Another day working on wheels (and so on).
↑The images above are of the front wheel (you can tell just by looking),
A customer left me Nomu Lab Wheel #2,
and asked me to rebuild both front and rear wheels
using disc brake hubs.
I rebuilt the rear wheel a while back (→here).
For the front wheel, I was planning to do a half CX Sprint build
and was waiting for CX Sprint rims to arrive,
but there haven't been any shipments from the distributors since February this year.
I sometimes use straight-spoke CX Sprint rims
for rebuilds like Rovāl wheels,
but those are specifications we have in stock at the shop or through our distributors.
Since I can't wait any longer for the CX Sprint, I'm building the front wheel anyway.
Even if it happened to arrive tomorrow,
I won't be rebuilding it with a half CX Sprint.
↑But honestly, I'll probably end up doing it anyway...
There's an important consideration for converting this front wheel to disc brake:
Since the original wheel was rim brake spec,
it has the standard hole count of 20H.
There are almost no options available for 20H disc brake front hubs.
Also, building a 20H disc brake front wheel with all CX-RAY spokes
is (for me) extremely risky.
On the other hand, if I build it with half-Compé or half-Champion,
and the customer's front brake happens to be an older SRAM model,
there's a possibility of spoke-to-banjo bolt interference.
So for the disc brake side of this front wheel,
I needed to choose flat spokes with greater weight ratio
than CX-RAY.
However, since it's confirmed to be a Shimano brake this time,
I decided to build it with half-Compé.
Regarding the spoke-to-SRAM brake interference issue.
The image above is a RED AXS front brake
that I took with the customer's permission for another project,
The brake hose runs straight out,
and there's enough clearance to avoid spoke interference.
The bolt heads connecting the left and right blocks
don't protrude so much that they'd interfere with spokes either.
For actual examples of interference with older SRAM brakes (→here).
The front wheel at that link was rebuilt with all CX-RAY,
but that works because it's 28H.
↑This is a Novatech D791 front hub.
When I search for D791, the earlier builds I can find are:
・Stans Arch 26" 32H all-black Champion
・Reynolds Assault T 20H black half CX Sprint
・Reynolds 32 (Thirty-Two) 20H half-Compé
・DT R470db 24H black Champion/Compé
And I've done the disc brake conversion of a 20H rim brake carbon rim front wheel in the past as well.
This hub's rotor mount is 6-bolt only.
To my knowledge, there are no 20H front hubs
with centerlock specification.
Edit: A customer who has visited the shop left a comment saying
there is a D791SB-CL hub (suffix CL = centerlock) with a 20H option available, and they actually own one.
Besides the D791, there's also an unnamed hub that is definitely made by Novatech,
and this one comes in 20H spec too,
but this one doesn't have high-low flanges.
There are other differences too, like no serrations on the dropout ends.
Built.
D791 hub, 20H, black half-Compé 4-4 reverse Italian lacing.
Wire tensioning is essential. I'll do that later.
I'm building the right side with 4-spoke lacing,
but when I did a trial build with 6-spoke lacing (6-4 lacing),
the inpoke trajectory overlapped with the outpoke head, so I gave up on it.
If spokes were guaranteed never to break, this would be better,
but of course there's no such guarantee.
Every time I build one, I realize this:
hand-built 20H disc brake front wheels are extremely difficult.
↑The images above are of the front wheel (you can tell just by looking),
A customer left me Nomu Lab Wheel #2,
and asked me to rebuild both front and rear wheels
using disc brake hubs.
I rebuilt the rear wheel a while back (→here).
For the front wheel, I was planning to do a half CX Sprint build
and was waiting for CX Sprint rims to arrive,
but there haven't been any shipments from the distributors since February this year.
I sometimes use straight-spoke CX Sprint rims
for rebuilds like Rovāl wheels,
but those are specifications we have in stock at the shop or through our distributors.
Since I can't wait any longer for the CX Sprint, I'm building the front wheel anyway.
Even if it happened to arrive tomorrow,
I won't be rebuilding it with a half CX Sprint.
↑But honestly, I'll probably end up doing it anyway...
There's an important consideration for converting this front wheel to disc brake:
Since the original wheel was rim brake spec,
it has the standard hole count of 20H.
There are almost no options available for 20H disc brake front hubs.
Also, building a 20H disc brake front wheel with all CX-RAY spokes
is (for me) extremely risky.
On the other hand, if I build it with half-Compé or half-Champion,
and the customer's front brake happens to be an older SRAM model,
there's a possibility of spoke-to-banjo bolt interference.
So for the disc brake side of this front wheel,
I needed to choose flat spokes with greater weight ratio
than CX-RAY.
However, since it's confirmed to be a Shimano brake this time,
I decided to build it with half-Compé.
Regarding the spoke-to-SRAM brake interference issue.
The image above is a RED AXS front brake
that I took with the customer's permission for another project,
The brake hose runs straight out,
and there's enough clearance to avoid spoke interference.
The bolt heads connecting the left and right blocks
don't protrude so much that they'd interfere with spokes either.
For actual examples of interference with older SRAM brakes (→here).
The front wheel at that link was rebuilt with all CX-RAY,
but that works because it's 28H.
↑This is a Novatech D791 front hub.
When I search for D791, the earlier builds I can find are:
・Stans Arch 26" 32H all-black Champion
・Reynolds Assault T 20H black half CX Sprint
・Reynolds 32 (Thirty-Two) 20H half-Compé
・DT R470db 24H black Champion/Compé
And I've done the disc brake conversion of a 20H rim brake carbon rim front wheel in the past as well.
This hub's rotor mount is 6-bolt only.
To my knowledge, there are no 20H front hubs
with centerlock specification.
Edit: A customer who has visited the shop left a comment saying
there is a D791SB-CL hub (suffix CL = centerlock) with a 20H option available, and they actually own one.
Besides the D791, there's also an unnamed hub that is definitely made by Novatech,
and this one comes in 20H spec too,
but this one doesn't have high-low flanges.
There are other differences too, like no serrations on the dropout ends.
Built.
D791 hub, 20H, black half-Compé 4-4 reverse Italian lacing.
Wire tensioning is essential. I'll do that later.
I'm building the right side with 4-spoke lacing,
but when I did a trial build with 6-spoke lacing (6-4 lacing),
the inpoke trajectory overlapped with the outpoke head, so I gave up on it.
If spokes were guaranteed never to break, this would be better,
but of course there's no such guarantee.
Every time I build one, I realize this:
hand-built 20H disc brake front wheels are extremely difficult.