11t cog on full width splines HG hub
 

I was under the impression that 11t cog requires the HG-C freehub where the splines stop short of the end. But today I put a 9speed 11-24t cassette on a FH6402 hub:

https://cimg2.ibsrv.net/gimg/bikefor...79babaf7e.jpeg
The small cog install just fine and pushes against the other cogs as normal. Lockring tightens up just fine and all the cogs are snug. Am I missing anything?

Yes, you're focused on the details instead of the required conditions.

All that matters is the difference in freehub and cassette width allows the 11t to slide on far enough to engage positively, yet not enough to bottom on it's closed end.

So compared to the normal design where last sprocket overhangs, only a slightly shorter freehub body, or a narrow taper or step at the end the splines is necessary.

That does make sense since an 8 speed cassette is 35.4mm and a 9 speed is 36.5mm (per Sheldon Brown). That extra mm does move the 11t out further.

John

So maybe the 9 speed cassette is a special case due to its thickness? The 10s cassette is actually skinnier because of the dished in back. The 9s cassette protrudes beyond the hub body quite a bit.

that is not an HG freehub.... that's a uniglide freehub.

just sayin'....

how does a 9 speed cassette fit on a 7 speed freehub?
was there ever an 8 speed uniglide freehub?
just curious... :foo:

It might be how my brain is wired, but I've never been good at.remembering details, though I great with parts within a bigger picture.

So, I don't bother trying to learn all the permutations of various bike parts. I just know what matters for any mechanical work, then verify if or not something will work accordingly.

I've also been around long enough to see countless examples of small running undocumented changes in products, so don't tend to rely exclusively on published specs.

Interesting question. The 6402 freehub is UG and HG.

IIRC, the interesting part is Shimano made a Dura Ace UG 8 speed cassette, but the 1st position threaded cog was not compatible with non-Dura Ace UG freehubs. I don’t recall a Shimano 600 UG 8 speed cassette, but they may have offered one.

John

The 7/ 8 speed generation used UG/HG freehubs which are backwards compatible with UG
https://cdn-0.sheldonbrown.com/image...3-stylessm.jpg

The only 8s uniglide was the Dura Ace one and that's an oddball one with stepped-down diameter threads for the small cog.

Shimano offered 2 DA 8 speed freehubs, the first was UG with the DA smaller thread diameter, so only DA cassettes. The second was UG/HG but with the larger thread diameter for UG cassettes with the larger thread diameter, so made to be backwards compatible with 7 speed non DA cassettes.

Don't recall any 8 speed UG cassettes for the Ultegra group, standard component for the group used a HG90-8 when the group went to 8 speed. MTB probably also was on HG when the groups went to 8 speed.

exactly why i asked the question... the only way i've heard to fit an 8/9/10 sp. onto a uni-capable 7 sp. FH is to file down the higher step on the splines( i always call the low "splines" grooves or valleys) and use a lockring that will reach the internal threads.

i did remove a snap ring from one a decade ago to allow fitting an 8sp. Cassette... the snap ring was the stop, and no higher stepped splines were noted on that old thing.

so even the backward-compatible DA 8sp. FH was sized for a 7sp. cassette.... noted.

the mystery continues....

and for the record, i always call the HG/UG compat. FH a Uni-HG.... guess i'm just quirky that way.

i keep a couple Uni-only hubs around, and i have had a few uni/hg's here too... not sure if one's still in the bins tho....... i may dig them out and do some measuring/comparing...

Not sure why you are mentioning 7 speed since as already pointed out, the OP is working with an 8 speed UG/HG freehub body.

But, since you mentioned 7 speed freehub and 8/9/10, see the attached, beginning on post #52 about being able to put a certain 10 speed cassette on a 7sp body.
10-speeds on a 126mm hub SUCCESS - Page 3 - Bike Forums

In regards to your comment of the DA UG/HG backward compatible body, it is 8 speed length and similar to the what the OP has as far as cassette fitment. It would take 8/9/10 HG cassettes, or any UG sprockets (except for the DA outermost threaded sprockets that had the reduced diameter). The first 8 speed DA freehub was UG only, but with the smaller outermost threads, and the only 8 speed 'UG' freehub it appears.

by way of explaining my remaining question.... i was involved with several other wheeled sports during the Uniglide age.... i'm trying to get caught up on it's ins and outs.
"But today I put a 9speed 11-24t cassette on a FH6402 hub:"
"I don’t recall a Shimano 600 UG 8 speed cassette, but they may have offered one."
"Don't recall any 8 speed UG cassettes for the Ultegra group, standard component for the group used a HG90-8 when the group went to 8 speed. MTB probably also was on HG when the groups went to 8 speed."

i'll assume that the 600 hub was updated to the DA Freehub at some point in it's life?.... as should IcemilkCoffee?
and, personally, being a big fan of 600 series components, this info is much appreciated! :D

My understanding of DA 1st position threaded cog differences from the standard threaded cogs has to do with running a 12t on a DA freewheel and 11t (I think) on Dura Ace freehubs.

To get there with a threaded cog the threaded diameter needed to be a smaller diameter than standard Uniglide.

Shimano 600/Uniglide never adopted the Dura Ace UG freehub, it just moved to HG.

John