rickrob 

I'm not sure how to remove this freewheel. It's a Dura Ace, and there's a cover /lock ring on it.

Are the splines under that cover? Is a special tool needed to get the cover / lock ring off?


Thanks

jethin

Show it some Campy kryptonite and it will become weak and fall off the hub like a greasy piece of over-ripe fruit.

rccardr 

That's a 7 speed DA 7401 UG freehub, not a freewheel. The outermost cog acts as a lockring.
Use two chain whips to remove- one to hold the cassette steady, one to remove the outermost cog. It's normal threading.

rickrob 

Thanks for the help.

dddd

It sort of looks like the smallest (threaded) cog is over-hanging the end of the freehub body, possibly a sign that the freehub body isn't meant for the 7s cassette that has been installed on it(???).

If there is less than three full turns of engagement of the smallest cog on the freehub body, I would call that dangerous.
Normally there is well more than three full turns of engagement.

rickrob 

The lock ring does turn a few times before it tightens up and seems secure. I did some reading on compatibility issues with Dura Ace / Uniglide hubs and most likely this hub is going to be replaced with one that has a Hyperglide freehub.

ThermionicScott 

I wonder if some 6-speed cogs got mixed in on this hub, and that's why it doesn't thread on all the way.

@rickrob, could you take a picture from the side of the cassette, 90 degrees rotated from what you have?

rickrob 

Sure, I'll take a picture when I get home. This wheel belongs to a relative and was purchased complete as part of a set in the mid 90's

Dave Mayer

Dura-Ace 7400 freehub. I am the unfortunate owner of a few of these. The first two cogs are as rare as the Holy Grail, and necessary.

Uniglide only. The later 8-speed 7403 freehub is Hyperglide compatible, and can take up to 10 cogs. But no 11-tooth first cog.

These freehubs are even harder to find. The special tool to remove the 7400 series freehubs: maybe 1 in 100 shops will even know what you need here.

good luck.

speedevil 

Having just gone through the 7401 to 7403 swap, I can tell you that 7403 freehubs are basically unobtainium. I got very lucky and picked up a set of 7400 hubs with a 7403 freehub off ebay. The special tool to remove the freehubs from the hub body is required. After removing 2 of them, I can say with certainty that there is no way to remove them without the tool.

I swapped the 7403 for the 7401 so that I can use a 10 speed cassette, and it does work and fits properly. The 7403 freehub has both internal threads (for a lockring) and external threads (for a threaded cog).

If you do get a 7403, take good care of it, they are very hard to find.

rickrob 

Thanks for the info-- At this point I'm going to replace the entire hub with something else and rebuild the back wheel. It's not worth the trouble. The bike is 126mm spacing and I built another set of wheels for it with 600 Tricolor 6401 hub/ 7 speed freehub that was hyperglide. Maybe I can find another FH-6401 with Hyperglide.

Any other recommendations for a 126mm freehub? I've used the RX100 FH-A550 as well.

ThermionicScott 

Are the rim and spokes anything special? You might consider starting with all-new parts at this point, since a different hub might mean new spokes anyway.

I've built a couple of rear wheels around 7-speed HG hubs (Exage HG50 and 1055) and have been pleased with both of them. The RX100 and RSX wheels that I didn't build are performing well, and I have a few 6400/6401 hubs waiting for a special project, as well as some other hubs for parts or whatever. The seals are better on the 600/105 hubs, but it's hard to go wrong with any of them.

Only downside to building for 7-speed these days is that Shimano isn't making cassettes in "road" ratios anymore, just wide-ratio stuff like 11-28, 12-28, 12-32...

rickrob 

The rims are Mavic GP4 tubulars in really great shape, with stainless spokes. It seems like a lot of money to me to buy a new hub and spokes for wheels that won't get ridden that much-- but the bike's owner wants to rebuild the wheel.
I think the clinchers I built recently up for this same bike with Sun CR-13's, Sapim DB spokes and the 6401 Tricolor hubs should stand up to just about anything. I'd just ride these tubulars as is and try to stay on flatter courses since the largest rear cog is a 24.

79pmooney

GP4s! Great rims. I built up a pair for the Mooney when they were current. Collapsed the rear slightly misjudging a bunny hop. Brakes had worn clear through. 17,000 miles. Saw a spoke wrench once.

That bike hasn't seen tubulars since but I am getting ready to go back. I miss the security of descending on tires that I know will never come off after a blowout. That and the sweet ride.

Ben

ThermionicScott 

D'oh! I keep forgetting these aren't your wheels. Good call.

Poking around on Spocalc, you should have no trouble relacing the spokes and rim from a 7400 7S hub to a 6401 (which has identical geometry to RX100 FH-A550 or 1055).

rickrob 

Dave Mayer

Hard to see any problem looking from the side. From an earlier pic, you do have the correct 7/8 speed first cog. It is stamped on the outside of the cog. The second cog has a built-in spacer, which is narrower in the 7-speed version. Maybe this is the problem: you have the wider 6-speed #2 cog.

Of course, for the rest of the (loose) cogs, you would need the correct (narrow) 7-speed spacers.

dddd

The side view was too perfect, still can't see how many threads are over-hanging the freehub body.

The spacing of the cassette looks correct to me, normal 7s cassette.

From the freehub part number in the axle dust shield you can ID whether this is a 6s or a later 7s Dura-Ace freehub.