I have a Sekai 2400 frame/fork from 1983 that I want to raise from the dead. The bike was made for a 6-speed freewheel, 27-inch wheels and nutted sidepull brakes. I have the original wheels and would like to add some components from that era to complete the build. I'd like to use indexed downtube shifters. Did they make indexed shifters for 6-speeds back then? What model brakes and shifters would fit my needs? Although I could buy all new components from Harris, I think it'd be fun, and cheaper, to find used stuff. Thanks.

As far as 1983, I think it was too early for indexed (other than Positron which I had on a 1979 Suburban, but I think that they faded from the scene before 1983).

I have four Shimano 600 derailleurs, and by their date codes I have been able to estimate that Shimano went to SIS on their 600 line in 1987. The derailleurs with that year's code were labeled as SIS, the previous year was not.

In the late 80's I have bikes from 88 and 89 with down tube shifters. The 88 has Shimano 600 7 speed indexed, the 89 has 6 speed Suntour indexed.

So I think the answer is that if you want to be completely period accurate on your bike, you may need to use friction. However, if you are looking to just stay close, you should be able to find something suitable from the late 80's...

suntour 6-speed indexed might be harder to find (at least in my experience) shimano 105 6-speed shifters are fairly common and not too desireable so you can find them easily. You will need an SIS derailleur and either a UG or HG 6-speed freewheel. The period look of the bike will be diminished, however.

Shimano's 6speed line was typically designated with the 105X (105 level), 6400 (600/Ultegra). There's also the RX100 out there that would work too. Shimano 6speed freewheels are still readily avaliable, as are the shifters (loosescrews.com was just throwing a sale on them, also often found on ebay).

dgregory is right though, the SIS stuff did appear later - late 86/87 sounds about right from what research I've done in the past. The only problem I've run into with running indexed shifters on older frames is the lack of shift bosses on the downtube to mount them to. Many frames didn't have any, others which did were not the right style for later Shimano levers. There are clamps out there with the correct boss style attached. One that comes to mind is the clamp that comes with the Shimano 105 Golden Arrow shifter (also sold on loosescrews and often seen on ebay). The Shimano 600 shift levers of simular age to the G.A. 105's are very abundant on ebay, but haven't seen with my own eyes that they have the same style clamp though.

Hope this helps a bit.

Why not simply build it up with friction shifting?

"Why not simply build it up with friction shifting?"

You're right. I could and probably will after unsuccessfully scouring ebay for indexed downtube clamp-on shifters that aren't ridiculously overpriced.

I'm still curious about what model non-recessed nutted brakes may work for my 27" wheels. Any ideas?

"Why not simply build it up with friction shifting?"

You're right. I could and probably will after unsuccessfully scouring ebay for indexed downtube clamp-on shifters that aren't ridiculously overpriced.

I'm still curious about what model non-recessed nutted brakes may work for my 27" wheels. Any ideas?