So you love the idea of a 12-speed Shimano drivetrain
but you don't have access to the magic Micro Spline freehub body?
Don't worry, SunRace has you covered with a couple of 12-speed options
and today we're going to look at the MZ903 cassette.
SunRace gave us a good alternative to the Shimano 11 speed
so I've been using this 11-46T for quite a while for 11-speed drivetrains,
then SunRace gave us the 11-50T cassette even before Eagle NX or SX were out
and today SunRace is giving us this 11 to 51 tooth cassette.
Yes, 11 to 51T so that kind of resembles the new Shimanos
that works with the old Shimano freehub body just like this one over here.
And that is because the only Shimano wide range 11-51T produced today
is this M5100 DEORE which as you can see here on the box it's an 11 speed not 12 speed.
For the price point, functionality and quality, the DEORE 12 speed it's been a very popular option.
However again, if all you have is this older splined Shimano freehub body
I would highly recommend looking at this SunRace cassette.
Interestingly enough, the 11 speed and 12 speed cassettes from SunRace come into the same box,
so if you see them on the shelf it's impossible to tell which ones which.
However if you look at this label over here you're going to see the details of your cassette.
In my case 12 speed 11-51T and then up top you're going to see the full product code for this MZ903.
On their website you're going to see that this cassette exists in both silver and black
and if you scroll down a bit you're going to see two similar products to this, the MZ902 and MZ901
What's the difference between the three?
Well, MZ903 has 3 aluminum cogs, MZ902 has 2, and MZ901 has one.
This is very similar to what Shimano does, this being equivalent to SLX, XT and XTR.
Aside from that there's not much information or useful information on the box
It doesn't have much inside the box aside from the cassette
there is no leaflet, there is no information about warranty or anything like that, everything is on their website.
And yes, the cassette is usually installed like this upside down.
You have the plastic tube keeping everything together,
and here is the 11 tooth cog, you can see SunRace
and also the 40 Nm that are needed when installing this lock ring.
Now if you watched my videos about the Shimano 12 speed cassettes
you know that they are built around this aluminum spider
and then they have a whole bunch of loose cogs and a couple of spacers over here.
One big huge carrier again and loose cogs followed by the lock ring as well.
Because it uses the old splined Shimano freehub body,
the smallest cog here can only be 11T so you have lock ring and 11T, and then you have the 13T,
15T, you see a spacer over there as well
I assume this is 17T and another spacer
and the last loose cog it's a 19 tooth.
That is followed by these two clusters, three cogs here on the first one followed by four cogs.
The small cluster has the 21, 24, and 28 tooth cogs.
Guess what? Those are exactly the same cogs that I have here on all the Shimano 12-speed cassettes.
And that is followed by 33, 39, 45, and 51 tooth cogs, exactly the way Shimano has them as well.
This is steel, and the remaining three cogs here are made out of aluminum this is painted aluminum.
And here on the back you can see 7075, that is the aluminum alloy that's been used for this 51 tooth as the largest cog.
From an installation standpoint, Shimano uses different thickness spacers here in between the small cogs,
and then the way the last couple of cogs are stacked in here is quite convoluted.
From that standpoint this SunRace uses the same type of spacers between the cogs,
and the installation is pretty trivial.
If you ever installed a cassette before this is going to be no different.
And with that 10 tooth, Shimano has 510 % gear range
as opposed to the SunRace that has 465 % gear range.
I mentioned weight, the SunRace comes up to 497 grams, that's about 25 grams heavier than the Shimano XT.
That is also about 100 grams lighter than this Deore 12 speed,
but this is a wider range cassette and also this has all the cogs made out of steel
so you could argue that it would last longer.
The CSMZ901, the version with 1 aluminum cog only it's about 90 grams more,
So only about 10 grams lighter than this Deore.
Now when you say Shimano 12 speed you should automatically think about Hyperglide Plus
or the ability of the chain to move up and down the cassette smoother than before.
Does this cassette provide that?
Will this cassette work with the Shimano 12 speed chain which as you know it's a bit different?
Well, keep watching, I'm gonna try and answer that during my test.
And even though this is suggested for Shimano 12-speed drivetrains
I expect it to work just fine with SRAM Eagle and with SRAM Eagle chains.
But let's test this out.
For installation, all you're going to need is a cassette tool,
leave that plastic tube inserted and if you look here at the back
you're going to see this notch in it.
Well, that notch is going to have to line up with the largest spline on the freehub body.
So line up the two, and then you're going to be able to slide the entire cassette
and the loose cogs onto the freehub body, it's that simple.
Lastly, take your 11T, cog line that up properly as well,
put a tiny bit of grease on the lock ring just like so,
and then start threading this by hand.
Finish the job with the cassette tool and a torque wrench,
again, you're going to tighten this to 40 Nm
And we're ready to give it a try!
First I'm going to try this cassette on an Eagle X01 setup.
Usually on my YETI SB100 I have a 10-50T cassette, this is 11 to 51T.
I didn't change the chain length, however I did adjust the B-gap using the X01 or the Eagle tool.
By the way, I have a video talking about the differences between these two.
So now everything is set up according to SRAM and let's give it a try.
The chainstay of the YETI is 437 mm so not super short,
and with the chain on the biggest cog, this is gonna drop the chain quite easily.
Now this cassette it's not built with the narrow wide profile teeth or anything like that,
so expected or not this is happening and it's happening quite quickly.
Let's see the shifting first from the high gears to low gears.
Now to the high gears.
So nothing to worry about, again this is on a bike stand.
If you look on their website you will notice that this cassette it's not mentioned to be for Shimano or SRAM.
The older SunRace 12 speed cassette, the MZ90 is specified to be just for Eagle setups and not Shimano.
So this can work quite well on the SRAM Eagle 12s drivetrain as well.
Remember to set up your derailleur and chain length based on the SRAM rules.
For the Shimano setup I'm going to use this Commencal, the chainstay here is 432 mm long.
And yeah for comparison, this is not going to drop the chain from that 51T.
And the same SunRace cassette and wheel in this setup,
but let's see the shifting, this is a mix of Shimano 12 speed
XT chain and derailleur, SLX shifter.
So starting on the highest gear, the 11 tooth cog
and back down the cassette
multiple at a time
There you have it!
So pretty good shifting nothing to complain about.
Obviously you heard the clunking over here, so obviously there is no Hyperglide Plus with this cassette.
However, this is a Shimano 12 speed chain so you will have no problem using these with the cassette.
If you find the Eagle 12 speed chains to be cheaper you could use those successfully on here as well.
In order to get the shifting that I just shared with you,
I had to use a little trick: if you look here on my B-gap adjustment
you're going to see that the highest tooth on the 51T is a bit below the adjustment line from Shimano.
I had to do that otherwise this cassette wouldn't have shifted cleanly in the middle of it,
so you can use that with Eagle as well,
so slightly slightly less B-gap than recommended by the manufacturer, and that seems to improve shifting.
So in conclusion a good cassette that works on the old HG freehub bodies.
It works well with both Shimano and SRAM 12 speed chains,
it has the same amount of loose cogs as with Shimano 12 speed for instance,
it's better than an Eagle NX cassette from SRAM
you can save some weight compared to that one as well,
but most importantly, if you couple that cassette with a DEORE shifter and derailleur
I would argue that you will end up with a really good setup that is bulletproof
and will be one of the best 12 speed entry level drivetrains that you can build out there.
What do you guys think?
Are you interested in this SunRace cassette in combination with any of the groupos that I mentioned?
I would love to hear your opinions in the comments below.
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and until next time hope to see you folks on the trails.
Cheers guys, cheers!