1984 Schwinn World Sport
 

Hello everybody

I'm new to the forum and just bought the above mentioned bike for a good price and have a question. I found alot of info in prior posts, but not exactly what I'm looking for. The rear derailleur is currently a Shimano SIS. The original was a Suntour AR I believe? It doesn't shift right and I'm assuming the derailleur is probably from a mountain bike with more gears on the back and the index vs. friction shift has something to do with it. I'd like to find a decent replacement derailleur (friction shift). I looked at second hand on ebay and I'm confused by the different lengths ect. Can somebody tell me if anybody makes a new one that will work with-out changing free-wheel, chain, shifters ect.? If not what second hand ones will work without changing anything else? Will a Shimano friction work with suntour friction shifters? I know the bike isn't worth much but I want a winter project and it's built a lot nicer than some of the junk I see in the department stores:(

thanks Darren

There are many reasons a bike will not shift right, but ANY derailleur will work with friction shifting, as long as the lever can pull the derailleur across the entire cluster. But if you want assistance the first thing we need to know is what do you mean by doesn't shift right?

Also, looking for any exact problem is not the best way to learn. A bike is comprised of several systems that both work together and interact with the others. One needs to understand the systems - drive train, wheels, brakes, frame and cockpit (where you meet the bike) not just the individual parts. You don't say if your reading has been confined to this forum but it's best to focus much of your attention on a site that explains the why, not just the how of bicycles. The two most highly regarded sites are sheldonbrown.com and parktool.com/blog.

It shifts beyond 1st. and 6th gear (chain comes off sprockets) and also wont stop at 3rd. I haven't really messed with the high and low stops much but I don't believe they can be set enough to stop the chain from coming off? I might be able to get it to work but figured you needed a friction derailleur made for the same amount of rear sprockets (six) to be able to shift properly? I also thought a mountain bike rear derailleur was longer than a road bike? I apologize I haven't worked on a bike since the early 80's when most of them only had 10 speeds.:( I'm trying to come up with a parts list before I disassemble the bike to lube the bearings and change the cables.

thanks Darren

Sounds like you just need some simple RD adjustments.

Set the high and low stops. You may have to turn the screws a lot for them to work corrrectly. The 3rd sprocket may not be working right because it is just plain worn out. 30 years can put a lot of wear on the sprocket teeth. Read Sheldons info on how to set the derailer correctly and follow it. In friction which your bike has any derailluer will work. The indexing if a bike has it is in the shifters not the derailluer. Roger

One of my wife's bikes is an 84 World Sport- a light blue with yellow accents- cool color scheme. The bike is unassuming but very solid for trail/town riding.

If the chain jumps off, that is just a matter of sitting down and adjusting the screws until the chain stops dropping.
One of the cheapest ways to try and fix the issue, and not really be out any money if it doesn't work, is to pick up a new freewheel. If the issue of skipping a middle cog isn't resolved, its only $15-20 that you have spend and you will still have a component that is going to perform better than the original. A sunrace or shimano 6 speed freewheel plus the necessary remover tool will be around $20 total, maybe $25. You could even get a freewheel that has different gearing than stock, to make it easier for hills or pulling a trailer etc. Actually, you could pick up a 7 speed freewheel too as they fit fine and just need a washer or two as a spacer to fit.
New freewheels are designed better than the original Suntour as they allow for easier(smoother) shifting.

Not a good idea to put on a new freewheel for two reasons. First, it's not skipping on 3rd - according to OP it won't stop at 3rd. Secondly a new freewheel may skip with a worn chain.

TO THE OP: You need to adjust limit screws first. Again, ANY derailleur can handle friction shifting. There is no reason I know that a friction derailleur can't stop at a middle gear. As you are out in the sticks of NY I know in-person help may be difficult (perhaps a more knowledgeable friend?) so need better info - more description, video, etc.

Thanks for the help everybody. I just bought the bike yesterday and assumed that I would have to get a different derailleur . I only spent a few minutes playing with the adjustments. I'm pretty sure I can get it to work now that I know any rear derailleur should work. It's in my unheated garage and was 10 deg yesterday so I didn't fuss with it much. The rear rim bearings are stiff and wobble a bit. The chain is also dirty so that doesn't help. The sprockets look to be in nice shape. The bike still has the original tires on it. They have little wear but are weather checked and need replacing. Even the "funky" foam grips are still in decent shape;) I'll move it to the basement and start stripping it down for a good cleaning and fresh grease. There is a good bike shop I bought my Trek from in 1988 that's still in business a little ways from here that I'm sure I'll stop by for parts and advice. I've rebuilt a few motorcycles so I'm hoping this will be a little less expensive and stress full.:) Still remember the days when I had the guy at the dump save all the bike parts and rebuilding bikes in the basement of my parents house back before they had BMX bikes, let alone Mountain bikes.

"Hold on, we have a flag thrown on the play..."
 

Correction. Newer twisted tooth (hyperglide type) freewheels offer smoother shifting transitions, but are less durable and have inferior mechanisms to those of SunTour, which used an earlier, flat-toothed design.

SunTour systems take a bit of finesse to shift efficiently, but the freewheels were really well made.

Is this the bike we're talking about here?:
http://i25.photobucket.com/albums/c9...d/clear001.jpg

This was my first 'real' bike when I was a kid.

Wow, what I wouldn't give to find one & restore.

Ok, I could have specified that the better design I was referring to was specific to shifting. The built in ramping makes shifting smoother, which is a better design than older freewheels.

I really cant speak on the innerworkings of older SunTour freewheels versus new ramped freewheels, but you are a random poster on the internet so I will take your view on the matter as gospel.
In all seriousness, the old SunTour Perfects that I have ‘worked on’(cleaned cosmetically and oiled) are impressive in that they all spin well after some cleaning and most have looked quite nice in the end. Impressive for 30 year old components that take a lot of abuse. I would imagine they were very well made, as you said.

Yes that's it but mine is black. Gotta love those grips:)

Consider getting a good new chain for the bike, a rusted chain is really not a good thing to ride with and the price is reasonable. Your bike sounds good once you get your bearings greased and adjusted, new tires, probably some new cables and the wheels trued. Those old bikes are great teachers to help learn bicycle mechanics, that's how I learned plus a few bicycle books and forums.

Edit: make sure your new chain is the right one for that bike, should be a 6-8 speed chain, not a 9 or 10 speed chain.

Could anybody tell me if the original derailleur (suntour AR) was a long cage or short cage?

thank you

I believe ARs are short cage derailleurs. If it looks like the one in the picture of the blue bike it is short cage. Roger

thank you Roger.

I have a bike almost exactly like that Schwinn, Velociraptor, that is for sale. Let me know if you like to see pics or anything.:thumb:

Me too! My HS graduation gift was an 85 WS in ice blue. Man, I miss that bike.

I would.

What size is it?

That is a 23" frame, and 25" wheels.http://bikeforums.net/attachment.php...hmentid=438556http://bikeforums.net/attachment.php...hmentid=438557http://bikeforums.net/attachment.php...hmentid=438558http://bikeforums.net/attachment.php...hmentid=438559http://bikeforums.net/attachment.php...hmentid=438560

25" wheels? That would be pretty unusual. How about 27"

I just bought my wife this 49cm World Sport yesterday. All original and I am the second owner.
http://bikeforums.net/attachment.php...hmentid=438661

Good place for the basics. Park Tool Co. » ParkTool Blog

Looks like it's been modified quite a bit.

How long have you had it?

And...

How much & where is it located?

From looking at pics online, I would also say it is not completely stock. I am a vintage store in rural North Central Washington State, and I just received it a few days ago. I was thinking of asking $119.99.