Shimano SIS System?
 

I picked up a late-80's Ross Gran Tour that uses a Shimano SIS shifter system. This seems to be an early version of indexed shifting. I have to say it works very well. Any experience with this? Problems?

https://cimg2.ibsrv.net/gimg/bikefor...b50d3e8003.jpg
https://cimg3.ibsrv.net/gimg/bikefor...9ab1a2d5fb.jpg

Simple and effective. Less gears for x-space means greater resolution and less finnicky.

Nice. Just go through the bike to check cable tension and the barrel adjusters to ensure reliable index shifting. I'm curious whether the SIS stem levers included indexed shifting for the front derailleur. Some Shimano SIS thumb shifters for triple chainrings were indexed.

My 1992 Univega Via Carisma had SIS thumb shifters. Worked really well for awhile, but by 2017 it was worn out and too difficult to repair. There was some complex gearing and the axle pins and support holes wore out. Eventually I switched to bar end shifters.

But that won't be a problem with your lever shifters. They're dirt simple and reliable.

At some point you might consider moving them to the downtube, but don't feel pressured to do that just because all the cool kids do. Stem shifters work just fine for casual recreational riding.

My 1976 Motobecane Mirage had stem shifters (friction only, no indexing back then) and when I realized I'd never be one of the cool kids I replaced the stem shifters with Suntour downtube shifters. It didn't really improve shifting feel, but did enable shifting from the drop position so I didn't lose any aero advantage during time trials and crits.

My Centurion Ironman has downtube shifters and I'll probably leave 'em that way. But for a casual riding bike I wouldn't turn up my nose at stem shifters.

Ditto, those "turkey leg" safety brake levers. Don't feel pressured to remove them. There are exaggerated claims that they're mushy or unreliable. Not true in my experience. They work just fine for casual or commuting rides while using the top of the bar. For fast rides in groups or downhill blasts, sure, move to the drops and use the main levers.

Good quality new pads will make more difference in braking. Kool Stops are great but Jagwire pads are better values and work just as well in my experience. The only exception would be Kool Stop Eagle 2 (formerly Eagle Claw) pads for cantilever brakes for mud and wet conditions -- there's nothing else like them by any other manufacturer. But your bike has sidepull brakes and you can find good new pads easily from a dozen different manufacturers.

BTW, the one reason I did remove the turkey leg safety brake levers from my old Motobecane wasn't for looks or to be cool. It was because I wanted to add padding to the brake hood. Those metal hoods were uncomfortable on long rides when we needed to get lower into headwinds.

Back then the hot ticket for comfort was foam rubber tubing, the kind of stuff sold as pipe insulation nowadays. Or one particular brand of thick, soft rubber bar wrap tape. But to pad the hoods I had to remove the accessory brake levers.

Also the turkey legs can interfere with some handlebar bags. Back then I used a Kirtland Tour Pak and sometimes when I filled the pouches facing the handlebar it interfered with the accessory levers. Just depends on the mounting system for a handlebar bag.

SIS means Shimano Index System... so it's kind of improper to say Shimano SIS... in case you're a pedant about such things.
It was the first really good indexing system that was available,and it's still what they call their non-brifter (STI) shifting system.
I have 9-speed downtube DuraAce shifters and they are SIS.

https://lh3.googleusercontent.com/o_...A=w563-h840-no

Front indexing is a generally new thing- if your chainrings aren't ramped and pinned, you generally don't have indexed front shifting. This bike looks to be around 86/87- long before ramped and pinned chainrings became common.

Did your Univega have thumb shifters or trigger shifters? Thumb shifters will last as long as DT shifters- trigger shifters will foul up- especially the earlier ones. I don't know of too many brands that were speccing thumb shifters by 1992- was there even an upper level Shimano group that had thumb shifters by 1992?

Thanks for the info. But if you want to be truly pedantic, DuraAce should be Dura-Ace. Just saying. :thumb:

Thanks guys. Info appreciated.

Pedant bro fist-bump

Probably should also be ALL-CAPS

Mine is a '92 Univega Via Carisma, the splatter paint era model with Bi-Axial Power Oval frame. Shimano 500 CX group, SG 30/40/50 triple chainring, indexed thumb shifters for both front and rear.

This is my bike, from 2016 -- first thing I changed back then was to replace the original flat bar with a riser bar. I've modified several things since: different saddle; Nitto albatross bar with Shimano bar end shifters; 130mm horizontal/0 angle road bike stem; different wheelset with 8-speed hub and MicroShift cassette.

The left/front shifter went bad first in 2016, skipping across the middle chainring. I replaced it with a cheap SunRace SLM10 friction thumb shifter. The right/rear shifter went bad after I was hit by a car last May. It worked for awhile then quit. I was switching to albatross bars anyway and bar end shifters work better with that setup. The old Shimano thumb shifters are in the junk box in case I ever get the urge to try to fix them. Degreasing/degunking didn't help.

https://cimg9.ibsrv.net/gimg/bikefor...89fcc0fe26.jpg

1992 Univega Via Carisma with original indexed shifters.


***
This is another BF member's identical mixte version, same year, paint and components including the indexed shifters.
https://cimg5.ibsrv.net/gimg/bikefor...82d3fa78af.jpg

Mixte version of the same model Univega Via Carisma

https://www.bikeforums.net/attachmen...1&d=1474171225

Yes, both derailleurs are indexed. And both work perfectly. No need for any adjustment. Personally, I like the brake safety levers and have added them to bikes of mine where they were absent - even my Fuji Team which has more of a racing pedigree. I doubt my riding will ever go past the "casual" state.

Bingo.

It's interesting- the under bar shifters are shifted with your thumb- but generally aren't referred to as "thumb shifters." Doing an image search for "thumb shifters" shows what's generally considered thumb shifters.

The second I saw your picture- I remembered my sister's 92-ish Trek 820 had the Exage shifters like that- with indexed front shifting!

Those marbled "bowling ball" finishes look cool!

The subject shift levers appear to be 5 speed version of the SL-S452, which were part of the Tourney group. These came out circa 1988-1989. The nicest feature is that they still have the mode lever for switching between friction and indexed shifting. My recollection is that these were only friction mode for the front derailleur.

According to wikipedia - "By 1985 Shimano introduced innovation only at the highest quality level (Dura-Ace for road bikes and XT for mountain bikes), then trickled the technology down to lower product levels as it became proven and accepted. Innovations include index shifting (known as SIS, Shimano Index System introduced in 1984)". Your timeline also makes sense since I believe my Ross is a 1988.

I will double check on the front indexing.

My 88 Peugeot was Index-only on the front. It was an Exage A350 shifter. Couldn't be switched between index and friction. Just a random note for you, confirming some trickle down of Indexing to lower groups in the late 80's.

Guys were correct. Indexing only on the rear derailleur.

The Wikipedia article is misleading. SIS was not Shimano's first indexed system. That honour belongs to 1975 Positron which was intended for low end models and was the first indexed derailleur system to achieve significant market share. It was followed in 1981 by New Positive Mechanism, which was simultaneously introduced on four different AX groups. SIS was an evolutionary change that would eventually lead to STI (Shimano Total Integration, generically known as brifters). However, SIS was historically significant in that it triggered the industry wide shift to indexed shift systems, with SunTour and Campagnolo quickly responding with their respective introductions of AccuShift and Syncro .

Also, while Shimano changed their marketing approach with the introduction of SIS, by introducing it on their top road group and then trickling it down the line, it had nothing to do with proving the product and customer acceptance. SIS was commercially introduced in the autumn of 1984 for the 1985 model year on New Dura-Ace (7400 series). It had already been thoroughly tested in professional racing during the 1984 season, notably with Urs Zimmermann using it to win the 1984 Tour de Suisse for the Cilo-Aufina team. Between that and in-house accelerated testing, Shimano already had the feedback on performance.

Regarding consumer acceptance, that was a calculated risk that Shimano was willing to take. SIS was trickled down to New 600EX and LIght Action in the autumn of 1985, for the 1986 model year. Production of these shift systems would already have started by mid-1985, before Shimano had much consumer feedback on SIS from New Dura-Ace. Furthermore, the 1987 model year groups receiving SIS (Santé, New 105, Deore XT and New Deore) were probably already on the drawing board before Shimano got any useful amount of consumer feedback. The circumstantial evidence suggests that Shimano was committed to SIS and quickly trickling it down through the majority of the product line, whether or not there was customer acceptance.

Yes, Shimano introduced front derailleur SIS for 1988, on Exage Sport and Exage Trail. While not bottom of the line groups, they were lower end, so front SIS was not a trickle down process. Indexed front derailleurs would become widespread in the early 1990s with Shimano's introduction of STI integrated brake and shift levers for road bicycles and RapidFire for ATBs.

While the hyphen is proper, all upper case is not required. Shimano's own literature uses mixed case when referring to Dura-Ace in common text. Witness the bottom line of the cover page for the 1985 New Dura-Ace brochure that introduced SIS. And yes, New Dura-Ace is the proper name for the 7400 series group. New is not an adjective but part of the group name that defines it as 4th generation Dura-Ace

https://cimg7.ibsrv.net/gimg/bikefor...982389a044.jpg

The history is interesting, but I was more concerned with any inherent flaws, or known problems. Not hearing any. The early SIS seems solid to me.

As far as upper/lower case and hyphens - I'll pass.

Since we're talking vintage shift levers, they almost always benefit noticeably from copious re-lubrication of the indexing mechanism and lever pivot.

Just as friction levers (and especially Synchro levers) benefit greatly from complete internal re-lubrication using any regular oil (no need to disassemble or clean first).

Foaming aerosol oils such as shown below are particularly effective when internal parts are not directly accessible, as the effervescing/expanding stream of oil saturates the entire mechanism even though non-removable parts or covers are in the way. Just be wary of those transparent indicator windows that some newer levers might feature, the oil usually does no harm but some clarity may (in theory) be lost over time.

https://cimg7.ibsrv.net/gimg/bikefor...2e24831770.jpg

In C&V Heaven, there will be an encyclopedia co-written by T-Mar and dddd. :beer:

I (and I suspect T-Mar) appreciate the compliments coming from Chicago!

Curiously, New 600 EX, while all-new in design, preceded the SIS era.
While certainly not the lightest 600 friction gruppo, I think of it as perhaps the pinnacle of Shimano's friction gruppos, Servo-Panta at it's very best, with robust durability, and I think newer in design than Shimano's last Dura-Ace friction gruppo.
As a serious Suntour partisan at the time, It escaped my notice. But I found a Centurion Elite RS a few years ago that was somewhat of a revelation in terms of friction shifting performance, once I updated the chain to UG Narrow (dimensionally identical to today's HG).
Oddly enough, Centurion offered bikes with both New 600EX and 600 SIS concurrently, as their prices were significantly different. The former gruppo may have had the aesthetic advantage, no? Sorry this photo isn't sharper.

https://cimg9.ibsrv.net/gimg/bikefor...f089953253.jpg