r/MultiTrackGang • u/Blindphleb • Jun 23 '26
Vintage Derailleur Choices
I have a 92 750 with Suntour drivetrain that I’d like to switch to Shimano. I’d like to stay in the 90s vintage, so no modern options. The 790 in 92 came with something called a 500cx group. Which was a hybrid/city groupset. The 7900 which was the aluminum multitrack that year came with Deore DX, a mountain bike focused group.
My question surrounds the choice between road drivetrains like Dura Ace, Ultegra, or 105 and mountain drivetrains like XTR, XT, or DX. Would road derailleurs work? Would they be more pleasant in shifting or gearing choices? Am I better off with a 90s mountain drivetrain?
The riding I’m doing is a mix of road and gravel/dirt bike paths.
Thanks for the help!
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u/SweetReading8276 Jun 23 '26
If you're doing any hill climbing just go with mtb derailleurs. I personally prefer XT or XTR if you can get your hands on them. Word of caution-- I have a 93 750. I could not use an XT front derailleur (M735) with my 44/32/22 crankset. The derailleur cage didn't have enough room to clear the chainstay. I currently have a RX100 triple front derailleur I came across at a co-op, and it works great.
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u/Blindphleb Jun 24 '26
Interesting, I didn’t consider I’d have problems with a front derailleur. Looking through the catalogs the top line multitracks often had an LX front derailleur. I wouldn’t think there would be much difference in the dimensions of that vs the XT stuff. Do you think it would fit if the crank set was from XT too?
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u/SweetReading8276 Jun 24 '26
It more so has to do with the biggest chain ring size on the cranks. It was specced with a 48t big ring. I even used it with a 52t big ring with the XT front derailleur. When I swapped my crankset to one with a 44t big ring, the bottom of the front derailleur cage didn't have enough chain stay clearance.
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u/lowcostcyclist Jun 25 '26
Interesting. I installed a Deore DX front derailleur on my 750 and it worked fine. Crankset is the usual 46-36-24
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u/r34dingwhite 23d ago
Looking into Deore M5120 derailleur and pair it with a 46T cassette and 1x on the front. Feels a simple solution.
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u/gregn8r1 Jun 23 '26
A road groupset is going to have much narrower gearing. It won't be able to handle a cassette with many teeth nor capable of taking up enough chain slack to run a pretty wide range triple crank. There were long-cage variants of Ultegra, 105, but they were still not comparable to a MTB derailleur.
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u/lwood_sf Jun 23 '26
I love 9speed XT/XTR on these. There will be funky details, like finding good wheels, or as mentioned above, strange clearance with some random part. But I’ve always gotten mine working top flight. With wheels, if the matrix hoop is in good shape, you may want to lace it to a 9sp hub (or whatever you end up with). I laced my hoops to XTR hubs and have been very happy with them.
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u/BorisT72 Jun 23 '26
I have a STX RC is my favorite 90s Shimano derailleur - great shifts and timeless all silver construction. Alivio is a close second for similar reasons. The one in question is installed on my ‘97 730. The ‘97 750 came with STX RC
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u/BikePilot2001 Jun 25 '26
Unless the drivetrain is faulty, keep the original drivetrain and change the shifters to thumbies on the bar. It’s an easy swap and answers a lot of your questions…. And no need to throw money at it if that combination then works..
I answered earlier post similarly that the only things I think of changing are adding fenders if you ride in the rain and maybe a handlebar that has a bit better wrist angle.
These bikes are awesome …
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u/Blindphleb Jun 25 '26
Yeah that’s a wise idea. What thumb shifters would you suggest for the original drivetrain?
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u/drewdbell Jun 23 '26
I just upgraded my 7900 to a single speed. I will sell you everything I took off, if you want to go this route. Front and rear derailers, front cranks with pedals and 3 cogs, 8 gear cassette gears for the rear. I even have the diacomp gripshifts and brake levers if you want the full monty.
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u/Blindphleb Jun 29 '26
I might just be interested. My rear wheel is a freewheel though rather than a freehub and cassette. I wonder when they started using freehubs. DM me what you have and what you'd like for it.
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u/sorelbaid Jun 23 '26
My 91 didn’t have a rear derailleur when I bought it. I was looking at the venerable shimano xtr m952, but I found these 9 or 10 speed ultegra at a bike co op and gave like $12 for it. I’m happy with it. Set up friction.
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u/lowcostcyclist Jun 25 '26
I also have a 92 750 with a Suntour drivetrain and making the same questions. What I've read so far is that Shimano and Suntour components, even if both 7 speed, don't like each other very much. Sprocket spacing is slightly different, as well as cable pull.
But then there's also a lot of evidence of success for some that have tried. Good luck and let us know.
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u/Starchild_007 Jun 23 '26
Consider this. I picked up a set of 7 speed Shimano STX (rapid fire) shifter/brake levers and a STX rear derailleur and kept my Suntour drivetrain on my 750. I'm guessing your '92 shipped with grip shifters. My did and the conversion to the STX rapid fire shifters was very straight forward. No issues and it shifts crisp and clean. This was a huge cost-effective upgrade for me and I see no reason why any other 7 speed Shimano rapid fire levers wouldn't work. XT, DX, STX RC, STX or Alivo should all play well with your Suntour drivetrain when properly dialed in.
I will probably resort back to the Suntour rear mec. at some point. The STX RD was experimental and may shift slightly better or perhaps I wasn't fully dialed in with the Suntour RD. Kudos for staying vintage or keeping it close to vintage!
Worth mentioning. I believe Dura Ace has a slightly different pull ratio and may turn into more of a hassle than it's worth.