Old freewheel replacement

[Captain Argo]

Hello everyone,

I'm trying to recondition an old Mongoose mountain bike as cheaply as possible for a friend who would like a bike just for getting around. It is an early 90s Mongoose Maneuver with a solid Cro-Mo frame that is in fine shape. It does have a couple of problems after sitting around for so long, however, and I need a bit of advice.

The main problem is that, if I pedal and then stop, the chain sags (on top) and bunches up; it seems that the freewheel is not so "free" anymore, and the sprockets themselves are pretty rusty.

The other problem is that the shifters are very, very stiff. I may be able to recondition them if I open them up, clean them out and re-lube them. At least one of them moves well enough for me to test the front derailleur, which seems to work fine.

With that bit of background, my concern is thus: The bike came with SunTour gear -- SunTour XCT AccuShift with X-Press shifters, to be precise. Even assuming that I can re-condition the shifters, is there any chance that I can find a new freewheel / cassette that will be compatible with the old shifters? Do I have to be concerned whether the old SunTour stuff is usable with any newer Shimano / SRAM / whatever equipment, or will any old derailleur work with most freewheels? I also don't know if it has a separate cassette and freewheel or whether it is a combined screw-on assembly.

Any help or insight would be very much appreciated. Thanks!

[nfmisso]

Accushift is 6 speed; please double check. REF: http://sheldonbrown.com/cribsheet-spacing.html
Accushift 6 speed has the same spacing as "Regular" 6 speed.

If it is six speed, it is a freewheel. http://sheldonbrown.com/freewheels.html

The old derailleur will work with most freewheels; it is the shifter that may cause issues.

[Captain Argo]

Ah sorry, I just double-checked and it is an AccuShift Plus. It definitely has a 7-speed rear gearset.
Here are a couple pictures:





Thanks for the info! So if there are no newer freewheels that are compatible with the old shifters I guess I'd just have to go with either friction shifters? Or would it be possible to buy indexed shifters and still use the old derailleur as long as they are compatible with the cogs on the freewheel?

[Captain Argo]

Looking at the info you provided (very helpful, thank you), it appears that I probably have either a Sun Tour "Ultra" 7 speed, or a Sun Tour "Microdrive". While the Microdrive appears to be fairly unique in its specs, the Ultra 7 seems like it has nearly identical cog spacing to the Shimano HG, and differs only in overall width. If I do indeed have the Ultra 7, can I assume that a Shimano HG freewheel would be compatible with the old shifters?

[nfmisso]

(03-04-2014, 10:46 PM)Captain Argo Wrote:  Looking at the info you provided (very helpful, thank you), it appears that I probably have either a Sun Tour "Ultra" 7 speed, or a Sun Tour "Microdrive". While the Microdrive appears to be fairly unique in its specs, the Ultra 7 seems like it has nearly identical cog spacing to the Shimano HG, and differs only in overall width. If I do indeed have the Ultra 7, can I assume that a Shimano HG freewheel would be compatible with the old shifters?

Measure, don't assume. Purchase a $20- (on sale) set of digital calipers from Harbor Freight. http://www.harborfreight.com/6-inch-digital-caliper-47257.html#.UxdQ34XjS8A

[Joe_W]

(03-04-2014, 10:26 PM)Captain Argo Wrote:  ...
Or would it be possible to buy indexed shifters and still use the old derailleur as long as they are compatible with the cogs on the freewheel?

That's a whole different can of wriggly things you want to open. The cog spacing is almost irrelevant if the amount of cable pulled "per click" is different (o.t.o.h. maybe it compensates), then you cannot mix and match the old RD and new shifters.
Look around, maybe there's a donor bike somewhere that you can scavenge the shifters and RD off? Maybe someone in the forum (you didn't write where you are) has some? You could have my old 7 spd Deore DX (I belive) shifters, but they need some (read: a lot of) care (gunk accumulated inside... very stiff) (+ I'm in Germany, so could be difficult to get them)



Actually that offer goes out to anybody who wants them. I'll be in Cape Cod in April, so if someone from that area wants them I can bring them (unless I forget). Mailing them makes no sense, postage is more than what they are worth...