ascherer 

Microshift R10 is pretty good. Looks the same as the Sun XCXD and easier to procure.

Positron400

Did you use them as is? because i have the same 105 RD5500 and cannot clear the 34 cog. Any advice is greatly appreciated

bwilli88 

Two things helped. 1, B screw turned all the way in. 2, Chain length worked in my favor, I used BIG-BIG no derailleur + 4 pins (2 links).
I feel that the geometry was perfect for both bikes with this setup, it allowed me to have the tightest chain that FIT and having that "tight" chain kept the RD off the largest cog.

Positron400

thanks! Very much appreciated. I never considered the chain length to be a factor in RD clearance. Just to be sure, before i go and cut a chain, you are using a 105 RD 5500 with a 36 cog ?

bwilli88 

See my above post with the blue bike.

The Golden Boy 

Remember those are GS cages- so technically 5503 and 6603.

Positron400

I am not that well versed in production serial numbers. could you maybe elaborate?

bwilli88 

55 is the series, 105, 03 is the cage length
66 is the series, Ultegra, 03 is the cage length.

The Golden Boy 

While not exactly the cage length- it's the 'triple specific components'

So a 6600 set is for an Ultegra 10s double, with a short derailleur cage and a back plate on the front derailleur that is specific for a double chainring crank.

The 6603 set is for an Utlegra 10s triple, with a long (GS) derailleur cage and a lower back plate on the front derailleur that is meant to work with a triple chainring crank.

GS cages are generally referred to as "long," but really SGS was the LONG cage and GS is medium... I don't think there are anymore SGS caged derailleurs anymore.

And just a word of warning- I've theorized that the "new-ish" triple front derailleurs are designed to ONLY work with the cranksets they're designed for. Not just the chainring sizes, but for the ramps and pins to be in specific places. I've not gotten a 7803 FD to work with either a compact double or an old school 28/38/50 triple. However, I have used a regular 7700 FD without issue. Go figure.

Positron400

thanks. Are there any other versions of the 105 5500 than the SS or GS? I am fairly certain (like 99 %) I have the long cage (GS) version. And RD-5500 is stamped into the back of the whatchamacallit.

The Golden Boy 

I just learned something new- I would have sworn it would be a separate model- but I just looked at my 7803 that I have handy- and it's marked 7800. Surprise.

Positron400

One more thing, what size are your front chainrings? I am using a 48/34.

Hondo6

They certainly no longer seem to exist in Shimano's road and Gravel lineups. But they're still out there in Shimano's mountain RD offerings.

Positron400

OT: but i use an Ultegra setup on my "let's call it a road bike" with a RD that clears a 34 cassette no problem. I'd consider that quite a long cage

bwilli88 

One was a half step 48-45 and the other was either a half step 49-46 or compact half step + granny 50-46-34

Positron400

Thanks! I am afraid that might not work for me then after all, seeing as i have a 48/34 crankset. Will give it a try though

dddd

I wouldn't fully count on any 5503 or 6603 rear derailer quite properly clearing even a 34t big cog without:
1) giving a very clunky shift onto the biggest cog-
2) having the top pulley contact the big cog's teeth noisily, and or jamming when/if the pedals are turned backwards-
3) requiring such a short chain such that shifting off of the largest cog is extremely hesitant.

The B-screw can be extended to increase clearance if needed (depending on factors such as the hanger's length and the chain length needed for the full range of the chainrings).
An "extending nut" can be fitted to the tip of the B-screw as installed, then secured with Loctite. I first grind the hex flats making the nut perfectly round, to reduce the diameter for turning clearance. At the same time, I give the nut's outer periphery a 45-degree cone profile to better interface with the dropout hanger's stop tang, all of which prevents a merely-longer M4 screw from slipping past the edge of the tang.
...((All this to gain B-tension adjustment range, so as to use a 6503 RD on my Holdsworth Special with a 12-34t 9s cassette)).

Earlier 6s-era and some 7s-era SIS RD's usually will not index an 8, 9 or 10s cassette perfectly, as these derailer's actuation ratio tends to be regressive when shifting to the largest cog. Those who are even moderately fussy about consistent index-shifting response may find a proper cable tension adjustment elusive for this reason.

Pre-index RD's and even most Accushift RD's (3040 series excepted) typically have a higher actuation ratio, moving a good bit further across the cassete for any given amount of cable movement. This accomodates certain older levers having less cable pull, and also makes for a quicker shifting action to the extent that the chain gap is a given.
The actuation ratio for most Suntour and most pre-index vintage derailers tends to mirror the lower "leverage" number associated with Dura-Ace 74xx rear derailers, and the 74xx front derailers also have greater cage movement for any given cable movement than any newer Shimano derailers!

But the chain gap for pre-index rear derailers (Suntour long-cage models no exception) tends to be relatively huge, since vintage (typically bushed, but even the bushingless Sedisport) chain is much stiffer, laterally, than any modern chain.
So, for responsive shifting, expect to have to possibly:
1) back out or remove the B-tension screw entirely-
2) carve metal from the B-tension screw's boss on the B-knuckle-
3) figure out a way to adjust a non-adjustable derailer's cage pivot's or B-pivot's spring tension-
4) use modern, HG-style, or at least UG-style cassette/freewheel cogs-
5) accept that the shifting will be lazy/unresponsive on the smaller end of the cassette-
5) bring the cable's path up to entirely plastic-lined (and index/compressionless) status-
6) keep the shift lever's friction surfaces (and pivot!) lubricated with light lubricant such as plain oil.

"New-ish" triple front derailers did indeed evolve during the 1990's to incorporate more-technical inner cage-plate shapes which are specific to the tooth-count difference between the middle and large chainrings. Changing this tooth count difference typically results in a very poor-shifting front derailer, particularly when shifting up to the big ring.

Various "Deore" mech's from the late eighties into the early 90's make a particularly robust, good-shifting and good-looking addition to a rando or gravel-y build.
These have been common to find on "garage-sale mtb's", so many Ebay vendors strip these bikes for such salable parts.
These derailers can be dolled-up with different branding decals if desired, as here on my 1968 Steyr-Sears, where I enjoy super-robust friction shifting over a 6s Uniglide freewheel:


The Holdsworth, Marlboro-era (mid-1980's) having an apparently relatively-short Campagnolo derailer hanger: