philbob57

I’d like to install 7 speed indexed shifting with downtube shifting on my 1973 bike with either a 7 speed freewheel or my current Ultra-6. The bike needs shifters with a clamp, since there are no useful braze-ons on the frame. I'm pretty sure my Suntour V-GT has enough range to handle the 7th cog.

What’s this group’s experience with the Sunrace SLR30 shifters? They can be seen at SunRace | SLR30.

I’d like to use Shimano parts, but I’ve found only one set of shifters with clamps, and it's ambiguous whether that's for 6 or 7 speed freewheels. (Velobase is ambiguous. I've got a query out to the seller.) I’ve got some Campagnolo shifters from the ‘80s. Will the Shimano shifters for braze-ons fit on the Campagnolo band (yes, no, maybe)?

Any thoughts on new Sunrace shifters vs. used Shimano?

Thanks in advance.

rccardr 

If you decide what you need is a nice clamp on set of Shimano indexed downtube shifters for a Shimano 7 speed cassette/freewheel, shoot me a PM.
I have what you need, turnkey.

JohnDThompson 

My concern would be whether the SunTour V-GT derailleur has the same cable-pull expectations an SIS-compatible shift lever expects. The SunTour V-GT pre-dates SIS shifting by many years, so if this works it would be plain serendipity.

If you intend to use friction shifting with the V-GT derailleur, don't even bother with an SIS shifter. Just get some decent friction shifters like the SunTour "Power Shifters" that were intended to be used with the V-GT derailleur in the first place.

dedhed

https://www.bikeforums.net/classic-v...untour-rd.html

https://www.bikeforums.net/classic-v...atibility.html

Andrew R Stewart 

Ultra 6 is a specific to SunTour design. "ultra six" is a generic reference to a 6 speed cog set with less then the usual 5 speed cog to cog spacing. SunTour cog spacing, back then, wasn't consistent across the cogs so Shimano indexing which is designed around the same c-c spacing for all the gaps wasn't intended to be compatible. Now with enough wear/slop and and looking the other way some cogs might index OK... Andy

andrewclaus

I used a set of Sunrace clamp-on indexed shifters for about a year on a vintage bike conversion, with a Shimano cassette and RD. It worked for casual riding but it was a little painful. Lots of "looking the other way" as Andrew says above.

I eventually salvaged some Shimano brifters.

philbob57

Closing the loop: I bought a Sunrace SLR80 8-speed downtube shifter to go with a Shimano 7-speed freewheel and my V-GT rder. Even with the 0.2 mm narrower 8-speed spacing, the only problem I've found is that if I shift with very light pressure on the pedal, the shift may not occur. If I put a few lbs of pressure, the shifts are fine for this old and slow rider. The shifts are positive. They're also loud (they sound loud to me even though I don't wear my hearing aids while riding). I'm very happy with the combo for now, though I'm looking for a good, cheap 7 speed rder. Not Brifters - too pricey for me.

cs1

Thanks for the links I just responded to the last one. I hope it helps everyone.

Ironfish653

The Shimano SL-S434 is a good shifter to use for conversions like this. The levers come on a band-mount so you can use it on a bike that doesn't have braze-ons. While they came in either 6- or 7-sp versions, they also have a friction mode that's really more of a 'micro ratchet' with lots of tiny 'clicks'

I tried a bunch of times to get my V-GT to work in index mode, with a 6-sp Shimano FW; I could get it to play nice for 3 gears, 'maybe' shift on to a 4th, and 'Heck No' for anything above that, especially the 34t MegaRange

Running a modern chain (KMC-Z51) and the modern FW still produces nice, smooth shifts, even in friction mode.