A buddy of mine bought a 1970s Sears Roper/Trail Tamer project a while ago, and gave up on it. He bought it because it had the reciprocating motor/rear suspension thing. Also this particular model had front suspension and a Comet 20 torque converter with jackshaft. Also the remote mounted gas tank and disc brake set up. As far as Ropers go, probably as advance as they made. But the project got over his time allotment, and he wasn't going to get it done.
So I took on the project. The biggest problem with the bike was lack of wheels. He had some random 6" front wheel and a 5" rear wheel. They were not original, and I'm not even sure how they would even work. He kind of knew this too, and had bought a pair of Azusa 10" wheels for the bike. Some Ropers did come with 10" wheels, and I am partial to 10" wheel bikes too. So I thought I could make this work.
Another problem was the front suspension. The stock chrome springs were wasted, compressed to nearly nothing, and ready to break. So I used a new pair of standard front fork springs as available from OldMiniBikes (ordered with new cups.) They are longer then the originals, so had to re-mount the lower cups in a new position to make it work (and maintain geometry.)
Another thing I did was to move the rear shock mounts. On original Ropers the shocks are basically vertical. But with the 10" wheels (and the new rear disc brake setup), this was not going to work. So i did a more conventional shock mount position. It increased the swing arm angle a bit, but overall I liked how this looked. And it would enable me to use a DB30 doodlebug style rear disc brake set up a lot easier (more on that later... remember no original rear wheel, so no original rear wheel disc brake rotor.)
Here's the bike mocked up with the Azusa wheel, just to see how it would "sit":
So I took on the project. The biggest problem with the bike was lack of wheels. He had some random 6" front wheel and a 5" rear wheel. They were not original, and I'm not even sure how they would even work. He kind of knew this too, and had bought a pair of Azusa 10" wheels for the bike. Some Ropers did come with 10" wheels, and I am partial to 10" wheel bikes too. So I thought I could make this work.
Another problem was the front suspension. The stock chrome springs were wasted, compressed to nearly nothing, and ready to break. So I used a new pair of standard front fork springs as available from OldMiniBikes (ordered with new cups.) They are longer then the originals, so had to re-mount the lower cups in a new position to make it work (and maintain geometry.)
Another thing I did was to move the rear shock mounts. On original Ropers the shocks are basically vertical. But with the 10" wheels (and the new rear disc brake setup), this was not going to work. So i did a more conventional shock mount position. It increased the swing arm angle a bit, but overall I liked how this looked. And it would enable me to use a DB30 doodlebug style rear disc brake set up a lot easier (more on that later... remember no original rear wheel, so no original rear wheel disc brake rotor.)
Here's the bike mocked up with the Azusa wheel, just to see how it would "sit":