rothenfield1

Don't want to bore you with the gory detail of this debacle; but, I have a wheelset with a 7400 Uniglide freehub. But, I have an 8 spd Hyperglide cassette. Is it cheaper to replace the cassette or can I replace the freehub?

mechBgon

The Uniglide cassette isn't made anymore and it would be difficult to find the HG freehub body for that hub, as you may already have noticed. And when it's all said and done, you'd still be running an end-of-life platform either way. How about rebuilding the rear wheel with a current-generation hub? Tiagra is $40, basically near Ultegra quality, and leaves all your options open.

rothenfield1

That sounds reasonable, normally. Except, I just bought this absolutely awesome wheelset of Torelli Master rims laced to DA 7400 hubs that was just made to order for the 7400 gruppo I was trying to put on this old Bianchi. Problem is that the group came with an 8spd Hyperglide cassette. Now I'm in a real jam. One of many lately.

Metzinger

SB wrote:
I happen to have an unused threaded UG top gear I could part with.
Brown also mentions freehub transplants on this page. Is that no longer possible with today's FHs?

rothenfield1

I'm sorry. I need to restart this thread. Assumptions are dangerous things when it come to bikes. I just tried to put a 7spd Uniglide cassette on this hub and it didn't fit. Now I don't know what I have. Can anyone tell me what type of freehub this is?

Metzinger

I was just digging through my parts drawer for the aforementioned cog. I found two. Both 13T, but with two different inside diameters. One is roughly 35mm, and the other 38mm.
Then I read this from Sheldon:
What's the approximate diameter of that FH?

rothenfield1

With my lame Park tape measure I measure about 34mm.

rothenfield1

If you haven't noticed, I don't blame you because neither did I; but, there appears to be threads at the ends of the hub?

Metzinger

I saw them. After remeasuring, I'd say that the smaller of my 13Ts would fit that body.
Then I measured a single HG cog, and the diameter seems the same.
Are you sure that was a UG and not an HG cassette that you tried to fit on there?

rothenfield1

I'm sorry! I've had so many problems with this bike which I am determined to overcome because I've ridden her, and she's worth it. I retried the 7spd uniglide, and didn't realize the one narrow slot. It went on to my relief. (I'm new in the school here) The 8spd wouldn't because it had a flat slot in one area. I thought this hub was supposed to take both UG and HG?

Metzinger

Looking closely at your FH, I'd say it's like the middle one on Sheldon's page that I posted earlier. 'Compatible with both' means that an HG lock-ring will fit into the inside threads at the end. So you don't need to find a threaded outer cog. You just need to figure out whether you're meant to grind off a spline of the FH or from each of the 8 cogs. I've never done this.

rothenfield1

Thank you for your responses. I've had so many issues with the build-up of this frame which I have come to love, that when I finally got the wheelset and couldn't fit the cassette, I think I over-reacted. The 7spd UG cassette that I have did fit after I realized the narrow slot hadn't lined up. When I first tried the 8spd cassette that I bought for it didn't fit, I kinda went into panic mode and the forum. I don't think this 8spd cassette was made for this hub. Need a new cassette I think.

This is a pic of the wheels.

rothenfield1

OK. I'll admit it. I'm a bicycle idiot. I've been talked into a new understanding of freehubs and the world, and my bike seems alright tonight. It was me, not the cassette that didn't fit. Now, if I could just figure out how to remove that frozen BB cup.

Gonzo Bob

From your pic, the freehub has both UG (external) and HG (internal) threading and should accept either type of cassette. The UG cogs do not need to be aligned to fit and can go on in one of 9 orientations (18 if you flip the cog). HG cogs need to align the fat tab on the cog with the fat slot in the freehub and can go on in only one orientation.

Dura-Ace 7400 hubs had a different freehub attachment method than other Shimano hubs and accept only Dura-Ace freehubs. But I don't think a Dura-Ace 7-speed HG/UG freehub was ever made. Dura-Ace was 8-speed by the time Shimano introduced HG and the hard-to-find Dura-Ace HG/UG freehub is 8-speed. If your freehub is only 7-speed, I don't think it is Dura-Ace. If your hubs are Dura-Ace, I have no idea how someone put a non-Dura-Ace freehub on an old Dura-Ace hub - could be it's just held in place by the axle.

mechBgon

If it's an Italian-threaded Bianchi, remember that the driveside cup is *not* reverse-threaded, for starters. In a worst-case scenario, heave it at your LBS. They'll get it out.

DannoXYZ 

It's hard to tell which model hub that is, but it very well could be a 7400-series hub that had the freehub-body replaced. At the time, there were 7-spd bodies available in UG/HG or HG-only versions. These went on the 600EX hubs and featured the same screw-on attachment as the Dura-ace.

rothenfield1, you have some terms mixed up I believe. The cassette you have is Hyperglide, not Uniglide:

Uniglide = twist-tooth, all teeth are the same. Slides onto freehub-body in any orientation, even inside-out to use unworn side of teeth
Hyperglide = flat-tooth with recessed shift-ramps on the side of the sprocket. Also has one wider tab on the inside that slides into the wider slot on the freehub (at 12 o'clock position on right cog).


Uniglide - left, Hyperglide - right

FH-7400 = 6-spd UG
FH-7401 = 6/7-spd UG
FH-7402 = 8-spd UG
FH-7403 = 8-spd UG/HG