Re: Shifting with downtube shifters
Posted: Thu Aug 16, 2012 8:55 pm
Now to really confuse the situation....
Any comments on downtube shifters vs headstem shifters?
Any comments on downtube shifters vs headstem shifters?
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Headstem shifters were usually installed on the low end "racers" of the 70s and 80s. Their best use is to indicate which bikes you should leave on the hard rubbish pile.Grog wrote:Now to really confuse the situation....
Any comments on downtube shifters vs headstem shifters?
+1 - and suicide levers. They're junk tags.rkelsen wrote:Headstem shifters were usually installed on the low end "racers" of the 70s and 80s. Their best use is to indicate which bikes you should leave on the hard rubbish pile.Grog wrote:Now to really confuse the situation....
Any comments on downtube shifters vs headstem shifters?
Well, Yes/No on that one. The limitation you mention is a limitation on all indexed gear systems not just downtube levers. Also, providing you stick to one brand you can generally use any number of sprockets up to at least 8 speed as the spacing stays the same. Assuming you are not trying to mix an 8spd block with a lever that only has 5 indexes of course . But if you have a 8spd indexed Shimano lever it will work with 5->8 speed Shimano spaced sprockets, Shimano spacing is virtually industry standard these days since SunTour and Campag gave up using their own spacing on sprockets.Big_Red wrote:I'd have thought that indexing on DT shifters would be limiting as you are constrained to only using a freewheel or cassette with the sprockets a particular distance from each other. I'm considering getting a new wheelset for my old Paconi, which will result in a replacement of the suntour 6sp freewheel with a shimano 9 speed (casette) and relish the fact that it'll be just a swap of the wheels to achieve as the trimming between the gears is all manual.
That's interesting to know. Thanks for the info!rkelsen wrote:Incidentally, I ran an A400 7 speed d/t shifter with an 8 speed cassette for a while. After the 6th click (at about 90 degrees) it goes into friction mode and you can keep turning it for another 90 degrees. The spacing of the cassettes is the same, and the 8th "click" into low gear was actually against the derailleur limit screw.
Interesting. I missed some of the transition stuff back then. More familiar with really old stuff, like me. What's the go with these, when I finally get the pedals in an get on the road? Don't have a pic right now on the RHS shift lever, but pretty sure it has a half-round flip-out tension ring as well. What are the adjustment procedures on them; with that slotted cap?rkelsen wrote:You can also turn off the indexing on many of the Shimano downtube shifters.
The LH downtube shifter in your photo isn't indexed. Most of them weren't. Some may have been, but I've never seen an indexed LH d/t shifter.frailer5 wrote:Interesting. I missed some of the transition stuff back then. More familiar with really old stuff, like me. What's the go with these, when I finally get the pedals in an get on the road? Don't have a pic right now on the RHS shift lever, but pretty sure it has a half-round flip-out tension ring as well.rkelsen wrote:You can also turn off the indexing on many of the Shimano downtube shifters.
.... while you're there.... That refers to spacers in the shifter spindle mech?koen wrote:All early indexing allowed a switch to friction except maybe some really cheapo shifters. I ran/raced with these right into the 2000s and usually with more gears than the clicks as someone mentioned. It is easy to get 7speed indexing off 6 speed shifters using the rear mech limit as the last "click". The middle few spacers need to be 6 speed width though. Some late eighties Suntour rear mechs I couldn't get to cover 8 or 9 speeds ...not enough movement in the mech.
munga wrote:so it was two-speed with five transitioning ramps
Got it, thanks Stuey. Would have taken a while to suss that out. Couldn't see any 'SIS'/'Fric' markings (though I may in full daylight ) but twisting through roughly 90ยบ gives the appropriate feel in the lever. Thanks!Stuey wrote:Frailer, you'll see that little red arrow on the RH shifter points to either 'SIS' or 'Fric.' for indexed or not.