Another day with wheels (and so on).
Continuing from yesterday. I'm rebuilding the rear wheel of the Stans Arch rim with
a BOOST hub.
The original configuration was FH-M8010 32H
with half-comp 4-cross JIS lacing.
The BOOST hub I'm using for the rebuild is
the REVO MTB hub, same as the front wheel.
Unlike the Evo disc hub, it doesn't have reverse high-low flanges
but rather flanges of equal diameter on both sides.
Like the front wheel, the comp spokes on the non-laced side—
the freewheel side—I'll cut and reuse.
I removed the spokes from the XT hub,
cut them, and transferred them to the REVO MTB hub.
This is what you see in the image above.
When I align the freewheel side flanges,
the non-freewheel side flanges differ by this much.
Since I'm comparing a non-BOOST hub with a BOOST hub,
it's obvious in a sense, but
I was worried it might be like "the REVO MTB is wider, but
the flange thickness only differs by one layer" or something.
If you're just converting to BOOST, you could just use
the same XT BOOST hub with "–B" added to the end of the part number,
and since the rotor mount standard is centerlock in both before and after,
it wouldn't change, so people might say that.
But while converting to BOOST, the customer also wanted
to switch to a SRAM XD freebody, so I chose this hub.
The manufacturer of this hub—the mighty Shimano—
initially wasn't licensed to produce
microspline freebody,
(which was a terrible move, and as a result,
accelerated the switch to SRAM among racers)
so the REVO MTB rear hub comes in two versions:
one with Shimano HG 11-speed freebody and
one with SRAM XD 12-speed freebody.
When I say "Shimano 11-speed" here, I don't mean
the "11-speed freebody with the same width as 10-speed freebody"
that applies only to 11–34T on both MTB and road,
but rather the same freebody as road REVO hubs and such,
so it's an "11-speed freebody that can accept road 11-speed sprockets."
As for the SRAM version, the distributor's site says
"SRAM XD 12-speed," but when I looked at the actual product, it was XDR.
If using it with XD, you need to install a 1.85mm spacer,
but it doesn't come with the rear hub.
The spline shape at the rear of the XDR
is the same as Shimano's HG freebody, perhaps out of respect for predecessors,
so the 1.85mm spacer that exists in both Shimano genuine and third-party versions
for converting 11-speed to 8-, 9-, or 10-speed can also be used.
There are two types of freebody for the rear hub,
and they're not compatible with each other, as announced beforehand.
For example, you cannot convert a Shimano 11-speed REVO MTB hub
to XDR 12-speed later by replacing the freebody.
By the way, here's the weight of the original rear hub.
Shimano's traditional cassette sprocket freebody
is an expansion of the bearing-to-bearing distance on the hub shell
from the boss freewheel hub that was the world standard before.
So, the bearings that support the load on the hub
are only at the left end of the hub shell and the right end of the freebody
(there are very small steel balls arranged inside the freebody),
which means that if you remove the freebody from this type of rear hub,
the wheel can no longer rotate.
For example, whether you actually do it or not is another matter,
but if you were to descend a pass that you could get down without pedaling
using only steering and braking, without pedaling,
with a Fulcrum rear wheel, you could attach one with the freebody removed
to the frame and ride it.
But with a Shimano traditional freebody rear wheel, that's not possible.
And this type of freebody hub cannot,
due to its structure, make the spline portion out of aluminum.
The reason Dura-Ace and XTR hubs or wheels use titanium
is for this reason.
You might say the 7800-era Dura-Ace had an aluminum freebody!
But that rear hub alone wasn't a Shimano traditional freebody
but rather had three-paw pawl springs,
with bearings on both sides of the hub shell plus
two cartridge bearings in the freebody.
While they're not dimensionally compatible, structurally they're the same as Campagnolo.
So the WH-7800 and 7801 rear wheels
can descend downhill in the situation I described earlier
with the freebody removed.
About 7800 and 7801 (→here)(→here)(→here) please check those out too.
It's built.
REVO MTB hub, 32H, half-comp 4-cross JIS lacing.
I'll do the spoke lacing later.
I haven't disassembled it to check, but this freebody
has ratchet teeth of 72 notches per revolution, apparently.
When there are more teeth, naturally the height of each tooth is lower,
but whether related to that or not, the mechanical braking during freewheeling is minimal.
In other words, when I turn the freebody backward by hand,
the resistance is very little.
If I place the wheel on a truing stand and,
aside from the wheel's own weight, test it under no-load conditions
by spinning the rear wheel smoothly, starting measurement at the same rotational speed,
and timing until the wheel stops,
I could get a result where it spins longer
by making the hub bearing balls ceramic, for example,
but if I add the condition of "always hand-holding the freebody in a freewheel state"
to that test, the ratchet resistance would
drastically reduce the spin time.
Among these considerations, this rear hub
has such minimal mechanical braking during freewheeling that
whether or not you hand-hold the freebody could reverse
the test results compared to other comparison wheels.
You can probably feel this freebody's unusually light, smooth quality by experience.
Continuing from yesterday. I'm rebuilding the rear wheel of the Stans Arch rim with
a BOOST hub.
The original configuration was FH-M8010 32H
with half-comp 4-cross JIS lacing.
The BOOST hub I'm using for the rebuild is
the REVO MTB hub, same as the front wheel.
Unlike the Evo disc hub, it doesn't have reverse high-low flanges
but rather flanges of equal diameter on both sides.
Like the front wheel, the comp spokes on the non-laced side—
the freewheel side—I'll cut and reuse.
I removed the spokes from the XT hub,
cut them, and transferred them to the REVO MTB hub.
This is what you see in the image above.
When I align the freewheel side flanges,
the non-freewheel side flanges differ by this much.
Since I'm comparing a non-BOOST hub with a BOOST hub,
it's obvious in a sense, but
I was worried it might be like "the REVO MTB is wider, but
the flange thickness only differs by one layer" or something.
If you're just converting to BOOST, you could just use
the same XT BOOST hub with "–B" added to the end of the part number,
and since the rotor mount standard is centerlock in both before and after,
it wouldn't change, so people might say that.
But while converting to BOOST, the customer also wanted
to switch to a SRAM XD freebody, so I chose this hub.
The manufacturer of this hub—the mighty Shimano—
initially wasn't licensed to produce
microspline freebody,
accelerated the switch to SRAM among racers)
so the REVO MTB rear hub comes in two versions:
one with Shimano HG 11-speed freebody and
one with SRAM XD 12-speed freebody.
When I say "Shimano 11-speed" here, I don't mean
the "11-speed freebody with the same width as 10-speed freebody"
that applies only to 11–34T on both MTB and road,
but rather the same freebody as road REVO hubs and such,
so it's an "11-speed freebody that can accept road 11-speed sprockets."
As for the SRAM version, the distributor's site says
"SRAM XD 12-speed," but when I looked at the actual product, it was XDR.
If using it with XD, you need to install a 1.85mm spacer,
but it doesn't come with the rear hub.
The spline shape at the rear of the XDR
is the same as Shimano's HG freebody, perhaps out of respect for predecessors,
so the 1.85mm spacer that exists in both Shimano genuine and third-party versions
for converting 11-speed to 8-, 9-, or 10-speed can also be used.
There are two types of freebody for the rear hub,
and they're not compatible with each other, as announced beforehand.
For example, you cannot convert a Shimano 11-speed REVO MTB hub
to XDR 12-speed later by replacing the freebody.
By the way, here's the weight of the original rear hub.
Shimano's traditional cassette sprocket freebody
is an expansion of the bearing-to-bearing distance on the hub shell
from the boss freewheel hub that was the world standard before.
So, the bearings that support the load on the hub
are only at the left end of the hub shell and the right end of the freebody
(there are very small steel balls arranged inside the freebody),
which means that if you remove the freebody from this type of rear hub,
the wheel can no longer rotate.
For example, whether you actually do it or not is another matter,
but if you were to descend a pass that you could get down without pedaling
using only steering and braking, without pedaling,
with a Fulcrum rear wheel, you could attach one with the freebody removed
to the frame and ride it.
But with a Shimano traditional freebody rear wheel, that's not possible.
And this type of freebody hub cannot,
due to its structure, make the spline portion out of aluminum.
The reason Dura-Ace and XTR hubs or wheels use titanium
is for this reason.
You might say the 7800-era Dura-Ace had an aluminum freebody!
But that rear hub alone wasn't a Shimano traditional freebody
but rather had three-paw pawl springs,
with bearings on both sides of the hub shell plus
two cartridge bearings in the freebody.
While they're not dimensionally compatible, structurally they're the same as Campagnolo.
So the WH-7800 and 7801 rear wheels
can descend downhill in the situation I described earlier
with the freebody removed.
About 7800 and 7801 (→here)(→here)(→here) please check those out too.
It's built.
REVO MTB hub, 32H, half-comp 4-cross JIS lacing.
I'll do the spoke lacing later.
I haven't disassembled it to check, but this freebody
has ratchet teeth of 72 notches per revolution, apparently.
When there are more teeth, naturally the height of each tooth is lower,
but whether related to that or not, the mechanical braking during freewheeling is minimal.
In other words, when I turn the freebody backward by hand,
the resistance is very little.
If I place the wheel on a truing stand and,
aside from the wheel's own weight, test it under no-load conditions
by spinning the rear wheel smoothly, starting measurement at the same rotational speed,
and timing until the wheel stops,
I could get a result where it spins longer
by making the hub bearing balls ceramic, for example,
but if I add the condition of "always hand-holding the freebody in a freewheel state"
to that test, the ratchet resistance would
drastically reduce the spin time.
Among these considerations, this rear hub
has such minimal mechanical braking during freewheeling that
whether or not you hand-hold the freebody could reverse
the test results compared to other comparison wheels.
You can probably feel this freebody's unusually light, smooth quality by experience.