A customer left me the front wheel of a general-purpose bicycle (mamachari) for repairs.
The hub is a Shimano Nexus HB-NX60,
which combines both a front roller brake and hub dynamo,
and the rim is a 27-inch stainless steel rim.
The part number on the sticker was HB-NX60-J,
so it might be a Japan domestic specification.
I didn't ask about the cause in detail, whether it was an accident or something,
but the rim is severely bent, so rewheeling is necessary.
If it were okay to lose the hub dynamo, there's always the option of buying
a stock front wheel from a general bicycle shop,
but if you buy a new front wheel with the NX60 hub separately, the cost approaches
the price of the entire bicycle, so reusing the hub and rewheeling is
the most economical way to restore it to its original condition.
So I asked a nearby shop to do the wheelbuilding,
but they declined the job, which is why it was brought to my shop.
I'm building the 36H hub with 13-14 gauge spokes (mostly 13 gauge, with only the threaded portion as 14 gauge)
in a 6x6 JIS lacing pattern.
Before rewheeling it had a stainless steel rim,
but after rewheeling it will have an aluminum rim.
In general bicycles, the stainless steel rim is positioned as
the higher-end specification in terms of price,
but weight-wise, the aluminum rim is naturally lighter.
If you have experience working at a general bicycle shop,
moving dozens of bicycles in and out daily,
you'll notice that stainless steel rim bicycles feel noticeably heavier to roll when you push them by the handlebar
compared to aluminum rim bikes.
And it's even more pronounced when actually riding.
Where stainless steel rims excel is in their resistance to buckling and
their tendency to stay true longer.
（Though in this case the rim has deflected too much to correct with truing
and an aluminum rim would have bent even more severely）
Also, something not widely known:
stainless steel rims wear brake shoes less.
The friction phenomena that occur with rubber might work differently on aluminum.
Since this wheel has a hub-side brake, there's no need to worry about that,
so I decided to rewheeling it with an aluminum rim,
prioritizing lightness in the rotating mass.
The nipple dimensions where the tool grabs
are currently almost 100% either 3.2mm or 3.4mm across flats.
DT and Sapim use 3.2mm, Japanese spokes use 3.4mm, so
general bicycle nipples are normally 3.4mm,
and 3.2mm ones are almost non-existent,
but this one was unusually 3.2mm.
Rebuilt.
For Shimano disc brake front hubs,
the specified lacing pattern in the manual is reverse Italian (→here).
Looking at the manual for the HB-NX60 hub, which is also a hub-side brake,
the illustration showed reverse Italian lacing,
so I changed from the JIS lacing of the previous build to reverse Italian lacing.
It's still a 6x6 build pattern.
I used DT Champion 14 gauge plain spokes.
For single-wall rims, it's usually better to build with
brass nipples. I can't go into details, but that's how it is.
I used an Araya LP-60 rim.
The rim weight changed from 861g to 632g before and after rewheeling.
The hub is a Shimano Nexus HB-NX60,
which combines both a front roller brake and hub dynamo,
and the rim is a 27-inch stainless steel rim.
The part number on the sticker was HB-NX60-J,
so it might be a Japan domestic specification.
I didn't ask about the cause in detail, whether it was an accident or something,
but the rim is severely bent, so rewheeling is necessary.
If it were okay to lose the hub dynamo, there's always the option of buying
a stock front wheel from a general bicycle shop,
but if you buy a new front wheel with the NX60 hub separately, the cost approaches
the price of the entire bicycle, so reusing the hub and rewheeling is
the most economical way to restore it to its original condition.
So I asked a nearby shop to do the wheelbuilding,
but they declined the job, which is why it was brought to my shop.
I'm building the 36H hub with 13-14 gauge spokes (mostly 13 gauge, with only the threaded portion as 14 gauge)
in a 6x6 JIS lacing pattern.
Before rewheeling it had a stainless steel rim,
but after rewheeling it will have an aluminum rim.
In general bicycles, the stainless steel rim is positioned as
the higher-end specification in terms of price,
but weight-wise, the aluminum rim is naturally lighter.
If you have experience working at a general bicycle shop,
moving dozens of bicycles in and out daily,
you'll notice that stainless steel rim bicycles feel noticeably heavier to roll when you push them by the handlebar
compared to aluminum rim bikes.
And it's even more pronounced when actually riding.
Where stainless steel rims excel is in their resistance to buckling and
their tendency to stay true longer.
（Though in this case the rim has deflected too much to correct with truing
and an aluminum rim would have bent even more severely）
Also, something not widely known:
stainless steel rims wear brake shoes less.
The friction phenomena that occur with rubber might work differently on aluminum.
Since this wheel has a hub-side brake, there's no need to worry about that,
so I decided to rewheeling it with an aluminum rim,
prioritizing lightness in the rotating mass.
The nipple dimensions where the tool grabs
are currently almost 100% either 3.2mm or 3.4mm across flats.
DT and Sapim use 3.2mm, Japanese spokes use 3.4mm, so
general bicycle nipples are normally 3.4mm,
and 3.2mm ones are almost non-existent,
but this one was unusually 3.2mm.
Rebuilt.
For Shimano disc brake front hubs,
the specified lacing pattern in the manual is reverse Italian (→here).
Looking at the manual for the HB-NX60 hub, which is also a hub-side brake,
the illustration showed reverse Italian lacing,
so I changed from the JIS lacing of the previous build to reverse Italian lacing.
It's still a 6x6 build pattern.
I used DT Champion 14 gauge plain spokes.
For single-wall rims, it's usually better to build with
brass nipples. I can't go into details, but that's how it is.
I used an Araya LP-60 rim.
The rim weight changed from 861g to 632g before and after rewheeling.