Spacer for HG500 10 speed cassette on Formula RX-142 alloy Shimano 11-speed freehub,

[pfm401]

Does anyone know the definitive answer to the spacer required to fit an HG500 cassette to a Shimano 11 speed freehub (Formula RX-142), on a Trek Domane AL4?

There's only one spacer on there at the minute, it's rusted quite badly so I want to replace it, and was looking at the 1.85mm one Y4T724000. Some google searches and suppliers suggest that this is ok, others that an extra 1mm spacer is also required!!

Does anyone know the "right" answer please?

Many thanks
Paul.

 

[Ajax Bay]

You need both to fit a 10sp cassette onto an 11sp freehub (2.8mm).
Without the 1mm you risk the lockring bottoming out.

 

[ColinJ]

You need both to fit a 10sp cassette onto an 11sp freehub (2.8mm).
Without the 1mm you risk the lockring bottoming out.

Which I discovered when I borrowed my cousin's bike in Scotland! He had forgotten to put the second spacer on. The cassette was rattling every time the road surface got bumpy.

 

[pfm401]

Mmm just took the cassette off and measured the spacer, don't have calipers but looks about 2mm using a metal ruler! Are all 11 speed hubs the same??

 

[chriswoody]

Mmm just took the cassette off and measured the spacer, don't have calipers but looks about 2mm using a metal ruler! Are all 11 speed hubs the same??

In a nutshell, no.

Shimano increased the length of the splines on their freehubs a while back, so originally they were 35mm long, now they are 36,8 mm long.

There's more information here:

https://www.wheelworks.co.nz/you-ne...DjZCuDr-puE6QsKpfFd0SilMuuUOrikajXgYi6SFGcyNH

and here:

https://www.bike-components.de/blog...body-function-compatibilities-and-conversion/

So dependent on which freehub spline length you have as to which spacers you need.

 

[Ajax Bay]

"In a nutshell" yes: 2.8mm of spacer. 11sp (Shimano) road freehubs are 'all the same. 11sp cassettes differ (road/MTB essentially).
Sounds as if you have a 1.85mm spacer there. You need to pop in a 1mm.
Chris above is liable to confuse: the difference is that one of those freehubs is a 10sp and the longer one is an 11sp. As said: "So dependent on which freehub spline length you have as to which spacers you need." OP has an 11sp freehub: clue's in the thread title.
https://www.bicyclechain.co.uk/shop...x-142-11-speed-road-freehub-body-9347/option/
From the link @chriswoody shared "HG35mm is commonly known as "Shimano 10 speed"" and "11 speed Shimano road cassettes require an HG36.8mm freehub body."
A 10sp cassette needs a 1mm spacer on a 10sp freehub.

 

[chriswoody]

@Ajax Bay I'm not trying to confuse, just making the OP aware that there are two free hub standards and 11/10 speed cassettes will fit on both.

The number of spacers needed will depend on which freehub standard they have. As mentioned in the first post there is lots of confusion around this and not everything is clear.

More than likely everything is exactly like you have advised, I just wanted to make him aware that there were two different spline lengths. It sounds like the cassette is already off, so a quick measure would soon confirm which freehub he had. I hardly find that confusing matters.

 

[Ajax Bay]

[What] spacer required to fit an HG500 cassette to a Shimano 11 speed freehub (Formula RX-142),

I refer the hon member ( @chriswoody ) to the OP and the thread title. OP has stated what freehub he has.
Please say if I'm wrong but an 11sp Shimano freehub doesn't come in "two different spline lengths" flavours: it has a spline length of 36.8mm. If the splines are 35mm it's a 8-9-10sp freehub.

 

[pfm401]

I'm afraid I got more confused so phoned Trek who make the bike - the "answer" in my case is 1.85mm spacer which I've ordered and will check against the one already in there!

 

[pfm401]

I did order the Shimano one given the Bontrager one has rusted after a couple of years!

 

[BrumJim]

I have one you could have for free. Bought an 11-speed wheel when I was still running an 8-speed groupset (Shimano 2300 for those who remember it). But the shifters failed and went for Shimano 105, using the new wheel.