Harold74

I've got a 1992 Miyata 1000 LT that is set up as 7 speed front to back. It's got Shimano SIS bar end shifters that, as far as I can tell, have no markings on them to indicate the model. I'm doing a major drive train upgrade that will involve a Sugino 9 speed crank and a nine speed chain. The cassette will remain 7 speed until I muster the courage to attempt to build new wheels.


I would love to replace the existing Deore 7 Speed long cage derailleur with a Shimano 10 Speed 105 medium cage derailleur. And my research thus far leads me to believe that there are reasons for hope. So my questions are these:


1) Is the pull ratio on a Shimano 105 10sp RD 1.7?


2) Is the pull ratio on a Shimano 7sp bar end shifter from 1992 1.7? My research indicates that Dura Ace shifters from this time period have pull ratios of 1.9. Unfortunately, I don't know how to figure out if my shifters are Dura Ace or not. "SIS" is the only marking, there is a lot of Deore group set on this bike. This is one of those rare cases where I'm rooting for lower quality components. This is what I've been able to find in the catalogs available online:


1993 Shirnano 600 Ultegra Sl-8S5 shifters

1992 No info available

1991 Deore DX Shifters


3) Any problems with my proposed setup that I may not have thought of?


Thanks, all, for your help with this.

dddd

If the existing Deore derailer works with the 7s bar-end levers then the 105 10s derailer will also index correctly.

70sSanO

1) Shimano Road 6-10 RDs have a 1.7 actuation rate. 10spd mtb and 11 spd road were the change points.

2) I don’t think Dura Ace 74XX, with the 1.9 rate, ever offered a bar end shifter. From what I have read 9 speed Dura Ace bar ends were basically Ultegra.

Only thing might be chain width through the 10 speed cage. I know 8 speed chain works with 7 speed freewheel/cassette and 9 speed RD. I think you can even run a 9 speed chain with a 7 speed freewheel/cassette.

John

John Nolan 

The 92 catalogue doesn't show at 1000. Is it possible it's a 91? It shows "Deore DX SIS" bar ends.

None of my business, but the original spec looks pretty sweet to me.

canklecat

Yup. On my 2014 Diamondback Podium crabon fibber frame I'm running a mish-mash of stuff I grabbed out of the junk box. Currently (subject to change at whim or whenever I finish overhauling my 10-speed DA stuff):

• Ultegra 6700 crankset/chainrings (nominally 10-speed)
• Older Shimano 600/Ultegra 8-speed front and rear derailleurs
• MicroShift 7-speed brifters
• SunRace 7-speed 11-28 cassette
• Shimano HG53 9-speed chain

Until a week ago I had a KMC Z72 "8-speed" chain on that bike, but most nominally 8-speed chains seem to work with pretty much any 6, 7 or 8 speed setup, and even with some 9 and 10 speeds although tolerances may be less than optimal.

I'd been using that KMC Z72 chain on the bike for about a year and the only issue was occasional chain rub on the FD. Usually I could reduce it with the trimmer clickstops on the left brifter, or just change gears more appropriately. I left the chain a link longer than normal to avoid damaging the rear derailleur in case I got tired and careless on a climb and shifted into the 28T big cog while still in the 53T chainring. And I did that a couple of times. No problems, just a bit of slop in the chainline but nothing that hindered function.

That chain finally seemed a bit worn so I replaced it with a Shimano HG53 9-speed chain, one of two I bought from REI last summer when they were blowing out components cheap. I snagged a couple of HG53 chains for around $5, and three BB-UN55's in various common sizes for around $7 each. No idea why REI was doing that during the peak of the pandemic-related shortage of bike components, but what the heck. I didn't buy 'em all and left a few for other folks.

I should have installed that narrower HG53 chain to begin with last year. It works perfectly, no chain rub. Feels smoother shifting and riding. Less slop on the chainrings, which might prolong the life of the chainrings compared with the wider 6,7,8-speed chains.

I had to adjust the RD barrel adjuster very slightly, maybe 1/8 turn to quiet the clinking. The wider KMC 72 chain had enough slop to make it unnecessary to fine tune the RD so carefully.

And I've had a few more chain drops with the front derailleur, possibly because the MicroShift brifters are set up for 7-speed and I'm pushing that shifter beyond its intended use with this mish-mash Frankenbike.

RiddleOfSteel

Shifters change their pull ratios for every "speed" or cassette cog count (7, 8, 9, 10-speed etc), so do not even worry about them. Other than 7400 (for road), all Shimano road RDs employ the same pull ratio. This is key. You can mix and match RDs all day long. Heck, you could run a fancy 7900-era 10-speed Dura-Ace STI 'brifter' with a cheap 'junk' 6-speed "Shimano SIS" RD from some big box store bike and it'd work.

Shimano road and mountain SIS RDs maintained the same pull ratio from 6-speed up until MTB went 10-speed. Then they changed it again for 11-speed. Shimano road ratio changed at 11-speed (as well as 4700-era Tiagra, which is 10-speed but the RD pull ratio is 11-speed--you could in theory use a Tiagra shifter with a R9100 Dura-Ace RD if you liked).

TL;DR: You're fine. Run that rear derailleur.

Harold74

Thanks for the assistance everyone.



I agree, and I officially make it your business to comment on what you think I should and shouldn't be modifying here. It's like this:


1) 1992 was an ugly Miyata year in my opinion. And somebody keyed up the paint before the bike found it's way to me. So it's never going to be super pretty.


2) My goal with the bike is to make it as mechanically awesome as I can. As a secondary goal, I may eventually go 100% 9 speed to make it easier to replace the consumables that I'll need in order to keep riding the bike until 2050. I'm hesitant to do that now though since a) I'm not sure that I yet have the wheel building skill to pull it off and b) I really like the stock, Deore hubs. I'm putting CX50 cantilever brakes on, subbing in a titanium seat post that I have lying around, switching out the crank and chain, replacing the cassette and, possibly, replacing the derailleur. I may ultimately go with Dia-Compe bar end friction shifters if I can't get the indexing to work on the new setup or my existing shifters eventually crap out.


3) I didn't even know about biopace chain rings until I got this bike. My initial, visceral, totally uninformed opinion of them was "Ick, not round??". Additionally, the chainrings are heavy and pretty ugly with beat up paint etc. So I went out and dropped a bundle on the Sugino crankset. Having ridden the bike a great deal more, and researched biopace a fair bit, I'm starting to wonder if those chainrings might actually be part of what's currently making the Miyata a wonderful ride for me. Maybe I'm a "biopace guy". Still, I'm going to try out the Sugino crankset. I certainly won't be tossing the biopace away though. I'm going to save all of the original stuff in case my "improvements" actually wind up making things worse.


4) I'm obsessed with great shifting and high end derailleurs. I don't really know why. The Deore was -- and probably still is -- a quality derailleur. That said, I feel that the long cage derailleurs tend to have harder lives than their short cage brethren (I'm a structural engineer which probably factors into my perception). The shifting is currently pretty great but the long cage is a bit clunky feeling at times, the chain slaps around a bit on rough terrain, and the spring seems a bit soft relative to the new Claris medium cage derailleur that I just bought for the bike and will likely abandon for the 105. The 105 may not change anything as the bike will still be a triple and the 105 is still a medium cage derailleur. It's an experiment for sure. And, like with the biopace, I won't be tossing the Deore derailleur.


So, with that information in hand, do you feel that I'll regret some of these choices?

icemilkcoffee 

The part number marking can be found on the underside of the rubber boots on the levers.
It will most likely be BS50. No problem using the 10 speed 105 RD. I prefer keeping every component shiny silver on classic bikes myself though.

madpogue 

Even on classic bikes with black, white, gold, etc. components?

John Nolan 

I have BioPace on several of my bikes and like it fine. I don't really notice much difference, but for me it seems to work best on mountain bike range gearing.