jtolive

Had some cracks on a Shimano WH-7800 rear rim. Decided to replace the wheelset with DA C24 clinchers. It came a 1.85mm spacer to use other cassettes.

When I removed the DA cassette(10sp) from the WH-7800 there was no spacer in use.

I installed the DA cassette on the DA C24 clinchers using only the 1.85mm spacer. It seems be just fine shifting wise - probably have ridden a few hundred miles.

Some things I have read indicate that you should use the 1 & 1.85 spacers with 10 speed cassettes on a 11 speed hub.


Should I have used a 1mm also?

FBinNY 

Rule No.1 for cassette installation.

The outermost sprocket must overhang the front of the cassette slightly so the lockring can compress the cassette without bottoming against the face of the freehub.

Rule Nos. 2-10 ---- see Rule No.1

Rules' covering when to use a spacer or not, see Rule No.1.

Rule No.11 --- As long you've met the condition of rule No.1 you may add or subtract thin spacers or shims, so the relative position of the cassettes on various wheels to the dropout face matches on all of them. This allows switching wheels without needing to adjust RD trim.

So in answer to whether to add a spacer, or which to use ----- See rules No.1 - 11

Andrew R Stewart 

+1 to Francis! I've installed cassettes that were otherwise the same (brand, cog count, range) but did/didn't need the spacer to positively secure the cogs when the previous cassette didn't/did need the spacer. Figure that one... Andy.

well biked

I've been using 2mm spacers for 10 speed Shimano cassettes on 11 speed Shimano hubs, works fine.

HillRider

As a rule, Shimano 8/9/10-speed freehub bodies require the 1 mm spacer behind a 10-speed cassette. Shimano 10-speed only freehub bodies do not require the spacer. 11-speed freehubs do require at least one spacer to use 8/9/10-speed cassettes but I don't know if the 10-speed cassette requires both. However, as Francis detailed, if it's tight, you are good.

jtolive

Thanks for the help!

Guess I have too much extra time. When installed it was good and tight but I was second guessing myself.

But now that I know to only worry about Rule #1 - problem solved. I was getting worried about Rules 2-10. My bad!

Thanks again,
Jay

FBinNY 

I only added rules 2-10 because so many people can't stand anything so simple. However Rule 11 is important for team mechanics, who platoon rear wheels, and anyone else who mover wheels bike to bike. Otherwise rule 1 covers everything.

Canker

One more little tid bit. 10 speed tiagra cassettes do not fit Shimano 10-speed only free hub bodies. They don't have enough clearance to fit over the over sized splines on the 10 speed only free hub body and the tiagra cassettes have the spacer built in. Just found that out and had to order a 105.

utoner34

Sorry to bring this old thread back but I have related question.

Want to use 10 speed road cassette on 11 speed Shimano road freehub.

If I need both spacers (1+1.85mm) in which order they go on the freehub?

FBinNY 

It usually doesn't matter, since its simply a question of using up the width of the freehub so the lockring can compress the cassette properly. I usually prefer to add spacers behind the cassette to improve spoke clearance. OTOH, if you find the outer sprocket to end up too close to the dropout, you might put one in front.

utoner34

I am asking because they look differently: (1mm spacer does not have teeth)

https://www.bike24.com/p259996.html?...1-67454825c04a

https://www.bike24.com/p2126329.html

I am not sure if 1mm linked spacer if the correct one.

choddo

They don’t need teeth. Isn’t the top one an inter-cog spacer? (Edit ah no, eyes working properly now, just looks a bit like one)

Never had to use 2.85mm of spacers myself. 1mm on its own has been enough for me to use a 10speed cassette on an 11 shimano freehub.
Doesn’t that description talk about MTB cassettes on road freehubs (if someone wants a big old cog I guess)

Duragrouch

I obtained a 1mm (may have been 1.5 or 2mm, can't remember) spacer to put behind my 7 speed cassette, because once the chain dropped between the lockring and the dropout, and was incredibly tight there, I had to loosen the axle nut. Figured spacing outboard a bit would prevent that. But I wasn't comfortable with the reduced thread engagement for the lockring, and the 11T cog with the freehub end, so didn't try on the bike, took out the spacer. If I convert the hub to 8-speed, that should do it, as 8-speed freehub is just a skosh longer.

wheelreason

Yeah, 4700 identifies as 105 most of the time...

Canker

since somebody bumped it I went and looked and still have pics of the funky situation I was in. You can see the extra tall ridges on the funky all aluminum freehub body and how the notches in the 10 speed tiagra aren't as deep as the ones in the 105 so the tiagra wouldn't fit. The tiagra would only fit over the smaller ridged section at the start of the freehub body.

Kontact 

So Shimano 10 road cassettes have the 1mm spacer so they can work on the 7800 wheelset with its special and short freehub body. You can't put a wider range MTB cassette or SRAM cassette on that wheel. (Shimano loves to make incompatible stuff for Dura Ace).

So a road 10 Shimano cassette on a normal 8/9/10 freehub should need the 1mm spacer. And the same cassette on an 11 speed freehub should need the 1.85mm spacer AND the 1mm spacer. Essentially this adapts 7800 to normal 10, and then 10 to 11.

And that's how it seemed to work when I was a mechanic. Leave the 1mm off and the lockring would bottom out.


So here's my weirdness: Last weekend I built a wheelset with some used 6800 hubs I got at the coop. 6800 was an 11 speed group, and the freehub looks correct with the grooved splines. But when I mounted a SRAM 8 speed cassette on it, there was not need for a spacer. Being SRAM 8, there would be no need for the Shimano 10 1mm spacer, but it should have needed the 1.85mm 11 to 10 spacer. Yet the lockring tightened down fine. It doesn't make much sense. At some point I'll pull the cassette off to measure it, but that's what happened so far.

zacster

An 11/12sp freehub HG Spline L needs both a 1.85 and 1 spacer behind a 10sp cassette for DA, Ultegra and 105 according to the Shimano Compatibility chart here: https://productinfo.shimano.com/#/co...544&acid=C-731 But that is only if you specifically have that freehub. Other manufacturers with compatible freehubs may have different spacing, you just don't know.

The 8/9/10sp freehubs required a 1mm spacer for 10sp cassettes, either road or mtb. 11sp freehubs are 1.8mm wider, hence they need an additional 1.8mm spacer. 11sp HG700/HG800 cassettes were made to be compatible wherever 10sp cassettes would fit and need the 1.8 spacer but used the 1mm in the cassette body itself so it does NOT need a 1mm spacer. They are 11-34 teeth and the 34 overhangs the rear, taking advantage of the dish so it doesn't take up additional body space. Other 11sp cassettes will only work with 11sp freehubs, and without a spacer. These used up the 2.8mm of extra space for the extra cog, with narrower cog spacing throughout, over 10sp.

11sp wheels are 131 spaced to make it all work. They fit on a 130 frame because the tolerances aren't that tight and they figured nobody would notice. They needed the extra 1mm to account for the extra 1.8mm of the freehub. The .8mm was probably shaved off some other part of the assembly. With thru axle 142 hubs (something I don't use myself) that spacing wasn't an issue.

Kontact 

This is wrong. 10 speed MTB cassettes were never intended to work on the 7800 wheel, so they are normal width.

11 speed Shimano hubs are just dished over more. I've used that dish as a guide to redishing a 126mm cassette hub to take a 10 speed freehub.

Duragrouch

Never mind that... you have spoke nipples at the HUB. And radial on drive side! Sorcery! Yeah I know you can transmit torque across a nice cylindrical hub body, but it still seems odd practice. I commonly see radial on the non-drive-side. Speaking of which, are the nipples at the hub on the non-drive-side too? If not, that's a weird combination.

And are a couple spokes bashed, or are shadows and fuzzy playing tricks?

choddo

Aha. Perhaps that explains why I only needed 1 spacer. Wasn’t a shimano freehub, was most recently the one on my Kickr. But now I am worried if I used a 1mm and it should have been 1.8. Would have thought the cassette would be noticeably loose though and this trainer gets used a lot so I’m sure I’d have noticed messed uo shifting.

Canker

I haven't had the bike for 10 years give or take. I just remember the rear was some funky shimano wheel.

zacster

That's the chart where it says "ALL" but then makes the exception for all road cassettes. You just gotta read the fine print.

Kontact 

I've installed dozens and dozens of 10 speed Shimano cassettes at work. Only the "road" gearing came with the 1mm spacer and the inset.

And that's what the chart shows - note #2 and #5 says that 1mm spacers are only for the listed 10 speed road cassettes, and nothing else.

Duragrouch

One of the other threads says lower number of crosses helps the thrust angle on the drive side of a dished wheel (same lateral distance but shorter spokes). That's my guess for them going radial on DS as shown in your earlier pic. And modern hubs with large cylindrical bodies make it easy to transmit the torque to the non-drive-side crossed spokes.

However, there was some hub for radial, not shimano, that had that same sort of slots for non-elbowed spokes, that had a recall, evidently the slots didn't hold over time.

zacster

That's what I'm saying, you gotta read the fine print. If you ask me the chart should've just had a column for a separate Road 10 category instead of as a footnote. Not everybody reads the footnotes.