Shimano R8000 cassette on a 10spd hub

[d_douglas]

I am searching for the thread on this but cannot find it.

My buddy is going to buy my group with an 11-32 5800 cassette. He would need to upgrade his DT350 freehub from 10spd to 11spd.

If he uses an R8000 11-34 cassette, he could use the 10spd freehub body as is, correct?

For reference it is a DT 350 10spd disc hub on an Aileron rim.

Thanks for your replies.

Darren

[hollowgram5]

As far as I understand it, you describe the situation and needs correctly.

[modernfuturist]

Yup this sounds correct and there's a few articles online describing that exact situation. One of them here: https://cyclingtips.com/2018/03/shimano-ultegra-hg-800-11-34t-cassette-review/

[d_douglas]

Bullseye - that is what I need to know. Thanks!

[zzy]

One note tho, the cassette you want is the HG800 (or the 105 HG700), both of which are technically MTB cassettes. Am using a HG800 on a 10sp 240 hub with no issues.

[d_douglas]

Ohhh, there’s a 105 level one?

[zzy]

Announced, but not available yet I think.

[stev0]

just fitted an HG800 cassette onto an old 10spd hub body earlier today! haven't finished the build, but the cassette installed like a charm! (i did sort of hold my breath until I completely tightened the locknut :D)

[loxx0050]

I think cost wise it'd be better to get the DT Swiss 11 speed freehub upgrade instead as opposed to getting an R8000 cassette. I upgraded my DT240s hub with the 11s freehub body. Requires no redish the way the hubs are setup supposedly. The DT350 uses the same one and for me got it for under $90.

[johnniecakes]

So if I understand this correctly a R800 cassette will fit on a 10 speed hub but a CS-R8000 will not? If I want a 12-25 11 speed cassette then I need to use an 11 speed freehub or have the cassette modified to use on a 10 speed freehub. Wonder why Shimano chose different cassette bodies between R800 and CS-R8000.

[Davist]

So if I understand this correctly a R800 cassette will fit on a 10 speed hub but a CS-R8000 will not? If I want a 12-25 11 speed cassette then I need to use an 11 speed freehub or have the cassette modified to use on a 10 speed freehub. Wonder why Shimano chose different cassette bodies between R800 and CS-R8000.

Yes, this is the case, from what I've read. Not sure of the reason, though.. maybe lots of pent up demand from mtb wheels ?

[old fat man]

So if I understand this correctly a R800 cassette will fit on a 10 speed hub but a CS-R8000 will not? If I want a 12-25 11 speed cassette then I need to use an 11 speed freehub or have the cassette modified to use on a 10 speed freehub. Wonder why Shimano chose different cassette bodies between R800 and CS-R8000.

Because they move the large 34 tooth closer to the center of the hub but it does not come close to the spokes whereas that same approach with a 25-30 tooth biggest ring would put the chain too close to the spokes for comfort.

[AJosiahK]

confirmed on my end too, old 10spd king hub fits a r8000 fine

Kind of a nice gesture even if unintentional to pose those previously dated 10spd hubs back into relevancy

[jemdet]

Because they move the large 34 tooth closer to the center of the hub but it does not come close to the spokes whereas that same approach with a 25-30 tooth biggest ring would put the chain too close to the spokes for comfort.

Yeah, my understanding is that the 34t cog can be slightly cantilevered over the inner edge of the FH body without spoke/chain issues.

[adampaiva]

the rear derailleur he's buying will need to work on the 34t cassette. Assuming that was considered already, sounds good to go.