replace suntour freewheel with what ?
 

My old British Tourer (Nigel Dean World Tour) needs a new freewheel, my LBS guy said don't replace the chain till you've replaced the freewheel. It came with the Accushift plus indexing and a seven speed 13 to 32(?) freewheel. Suntour have long gone and NOS Suntour freewheels are fetching absurd monies on eBay, especially the wide range freewheels "like what I have got". Are there any "good enough" index compatible freewheels that would work with the Suntour indexed shifters and derailleur. It is not a bike I ride often so I don't want to go mad on replacing it but I'd like to keep it running for sentimental reasons. Cheers.

OK... so what kind on freewheels can you get? And what cogs exactly are worn out?

Maybe you should consider just replacing the cogs...

Have a look-see at your current freewheel gears closely. If the teeth are still squared off, or mostly squared off at the top of the teeth, I would not worry too much about it. If they are round, or shaped like a shark fin, then it is time to replace. I am prone to pushing the life envelope of my vintage rides, and knock on wood, I have not had any problems with just changing the chain when it starts making noise coming off the freewheel or derailleur cogs. Not "correct," but then neither am I.
There are other brands of freewheels that may give you the same gearing, they just won't be Suntour. The few seven speeds I have replaced, ranged in price from $10-$20.
You could also rob a freewheel from an old junk bike if it's in decent shape or the brand you want, overhaul it, and put it into service.
Just some ideas.
​Eric

Does it have a hub that ordinary freewheels fit? If so, look for any freewheel with gears you are happy with. The derailleur should work, unless you go to a larger gear range.

You do not need to replace your freewheel before replacing your chain. It is more important to replace your chain whenever it has elongated more than 0.5 percent, to avoid accelerated wear on the chainrings and freewheel cogs.

Pastor Bob in NH in our C&V forums is the resident freewheel restoration expert.

The chain is already more than 0.75 percent out so it has probably done some damage, it has not been changed since 1990.

I believe it is a standard "English" thread I do not need a wider range , no serious hills near me :-)

Chains are cheap. I would replace the chain and only worry about replacing the freewheel if it starts skipping with the new chain.

If you go to friction, finding a replacement freewheel will be easy. If you want a freewheel that indexes with suntour, I'd put out a WTB in the C&V for sale forum. Prices there should be better than eBay.

If you are shifting in Suntour index mode, you need to match up the spacing.

Typical Shimano 7 speed UG/HG freewheels and cassettes are spaced at 5mm, (cog thickness 1.85mm + spacer thickness of 3.15).

First thing is to measure your current Suntour freewheel spacing. I think some are spaced at 5mm and others are split spaced. Three are at 4.8mm and 3 at 5.0mm. You might still be able to fudge it, but you might not get it to work well.

If you are friction shifting, any freewheel will work.

John

If it was me, I would just go and buy a new freewheel with the same number of sprockets, and a new chain, and fit them.

If you can ride the bike ok as it is, there is no urgency. You can order online, and wait for it to arrive.

If you want to do it yourself, also order the appropriate tools.

You have an old bike that has hard to find obsolete parts but for which you have a sentimental attachment.

If it was my bike, I'd replace the freewheel with a modern one, convert the shifter to friction, and continue to enjoy it for what it is. My bet is otherwise you'll drive yourself crazy trying to make the indexing reliable and you won't be able to enjoy the bike.

Why not replace the freewheel with a modern one, and see how it goes. If it works well, job done. If it does not work well, then consider other things.

This is what I would do. Older freewheels just didn’t wear out like lightweight modern cassettes. If you did identify skipping in a particular SunTour freewheel cog, you could replace the worn cog instead of the entire freewheel. Accushift freewheel spacing was asymmetric (as stated by 70sSanO ).

Have you tried a new chain to see how it runs? 0.75 elongation is not bad.

I replaced my 6 speed Suntour with a 7 speed Shimano freewheel. The Campy Nuvo group on my Raleigh worked will with the extra gear and my friction downtube shifters didn't care one bit. I think I had to play with some axle spacers to keep the chain from rubbing the stay near the hub.

The new freewheel only cost $18 back in 2011, so it's not like it was a budget buster.

Change your chain. They are inexpensive too in the grand scheme.

Unless that freewheel has more than 10,000 miles on it I'd be surprised if it needs to be replaced -- unless it was ridden gritty for many miles.

However if you decide to swap, try the SunRace freewheels. I switched my '89 Ironman with Suntour GPX group from the original Suntour Alpha freewheels to SunRace MFR30 and MFM30 chromed 7-speed freewheels. The MFR30 (R for "road") is 13-25; the MFM30 (mountain) is 13-28.

Those SunRace models are outstanding values and a good replacement for both Suntour and Shimano freewheels. I've used them on bikes with Suntour Accushift and Shimano SIS systems, no problems. The SunRace run more quietly and smoothly and shift more crisply.

The Suntour Alpha freewheels have squared teeth with little or no ramping or beveling, and shifts tend to clunk loudly. The shaped teeth on the SunRace shift crisply and quietly. My guess is the Suntour squared teeth catch the chain for a split second, stretching the rear derailleur spring slightly until it overcomes resistance and snaps back with a loud clunk. The SunRace doesn't do that.