Today it's wheels again (etc.).
I received wheels from a customer that came stock on a Cannondale Topstone gravel bike complete bike.
Today I'm just working on the front wheel though.
The rim is a WTB ST i23 model, and it's extremely heavy.
Contrary to what you'd expect, when looking for lighter tubeless rims,
currently MTB rims are actually lighter than road rims.
It's strange that rims in the 200g range don't break when used for cross-country racing,
but it seems the cushioning from the air volume created by tires that are 50C or 55C wide is a factor.
The tire size that originally comes on this wheel is 47C,
but based on the intended use, it doesn't seem like it will be ridden on terrain as harsh as an MTB,
so there's no need to make the rim especially heavy for strength.
Well, since it's a complete bike component, it makes sense that lightweight rims aren't used,
but this rim weighs around 500g, which is particularly heavy.
The "i23" in the rim model name means the rim has an internal width of 23mm,
and WTB's lightweight rims (around 410g depending on diameter and width)
have the KOM Lite series with three options: i21, i23, and i25.
The higher-end Topstone complete bikes also use the KOM Lite i23,
so this 500g rim is not "necessarily heavy due to the bike's characteristics."
In short, it's just "unnecessarily heavy."
Because it's so heavy, the customer wanted the rim replaced.
When I change the diameter to 700C and use a narrower tire,
it fits on the current frame and fork, so
I decided to rebuild it with a lightweight 700C rim.
The spokes are CN spokes, #14 plain in black,
and the nipples are black long brass nipples.
The spoke length is short, flush with the nipple slot, which is intentional.
There's a reason for this length: if I do the preliminary build with an automated wheel builder,
the minus driver bit can slip and the black coating gets scratched, revealing the brass underneath,
so the spoke length has to be such that the bit and spoke end face don't contact each other.
This particular Topstone model has a Lefty suspension fork,
so the front hub is a Lefty-compatible hub.
Since I'm disassembling it anyway, it doesn't really matter,
but with the original mounting adapter attached,
there was this much center offset. The radial runout was bad too.
This isn't unique to this wheel—hand-built disc brake wheels in mass production
seem to get sloppy with precision issues like runout and center offset
because they're not as easily detected as with rim brakes.
Also, WTB does it right, but aluminum rims with seam steps large enough to prevent rim brake use
are becoming increasingly common. ALEXRIMS and their complete wheel brand A-CLASS in particular
have been especially bad lately.
Since it's a WTB rim, there was a solid strip underneath the tubeless tape.
For details on that (→here) (→here).
The replacement rim is the Stan's Crest MK4, the successor to the Crest MK3.
This is an aluminum rim that's not quite as light as ultra-lightweight carbon rims,
but comes in under 400g, so that's about 100g of weight savings just from the rim.
Even compared to WTB's KOM Lite with similar internal width,
this one is lighter,
but the fact that the MK4 became an offset rim
is something I can't welcome.
Part of it is that the rim gets slightly heavier,
but that's not the only reason. I'll write about that when I do the rear wheel.
It's built.
28H, half-black CX Sprint 64 reverse Italian lacing.
I'll do the rim tape later.
I received wheels from a customer that came stock on a Cannondale Topstone gravel bike complete bike.
Today I'm just working on the front wheel though.
The rim is a WTB ST i23 model, and it's extremely heavy.
Contrary to what you'd expect, when looking for lighter tubeless rims,
currently MTB rims are actually lighter than road rims.
It's strange that rims in the 200g range don't break when used for cross-country racing,
but it seems the cushioning from the air volume created by tires that are 50C or 55C wide is a factor.
The tire size that originally comes on this wheel is 47C,
but based on the intended use, it doesn't seem like it will be ridden on terrain as harsh as an MTB,
so there's no need to make the rim especially heavy for strength.
Well, since it's a complete bike component, it makes sense that lightweight rims aren't used,
but this rim weighs around 500g, which is particularly heavy.
The "i23" in the rim model name means the rim has an internal width of 23mm,
and WTB's lightweight rims (around 410g depending on diameter and width)
have the KOM Lite series with three options: i21, i23, and i25.
The higher-end Topstone complete bikes also use the KOM Lite i23,
so this 500g rim is not "necessarily heavy due to the bike's characteristics."
In short, it's just "unnecessarily heavy."
Because it's so heavy, the customer wanted the rim replaced.
When I change the diameter to 700C and use a narrower tire,
it fits on the current frame and fork, so
I decided to rebuild it with a lightweight 700C rim.
The spokes are CN spokes, #14 plain in black,
and the nipples are black long brass nipples.
The spoke length is short, flush with the nipple slot, which is intentional.
There's a reason for this length: if I do the preliminary build with an automated wheel builder,
the minus driver bit can slip and the black coating gets scratched, revealing the brass underneath,
so the spoke length has to be such that the bit and spoke end face don't contact each other.
This particular Topstone model has a Lefty suspension fork,
so the front hub is a Lefty-compatible hub.
Since I'm disassembling it anyway, it doesn't really matter,
but with the original mounting adapter attached,
there was this much center offset. The radial runout was bad too.
This isn't unique to this wheel—hand-built disc brake wheels in mass production
seem to get sloppy with precision issues like runout and center offset
because they're not as easily detected as with rim brakes.
Also, WTB does it right, but aluminum rims with seam steps large enough to prevent rim brake use
are becoming increasingly common. ALEXRIMS and their complete wheel brand A-CLASS in particular
have been especially bad lately.
Since it's a WTB rim, there was a solid strip underneath the tubeless tape.
For details on that (→here) (→here).
The replacement rim is the Stan's Crest MK4, the successor to the Crest MK3.
This is an aluminum rim that's not quite as light as ultra-lightweight carbon rims,
but comes in under 400g, so that's about 100g of weight savings just from the rim.
Even compared to WTB's KOM Lite with similar internal width,
this one is lighter,
but the fact that the MK4 became an offset rim
is something I can't welcome.
Part of it is that the rim gets slightly heavier,
but that's not the only reason. I'll write about that when I do the rear wheel.
It's built.
28H, half-black CX Sprint 64 reverse Italian lacing.
I'll do the rim tape later.