Another wheel day (you know the rest).
I built a front wheel with the WTB semi-fat rim, the Scraper i40 rim.
I had planned to build both front and rear wheels today, but things got too busy.
The hub is an HB-M8010-B, built as a full-competition 32-hole 64 JIS lacing pattern.
There's a reason it's not reverse-Italian lacing, but I won't write about that.
The "i40" in the rim's model number
refers to the rim's internal width (not external width) being 40mm.
There's also an i45 rim as a separate offering.
The wheel sizes come in 26-inch, 27.5-inch, and 29-inch,
but this one is 27.5-inch.
Although it's a double-wall rim, it's extremely thin, so
if the rim tape compresses significantly under pressure,
there's a non-zero chance of contact with the end face of the nipple.
So I added a correction factor to the spoke length calculation to make them slightly shorter,
but there were still spots where the length was cutting it close.
I'm applying Stans tubeless rim tape,
using the widest option in their lineup at 39mm.
Stans rim tape comes in lengths of 10 yards and 60 yards with widths of 21, 25, 27, 30, 33, 36, and 39mm.
If the widths were arranged as 21, 24, 27... in clean 3mm increments,
but for some reason they aren't.
There's no useful 23mm width for road tubeless, which is a bit inconvenient.
As the width increases, the price goes up slightly, but
if there were a 42mm option after the 39mm
and its price were less than double that of the 21mm,
I'd think about making a tool to cleanly split rim tape in half—
then you could get two double-length sections of 21mm from a 42mm roll.
I've applied the rim tape.
Once I mount the tire and pressurize it, the tape will conform to the rim's shape,
but we don't currently have a tire in stock that fits this rim.
I've wrapped the rim tape just over two complete wraps (three wraps around the valve hole area only), but
the 10-yard (9.14m) package states it's enough for five applications on a 26-inch rim or four on a 29-inch,
so calculating from that, one application means one complete wrap,
and checking Stans' official website confirms
that one wrap should be sufficient.
However, Stans tape doesn't stick particularly well to the rim itself,
but adheres well to overlapped tape, so
I often do two wraps.
Especially on this rim, where the surface finish is rough like sandblasting,
the tape adhesion is poor, so I went with two wraps.
Two wraps might not be ideal
on rims with low vertical clearance inside the bead hook.
This rim does appear to have that low vertical clearance,
but the inner rim edge forms a square groove,
so I judged that two wraps would work fine.
I built a front wheel with the WTB semi-fat rim, the Scraper i40 rim.
I had planned to build both front and rear wheels today, but things got too busy.
The hub is an HB-M8010-B, built as a full-competition 32-hole 64 JIS lacing pattern.
There's a reason it's not reverse-Italian lacing, but I won't write about that.
The "i40" in the rim's model number
refers to the rim's internal width (not external width) being 40mm.
There's also an i45 rim as a separate offering.
The wheel sizes come in 26-inch, 27.5-inch, and 29-inch,
but this one is 27.5-inch.
Although it's a double-wall rim, it's extremely thin, so
if the rim tape compresses significantly under pressure,
there's a non-zero chance of contact with the end face of the nipple.
So I added a correction factor to the spoke length calculation to make them slightly shorter,
but there were still spots where the length was cutting it close.
I'm applying Stans tubeless rim tape,
using the widest option in their lineup at 39mm.
Stans rim tape comes in lengths of 10 yards and 60 yards with widths of 21, 25, 27, 30, 33, 36, and 39mm.
If the widths were arranged as 21, 24, 27... in clean 3mm increments,
but for some reason they aren't.
There's no useful 23mm width for road tubeless, which is a bit inconvenient.
As the width increases, the price goes up slightly, but
if there were a 42mm option after the 39mm
and its price were less than double that of the 21mm,
I'd think about making a tool to cleanly split rim tape in half—
then you could get two double-length sections of 21mm from a 42mm roll.
I've applied the rim tape.
Once I mount the tire and pressurize it, the tape will conform to the rim's shape,
but we don't currently have a tire in stock that fits this rim.
I've wrapped the rim tape just over two complete wraps (three wraps around the valve hole area only), but
the 10-yard (9.14m) package states it's enough for five applications on a 26-inch rim or four on a 29-inch,
so calculating from that, one application means one complete wrap,
and checking Stans' official website confirms
that one wrap should be sufficient.
However, Stans tape doesn't stick particularly well to the rim itself,
but adheres well to overlapped tape, so
I often do two wraps.
Especially on this rim, where the surface finish is rough like sandblasting,
the tape adhesion is poor, so I went with two wraps.
Two wraps might not be ideal
on rims with low vertical clearance inside the bead hook.
This rim does appear to have that low vertical clearance,
but the inner rim edge forms a square groove,
so I judged that two wraps would work fine.