I have a Ross Signature 292S with brazed-on shifter bosses

I removed the Shimano 105 (gloden arrow) derailleurs and shifters, and want to replace them with Suntour VGT Rear and Compe-V Front but I need Suntour shifters, will these work?

Shimano had their own shaped lever bosses as well as the "common type" that Campy and most other levers use. Can you post/link an image of yours? Andy

As Andrew notes, check to see what type of shifter braze-on is on your frame. If it is the Campagnolo style, the shifters in your picture should mount fine, but they are "Accushift" indexed levers while your derailleur is pre-index VGT. It is doubtful that the indexing will work. A set of plain braze-on friction shifters (doesn't even need to be SunTour) would be fine, and likely cheaper than the Accushift levers.

You haven't said what freewheel/cassette you will use or how many cogs/speeds. According to Sheldon Brown, the six speed Accushift had sprocket spacing of 5.5 mm. Later Sun Tour Microdrive seven and eight speeds had 4.8 mm spacing of the lower cogs and 5.0 spacing of the higher cogs. I'm assuming you are probably using a shimano compatible cassette/freewheel that has 5.3 mm spacing in 6 speed, 5.0 mm spacing in 7 speed and 4.8 mm in 8 speed. The take away of all these numbers is that you probably won't be able to get accurate indexed shifting without the appropriate cassette/freewheel.

Others have mixed and matched Shimano and Sun Tour drivetrain components with acceptable results but it is a crap shoot at best and often involves alternate cable attachment. For example, I have combined 7 speed 105 downtube shifters with a late 80's alpha 3000 Sun Tour long cage rear derailleur and a shimano 7 speed cassette successfully. I had to use an alternate cable attachment at the derailleur to compensate for the different cable pull of the Shimano shifters and Sun Tour derailleur. Shifting was very nice for an early 7 speed but was nothing like modern indexing.

It looks like they are Shimano "A" type according to the diagram, thank you for posting it.

Any suggetions for shifters? I'd like to keep this project low tech and low budget

The only reason I considered those particular shifters was cost and that they were Suntour. I don't need indexing.

This will probably answer whatever questions you have including work arounds.

Shimano A Type boss coversion index shifters

Good luck!

John

Thank you

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will these allow me to use levers from Shimano clamp-on (friction) shifters on my Ross frame?

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Those appear to be SIS (indexed shifter) mounting pieces. They could allow you to mount Shimano SIS shifters, which could work in friction-mode with your SunTour derailleurs.

I see, thank you.

I'm going to rethink this project, I don't want a mish-mash of parts and brands. The bike came with Shimano Golden Arrow derailleurs and shifters, I want to use them for a different project.

Is there a low to medium end Shimano system that would work with these braze-on bosses?

Question John,

Are the two mounts in the picture above on the right are for bosses on a flat surface and the two on the left for the round down tube?

I have a mid 80s Asian frame that wasn't index shifting when new and has only 1 boss in the down tube that is facing the seat tube. Attached to that boss is a bracket that the ratchet shifters are mounted to. Everything is Shimino. In this case the mounting surface for the shifters is flat not a curved down tube. I have a set of 7 speed Shimano 105 indexed down tube shifters. If I'm explaining this correctly do you think using the flat adapters on the right of the above picture will allow me to use the shifters as index shifters? Sorry if this is convoluted.

Convoluted and off-topic.

Maybe start a new thread

If you don't need indexing, which is unlikely to work with that derailleur no matter what you do, and you don't want to keep the bike all original, which you clearly don't, keep the Shimano levers on the bike that they fit, because that's likely to be the only frame you'll ever own that they fit, and upgrade your derailleur to Suntour. The Suntour derailleurs from that era shifted better than anything else. Upper-end Suntour derailleurs from the early late 1970s and 1980s are, to this day, the best friction-shifting derailleurs ever made by anyone. The Shimano levers will shift the best that they're capable of with a Suntour RD, and the really great Suntour levers didn't come out until later, and they don't fit your bike without adapters anyway, so you're not losing anything.

--Shannon

You're right, the original shifters are the best option for this frame.

Yes, commonly used to mount the shifters on triathlon-type aero handlebars.

If the adapters fit on your frame's shifter bracket, it could work.

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Here are the 105 shifters that came off of the bike, they are identcal in structure to 600 (arabesque) shifters with the exception of the plastic stand-offs and two of the washers....





600 Arabesque
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These are worth more as parts. The little tabs break off and they don't make them anymore.