About that bumper thing that keeps the spring fork from banging the frame.....

[bloo]

About that bumper thing that keeps the spring fork from banging the frame.....

I bought a reproduction one for my 41 straightbar. This is one rubber piece that snaps around the frame where the fork legs would hit. Some frames have a little steel tube welded under the downtube that accepts 2 rubber bumpers. My frame does not have that. Here is a picture of reproduction part I bought:

So this is made of pretty soft rubber. What holds it on? Does it glue in place or was it just supposed to stay put on its own?

It came in a baggie with a piece of string. What is the string for?

The auction showed one on a bike with a tank. The gap was pointed up to clear the tank. Would it have gone the other way on a bike with no tank?

 

[Freqman1]

It should just stay in place. Its to keep the fork legs from denting the tank--no tank no function. Some DXs and Autocycles '39-41 had the little tube with the two bumpers. No clue why a string was included. V/r Shawn

 

[rustjunkie]

didn’t the originals have a spring steel band inside so it held tightly onto the tube?

 

[bloo]

With no tank, the fork legs crash into the frame and clobber the paint. Did Schwinn really send them out the door like that?

 

[GTs58]

Isn't that some aftermarket dohickey? So maybe the string is tied around that real tight and it keeps it from rotating on the down tube when the fork leg hits it?
If you need to glue I'd use 3M's weatherstrip adhesive. I tried silicone to glue on the bumper strips on my Ma's Buick and that only lasted a little longer than a year.

With no tank, the fork legs crash into the frame and clobber the paint. Did Schwinn really send them out the door like that?

Yup. The only bikes that had the tube and bumpers were bikes that were factory ordered with a tank and a springer. I have about 10 Corvettes and those Mayweg front carriers always make a scratch on the downtube 1.25" long on the right side. Some have a V scratch.

 

[bloo]

I think it is a repro of a real Schwinn prewar part, but can't swear to it. I have a vague memory of seeing it in some old catalog and trying to get one back in the mid 70s. No luck with that.

 

[cyclingday]

The original Double Duty/Spring Fork bumper had a spring steel clip embedded in the rubber, that kept it held tight to the frame.
The reproductions do not have this, so they don’t clip tight enough to stay in place.
They would probably work better if they were made of a harder compound.
The built in tube type bumper was definitely an improvement over this first apparatus.

 

[the tinker]

Make your own if your worried about it. Truss rods and springers of every make always hit the frame or tank. These bikes were for kids that beat the heck out of them[except the girls], and I don't think the bike manufacturers had many complaints about it . Some Monark Super Deluxe had the tubes to hold bumpers welded on like the 41 Schwinn's. I've had two Monarks that have had them and at least two Schwinns.

I took the tank off this Murray yesterday, to paint some flames on it. I make bumpers out of anything I can find. On the Schwinns, I've cut out pieces of thick rubber from an old auto floormat,[with a 3/4 ' round gasket punch] and glued them to the frame to protect the tank. It is aggravating to dent a fresh paint job. Just have to think out of the box and make whatever you have at hand work. Looks like crap though.

 

[bricycle]

The owner sells similar... maybe ask him. @sm2501

 

[cyclingday]

It always seemed odd to me, because Schwinn had the fix for this back in 1934, with the Streamline Aerocycle.
They had welded a tab on the underside of the downtube, that would stop the fork crown from rotating past 90 degrees.
It was solid, worked flawlessly, end of story.
So, why all of the hokey stuff later on?
The Aerocycle tab was the way to go.