Freddyonabike

Hello!

I have a Koga Miyata with Dura Ace hub, which I believe is the 7403 version that is uniglide & hyperglide compatible. Atleast to my knowledge.
Does anyone know if its possible to mount a 9 speed on it?
Does it matter which Shimano cassette I choose as long as its a CS-HG?

Thank You!

Dave Mayer

Rare hub. The 7403 will accept a 8, 9 or 10 speed Shimano or SRAM cassette, as long as the cassette doesn't start with an 11-tooth cog.

If you have the rarer Uniglide-only 7402 hub, then good luck at finding anything to fit. Which is the reason why these (orphaned and useless) hubs have cluttered up Ebay for years.

Freddyonabike

I'm 100% sure its a 7403 hub, because it has threads to install a cassette!
I cant even find 8 speed that doesnt start with a 11-tooth cog...

rccardr 

One of the best hubs Shimano ever made, IMO.

Lots of 8 speed cassettes out there that start with a 13 (e.g. 13-26). But you originally inquired about 9 speed cassettes, common ones are 12-25 and 12-27.

veganbikes

I did replace a uniglide freehub on a 600 tricolor hub. I believe it was an LX freehub and it worked well. It was an ex-coworkers hub and he is riding it today. If you want 11-xx you might look for an older 90s era Shimano freehub body somewhere and try that out. If not try a 12-xx which is just fine.

Freddyonabike

Oh ye I misread! Thanks alot for help guys!

Does it matter which Shimano or Sram series it is? Basicly, is it worth getting a expensive cassette?

Dave Mayer

Nope. Only Shimano 740X series freehubs fit on these hubs. Completely incompatible design. You also need a special tool to remove these special freehubs, unless your plan is destructive removal involving a bench vise.

The tool is near impossible to find. As are replacement 7403 Hyperglide freehub bodies.

veganbikes

I should have figured. The 7400 stuff has always been listed as compatibility challenged with other stuff. Kinda sad as it is probably one of the best performing gruppos ever. 600 Tricolor is best for looks and the 6800 stuff is my favorite modern wise.

Freddyonabike

Is it possible to maintain the hub then, if you cant get it off without a special tool or breaking it?

rccardr 

Yes, you can maintain the hub bearings just as with any other Shimano freehub setup. Just don't expect to remove the freehub itself.
Thankfully, they seem to last pretty much forever. I have that hubset on a half dozen bikes and they operate just fine.

Dave Mayer

Dura-Ace 740X hubs are about the easiest to service of any I've come across. You rotate the little plastic covers until the mark indicates: OPEN. Then you take your grease injector and squirt until some of the old contaminated grease oozes out. Over the next couple of rides you'll have to clean up some excess. 60-second overhaul. Done.

The freehub is another matter. Fortunately, Shimano cassette hub freehubs are very well sealed: best in the business. Just don't do anything stupid like wash your bike with a hose, or submerge your bike, or drive in the rain with your bike on a rack.

Freddyonabike

I've been riding the bike in heavy rain, and the freehub sounds kinda dry, which is why I'd love to clean it and re-lube.

speedevil 

I just swapped a 7401 UG freehub for a 7403 UG/HG freehub. The special tool is the only way it's coming off short of destructive removal. But don't do that, please. 7403 freehubs are basically unobtainium. They work for 8-9-10 speed cassettes.

After I removed the 7403, I cleaned it out with solvent, and then let it sit in a bath of mobil 1 synthetic gear oil for a couple of days. I let it drain for a couple of days afterwards. Installed it and it works perfectly. it's almost silent when freewheeling, and engages quickly. On the maiden voyage, I had some grease work it's way out of the hubs (both front and rear), and I just wiped it clean and checked the preload. All good.

In my admittedly limited experience with DA hubs, these are smooth and well worth the effort to maintain them.