Minimum rim wall thickness for Alex Adventurer rims

On 26/08/2020 22:38, Frank Krygowski wrote:
On 8/26/2020 2:19 PM, AMuzi wrote:
On 8/26/2020 10:54 AM, Ralph Barone wrote:
I found myself looking at the rims (Alex Adventurer, 26�, 36h)
of my touring bike because the front brake was grabbing slightly
at the seam where the rim is pinned together. I could not see the
rim wear indicator lines, but then again, a web search was
inconclusive in telling me whether these rims had wear indicators
machined into them when they were made. Can anybody (Andrew?)
tell me what the minimum rim wall thickness is for these rims
before I should replace them? I’ve got about 10,000 km on the
front (I built a new wheel for a dynamo hub) and around 20,000
km on the rear.

Secondly, if they do need replacement, my plan was to tape the
new rim to the old one, loosen all the spokes, and move the
spokes and nipples over one at a time to the new rim, reusing the
existing hubs, spokes and nipples, since these wheels have been
completely trouble free since I got them. Is this sensible,
assuming I can actually find replacement rims?


I have no idea. You could try Alex directly maybe?

Find something dead straight such as the side of a caliper or other
precision thing. Remove tire and lay that straight face on the
rim. You'll probably gasp at how gouged out the brake track has
become.

http://www.yellowjersey.org/photosfr...st/CONCAVE.JPG

I wonder if people have measurements of how thin rim walls are at
failure. Obviously it would vary with the rim's mechanical properties
and the tire pressure, etc. But since I've never had that type of
rim failure, I have no idea how thin is safe. Any info might help.

Two I've seen get down to coke can thickness. think the rim integrity
is maintained by the bead seat and the hook. These having more material.

I suppose someone could measure the thickness from the bottom of a
rim wear indicator groove. (None of my rims have those.)

I never thought about it, but a depth guage might produce some numbers.

On 26/08/2020 23:38, Lou Holtman wrote:
On Wednesday, August 26, 2020 at 10:38:27 PM UTC+2, Frank Krygowski
wrote:
On 8/26/2020 2:19 PM, AMuzi wrote:
On 8/26/2020 10:54 AM, Ralph Barone wrote:
I found myself looking at the rims (Alex Adventurer, 26†,
36h) of my touring bike because the front brake was grabbing
slightly at the seam where the rim is pinned together. I could
not see the rim wear indicator lines, but then again, a web
search was inconclusive in telling me whether these rims had
wear indicators machined into them when they were made. Can
anybody (Andrew?) tell me what the minimum rim wall thickness
is for these rims before I should replace them? I’ve got
about 10,000 km on the front (I built a new wheel for a dynamo
hub) and around 20,000 km on the rear.

Secondly, if they do need replacement, my plan was to tape the
new rim to the old one, loosen all the spokes, and move the
spokes and nipples over one at a time to the new rim, reusing
the existing hubs, spokes and nipples, since these wheels have
been completely trouble free since I got them. Is this
sensible, assuming I can actually find replacement rims?


I have no idea. You could try Alex directly maybe?

Find something dead straight such as the side of a caliper or
other precision thing. Remove tire and lay that straight face on
the rim. You'll probably gasp at how gouged out the brake track
has become.

http://www.yellowjersey.org/photosfr...st/CONCAVE.JPG

I wonder if people have measurements of how thin rim walls are at
failure. Obviously it would vary with the rim's mechanical
properties and the tire pressure, etc. But since I've never had
that type of rim failure, I have no idea how thin is safe. Any info
might help.

I suppose someone could measure the thickness from the bottom of a
rim wear indicator groove. (None of my rims have those.)


-- - Frank Krygowski

That is almost impossible to measure without making a cross section
AKA destructive research. If I eyeball the depth of the wear
indicator I would say they are about 0.5 mm deep, tops.

Jobst suggests 0.5mm

https://yarchive.net/bike/rim_wear.html

But you still can't really measure it.

Tosspot wrote:
On 26/08/2020 23:38, Lou Holtman wrote:
On Wednesday, August 26, 2020 at 10:38:27 PM UTC+2, Frank Krygowski
wrote:
On 8/26/2020 2:19 PM, AMuzi wrote:
On 8/26/2020 10:54 AM, Ralph Barone wrote:
I found myself looking at the rims (Alex Adventurer, 26†,
36h) of my touring bike because the front brake was grabbing
slightly at the seam where the rim is pinned together. I could
not see the rim wear indicator lines, but then again, a web
search was inconclusive in telling me whether these rims had
wear indicators machined into them when they were made. Can
anybody (Andrew?) tell me what the minimum rim wall thickness
is for these rims before I should replace them? I’ve got
about 10,000 km on the front (I built a new wheel for a dynamo
hub) and around 20,000 km on the rear.

Secondly, if they do need replacement, my plan was to tape the
new rim to the old one, loosen all the spokes, and move the
spokes and nipples over one at a time to the new rim, reusing
the existing hubs, spokes and nipples, since these wheels have
been completely trouble free since I got them. Is this
sensible, assuming I can actually find replacement rims?


I have no idea. You could try Alex directly maybe?

Find something dead straight such as the side of a caliper or
other precision thing. Remove tire and lay that straight face on
the rim. You'll probably gasp at how gouged out the brake track
has become.

http://www.yellowjersey.org/photosfr...st/CONCAVE.JPG

I wonder if people have measurements of how thin rim walls are at
failure. Obviously it would vary with the rim's mechanical
properties and the tire pressure, etc. But since I've never had
that type of rim failure, I have no idea how thin is safe. Any info
might help.

I suppose someone could measure the thickness from the bottom of a
rim wear indicator groove. (None of my rims have those.)


-- - Frank Krygowski

That is almost impossible to measure without making a cross section
AKA destructive research. If I eyeball the depth of the wear
indicator I would say they are about 0.5 mm deep, tops.

Jobst suggests 0.5mm

https://yarchive.net/bike/rim_wear.html

But you still can't really measure it.


If I’m losing 0.1 mm every 10,000 km, and I can take the rims down from 1.5
mm to 0.5 mm wall thickness, that implies I can get 100,000 km out of those
rims. ****... If I don’t start braking harder, I may end up getting
replaced before my rims.

On Thursday, August 27, 2020 at 6:11:52 AM UTC+1, Tosspot wrote:
On 26/08/2020 23:38, Lou Holtman wrote:
On Wednesday, August 26, 2020 at 10:38:27 PM UTC+2, Frank Krygowski
wrote:
On 8/26/2020 2:19 PM, AMuzi wrote:
On 8/26/2020 10:54 AM, Ralph Barone wrote:
I found myself looking at the rims (Alex Adventurer, 26†,
36h) of my touring bike because the front brake was grabbing
slightly at the seam where the rim is pinned together. I could
not see the rim wear indicator lines, but then again, a web
search was inconclusive in telling me whether these rims had
wear indicators machined into them when they were made. Can
anybody (Andrew?) tell me what the minimum rim wall thickness
is for these rims before I should replace them? I’ve got
about 10,000 km on the front (I built a new wheel for a dynamo
hub) and around 20,000 km on the rear.

Secondly, if they do need replacement, my plan was to tape the
new rim to the old one, loosen all the spokes, and move the
spokes and nipples over one at a time to the new rim, reusing
the existing hubs, spokes and nipples, since these wheels have
been completely trouble free since I got them. Is this
sensible, assuming I can actually find replacement rims?


I have no idea. You could try Alex directly maybe?

Find something dead straight such as the side of a caliper or
other precision thing. Remove tire and lay that straight face on
the rim. You'll probably gasp at how gouged out the brake track
has become.

http://www.yellowjersey.org/photosfr...st/CONCAVE.JPG

I wonder if people have measurements of how thin rim walls are at
failure. Obviously it would vary with the rim's mechanical
properties and the tire pressure, etc. But since I've never had
that type of rim failure, I have no idea how thin is safe. Any info
might help.

I suppose someone could measure the thickness from the bottom of a
rim wear indicator groove. (None of my rims have those.)


-- - Frank Krygowski

That is almost impossible to measure without making a cross section
AKA destructive research. If I eyeball the depth of the wear
indicator I would say they are about 0.5 mm deep, tops.

Jobst suggests 0.5mm

https://yarchive.net/bike/rim_wear.html

But you still can't really measure it.

I miss Jobst, not least for his earned certainties. I've been over the Stelvio with dicey brakes in a Lancia 2.8 GT car and wouldn't try it on a bicycle with only a rear brake. Jobst had the cohoes of a brass monkey. -- AJ

On 8/26/2020 11:15 PM, Ralph Barone wrote:
Frank Krygowski wrote:
On 8/26/2020 10:32 PM, Ralph Barone wrote:
Frank Krygowski wrote:
On 8/26/2020 2:19 PM, AMuzi wrote:
On 8/26/2020 10:54 AM, Ralph Barone wrote:
I found myself looking at the rims (Alex Adventurer, 26”, 36h) of my
touring bike because the front brake was grabbing slightly at the seam
where the rim is pinned together. I could not see the rim wear indicator
lines, but then again, a web search was inconclusive in telling me
whether
these rims had wear indicators machined into them when they were made.
Can
anybody (Andrew?) tell me what the minimum rim wall thickness is for
these
rims before I should replace them? I’ve got about 10,000 km on the
front
(I built a new wheel for a dynamo hub) and around 20,000 km on the rear.

Secondly, if they do need replacement, my plan was to tape the new rim to
the old one, loosen all the spokes, and move the spokes and nipples over
one at a time to the new rim, reusing the existing hubs, spokes and
nipples, since these wheels have been completely trouble free since I got
them. Is this sensible, assuming I can actually find replacement rims?


I have no idea. You could try Alex directly maybe?

Find something dead straight such as the side of a caliper or other
precision thing. Remove tire and lay that straight face on the rim.
You'll probably gasp at how gouged out the brake track has become.

http://www.yellowjersey.org/photosfr...st/CONCAVE.JPG

I wonder if people have measurements of how thin rim walls are at
failure. Obviously it would vary with the rim's mechanical properties
and the tire pressure, etc. But since I've never had that type of rim
failure, I have no idea how thin is safe. Any info might help.

I suppose someone could measure the thickness from the bottom of a rim
wear indicator groove. (None of my rims have those.)



Since “The Lord helps those who help themselves�, I grabbed a vernier
caliper and some #14 copper wire (1.6 mm diameter) and proceeded to take
some measurements on my rims. I measured the thickness of the rim wall
between the bead hook and the base of the rim using the wire on both sides
to space the flat caliper jaws away from the not so flat rim inner and
outer walls.

On my old front wheel (which doesn’t have a tire or a bicycle mounted on
it), I took four measurements and got an average rim wall thickness of 1.53
mm.

I then used the end of the caliper to measure the concavity of the braking
surface. On both front rims (which each have around 10,000 km on them, I
measured something in the range of 0.1 mm, and on the back rim (which has
20,000 km on it), I saw up to 0.2 mm wear.


An old Wolber AT 18 rim that was lying around had a 1 mm rim wall
thickness, and 0.5 mm of concavity.

Given all that, I’m concluding that:

1) These rims never had wear indicators when manufactured. Some online
reviews said that they had them, but the manufacturer’s pictures never
showed them.

2) These rims are just fine and probably have at least another 20,000 km
left in them, by which time rim brakes will be so obsolete that I’ll be
forced to buy a new bike.

PS: It’s actually very difficult to measure the depth of a rim wear
indicating groove because they’re only about 0.5 mm wide, so it’s hard to
find a measuring instrument that fits into the slot. So I didn’t...

Thanks for the numbers, Ralph. It's nice to get some factual information.

Regarding the difficulty of measuring groove depth: I used to have
access to an amazing collection of machinist's measuring tools, some of
them quite uncommon. There might have been something in that cabinet
that could be used for that measurement.

But then I retired.


I always could have ground down the depth measuring portion of my vernier
caliper until it fit into the slot, but by the time I found a rim with a
wear indicator slot, I’d already convinced myself that my rims were fine,
so taking a Dremel or bench grinder to a semi-precision measuring
instrument was easy to not do.


If you want to measure depth of a small hole, perhaps a
needle in a pin vise then just measure the protrusion with a
caliper or micrometer.

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

On 8/26/2020 11:30 PM, Steve Weeks wrote:
On Wednesday, August 26, 2020 at 9:32:25 PM UTC-5, Ralph Barone wrote:
Can anybody (Andrew?) tell me what the minimum rim wall thickness is for these rims before I should replace them?


Secondly, if they do need replacement, my plan was to tape the new rim to the old one, loosen all the spokes, and move the spokes and nipples over one at a time to the new rim, reusing the existing hubs, spokes and nipples...

I tried this once, and it was very awkward. I found it much easier to just build the wheel starting from scratch. This was a 20" wheel, so maybe that was the reason I had trouble. Others have recommended this method, so I defer to their expertise. But it's not that hard to lace a wheel, and it still has to be trued, which I think is the harder part.

I've used the side-by-side method to transfer spokes. For me it was much
easier than starting fresh.

I suppose if you built wheels frequently, you'd quickly know which
spokes go which direction in which holes, but I build wheels only
occasionally. The side-by-side method saves me much head scratching.

I'm talking about full size wheels. I've built several 20" wheels, but
I've never worn out that size rim.

--
- Frank Krygowski

On Wednesday, August 26, 2020 at 10:05:14 PM UTC-7, Tosspot wrote:
On 26/08/2020 22:38, Frank Krygowski wrote:
On 8/26/2020 2:19 PM, AMuzi wrote:
On 8/26/2020 10:54 AM, Ralph Barone wrote:
I found myself looking at the rims (Alex Adventurer, 26†, 36h)
of my touring bike because the front brake was grabbing slightly
at the seam where the rim is pinned together. I could not see the
rim wear indicator lines, but then again, a web search was
inconclusive in telling me whether these rims had wear indicators
machined into them when they were made. Can anybody (Andrew?)
tell me what the minimum rim wall thickness is for these rims
before I should replace them? I’ve got about 10,000 km on the
front (I built a new wheel for a dynamo hub) and around 20,000
km on the rear.

Secondly, if they do need replacement, my plan was to tape the
new rim to the old one, loosen all the spokes, and move the
spokes and nipples over one at a time to the new rim, reusing the
existing hubs, spokes and nipples, since these wheels have been
completely trouble free since I got them. Is this sensible,
assuming I can actually find replacement rims?


I have no idea. You could try Alex directly maybe?

Find something dead straight such as the side of a caliper or other
precision thing. Remove tire and lay that straight face on the
rim. You'll probably gasp at how gouged out the brake track has
become.

http://www.yellowjersey.org/photosfr...st/CONCAVE.JPG

I wonder if people have measurements of how thin rim walls are at
failure. Obviously it would vary with the rim's mechanical properties
and the tire pressure, etc. But since I've never had that type of
rim failure, I have no idea how thin is safe. Any info might help.

Two I've seen get down to coke can thickness. think the rim integrity
is maintained by the bead seat and the hook. These having more material.

I suppose someone could measure the thickness from the bottom of a
rim wear indicator groove. (None of my rims have those.)

I never thought about it, but a depth guage might produce some numbers.

Since the rim-wear indicator is go/no-go, measuring the depth remaining is probably not necessary unless you're really fussy about timing replacements..

This is why I like disc brakes, particularly when the rims are super-expensive. I'd rather sacrifice a rotor than a $400 rim on a Shimano C40 or something like that.

-- Jay Beattie.

jbeattie wrote:
On Wednesday, August 26, 2020 at 10:05:14 PM UTC-7, Tosspot wrote:
On 26/08/2020 22:38, Frank Krygowski wrote:
On 8/26/2020 2:19 PM, AMuzi wrote:
On 8/26/2020 10:54 AM, Ralph Barone wrote:
I found myself looking at the rims (Alex Adventurer, 26†, 36h)
of my touring bike because the front brake was grabbing slightly
at the seam where the rim is pinned together. I could not see the
rim wear indicator lines, but then again, a web search was
inconclusive in telling me whether these rims had wear indicators
machined into them when they were made. Can anybody (Andrew?)
tell me what the minimum rim wall thickness is for these rims
before I should replace them? I’ve got about 10,000 km on the
front (I built a new wheel for a dynamo hub) and around 20,000
km on the rear.

Secondly, if they do need replacement, my plan was to tape the
new rim to the old one, loosen all the spokes, and move the
spokes and nipples over one at a time to the new rim, reusing the
existing hubs, spokes and nipples, since these wheels have been
completely trouble free since I got them. Is this sensible,
assuming I can actually find replacement rims?


I have no idea. You could try Alex directly maybe?

Find something dead straight such as the side of a caliper or other
precision thing. Remove tire and lay that straight face on the
rim. You'll probably gasp at how gouged out the brake track has
become.

http://www.yellowjersey.org/photosfr...st/CONCAVE.JPG

I wonder if people have measurements of how thin rim walls are at
failure. Obviously it would vary with the rim's mechanical properties
and the tire pressure, etc. But since I've never had that type of
rim failure, I have no idea how thin is safe. Any info might help.

Two I've seen get down to coke can thickness. think the rim integrity
is maintained by the bead seat and the hook. These having more material.

I suppose someone could measure the thickness from the bottom of a
rim wear indicator groove. (None of my rims have those.)

I never thought about it, but a depth guage might produce some numbers.

Since the rim-wear indicator is go/no-go, measuring the depth remaining
is probably not necessary unless you're really fussy about timing replacements.

This is why I like disc brakes, particularly when the rims are
super-expensive. I'd rather sacrifice a rotor than a $400 rim on a
Shimano C40 or something like that.

-- Jay Beattie.


Certainly if you don’t have rim brakes, it’s hard to wear out your rims.
However, as a counterpoint, it appears that with my riding style and annual
mileage, my current rims should last between 25 and 50 years, so it’s not a
universal truth. I’d consider switching to disks to make the damn bike stop
better (currently Tektro Oryx cantis, but my fenders won’t let me drop the
straddle wire any further), but that’s another discussion.

On Thursday, August 27, 2020 at 9:06:00 AM UTC-7, Ralph Barone wrote:
jbeattie wrote:
On Wednesday, August 26, 2020 at 10:05:14 PM UTC-7, Tosspot wrote:
On 26/08/2020 22:38, Frank Krygowski wrote:
On 8/26/2020 2:19 PM, AMuzi wrote:
On 8/26/2020 10:54 AM, Ralph Barone wrote:
I found myself looking at the rims (Alex Adventurer, 26†, 36h)
of my touring bike because the front brake was grabbing slightly
at the seam where the rim is pinned together. I could not see the
rim wear indicator lines, but then again, a web search was
inconclusive in telling me whether these rims had wear indicators
machined into them when they were made. Can anybody (Andrew?)
tell me what the minimum rim wall thickness is for these rims
before I should replace them? I’ve got about 10,000 km on the
front (I built a new wheel for a dynamo hub) and around 20,000
km on the rear.

Secondly, if they do need replacement, my plan was to tape the
new rim to the old one, loosen all the spokes, and move the
spokes and nipples over one at a time to the new rim, reusing the
existing hubs, spokes and nipples, since these wheels have been
completely trouble free since I got them. Is this sensible,
assuming I can actually find replacement rims?


I have no idea. You could try Alex directly maybe?

Find something dead straight such as the side of a caliper or other
precision thing. Remove tire and lay that straight face on the
rim. You'll probably gasp at how gouged out the brake track has
become.

http://www.yellowjersey.org/photosfr...st/CONCAVE.JPG

I wonder if people have measurements of how thin rim walls are at
failure. Obviously it would vary with the rim's mechanical properties
and the tire pressure, etc. But since I've never had that type of
rim failure, I have no idea how thin is safe. Any info might help.

Two I've seen get down to coke can thickness. think the rim integrity
is maintained by the bead seat and the hook. These having more material.

I suppose someone could measure the thickness from the bottom of a
rim wear indicator groove. (None of my rims have those.)

I never thought about it, but a depth guage might produce some numbers..

Since the rim-wear indicator is go/no-go, measuring the depth remaining
is probably not necessary unless you're really fussy about timing replacements.

This is why I like disc brakes, particularly when the rims are
super-expensive. I'd rather sacrifice a rotor than a $400 rim on a
Shimano C40 or something like that.

-- Jay Beattie.

Certainly if you don’t have rim brakes, it’s hard to wear out your rims.
However, as a counterpoint, it appears that with my riding style and annual
mileage, my current rims should last between 25 and 50 years, so it’s not a
universal truth. I’d consider switching to disks to make the damn bike stop
better (currently Tektro Oryx cantis, but my fenders won’t let me drop the
straddle wire any further), but that’s another discussion.
Disks feel a hell of a lot more positive than rim brakes do. But what does that actually give you?