam where the two ends of the rim extrusion are pinned
together. The gap is slight (0.25 to 0.5 mm at most), but noticable.
The rim appears solid in all other respects (no looseness of the rim
joint).

I answer-" It's not unheard of and when you build the rim, it should tighten
up. If it doesn't, that will be a problem."
I have never seen a gap like this in a standard (sleeved / pinned) rim
before. Is this "normal"? >><BR><BR>

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