MassCommuter

Hi folks,

New to this forum and pleased to have found it.

As the title states, I've got a nice vintage touring bike that needs a new rear cassette. The original Suntour New Winner 5-speed just had a cog break off.

The bike is mostly stock and original, and in excellent shape, including the original 27" Wolber Super Champion wheels that I'd like to keep, and the downtube Suntour Superbe friction shifters. The rear spacing is 124mm, and the front cranks are Sugino TAT w/half-step gearing (50/46/30).

With that in mind, I'm trying to learn about what options I have for replacing/upgrading this cassette. It also seems like the ideal time to modernize to perhaps a 6 or 7 speed hyperglide or something similar.

I'm hoping to get some advice/suggestions on the matter, and whether this is something I can do myself.

Thank you -- I appreciate your time and advice.

HillRider

Your bike has a freewheel, not a cassette. If the dropout spacing is 124 (or possibly 126 mm) it should accept a 6 or 7-speed freewheel and these are still available. Your friction shifters will work with either one as will your crank.

If you go to a 7-speed freewheel, you will need a 7/8-speed (narrower) chain as the cogs are closer together than a 5 or standard 6-speed freewheel.

MassCommuter

Thanks for the reply and clarification.

Do you have any suggestions for a 7-speed freewheel? Would 7 as opposed to 6 be optimal for touring? I do have an 8 speed chain.

TallRider

Also worth considering: more gears = more total width between dropout and hub on a freewheel hub, and therefore more bending force (moment) on the exposed axle between bearings and dropout. I'm 6'5", 190#, and always bent the axles on freewheel hubs, even with just 5-speed freewheels, so I've updated some of my bikes to 7-speed freehubs (building new wheels in the process).
Do you tend to bend axles, or do actual loaded touring on this bike?

Modern cassette hubs have bearing lined up with the edge of the hub shell underneath the actual gears, whereas freehubs have the bearings at the point where the freewheel screws onto the hub shell.

HillRider

Basically, freewheels are obsolete, having been replaced by cassettes over 20 years ago so the demand and supply are rather limited.

Shimano still makes 7-speed freewheels, although in very limited ranges. Sun Race also makes them and Nashbar sells them under their house-brand name. 7-speed obviously gives you more ratios than 6.

Here are a few references for freewheels:

6-speed:

https://www.biketoolsetc.com/index.cg...wheels-6-Speed

7-Speed:

https://www.biketoolsetc.com/index.cg...wheels-7-Speed

And here is a source for both types: https://www.thethirdhand.com/index.cgi

BTW, The Third Hand web site shows an 8-speed freewheel. Don't do it. It won't fit your frame and these are an invitation to broken axles.

MassCommuter

Thanks for the visuals, Tall Rider -- they did a good job in illustrating the differences.

I'm 5' 8", 165lbs., and I can't say that I've ever had trouble bending axles. I do ride with a load on a regular basis, though, primarily when commuting. Nothing too serious -- about 20 to 40 lbs. in two rear panniers. The back wheel does have 40 spokes and is pretty robust, from what I gather, if that matters.

HillRider, if I make the change to a cassette, it appears I also have to change the hub, which are original Suntour and appear to be pretty nice. What are the advantages to moving to a cassette as opposed to sticking with the freewheel? And if I stick with the freewheel, would it be worth trying to find a NOS Suntour New Winner?

HillRider

If you want to use a cassette, the only reasonable move is to obtain a complete new wheel. Retrofitting a new freehub to your existing rim and spokes will be more expensive than starting from scratch.

As TallRider noted, a cassette hub is stronger due to the outboard bearing placement and cassettes are available in a much wider range of ratios than current freewheels. Sun Tour made some nice components but they are out of production and have been for quite some time. Their freewheels were good but not as good as newer ones. The newer Shimano and even Sun Racefreewheels have shaped and enhanced tooth profiles similar to current cassettes and shift MUCH better than the older Sun Tour freewheels.

MassCommuter

So it sounds like I would need to replace the rear wheel (moving to 700C), and therefore the front to match (with new tires) -- despite my affinity for the rims. Plus a new cassette. I guess I was hoping for a simpler fix with only one broken cog. I didn't realize there was so much involved!

I would also need to make sure my cantilever brakes would have the proper reach with the new wheels. Correct?

HillRider

The simplist "fix" is to buy a replacement 5-speed freewheel and be done with it. You can do that. Anything more and you open several expensive cans of worms.

TallRider

if you're going to more to a freehub instead of freewheel rear hub, you'd need to build or buy a new rear wheel. If your bike presently has 27" rims, you could build a wheel with freehub and 27" rims - I've done this for two older bikes, using 7-speed freewheels (older bikes have narrower rear spacing as HillRider mentioned). But you may not be up for building wheels, and it costs a lot to have someone else build them.
changing over to 700c is a bigger deal.

I'd recommend you just get another 5-speed freewheel, or maybe 6-speed if you have room without re-dishing the wheel. Unless you want to put a lot of money in and update lots of things on the bike.

JiveTurkey

+1. Another option, if it's friction shifting (I'm assuming so), is to find an Ultra-spaced 6-speed freewheel. They are just as wide as 5-speed, so will fit on the same hub, but the cogs are more closely spaced. A modern 7- or 8-speed chain will fit it. They're spendy though; here's the cheapest I found with a quick eBay search ($47 incl. s/h): https://cgi.ebay.com/NOS-Suntour-6-Sp...item483a78b522

dscheidt

six and seven speed freewheels will fit this frame just fine.

JiveTurkey

True, but it may require re-spacing and re-dishing the rear wheel, which I guess isn't a huge deal.

caintuck

Seems like an Interloc Defiant 5-speed Freewheel would be a good solution, though they are a bit pricey at about $41.00 (Universal Cycles). Don't have time to provide a link because I'm at work.

dscheidt

shouldn't require either. It'll require a bit more care to install the wheel, but it'll fit in 124mm dropouts, no problems.

HillRider

I had them on my bike in the late 80's and they shifted very poorly.

MassCommuter

Thanks for the great suggestions -- I learned a great deal.

Just finished reading Sheldon Brown's Web page on freewheels -- https://sheldonbrown.com/harris/freewheels.html#7 -- and it looks like Harris has a few options for me.

Luckily, I'm only about 10 miles from there.

TallRider

Glad you can go to Harris - they'll give you good help.
If your wheel is ideally spaced for minimal dish, you actually would have to re-dish the wheel for installing a 6-speed freewheel (slightly wider than 5, unless you go for a Suntour Ultra6 as JiveTurkey mentioned) and definitely have to re-dish if you go for a 7-speed freewheel.
Unless your rear wheel isn't close to being ideally-spaced. there were many wheels back then which were built up with a lot of extra spacing on the freewheel side. This has the downside of longer axle "exposed" between bearings and dropout, which makes it more likely to bend the axle. But is convenient for updating to wider freewheels with more gears.
The guys at Harris will be able to guide you on this.