Hi all, I am looking to replace the rear derailleur on my 1985 lotus excelle. It has the standard long-cage shimano 600EX. It was working fine until someone whacked into it while chained to a bike rack and broke off the fitting where the limit screws exist. So i'm missing the piece of metal with that fitting on it now. (part of it anyway)
Soooo, I already have a new Shimano cassette hub on the rear rim (which I built myself) so I'm using a 9 speed cassette now. So I thought maybe just upgrade the derailleur as well? Any recommendations? Maybe a compatible dura ace or something? Key is that I have a 11-30T cassette on there now, So I need something can handle that 30.

Are you using friction shifting (no clicks)? Is the crankset a double with standard size rings, 52/42 was pretty common in '85? Do you want brand new or used?
Based on the 30T cassette, a mountain bike RD would be good option. If you use friction and buy used, most long cage models should work fine. Many older short cage RD won't comfortably do a 30T cogs or have a the total capacity for a 29T wrap. Older MTB RD can be found at good prices. If you currently use a 9 speed chain or plan to soon, a 9 speed RD has slightly narrower pulleys, but this not too critical.

Friction Shifting. Yes, standard double front crankset, yes. Brand new is better, but lightly used is okay. Yes, I'm using a "narrower" 9 speed chain already because I thought it would be necessary for the 9 speed cassette I bought for the back.

Thanks for the MB suggestion, maybe the best option.
For RB stuff, It seems like the only "long cage" models are the 600EX that I'm replacing and the GS dura ace stuff from the 70's. If I'm missing something super obvious, would be open to suggestions!
Thanks again,

Hi, thanks for the added info.
The 30T cog is right about the limit for many Shimano road RD made through the early 2000. Some of the newer ones are supposed to handle a slightly bigger cog. I hope that others will chime in with their experiences. For road derailleurs, I like the 5500 & 6500 series and these are available in a GS (mid-cage) version which will easily handle the total capacity but I'm not sure about the 30T cog clearance (anyone???). I use the short cage on my road bikes and GS on my MTB but don't use any large cogs on any of my bikes.
MTB RD usually have a different configuration to give the upper pulley more clearance for larger cogs. I have used XT & LX level MTB parts and found them to be quite good.

The Tri-color mentioned above is the next generation from the 600EX & works well, but did not come in a GS from what I can recall.

Hopefully others will have more info.

You can pretty easily use most any 6-9 speed derailleur. My hybrid uses a early 90s 7-8 speed XT derailleur with a XTR 9 speed shifter and a 11-32 9 speed cassette and it works flawlessly. I have also seen plenty of friction set ups that use all manner of derailleurs so you should be pretty good with most anything however I would probably keep to Shimano because Shimano is just better and some may disagree but they are certainly all wrong

For lower cost, get one of the Shimano "A" (Altus, Acera etc.) RDER's in 8 or 9 speed.
If you plan on "upgrading" to index shifting, I'd stick with the 9.
I can see where you might want more of a "road" looking RDER to better fit with the bike, but the above mentioned RDER's are designed for your type of gear range on the cassette.
They shift my "road" cassettes fine too.

If you prefer new and not vintage, I've had very good service from the Shimano Acera RD-M360 derailers. Altus level is RD-M310 and, though I haven't used one personally, Grant Petersen is all over it. Both of these derailers use larger-than-standard sprockets (13T on both for the M360 and 13T upper/15T lower for the M310).

I use my M360s indexed on 7-, 8-, and 9-speed bikes, and it would work just fine in friction mode as well (or for 6-speed, etc). They run smooth, they run silent, and they're inexpensive. They've been out long enough that they're plentiful in both legitimate and counterfeited versions as well (I imagine many/most/all that come from China on eBay are counterfeited). They're also on Amazon and, of course, at your local bike shop.

Back then, Deore and Deore XT derailleurs were used on "road" bikes needing wide-range gearing. A late-'80's 6/7-speed derailleur would be period-correct upgrade and would function just fine with your setup.

yes, it's 600. i guess i want to change it because i don't really care about keeping it "original," just want to keep it sort of period-correct looking to some degree. also, the piece of the derailleur that broke off where the set-screw goes in appears to be pot metal, and i think another one could just break. the deore xt and dura ace stuff seems to have stronger looking parts.

ah. thank you. this is coming back to me now. i used to have a schwinn impact that had deore stuff, and i remember it being cross on some of the touring models and crossovers.

Thanks everyone. I think I'll just pick a good dura ace, like a 7400 seems to look like it would make sense on my bike and just go with that. also, i can get a matching front derailleur which i think i need now after i changed the bottom bracket and my chainline got pushed out a touch.

The 7400 series RD is great, but not rated for a 30T cog, 26T was the max cog per Shimano recommendation for most racing RD back then. No GS version of this if I recall.
Another option may be drop-out hanger extenders, which bolts to the existing hanger and make it effectively longer. Seen these on ebay for use on MTB for people who want really large cogs. Don't know how well these work.
In addition to XT & LX there was a DX line back then that was high quality and used on touring bikes with larger cogs.
Good luck.

7400 was a well-made derailleur, but it had possibly the smallest chain wrap capacity of any derailleur ever made. It was designed for 42/52 rings and a corn cob racing block in the rear. And as correctly posted earlier, it could only handle a 26 tooth cog. Yes, seriously. Finally, in terms of index shifting, it was only compatible with 7400-series shifters; nothing else in the Shimano lineup, then or now.

600EX and other such Shimano derailleurs that predate the Suntour patent expiry, lack the slant parallelogram feature; a critical bit of technology. Hence they produce hesitant, clunky shifting. I've used them all.

Want something functional and somewhat vintage? I suggest Shimano DX, XT or Deore from the late 80's. Derailleur technology hasn't progressed since this.

thanks for that. i didn't buy anything yet, so i can still buy something that works. I suppose the M735 with a long cage looks like a good candidate. it's got the black painted area, but I think it looks period enough to suit me

also, i have no indexed shifting, but maybe i could introduce it? it'd have to be down-tube located friction shifters because i don't have the room on my bars for them and don't want bar ends
any ideas on that?

thanks. i'll go with the xt stuff.

i wonder if i can get down-tube located indexed shifting? i think based on what i learned in post#14, the 7400 shifters are not compatible. perhaps the 6400 series ultegra stuff? or would i have to go for a bar solution like the SL-MT62 to get indexed?

You say you want indexed shifting, and in the same sentence: "friction shifters"; not the same thing.

So I'll assume you want 9-speed downtube indexed shifters. These exist, but are not common. Ebay.

I volunteer at a high-volume big-city bike Co-op. We have several pounds of old shifters, including many sets of Shimano's excellent 7-speed indexed downtube shifters. We rarely see the 8-speed versions, and they will get snapped-up fast.

​​​​​​​9-speeders? Never had a set come in.

ok. sorry about the nomenclature. in my mind, "friction" meant any of the shifters that sweep when pushed, regardless of the indexed notches. (as opposed to the clicky-clicky variety)

so, in actuality, "friction" simply means "non-indexed" then?

ahh. so it's hard to find. doesn't suprise me. i have a RB-018 bar, so there isn't much room for bar shifters, and combo units don't really make sense. i guess i'll just keep the "friction" shifters and hope i can spot a 9 speed on ebay at some point.

thanks,

Not many 9 speed down tube shifters models as Shimano had transitioned to Brake/Shifter combo units by 9 speed era. Only ones I've seen are Dura-ace, and MicroShift generics. Suntour was pushed out by this time.
You mentioned getting a RD-M735 and the long cage version should work well in friction mode. The RD-M735 is one of the few Shimano RDs that have a tension adjustment on the parallelogram. Control is via the small screw behind the cable attachment bolt. Could be useful when running friction mode to balance how tight the shifter attachment screw needs to be to keep it in gear. Down tube shifters usually don't have as much cable drag/stretch and won't require high tension from the RD.
Good luck.

https://www.amazon.com/SHIMANO-SL-77.../dp/B000NOPN4Q

https://www.ebay.com/itm/microSHIFT-...EAAOSw-QBb-H4X

https://www.ebay.com/p/Shimano-Dura-...d=283411422142

thanks, i wasn't clear on the dura ace compatibility, and i didn't realize you can use these newer 9 speed shifters on the SIS stuff. i read up on it at sheldon brown

thanks for the info.

i did indeed pick up a rd-m735. probably get it by the end of the week or so

it was mentioned in an earlier post that derailleur technology had advanced in the geometry department in the late 80s. would this apply to front ones too?
i have an issue with my front derailleur; i put in a sealed bottom bracket and it pushed my chainline out just a tiny bit, but it's enough to make the inside ring just barely shiftable.
also, the limit adjuster screws got corroded into the housing, and i stripped the heads getting them free. i can turn them with great effort, but days are numbered.
so, i'm going to have to replace it anyway, should i go for a later derailleur?
any opinions?

thanks,

IMO, no, don't go for the "latest". Front derailleurs have evolved over the years so that they are very specialized- that is, they are designed to work with only a limited selection of chainrings. In addition, they somewhat depend on ramps and pins on the chainrings to facilitate the shift.

OTOH, since you have a 42-52 double (correct?) almost anything will work fine. Any '80's to '90's "road" front derailleur should be OK.

Replace them. They're just a 2mm screw.

I guess my question that i didn't really ask is; because i messed up my chainline a bit, is a different front derailleur going to give me a bit more room on the inside for my smaller chainring?
if so, i probably won't bother with the screws...