mishmashmusic

I managed to end up with a Suntour AP 7 speed freewheel that needs help, and I'm confused about what to do. The smallest cog (13T) has a broken tooth. Here are my options as far as I can tell:

1- Buy a NOS freewheel --- does anyone know which one will work --- Winner, New Winner, Winner Pro, Ultra...??? This is where I'm confused.

2 - Buy another 13T cog if I can find one --- again, which one should I look for?

3 - Change out the freewheel to SIS and change to friction shifter

4 - Change out everything

5 - I found a post by Sheldon that suggests that Suntour derailleurs might work smoothly with Shimano HG --- has anyone tried this?

I really don't want to spend much on this one, just trying to get it back online.

Any suggestions? Here are a couple of photos for your viewing pleasure.

HillRider

Winner, New Winner and Winner Pro were all interchangable AFAIK. Just a difference in cog finish and, possibly, bearing quality.

The "Ultra" may refer to an Ultra-6 freewheel, i.e., a narrow spaced 6-speed intended to fit into the width of a standard 5-speed on 120 mm spaced frames.

randomgear

I just replaced an old suntour freewheel with a new Shimano Hyperglide freewheel - it works even better than the Suntour freewheel with my friction only Suntour Sprint derailer.
The hardest part for me was getting the old one off - had to take it to the LBS to be put in a vise, only ran $5 or so.
Just remember to grease the threads before you attach the new one - it will make removal in the future much easier.

DannoXYZ 

The missing too won't affect shifting at all and I doubt it'd skip. I wouldn't worry about its functionality.

I've used Suntour freewheels with Shimano shifters/derailleurs. The Uniglide twisted teeth freewheel or the Hyperglide ramped freewheels works much better though. I have improved the shifting of Suntour freewheels by taking the cogs off and grinding two diagonal corners to give the teeth that diagonal twisted shape like Uniglide cogs. That's to match the angle of the chain as it's pulled over by the derailleur during a shift.

tellyho

Yeah, I'd just buy a new freewheel. While greasing the threads will help, all freewheels get cranked on and are pretty much universally difficult to remove. Unless you plan on doing more, the LBS is the place to do it for you.

LWaB

Replacement top cogs are still available from some old shops. It is the commonly used sizes that are worn out.

Sixty Fiver

With the right tool and a vice, most freewheels come off with very little trouble.

You need a 4 pronged Suntour freewheel tool and need to clamp it in place with the wheel nut or QR to keep the tool from slipping and damaging the freewheel or the tool itself.

Once that is mounted flip the wheel with the tool side down, clamp the tool in the vice and pretend the wheel is on a bus that needs to turn left.

Once the freewheel breaks loose you will need to loosen the nut or QR to allow the freewheel to spin off.

A little WD40 shot in behind the freewheel to the hub threads will help in removal.

rocoach

My 1984 friction Suntour Cyclone RD/FD work fine with the 8-cog Forte 11/28 cassette that is on my new Ultegra/Mavic Open Pro wheelset.

DannoXYZ 

I found six 13t Suntour 1st-gears on my cog-board (3 different kinds). Gimme the ID of that gear when you've got it off the freewheel and I can send you a replacement. Just pay for the shipping and it's yours.

mishmashmusic

Thanks for the replies and the help! Danno thanks for the offer, I will probably take you up on that if I can't find a complete freewheel that works for a decent price.

Just found this on eBay --- a 7 speed Suntour Powerflo... Would this work?

https://cgi.ebay.com/New-Suntour-7-sp...QQcmdZViewItem

HillRider

The ones you found on e-bay will work but it require a "two-notch" remover, not the newer (and better) four-notch type. Are you sure these are new? They look a bit worn in the picture.

mishmashmusic

Says "New", but that doesn't mean anything, I know. The price looks right if the shipping is reasonable...

DannoXYZ 

The thing you want to verify is that the cog-spacing is the same as your existing AP freewheel. Please review this thread and the links within for technical info on the inconsistent spacing between cogs on various Suntour freewheels.

mishmashmusic

Thanks, that's a lot of info. No wonder I'm confused...

rocoach

Surely only a problem with indexed shifting? If he's still frictioning the spacing shouldn't matter...

mishmashmusic

So I call the LBS to ask if they can remove the Suntour freewheel, and the guy tries to pitch me on doing extensive work on the bike. I kindly explain that I've been fixing it up and wanted to replace the freewheel as it is the only major problem, and he says something to the effect of "there has to be a lot of things wrong with a bike that old, you should bring it in and let us look at it". Even after I said no thanks, he was still pretty insistent about it. Like I'm going to bring it in to him now after he says that.

Maybe he was just being helpful, but it rubbed me the wrong way.

sfclearwater

Freewheels can be a pain to get off, but they are really not that hard. The 2 notch or 4 notch Suntour tools are generally about $8 (here anyway). You can use the 2 notch tool on a 4 notch freewheel (but people generally recommend not doing so); as other people have said the key is making sure the tool stay clamped against the freewheel.

Check out parks website for info on freewheel vs. cassette and removal:

https://www.parktool.com/repair/readhowto.asp?id=48

I have replaced old Suntour 7 speed freewheels with 7 speed Shimano ones in index systems with no problems. It seems that as long as the index shifter and derailleur are both Suntour then the cog spacing of the Shimano freewheel is close enough to the old Suntour.

As for the bike shop; just take the wheel in and they should be able to pop the freewheel off for you. That is, if you decide not to try it yourself.

mishmashmusic

OK, I take back what I said about the LBS. I went by there today at lunch, and one of the mechs took the freewheel off at no charge. I ended up buying a little something to assuage my guilt.

I have the freewheel on order from the earlier eBay post. I'll let you know if it works when I get it.

mishmashmusic

Here's the update if anyone is interested...

I bought the freewheel on eBay, had to wait a while for it to arrive from the UK. I examined the new and old side by side, and they matched almost perfectly.

Tonight I put it on and it seems to work fine. It's dark out, so I didn't have a chance to really test it, but it went through each gear without any mishaps. Pretty good considering I didn't have a top gear at all with the old one. Tomorrow if I'm brave enough I'll take it on my commute and give it a run through.

The big decision now is whether to keep or sell the bike, which is a late-80s/early 90s Specialized Hardrock.