Does anyone know if the Shimano Hyperglide freewheels are interchangeable with one another?......eg, If I took the cogs from a Megarange, could I swap a few from the standard 13-28......both freewheels offered on Harris Cyclery....and build more of the range I wanted while having the benefit of HG design without having to build a freehub wheelset?

Thanks!

You can swap the cogs on those? How do they come apart?

You can only maintain the benefits of HG as long as you maintain the intended relationships between cogs, so if you had a 28-25-22-19-17-15-13 and a 32-28-24-20-17-14-12 and you wanted to make a 32-28-24-20-17-15-13, shifting would suck between 20-17 or 17-15, depending which 17 you used. Merging HG cassettes only works when there's three consecutive cogs of the same size between them.

IMO you should quit futzing around with freewheels and rebuild the rear with a freehub; there are bound to be more options that way. Prolly get away with the same spokes.

Well, I don't follow quite WHY you say that about the relationships. I've read about folks customizing HG cassettes to suit their needs. But, indeed I don't know much about it and, indeed, I am asking about a freewheel and not a cassette.. I'll simply have do more research and look at the differences on cogs.

I do know freehubs are a much better way to go, but I'd have to rebuild the rear wheel and I don't have a truing stand. It'd cost more for me to either buy the stand or take it to the shop and have them rebuild the wheel. I have the hub to do such a thing, and the spokes wouldn't be but about $35 for a set of basic stainless, but add it all together and I just figured building a HG freewheel might come out cheaper and get me where I wanted for now. Hmmm....

Okay...........so what I think you're saying.....

Starting from the smallest cog, I'd need to go 13-15-17 and, then, say 20-23-26. IOW's, 2 tooth jumps three times and then 3 tooth jumps three times. NOT 13-15-18 to 22-26-32 or something like that??

Now, are you only saying this from an indexed shifting standpoint or a friction or simply both/either? The crappy shifting issue, that is...

Lemme ask you something, dude. The wheelset with the freewheel hub I have is 32H. The freehub I have that I could use to rebuild the rear wheel has 32H's. Could I simply reuse the original spokes and just swap the hub provided I keep the spokes in the same order as they came off the wheel?? The flange height is the same on both the FW and the FH hubs.

Swapping the hubs should be easy enough. Don't listen to the FUD about re-using spokes; just inspect them for damage. And you don't need a wheel stand to build wheels; I can get a front quite close to true just by doing up the nipples till the threads just disappear (careful of sleeved rim joints), then just adding equal tension around the wheel. I just put it in the bike to finish it off, using the brakes as guides, flip the wheel to establish dish. The rear's different only in that I put it in the frame earlier to check roundness before I really crank up those DS spokes.

As for mixing HG cogs, it's about the fact that a 17 from a 28-25-22-19-17-15-13 is designed to sit between a 19 and a 15, and is a different animal to a 17 from a 32-28-24-20-17-15-13. HG cogs don't play nice where they don't belong; all those fancy cutouts and chamfers allow the chain to ride lower over the cogs during a shift, eliminating the chain jump from the higher chain falling into place as the shift completes. When you mess with the HG program, that old jump comes back.

Hmmm......I wonder why, then, the folks advocating and practicing swapping cassette cogs to customize never make mention of the chain jumping issue. No matter. I guess I'll just stick with pre-assembled equipment.

Thanks for the tip on wheel building. What do you mean, though, about "flipping the wheel" to establish dish in the rear? And, how are you checking for roundness? What are you using to guage that by?

In my experience, the 13-28 7 speed freewheel has a different spline pattern than the older 14-28 7 speed freewheel. The 13t is internal threaded versus the 14t external thread. If your freewheel bodies are the same, swapping should be okay. HG only matters if you're using indexed shifting.

You are referring to Shimano HG freewheels, right? As in the ones offered on Harris Cyclery's website?

And, I did ask about the shifting issue in relation to index vs. friction above. It make sense to me that switching to a freehub is just simply stronger and has more options in the way of gearing, but on some of these vintage bikes I have with old, high flange hubs.....well.......a modern freehub just looks funny. That's why I ask about swapping HG freewheel cogs. I get to keep the old, freewheel hubs and still have some of the benefit of technology. As well, old freewheels....the good, wide range ones........are getting stupid expensive.

I exchanged some emails with someone at Harris Cyclery this morning. Apparently, just like any HG cassette, the cogs on the HG freewheels are interchangeable........although Harris doesn't do it themselves for customers. All you need to do is drill out the rivets......just like on cassettes.....and you can swap out however. They didn't make any mention of shifting issues in regards to indexing, but then I didn't ask.

Anyway, that's that. Now, my quandry is do I want to mess with that or just build a rear wheel or two with freehubs. Bah!!!

Thanks for all the input.......especially the wheel building tips.

Ciao!

So can you put cassette cogs on a freewheel?

Flip = turn it around. If the dish is out, it'll change its distance to the stays. It's important to flip it in case there's some frame or dropout misalignment that might mean the wheel isn't properly dished even if it's sitting halfway between the stays. Also a good move to turn the spindle in the dropout before clamping to ensure that's straight too.

To gauge roundness, I usually just check it by eye, looking at the rim from the side. If I need to get more accurate, I tape a bit of plastic or something onto the chainstays that hinges up on the tape when the rim hits it.