Stem shifter cable options?

[LifeBehindBars]

I have one bare Schwinn Cruiser 5 frame I was going to build a klunker out of and I also have a 84 Cruiser 5 that’s mostly stock but was converted to a thumb shifter. I’d like to run stem shifters on both but I don’t know much about them. I’ve come across a couple of post talking about the cables used and replacements being difficult to source. Is there a modern solution or DIY hack to replace the cable besides relying on scarce NOS replacements?

 

[AS-1]

Go to Ebay and search for:

NOS Suntour Ratcheting Stem-Mount Road Bike Power Shifters-Friction-21.1-Schwinn.

The installation will be easy and you should be all set.

 

[acg_schwinn]

Go to Ebay and search for:

NOS Suntour Ratcheting Stem-Mount Road Bike Power Shifters-Friction-21.1-Schwinn.

The installation will be easy and you should be all set.

I loved those shifters. Several decades ago now (cough), my mother, who loved estate sales, came back from one with a trunk full of some unbranded but nicely repainted 10-speed lightweight frame and a box of assorted parts. The story was that the owner had taken the bike all apart for upgrading and refinishing, which he did, after which he promptly expired without ever putting it back together. My mother bought the whole pile (car trunks were much bigger in those days), saying she thought I might like to have a go at reassembling it.

Most of the parts appeared to be department-store quality (perhaps removed in anticipation of getting better hardware), but then there was also this brand new set of Suntour Power Shifters, which were just the coolest things I had ever seen at my age of... I dunno, 15 or so. I thought the design was ingenious. I put the bike back together with mostly its original stuff, but I did install the Power Shifters in place of the plasticky originals, and they worked beautifully. I see they're plentiful and cheap on eBay these days...

 

[AS-1]

Great story, great memories. Suntour components were excellent.

 

[WillWork4Parts]

I have one bare Schwinn Cruiser 5 frame I was going to build a klunker out of and I also have a 84 Cruiser 5 that’s mostly stock but was converted to a thumb shifter. I’d like to run stem shifters on both but I don’t know much about them. I’ve come across a couple of post talking about the cables used and replacements being difficult to source. Is there a modern solution or DIY hack to replace the cable besides relying on scarce NOS replacements?

Shimano Positron controls are the ones that are difficult to find replacements for because they are a solid wire inner used to push AND pull the derailleur, plus the outer housing has plastic fittings that clip into the shifter and the derailleur. There is nothing standard about them and no one offers a remanufactured replacement. The Shimano Positron (II) system was original equipment for these later Chicago Schwinns...and yes control "cables" are continually getting harder and harder to find in functioning condition. I have tried finding used bikes to rob the housing from and constantly find them split in the bends or with broken off plastic ends where someone tried to forcefully remove them...or bent and broken ends of the solid inner wire... You can't just replace the controls with a standard cable and housing either because the derailleur is setup with detents(indexing) and it does not have a return spring like most standard derailleurs. The outer housing has to be the correct length for the bike and requires multiple well placed clamps all along the frame that attach with screws...NOT a fun system to work on...mostly because you have to tell the customer that their entire derailleur, cable, and shifter need replaced, unless they happen to have an NOS housing in their back pocket.

There are plenty of other models of stem shifters and standard derailleurs to pick from that will work just fine though. Use friction shifters to avoid shift pattern compatibility issues.

This just made me think of a great idea, we need someone to manufacture a housing adapter with a threaded barrel fitting that will compress around a standard linear housing and can be used to replace all of these broken controls with new housing. That won't fix the broken inner wires, but those parts can be reused and can still be found in working condition.

 

[LifeBehindBars]

Are the older Schwinn 5 and 10 speed bikes with stem/headset mounted shifters friction shifters if they’re not branded positron?

 

[mongeese]

The Mr. Belvidere of Schwinn has spoken .

 

[mongeese]

 

[acg_schwinn]

Are the older Schwinn 5 and 10 speed bikes with stem/headset mounted shifters friction shifters if they’re not branded positron?

Those older ones are indeed friction shifters, as the wing nut on each maintains pressure on a fiber inner washer that holds the lever in its current position. You pull the cable lever downward against the force of the return spring in the derailleur to downshift (rear) or upshift (front), and then lift the lever for the opposite direction, at which time the return spring in the derailleur shifts the chain appropriately and takes up the slack in the cable. The Positron system (as noted) is entirely push-pull using a solid wire, sort of like a Bowden cable setup you'd find on the HVAC controls of a vintage car.

I'm not sure what you have to start with here... are you building off of a bare frame, or are you trying to match shift levers to existing derailleur hardware?

 

[mongeese]