jamesteoh8177

Hey guys...

Thought of doing something silly. I am wondering is it possible to swap Dura ace 9-speed 7700 free hub with 7800 cassette and vice versa?
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70sSanO

Nope not a chance. The 7800 freehub body had a totally different attachment system.

The 7700 attached with the standard fixing bolt and was compatible with earlier “non-DA” freehub bodies, (7/8 speed) depending on whether the freehub body was shallow or deep flange.

As for the cassettes, the 7800 had the tall splines for the aluminum body. 7700 used the standard hyperglide cassette splines.

John

jamesteoh8177

I see...
U mentioned that 7700 free hub may fit earlier non-DAs but would it be able fit to DA 7400 8-speed hyperglide cassette?

As for 7800 free hubs, can I modify them to 9-speed instead of its original 10-speed?
AND
Would it be easy to do so?

70sSanO

There is a BF member, miamijim who has posted extensively on the 74XX series. My understanding is that only 74XX freehub bodies will fit on a 74XX freehub and nothing else.

In my limited, and overly simplistic experience, Shimano had 2 basic 90’s freehub and body types (they had others), but for this we will call it 2.

Some hubs had a shallow recess and the freehub body had a thin flange. Other hubs had a deeper recess and the freehub bodies had a thicker bevelled edge flange.

The FH-7700 has a thicker flange, so do other freehub bodies, including, for example, the FH-M732 7 speed. I believe the 6500 and 737 were thick and the 6400 was thin.

7800 is considered a major mistake by Shimano, so 10 years from now NOS hubs and a cassette will probably go for $1k... lol.

I believe the 7800 cassette is spidered with carriers to reduce weight. Because of this you can’t split it apart and remove a cog and respace to work with 9 speed shifters.

I’m sure there are others here who know a lot more than I do about 7800 freehubs and cassettes; although it may conjure up suppressed feelings of hate.

John

jamesteoh8177

My opinion on DA 74xx series are kinda weird cos some of it has uniglide and and some hyperglide... I have some 74xx cassettes in my store room and would like to make use of it if it's compatible with my 7700 free hub.

Well...looks like it may not b a good fit after all.
What can I do with my 7700???

As 7800 going 1k in 10 years from now. Hahaha... I doubt it... Probably a hundred or two hundred bucks more than current value but won't be any higher.

70sSanO

I really like the 7700 hubs, even the front hub with the aluminum axle.

I can’t tell you want to do with them, but for a vintage build, I did take the 9 speed titanium freehub body off the replaced it with the 7 speed XT-732 UG/HG freehub body. Spaced it to 126mm, re-dished it, and I am running it as a 7 speed HG cassette... with a twist. I picked up a UG threaded 1st position cog.

The 7700 looks close enough to the 7400 freewheel freehub, but I get the advantage of a freehub with a HG cassette.

John

HillRider

I do too. I have an FH-7700 rear hub in daily use with 73,000 miles and still all-original except for the bearing balls. It's on it's third rim but the hub has been flawless. The front hub is laced into a wheel in perfectly usable condition but not currently in service. Great hubs.

masi61

Could you post a picture of your 7700 freehub? What about it did you want to swap again? If you want to mount a 7800 (10 speed) cassette on the titanium 7700 freehub body, the answer is yes it can be done. The 7700 (Dura Ace 9 peed series) freehub is 8, 9 & 10 speed compatible. I believe that 8 speed HG cassettes require a spacer but I don’t recall the thickness required.

You mentioned you might want to run a Dura Ace 8 speed 7400 series cassette on the 7700 hub. If it is the Uniglide only 8 speed 7400 you are out of luck. I believe the HG compatible (HG lockring mount) 8 speed cassette is compatible. I would have to check the 8 speed Dura Ace HG cassette part number (7401?, 7403?)

jamesteoh8177

Seriously!!! 73k miles???

Unbelievable...

jamesteoh8177

I am thinking of putting a 7800 cassette into 7700's freehub
7800 is 10-speed cassette, I would happy if it is compatible.
My 74xx is UG 7-speed ones.

masi61

No problem running 7800 10-speed cassette on 7700’s (8/9/10) titanium HG freehub body. The box for the 7800 cassette should have the correct spacer folded in with the documentation. I believe that spacer is necessary to permit proper torque spec on the 7800 HG lockring.

The UG 7-speed Dura Ace cassette should just be run in the old school configuration for use with 6/7 speed frames with 126mm spacing. I have this on my touring/commuter bike with 3x7 gearing. I’m running a well used Shimano 105SC GS cage rear derailleur with Shimano s.i.s. 7-speed shift levers mounted on Gevenalle (RetroShift actually) shift pods on Tektro aero brake levers.

70sSanO

I always learn stuff here. I’ve never entertained using any 7800, so it never occurred to me that taller freehub splines didn’t prevent a 7800 cassette from being installed on a normal HG freehub body.

Not that it matters at my age, and current wider range cassettes, but it is good to know.

Thanks!

John

HillRider

The Dura Ace and Ultegra level 10-speed cassettes that had deeper notches making them compatible with the taller splines on the 7800-series freehub bodies (and contemporary Ultegra and Dura Ace complete wheel sets) worked just fine with the shallower notches on the 7700-series Dura Ace and all other 8/9/10-speed Ultegra, 105, etc. freehubs. The 7800-freehubs only accepted the 7800-series cassettes but those cassettes also worked everywhere else.

And yes, a documented 73,000 miles (and counting) on my 7700 freehub.

Dave Mayer

Dura-Ace 7700 hubs: best ever. Superior cup and cone design, first-rate materials and finish, well sealed and resistant to water and dirt, and standardized parts that allow these hubs to keep functioning indefinitely. About the only way to kill one of these is to crack the hub shell, by means of which I cannot envision.

If you have these, cherish them and dignify them with some occasional maintenance. The balls are standard 3/16" on the front and 1/4" on the back. If you are doing heavy miles, you may have to spend like $5 to replace these every 5 years. Cones are easy to find, as are replacement freehubs. I have a drawer of replacement titanium freehubs, but you can also retrofit these with the cheaper and easily obtainable steel freehubs from the lower-line hubs. Axles are standard 9mm and 10mm threaded; again, these are widely obtainable.

Even if you expose these hubs to an immense amount of neglect, and you somehow kill the pressed-in cups, these can also be replaced to using scavenged parts from donors. Same technique and tools as replacing cartridge bearings in hubs.

Dura-Ace 7800 hubs? A short-lived mistake. Ditto for 7400 freehubs. If you own these (and I have), cut your losses and fob them off to someone else - cheap.

jamesteoh8177

i missed out this thread... apologies to you.

please refer to the attached picture for my current 7700 freehub with 9-speed cassette. at the moment, i still have another 2 sets of 9-speed 7700's cassette (12-25).
what i would like to swap is:


1. 7800's freehub using 7700's 9-speed cassette - possible?
2. 74xx's freehub (hg body) using 7700's 9-speed cassette - possible?
3. 7700's freehub using 7800's 10-speed cassette - possible?

what say you?

masi61

1) 7800 is 10 speed only
2) 7403 freehub (with the UG/HG body) - yes 9 speed possible
3) 7700 - yes 10 speed possible.

That silver 7700 in the black frame looks really classic BTW.

jamesteoh8177

I see...
Looks like:
1. I don't have waste my time searching for a 7800's freehub.
2. My 7403's freehub does have a chance to a second life. Do I need to modify anything on the 7403's hub body in order to fit in my existing 7700's cassette?
OR, it's just removing the old 8-speed cassette on 7403 and fitting in a new 7700's cassette?
3. I will maximised my two 7700's cassettes first until it is worn out. Then, I will start to source for 7800's cassette.
Yea... Black and silver is such old school setup...

masi61

1) 7800 rear freehubs were unloved for years due to the proprietary deeper aluminum splines that made it 10 speed only. A few years ago people were selling NOS ones off for about $50. Now they are sold out it seems but people prefer other iterations that are more versatile. I did build a wheelset up around a 7800 hub set (24 front, 28 rear) on my 7800 2x10 bike and I think they are great hubs but I digress...
2) Not sure if you are building the 7403 into a backup wheelset or if you have a 7403 for another vintage-y road bike build, but... The 7403 HG compatible freehub body accepts a Hyperglide lockring just like other Hyperglide (HG) freehub bodied hubs. I don’t believe you need a spacer to torque the 9 speed cassette onto the hub with the provided HG lockring. The only limitation I can think of for 9 speed is that the smallest cog must be at least a 12 tooth (not an 11). Also, if you want to run a 7700 cassette with it’s titanium larger cogs that is fine. But for 9 speed you can mount 6500 Ultegra or 5500 105 9-speed cassettes as well. These have different materials and different finishes and are a bit heavier than 7700 but much longer lasting and potentially much cheaper.
​​​​​​3) If your intention is to change shifters after you wear out your last 2 7700 cassettes then migrate to 10 speed, it is not necessary to run 7800 (or 7900 for that matter). 10 speed Ultegra 6600 and 6700 series 10 speed cassettes are really nice and worth the money even at average prices of about $70 each. 7800 or 7900 titanium 10-speed cassettes NOS are getting more scarce and more pricy. I would not run a used Dura Ace cassette BTW. To me it is too risky unless the used cassette is really low miles. I high mileage used Dura Ace cassette is more likely than not to have scalloped out teeth gullets making it more likely to skip with a new chain.

jamesteoh8177

1. I am sure there is a lot of love-hate stories about 7800's freehub. I cant comment much cos I dun have them and given a chance I would like to try them. I tend to think dura ace did well until 7800 series, 7900 onwards I digress. Well, I dont mind trying 7800's freehub, if I am able to get one at a decent price. From what see I in eBay, prices of 7800 seems to be kinda out of this world.

2. 12T cogs are fine with me. As for the ultegra's 6500 and 105's 5500 cassettes, I will keep that in mind. thanks for the tips. Well, at the moment, my inventory are:
- 2 units of 9-speed cassette
- 1 unit of 7400 front hub
- 1 unit of 7403 freehub
- 1 pair of cxp 33 rims
- 1 unit of atax seatpost
- 1 unit of headset (no brand)
- 1 unit of handlebar (no brand)
- 1 set of brake cable
- 1 set of shifting cable
- 1 pair of 600's 6401 calipers
- 1 unit of 600's 6401 front derailleur
- 1 pair 7700's pedal (SPD-R)

3. pretty sure that my 2 units of 7700 cassette will last for years to come cause I am not hardcore rider rather, I am just weekend and casual rider. Anyway, I just pick up this new hobby of building vintage bikes. Will consider 10-speed after maxing my current 9-speed. Who knows I may just stick with my 9-speeder. Personally, I always put my bet 7700 series, as they are the best dura ace series made (except the pedals). hehehe...

masi61

1) yeah Dura Ace 7800 components seem to have either a cult following or have become highly collectible, or both. Do you have the Dura Ace 7800 (or 7801) integrated shift levers? I have 7800 on one bike and 7700/7703 on my main bike. The shift cable housing out the side of the lever makes the shifting crisp and lets the inner wires last longer. Some folks don't like the clutter in the "cockpit" area. I don't mind.
2) If the spoke drilling of the Mavic CXP rims match up to the 7400 front, 7403 hub why not get a local wheelbuilder to build them up for you into another wheelset? Might as well keep running the gear if you can right.
3) well if you already have the 7700 cassettes and they are working well for you then that is great. I a 200 pounder and I ride a lot of hills and stand to climb and even though I spin smoothly I have worn out a few cassettes over the past 10 years. I bought a used 7700 cassette and road tested it thinking it would be alright but it skipped with the new chain that I was running. Do you run Shimano or some other brand of chains?

HillRider

Why??? Nearly everyone, including Shimano, considered them a mistake. The taller splines made them incompatible with all but their very specific 10-speed only cassettes and the freehub design with it's right side bearing inboard of the freehub body was less durable than Shimano's other freehub bearing designs. There were good reasons this series disappeared quickly from Shimano's product line.

I do agree that the 7700-series hubs were among the best Shimano, or anyone else, ever made. Their only current disadvantage is they won't accept 11-speed and above cassettes.

masi61

I decided to build a wheelset up using 7800 front and rear hubs and it is fine.

HillRider

Sure, they were functional but limited. If you already had them and have compatible cassettes there is no reason not to use them. My point is why seek them out if you don't already have them.

masi61

I agree. I had purchased 2 NOS 7800 rear freehubs for like $39 each from Bikewagon a few years ago when they were blowing them out. So I wanted to go ahead and build it up more as an exercise to try out that implementation of Dura Ace hubs with very little outlay of cash. I used DT Swiss R460 rims which are super affordable "OEM" Chinese manufactured tubeless ready rims that seem to be of perfectly fine quality and (when I got them) they were under $40 each.

If the OP likes 9/10 speed and Dura Ace, there are more versatile options such as 7850 or 7900 hubs or even complete wheelsets which people are getting rid of since they are not 11 speed compatible. I have a 7850 tubeless wheelset that I bought for under $200 which I am about to put into use with tubeless tires.

jamesteoh8177

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Personally, I feel 10-speed is sufficient. Unless u are going for a race and needs max all out on ur bike, then maybe 11-speed would be the ideal.

Like I said earlier, I am just a casual rider, 9-speed is just nice and 10-speed would b more than enough.