cid499

I really can't tell.


The rusty little lockring around it spins with the cogs when I spin them backwards. The lockring has a 4-slot pattern to it (which you probably can't see from the picture). Also, I can read the words SunRace 2080 when I look at the part inside the lockring.

Any ideas?

Thanks,
Phil

ISeeDeadHuffies

Freewheel.

cid499

Cool. How do you know?

Rowan

I'd say freewheel.

For me, the bit that has SunRace on it was the clue. When the freewheel is off the bike, it undoes clockwise to enable the cogs to be removed from the freewheel body, letting lose about 100 tinyball bearings. You still need a four-pronged freewheel remover and a long, large ring spanner to undo the entire freewheel from the hub.

But smarter and more experienced people will know that the SunRace Megadrive was a freewheel.

ISeeDeadHuffies

Its kinda hard to describe exactly. The deep well of the internal spline is one example of the many visual differences. I think I saw some good photos of the two types at Sheldons' site.

bykerouac

Looks like a 13 to 34 Megarange freewheel.

cid499

Well. I would make a new thread but it seems like people are actively reading this one.

Using the wheel pictured above, I want to go single-speed as cost effectively as possible. Is a BMX freewheel the best way to go? I fear re-dishing costs if the chainline doesn't work out well.

Rowan

Yes you could. Unthread the freewheel and thread on the BMX freewheel. Only... you may find the chain pitch between BMX and the front chainrings might not be compatible. If you wanted to go SS in the most economical way, leave the freewheel on there, remove the derailleurs front and rear along with cables and shifters, decide which cog on the rear you want, and rejoin the chain to the required length. Hey presto! Single gear, no money spent, and you can change to a higher or lower gear if the one you select doesn't suit your riding conditions (keep the additional links you initially cut from the chain). Chainline shouldn't be an issue if you have two chainrings up front and you select, say, the middle cog on the rear. And it will confused the hell out of anyone looking at your set-up. Plus no redishing of the wheel to worry about.

cid499

Thanks for all your replies. A few more q's.

Well I would like to get rid of the excess cogs on the back. If I were to use a BMX freewheel, how would I accomodate the space that was once filled by the width of the other 6 cogs?

Rowan

You'd have to use different width washers and adjust the cones and locknuts to reposition the hub and BMX freewheel so it was centred between the dropouts. In that case, you would have to redish the wheel. It shouldn't need an entire rebuild, just spoke adjustment. You might also then have to look more closely at your chainline from the chainring/crankset you choose to use.

cid499

Thanks for the help Rowan. I think I'll just go ahead and do it the "right" way with a BMX freewheel and redishing if necessary. I don't know if how much redishing (if any) will be necessary because I haven't chosen a crank/chainring yet.

Thanks again. I'll post in the SS section when it's done.

Little Darwin

You may also want to search the Single Speed/Fixie forum for ideas from other people who can make suggstions based on experience as well.

Grand Bois

Don't let the comment about the difference in chain pitch with a BMX freewheel confuse you. There is no difference.

TallRider

Yup. Sometimes SS freewheels or track cogs are wider (and take a 1/8" chain instead of a 3/32") but the pictch (distance between the teeth) is nearly always standard.

Also, the picture is clearly of a freewheel, and I can say that for more reasons than just knowing that Megarange only comes in freewheels (I think). With a cassette, you'd see a lockring on the outside, whereas with this freewheel there is no external lockring visible, but just a hole where the spline tool freewheel-remover fits inside.

false_cause

On an older Sun Tour freewheel, I removed the cogs from the freewheel body and just screwed the larger of the two threaded cogs back onto the end of the freewheel body. Only one cog in back and no need for redishing. Looks funky, but what the hell, it was as cheap as it can be done.

Tried to put a BMX SS freewheel on another conversion, but the spokes on the wheel didn't work out for redishing so I bought another wheel rather than deal with replacing ~half the spokes on a 20 year old, cheap-ass hub/rim.

Rowan

oops, yes, my mistake. It is the sprocket width that differs between SS and derailleur equipped bicycles. I built my FG using a threaded sprocket from an old five-speed cassette and a BB lockring, and didn't need to worry about the which width chain to use.

cid499

Hey faulse_cause,

Got any pics of your setup? I was wondering if/how the cogs could be removed from my freewheel.

Phil