I have a Zenith Marshall Wells bicycle that has a collet seat post clamp (like a drill bit clamp). It looks like a rain bow Snyder frame. I have been told that they only made this frame with the collet for one year? Can anyone tell me what year this might be? looks like junk but rides good. I put a skip tooth chainring from a 24 inch bike that was run over by a car to lower the gearing. I'm wondering if it had 28 inch wheels. I have no way to post pictures on my computer right now but tomorrow is the annual classic cruiser ride so I will post photos of the bike from my phone. We get over 200 classic cruisers at this ride. Currently it has 26 inch double drops center rims that are real thin.