ramuji

I installed a set of new (NOS) Dura-Ace SL-7700 downtube shifters in early April, and they have been great so far after 2400 km.

Now, I'm thinking about upgrading all of the components on my 30-year-old Bianchi, from the original 105 to Dura-Ace 7700.
I would be making the upgrades piecemeal, as my budget allows and as I'm able to find NOS or used components in good condition.
So, that means I would have a mixture of 105 and Dura-Ace for a while, until I'm able to complete the entire set.

Would a Dura-Ace (10s) rear hub be compatible with my 105 (8s) rear derailluer?
I use downtube shifters set to friction mode, so I shouldn't have to worry about shifting inconsistencies other than adjusting the limit screws, correct?
Maybe I'll need a new chain?
Are there any other issues I should be aware of?

georges1

Normally it would be compatible but for total compatibility, it would be wiser to buy a RD 7800 if you wanted to go 10 speed, or a RD 7700 if you want to go 9 speed also a new chain will be manadatory. SL 7900 are Dura Ace down tube 10 speed shfting levers.

rccardr 

I suggest caution with regard to Dura Ace 10 speed hubs. IIRC, 7800 hubs are limited to DA/Ultegra 10 speed cassettes due to the taller splines.

smd4

You won't be disappointed.

georges1

I totally agree with that

ramuji

I've been using the Dura-Ace SL-7700 shifters since early April. They're great!

KCT1986

Yes, the FH-7800 uses a aluminum freehub body that had the taller splines to prevent the cassettes from damaging the body. This limits the compatibility, and will not allow the use of most common Shimano HG or HG compatible cassettes from other manufacturers. This limitation means that speed will be limited to 10 speed only.

Dura Ace FH-7402 takes a special 8 speed cassette and requires a threaded outermost sprocket.

Other models of Dura Ace FH (7403, 7700, 7900) don't have the same cassette compatibility limitations but could present a problem if the freehub body needs to be replaced. The DA models use a different mount from most Shimano models and accepts only certain freehub bodies. Since these are usually quite old, parts availability is very scarce and expensive.

ramuji

Thanks to georges1 rccardr KCT1986 for info about Dura Ace 7700/7800. Obviously, there is a lot I don't know about these components, and the help/suggestions is a big help.
I'm not set on upgrading to Dura Ace, I just chose that because I recently installed the Dura Ace downtube shifters and really like them.

I'm looking at Ultegra now. I've spent the past few weeks trying to read as much online as I can find about Ultegra 6600 mainly, since I think I want a 10s cassette.
If I understand what I've read, the Ultegra FH-6600 is 8s 9s 10s compatible, correct?

I should probably also consider 105 5600. (My 1993 steel frame still has the original 105 1056SC groupset.) Are there any significant differences between Ultegra 6600 and 105 5600 other than weight?

Apologies for the vague questions. I'm still trying to suss out what I don't know that I don't know.

rccardr 

Everything you mention above is cross-compatible and works with 8-9-10 speed systems.
No real performance difference between 6600/6700 and 5600/5700, but if you are looking for bright and shiny there were polished versions in both of those series.
It is not unusual to find new or almost-new 5000 series RD's at really good prices.

georges1

I agree and concur with you, 6600/6700 offers alot for the money so does 5600/5700 maybe the choice of gears was bigger on Ultegra but quality wise it is working flawlessly and it is very reliable.

blamester

Dura ace 7850 hubs have normal splines.
And they are excellent.

georges1

I agree and they are top notch quality hubs

KCT1986

The FH-7850 was an interesting piece and somewhat limited, since it was quickly superseded by the FH-7900. It was very similar to the hub used in the WH-7850 wheelset.

As with most DA, it has a 'special' look. Replacement parts for the unique designs of the DA is now the challenge.

georges1

You can find hubs or anything on ebay or on some speciliazed shimano websites, you will find replacement parts, but generally Dura Ace hubs last a lifetime.

ramuji

If I go with Ultegra 6600 crankset/rear hub/rear derailleur, are 8-9-10 speed cassettes from the past 20 years backwards compatible with 6600 or do I need to look specifically for a 6600 cassette?

rccardr 

All Shimano HG cassettes (except- possibly- 7800?) are cross-compatible with that freehub.
The less expensive 105 series cassettes are slightly heavier but work just as well and are much less expensive than Ultegra or DA.

KCT1986

The FH-6600 has a steel freehub with standard splines and will accept most common Shimano compatible cassettes. Use a spacer behind the cassette for those that calls for it.

Even the 7800 cassettes will fit on the FH-6600. It just doesn't work the other way around. The FH-7800 uses an alloy freehub body with taller splines, so the CS-7800 is required.

Correction, the 6600 cassette in most combos with a 11t or 12t smallest sprocket should work with FH-7800. Also the 5600 cassettes should work.