ndrose

For those still interested, I finally had a chance today to take it back to the shop. The mechanic looked it over again, and said maybe the teeth weren’t too worn for a new chain. He suggested that I could try a new one and keep the old one, and if the new one won’t work well I could swap it back out. So we’ll try that.

ndrose

I think I can now post pictures, so I will try to attach one of the chain and cassette. I hope it’s sufficiently visible through the struts of the rack and the grime of the C&O Canal....

rumrunn6

that little cog looks more worn than the rest (especially compared to mine)



I try to stay out of my small cog if I have other usable options to extend the life of the whole thing

ndrose

That’s a thought. It’s not a problem for me to stay out of it these days. When I was in my twenties 3-6 was my ordinary running gear (which I think on the Crisscross is 48/15), and if I was really hurrying I’d take it into 3-7 (48/13). Nowadays, 3-5 (48/17) is pushing hard. Can’t remember the last time I used the top gear, but I certainly may have given it some wear back in the day.

rumrunn6

lol, yup, that's where I lived. when I was a teen, I even had our bike shop put in a smaller cluster on my old Schwinn 10 speed Varsity. oh, to be 16 again ... at 60 now, I'm a bit more flexible w/ my gearing

btw I bought mine 2nd hand from a woman the same height as me. she used it recreationally. I used it for a cpl years & tortured it pretty good, mostly off-road but not necessarily a ton of miles

WizardOfBoz

So how does it work?

I was trying to research this and found the Schwinn spec sheet for the 1991 CrissCross here. It specifies a 13-28 tooth Sun Tour Accushift Plus 7 speed, but does not say freehub or freewheel.

The 1991 Sun Tour groupset specifications seems to indicate a freehub design. Some specs on the cassette cogs available are here.

I'm thinking that you can probably find (or "vultch" as in wait like a vulture for the desired part to appear) a NOS replacement 13t cog for that freehub on eBay. May be worth it: a 10-20 buck expense rescues the rear wheel (that would cost perhaps 100 bucks to replace) which rescues a reasonably nice bike (that would probably cost 250 to replace). I'd do it: those cogs probably aren't getting any easier to find.

Let us know how the thing rides with the new chain, though.

ndrose

Well, we finally had good riding weather yesterday so I tried a little nearby gravel grinding. Although it had seemed to shift well in the shop, on the road I found it skipping between two of the middle cogs in back, and I couldn’t get it onto the small crank in front at all. When I got home I futzed with it a while but couldn’t get it right, so I took it back to the shop. The mechanic didn’t think the new chain was causing the problem. He ended up replacing cables and housings. It seems to be ok now (i.e. seemed ok in the shop again). But weather doesn’t look like permitting a real world test for a few days.

So we’ll see. I still have the old chain in case that becomes necessary. I have browsed around on eBay a bit, but haven’t decided yet how much effort I’m willing to put into this bike.

Wilfred Laurier

Replacing just the chain on a worn cassette will almost always result in skipping under load. I believe this is more pronounced on the ramped and shaped and manipulated cogs of modern indexed shifting systems, but I would be surprised if you can just swap in a new chain on a well used 30 year old bike and not have any problems. This is likely what the shop tech was thinking of at the time. Visual inspection is not a reliable indicator of cog wear.

People posting above to just change the chain and ride don't know what they are talking about. I am adding those people to my 'Do Not Listen to this Person' list. This advice is right up there with repairing a frame with JB Weld or using red Loctite to hold crank bolts on.

The real trick, if the chain doesn't mesh with the old cogs, might be to get the old Suntour freewheel off - they used a (iirc) four prong freewheel remover that was sometimes difficult to keep engaged and not damage the tool or the freewheel. It was a minor improvement over two prong freewheels (average of about three freewheels removed before the tool or freeewheel was damaged), but not great. Shimano and others now use internal splines that ~never fail if the correct tool is used.

Once the freewheel is off, I don't know if Shimano 7 speed has the same spacing as Suntour 7 sp, so finding a good replacement may not be easy. Or it might. IDK.

WizardOfBoz

Agree, but this was not the information given. The LBS implied that the whole drive system needed replacing and that a new chain wouldn't fit Sun Tour parts and that the OP would be better off getting a new bike (my interpretation). This seemed sketchy to me. I've fixed skipping multiple times (on my 79 Paramount, for example) by just replacing the chain. In fact, replacing the chain on that 30 year old bike fixed a skipping issue (I then got a 6 speed freewheel, but this was after the skipping was fixed). Most discussions of fixing skipping suggest that the chain wears faster than the cogs. Or, put another way, you should be able to replace the chain a few times before you need to mess with cogs and chainrings. This is why you read about "replacing bike chains" a lot more than "replacing bike chains, cassette cogs, chain wheels, and derailleur jockey wheels". As you point out, for moderate wear, visual cog inspection probably won't indicate a cog that will skip. For this reason, I think switching a chain to see how it goes is exactly what you should do to start out. Certainly replacing the chain, cog, and chainrings is NOT a cost-effective way to repair a bike that has skipping gears*.

For reasons I state above, I think this is a wild overreaction. Unworthy of someone with your manifest expertise and experience. I mean, feel free to put me on the ignore list (there is such a facility in BF, btw). But I'll still be reading your posts, to my advantage.

Here is an example of that experience (which dovetails with my bike mechanic experience from long ago). WRT the number of slots, a 4 tab tool is better. Also, the Sun Tour shell was thicker than earlier European models. Both the number of tabs and the tab thickness help the issue: I've both broken the prongs off tools and or rounded off the freewheel slots trying to remove an old Regina d'Oro. Good times. But as the cited URLs above seem to indicate, this may have been an early freehub. The CrossCut (next model up from the CrissCross) in 1991 specified a Shimano freehub. The OP will have to get back to us on the freehub/freewheel question (unless you can tell from the pics, which I can't). But a brief search of ebay indicates that cogs for both freewheel and freehub designs are available.

*Unless the cog teeth look like sharpened fishhooks, in which case, fine, go ahead and replace 'em.

Wilfred Laurier

Thanks for the kind words.
Perhaps I was too unequivocal in my criticisms.
The only true wisdom is knowing that you know nothing. Maybe someday I will start to learn this.
The first ~2 decades of my working life was spent becoming decreasingly gruntled in the back of bike shops fighting with seized bottom brackets and seatposts. I moved to a new career before someone got the sharp end of a Tourney crankset to the skull.

Anyhoo,
I specifically did not say 'ignore list' as I like to debunk obvious falsehoods and misunderstandings when I see them. Only people who are abusive or otherwise can't play nice get a full 'ignore'... so far this is a total of about three people over the years I have been using these for a under multiple user names. Being 'wrong' doesn't warrant exclusion from conversation. My personal 'do not listen' list is not written down anywhere, but I try to keep it in mind when reading others' advice, so I know to whose advice a grain of salt should be added. Debunking entrenched mistaken beliefs is a hobby I use as a logic and writing challenge.

WizardOfBoz

Mr. Laurier,
Thanks for caring enough to send a kind note. It means a lot because I do enjoy reading your notes and getting the benefit of your technical knowledge. As for me, as my wife will attest, I'm never guilty of hyperbole. [Wait! Sweetie, what do you mean that you won't errr, attest.] Ahem. As I was saying I sometimes often [Editor's change] make statements that are, ...errr, hyperbolic.
Warm regards,
Wiz

PS I suspect that almost anybody, in any career, gets frustrated enough to feel like going full crankset to the cranium sometimes. Hope you found something you enjoy better before being the inspiration for a modern day Perry Mason episode "The customer with the chain-ring cranium".

ndrose

Finally had a chance to take it out again. It was mostly ok but had problems in a couple of gears, skipping back and forth under load. I had to go back to the shop anyway for a new front tire 😕 so decided to just put the old chain back on for now. Obviously that’s not a permanent solution. Have to decide whether to replace the whole drivetrain, or see whether I can find replacement Suntour components on eBay, or just retire the bike.

ndrose

I think the right answer is: I should just use the old chain until it starts causing problems, since I don’t have to worry about it causing further wear to the cogs, as that ship has sailed. Only when that happens do I need to choose between a new drivetrain and trying to assemble replacements from eBay. Unless there’s a factor I’m not considering?

ndrose

Now I’m wondering if there’s a reason I can’t just replace the chain and freewheel, without getting a whole new drivetrain. Is the issue with putting a new Shimano freewheel on it that the derailleur indexing might not be the same?

mitchmellow62

Please read the above quote.

ndrose

I wasn’t sure whether you were saying replaceable-by-Shimano
applies if it is a freewheel also, or only for sure if it’s a cassette. I think it is a freewheel, but I need to take off the rear rack to get a better look.

dsbrantjr

https://www.sheldonbrown.com/free-k7.html

mitchmellow62

https://waterfordbikes.com/SchwinnCa...0/1991_18.html
https://waterfordbikes.com/SchwinnCa...cc_specsb.html

According to the above, the '91 and '92 used the same freewheel. Notice that "cassette" is specified in the description on other bikes that do not have freewheels.

Archival Reviews of Suntour Freewheels/Cassettes - the Buyer's Guide, 2015

From the above:
"As many readers are already aware Suntour has vacated the bicycle parts market. These leaves anyone who ever relied on them for freewheels or uses a Suntour cassette rear hub with no real alternatives. If you were using a Suntour freewheel, the Sach Aris is your last full range freewheel alternative. If you own a Suntour cassette rear hub, you may still find a Suntour splines cassette at your local bicycle store, but you should mentally prepare to replace the rear hub, with something that has the Shimano Hyperglide spline pattern."

"SUNTOUR ACCUSHIFT PLUS / POWERFLO

Suntour has their own version of index shifting, they call Accushift Plus. It uses cogs which are narrow to permit more rear sprockets within the same space. The sprockets are 1.9mm thick (like HyperGlide), with 3.0mm spacing between each of the rear cogs so they can be used with all current index systems."

"SUNTOUR AL10-K7 POWERFLO 7 SPEED FREEWHEEL

Suntour has always made well constructed freewheels. They will likely inherit the market that Shimano departs. The AL10 is an Accushift Plus compatible freewheel, so it works very well under all Suntour index shifting systems. Because it use cogs that are 1.9mm thick with 2.8mm to 3.2mm spacing between them, it should also work well with any other index shift system on the market. "

One should always verify physically but it appears you have a freewheel. Most new 7 speed freewheels (shimano, sunrace, etc.) have the same center to center cog spacing and should work for you (.https://www.sheldonbrown.com/cribsheet-spacing.html ).

ndrose

Thank you, that is very helpful information. So it sounds like I should be able to put a Shimano freewheel on it without necessarily replacing the derailleur and shifters.

Since I have already semi-ruined the old freewheel, there’s no great urgency. So I think what I may do is wait until I have the new bike, then make this one a project bike to try to learn to do more things myself. Kind of tired of trying to get the shop mechanic interested in fiddling with a bike that, as he put it, is older than he is. Yikes.

mitchmellow62

Often when Tom and Ray of Car Talk got a call involving carburetor problems they would tell the caller that he/she needed to find a mechanic who no longer had all his teeth. That mechanic would be old enough to have the experience needed. You need an older mechanic who appreciates the older stuff (whether he has all his teeth or not).

ndrose

Not all the mechanics there are as young as the one who said that. There is one in particular who’s a little more on my wavelength. He’s not as old as I am, but at least he’s older than my bike.

But I’ve reached the conclusion that it’s going to take enough fussing and tinkering that I’ll go broke having someone else do it, so I should make it a project bike for myself. First I’d better get another bike so I’ll have something to ride while I devastate the Schwinn.

WizardOfBoz

Did we ever verfiy that this was a freehub? Or is it a freewheel? If the latter, the fix should be fairly easy. 1) But replacement (Shimano, or whatever) freewheel, 2) replace old freewheel, 3) replace (or reinstall replacement) chain.

Good luck.

ndrose

It is a freewheel. The mechanic didn’t seem sure it could be replaced without replacing the derailleur etc., because he thought the spacing might be different. But according to the Sheldon Brown info referenced above by mitchmellow62, if I’m reading it correctly, a Shimano freewheel should work.

Anyway, for now the old chain is back on the bike, which works fine. Replacement no longer seems urgent since I now know the cogs are already worn to the point where they need replacement also. So my plan is to get the new bike I’ve been planning to get, then work on the Schwinn myself as a self-education project. (The point being that if I have another bike to ride it won’t matter so much how long it takes me or how many mistakes I make.) As long as it doesn’t completely break down before I’ve chosen a replacement....

WizardOfBoz

Cool. Replacing a freewheel is a nice project. Usually not too difficult, and satisfying in both doing it and riding the repaired bike.

Either go to the LBS (who has the right freewheel removal tool) or buy the appropriate tool. Then the easiest way to do this is to remove the quick release, put the tool on the freewheel, replace the quick release WITH A LITTLE SLACK to hold the tool against the freewheel. Put the flats of the freewheel removal tool in a bench vise, and use the wheel itself like a wrench handle. Freewheels on the right side of the bike (like most bikes including yours) are right hand thread. Turn just enough to break the freewheel loose. Then stop and remove the quick release (if you try to unscrew the freewheel too much, or have the QR tight to begin the operation, you can break the QR). After you loosen the freewheel, the tool should allow you to spin it off easily. Clean the hub threads with a paper towel and min spirits or water and simple green or somesuch. Dry throroughly. Grease the threads, and put your new freewheel on by hand. You can tighten it a bit with a wrench (holding the tool on with the QR improves stabilty of the operation). Your pedaling will fully tighten the thing. The first time will seem like an adventure. If you have to do it again, you'll be an old pro and it will take less than five minutes. Might take you less than 5 minutes the first time.

The bench vise makes a big difference. If you don't have one, buy a friend with one a six pack so that he'll allow you to use theirs.

Not to mess with your plans to get a new bike (carry on, by all means) but with the right tools (freewheel removal too and a chain breaker) you could have a new freewheel and chain on your bike in less than 15 minutes. It might take a little adjustment of the derailleur limit screws and you may have to slacken or tighten the cable, but seriously, the whole think should take you less than an hour. I think you'll run up against some things you have to think about. You'll solve them, and will have taken one step towards learning to wrench bikes. Good luck, have fun.

ndrose

Those are good, clear instructions—thank you. And thanks to everyone for valuable information. When I get to this project I’ll return to this thread and report how it went.