anixi

Hello all,
thanks for reading. This is a build that has severely limited cost issues. I'm trying to get it working with no to little additional cost for a fix-income situation.
I've got a build going on with a problem: 7-speed Shimano Tourney shifter/brake integrated; 6-speed Suntour Perfect freewheel; I'm assuming an 8-speed chain is appropriate
I'm hoping someone has an idea for a rear derailleur solution.
The front is fine, with a Campy/Suntour combo that works just fine with a Suntour FD.
An appropriate rear derailleur either straight cable, or with alternate cable routing, doesn't matter to me, have done lots of both.
Thanks in advance!

icemilkcoffee 

The 7 speed Tourney shifter will work with any 7-10 speed Shimano road RD's (except the 4700 Tiagra) and 7-9 speed MTB RD's. 8 speed chain is fine.
Oh yeah- is that 6 sp Suntour Perfect freewheel 'Ultra' spacing? If it's non-ultra spacing, it won't work with the 7 speed brifter.

anixi

Thanks for the help.
I don't know if it's a Perfect Ultra or not. The spacing is about 5.5mm or 0.22" between cogs.

anixi

OK, Sheldon Brown says that the 5mm is the ultra, so this is the "regular" Perfect freewheel. I've got a 9-speed Tiagra 4400 in my sights. I'm assuming this one will work...it's not a 4700 at least.

Bill Kapaun

Regular 6 speed has 5.5mm spacing vs 5.0 for 7 speed.
https://www.sheldonbrown.com/cribsheet-spacing.html

I'd just get a 7 speed Free Wheel.

squirtdad

simple solution, go friction https://www.amazon.com/Sunrace-SLM10...40701881&psc=1

anixi

Thanks,
What rear derailleur would you use?
I'll look around for a 7-speed freewheel, but, that's a long shot.

anixi

It's been a LONG time since I've been to Willow Glen. How's the traffic?

Bill Kapaun

Is the shifting friction or indexed?
If indexed, get a cheap Shimano to match up with the Shimano shifters.
If friction, it doesn't matter as long as it can handle the largest cog & chain wrap. (Tourney)

squirtdad

traffic in san jose is getting LA like.

I commute to work by bike...so only traffic issues are crazy parents dropping kids off to Booksin, Willow Glen Middle and High, St. Chris and Presentation

most importantly La Villa deli is going strong

anixi

It's a Tourney 7-speed Brifter.

Bill Kapaun

7 speed FW's seem to be abundant on Google?

For a 7 speed, I wouldn't go any higher level than Altus. (older? 8 speed)
As the # speeds goes up, chain & DER's get narrower.
You're more prone to chain rub/noise etc. with the wider 7 speed chain and the narrower cage of the higher speed DER's.

70sSanO

For a freewheel any 7 speed Shimano compatible will work… Shimano, SRAM, Sunrace, or any Amazon alphabet soup brand.

If you want to replace the rear derailleur, get a 9 speed Deore. It will work with 6-9 speeds and almost any freewheel max cog.

John

anixi

I've found a Shimano RD-M200 aka 200 GS rear derailleur in my stash. It says on the internet that it's 6/7/8spd compatible. I'll try that next!
Thank you all!

Hondo6

Assuming it's in good repair, the RD-M200 should work nicely - particularly if you are sticking with a freewheel and not planning on using extreme gearing.

Shimano docs say the long cage version of the RD-M200 (GS cage) will handle a 12T smallest cog, a 30T largest cog, and has a total capacity of 36; the extra long cage version (SGS cage) will handle 12T smallest/32T largest and has total capacity of 38. (In practice, I don't think you'll have a problem with an 11T smallest cog if you can find a freewheel with one. Not sure how far you can "push the envelope" vice largest cog.)

The most common current 7-speed freewheels seem to be 14-28, which the RD-M200 should handle with no issue at all. Those can be obtained for a reasonable price.

anixi

It is the SGS cage, lucky me!

Hondo6

That does give you more flexibility. But either cage should have the capacity to handle the most common (14-28) current 7-speed freewheels easily, even if you pair it with a 20T difference front triple (e.g., 48/38/28 or 42/32/22).

I'd guess you should be able to do a bit more than Shimano specifies with either model - Shimano appears rather conservative in their RD capacity and cog ratings. Other RDs of that era were often specified as requiring a min 12T rear cog, and I've used a different model from that era w/o problems with an 11T min rear cog.

How much more, and how big of a max rear cog? Can't answer that from personal experience. Maybe someone else on BF can.

70sSanO

Over the years, I’ve found that a 2t over specified max cog has worked for me with a number of different Shimano RD’s.

Obviously the derailleur hanger length plays a part and you can also use a longer B screw, if necessary.

John