I am getting my head in a spin about DT Swiss freehubs. For GRX 1x12 do I need microspline or microspline road freehub? What’s the difference?
2 sets of wheels with DT Swiss 240 hubs: 1 is exp, 1 is non exp
New pivot vault with grx 1x12 Currently using a 12 speed hg cassette (from Airbike Uk) works ok but want to use proper shimano cassette for better shifting. I will use an SLX 10-45 cassette
Speaking with DT Swiss UK support they say I need microspline road freehubs with following part numbers:
EXP version - HBDT1960S
Standard Ratchet - HBDT1961S
Being the cheapo I am I hoped I could use this from Merlin:
DT Swiss Ratchet EXP Freehub For Shimano MS12
It says for 142x12 or 148x12 but am confused whether it is ms road, ms mtb or if there is a difference? (Merlin weren’t so helpful, no product code on the website and told me to contact DT Swiss).
If only we could have stuck to a single freehub standard…
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The easiest way to think about it is referencing what freehub you’re removing. If you’re removing an XDR or HG11 Road freehub (it’s called that even though it fits Shimano 12 also), you get the Microspline Road replacement. If you are replacing an XD or HG10 freehub (it’s called that or HG11 Mtn), then you use the “standard” Microspline freehub. The road freehubs that aren’t Microspline are 1.85mm longer. With that, the right end cap is longer, and the hub shell is technically about 1mm shorter. If you stuck a standard Microspline freehub and end cap on a “road” hub, the axle end to end would measure 141mm instead of 142.
There are other side effects, cross compatibility issues and workarounds, but I feel like I’ve already said too much.
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Awesome thank you. That makes sense.
I hadn’t appreciated the difference between MS and MSR. I understood XD and XDR. Cheers
I had to do a fair amount of internet digging to figure this one out, so thought I would add to this helpful thread in case anyone stumbles on it trying to understand MS vs MSR in the future. Here is a picture of what they look like for DT EXP hubs.
Key points:
- The 1 mm-ish of extra space on MSR is primarily from the flat shelf the cassette sits on (essentially a built in spacer).
- The spline sections are identical in length on both.
- The end cap is also about 1 mm longer but also sits a bit deeper in the free hub body.
- Unlike the XD vs XDR you DO NOT need a spacer behind the cassette despite what some inter-web posts say. The cogs will actually not seat properly on the splines if you do try using a spacer. The SRAM XD vs XDR spacer thing is addressing a different issue with different road vs MTB cassette widths which doesn’t exist here.
Like the OP, I did not understand the MS vs MSR differences in the beginning, and didn’t even know the MSR existed until I was trying to improve noise in the large cog for my 1 x road XTR install. For my application anyway, the MS worked, but changing to the MSR quieted things down in the larger cogs and shifting quality improved slightly likely due to a more optimal chain line. Plus not having to close the extra mm on the rear with more torque on the through axle and unknown impact to the stays being pressed in a bit tighter.
