What freewheels can swap with Shimano 6208?
 

I restored and have been riding an '87 Bridgestone Radac but the gearing was intended for the Flat and alas, I live in the Mountains. I'm looking to swap out my original 600 MF-6208 6-speed 13-22 corncob for something with a little more range. Ideally I'm hoping to find 13-28 since I do like the 13t but it seems most of the Shimano freewheels I find online are 14 and up. My biggest question, though, is; what freewheels out there are compatible? I've seen Suntour and Shimano HyperGlide come up in searches and wonder if any of those would fit, also the crazy looking Shimano "Mega Range" with the big 34t on it.
If 14 is the lowest I can go then it's a sacrifice I'll have to make. With the grades I'm climbing, I just have to get a bit more range.
Thanks!

You can use any shipmano 6spd FW but also the older Sachs 6spd were spaced for shipmano. I think you can also use Sunrace 6spd too.

Most likely, your RDER wouldn't handle a 34T cog.
28T "might" even be pushing it??

indexed or friction shifting? what rd?

Hahaha I'm not serious about the 34t, that would be a tree climber for sure ;). The RD is a Shimano 105 1050 indexed -I think it should certainly be able to handle a 28t. I just gave it all a little stretch and it looks like it would easily go up to that. I just wasn't sure if the Suntour FWs or Hyperglides that pop up in online searches would work or not. Also if I am able to score a 14-28 Shimano -hoping there's a possibility I could replace the 14t with my 13t cog if the splines indeed match up.
Thanks!

Your RD will handle a 28t no sweat; I've run the same unit with 30t.
If you want to switch out the shifters (or run index) why not go 7-speed? SunRace makes a decent 13-28 seven-cog freewheel.

Top

oh I was reading somewhere about using the current 6sp indexed shifter for 7sp SunRace I believe -something about using the limiter screw on the RD to allow the 6sp shifter to get to the 7th cog. I'm on a tight budget and would rather not bother with changing shifters as well though so I'm ok with 6 speeds unless that 7sp thing will work. I'm just not quite sure I can see how it will work since there doesn't seem to be any play in the downtube boss mounted shifter lever. Also, Harris Cyclery wrote back and said unfortunately the new 14-28 Shimano freewheel can't be modded either -bummer.

I have a MF-7400 6-speed and MF-6208 6-speed. Originally they were both 13-21. That was fine for the terrain where I live when I was in my 20's and 30's but I'm now in my 50's. I hate to toss perfectly good freewheels so I changed them to 13-26 and 13-30 by buying loose cogs at http://www.loosescrews.com/index.cgi...d=908719015952 . Looks like they still have a 26 but not a 28 or 30.

You can get a 13-28 6-speed freewheel which is Shimano compatible at IRD - http://www.interlocracing.com/freewheels_steel.html

Gonzo Bob: absolutely brilliant hahaha -26 is better than 22 -I'm checking into it right now. Also sent an inquiry to IRD. My coworkers wonder why I bother to fix up old bikes -but it's just plain fun ain't it? ;)

Well dang, I am indeed tempted to go with one 26t cog and just drop the 14t... Now I wonder how his particular FW comes apart. It looks like the 13t threads on and holds the rest in place but I worry that the 14t may thread on as well. Any one have experience with removing individual cogs on this guy?

Only the top cog is threaded. The next two slide on with a small spline pattern and the biggest three have a large spline pattern. Note that the 14t has a built-in spacer so you will be removing a cog *and* a spacer meaning that you will need another loose spacer. Also, your current 4th cog (a 17t?) can't go in the 3rd position since the spline size is different so you need to get a new cog with a small spline for the 3rd position.

aha, I gotchya. It also appears the 4th cog may have a spacer as well. For this mod I'd definitely have to go with three cogs and a spacer or maybe two and at that only up to 26t. I may just lean toward the IRD freewheel that has two cogs above my top 22 at 24 and 28 with the 13 on the bottom to boot! A simple ParkTool FR-1 to change ;)

Thanks for all the help! I did a lot of researching before going with keeping the 600 and getting cogs from loosescrews (great people) I must sheepishly admit that what I thought was 13-22 (I just got the bike and had simply looked up the old Bridgestone catalog PDF from Sheldon Brown and went with that. I rode it maybe all of fifty miles before figuring out that I actually have a true corncob 13-18 HAHAHA shame on me ^^ Good news though -13,14,16,19,22,26 is wonderful gearing for the mountains -still have to stand up on some serious grades but over all this bike is so much more fun to ride now!

What's this about? Autocorrect gone weird, or some editorializing?

Although Velobase specs the 6802 as handling up to 26T, I've been using one on a Shimano 14T-28T. Up Front is a Cyclone 52-42 crank-set. Recently I have been reviewing comments around the net concerning the 6802 in regards to another build. I've come away impressed by its apparent versatility.

scapegoat, you didn't mention your front gearing at all, but if not already a triple, upgrading to a triple will make a huge difference for mountain riding. You can optimize the outer two chainrings and the rear cluster for cruising and downhill, and select whatever size inner chainring you need for your most challenging uphills. If you buy used parts from Ebay, a triple upgrade needn't be all that expensive. I've done three triple upgrades and did not need to change the bottom bracket or RD in any of them, and only needed to change the FD in one case.

Thanks for the link GonzoBob! I'm building up a vintage Ritchey MTB that deserves a new freewheel. The vintage Uniglide-compatibles bring a hefty price on eBay if you can find them. Nice to have other options.
jw

Oh gads, you're right I forgot the front rings -they are 52 and 42. I'm on a super tight budget and felt regardless of the rest of the setup that the 13-18 flat racing sprocket needed to be changed for mountains. I've put quite a few more miles on it now with the new cogs and won't need granny -I'm all about standing up on some hills still even with 26t but those grades are not as often and usually only when I'm cookin' it ;)
Thanks again!