6 speed freewheel hacks?

[doctor-bond]

So I’ve got a Shimano MZ hyperglide 6 speed freewheel on my, ahem, gravel bike: these max out at 28t and don’t appear to be crackable. They’re great though.

And while I don’t need 40t at the rear because I’ve got a 26t ring up front, 30 would t hurt and I’m curious to know if it’s possible to contrive a 6sp freewheel with customisable hyperglide cogs (hyperglide being prolly the best invention since the slant parallelogram derailleur). Maybe using Sachs, sunrace, etc?

Anyone know?

Gravel

 

[Rod_Saetan]

Suntour and Regina are your best bet for custom ratios with 30t+ on a 6 speed block. Fully rebuildable and sprockets available separately, I suspect it would be neither easy or cheap though!

 

[bikeworkshop]

Shimano Mf-tz30 6 speed tourney did 14-34,
although if you're not using one of the tourney Megarange dérailleurs
(and you wouldn't really want to)
you might need to choose your r.mech carefully - some can be adjusted to handle 34, some can't.

If its all shimano, the indexing should be spot on.

 

[doctor-bond]

Yes, the changeability of Suntour cogs (and Malliard) is what I’m after but with those lovely hyperglide ramps. Mega range is an option but the 6 speed ones seem to jump from 23 to 34.

Is there a way to crack these? Looks like the small one might screw and then the first few slot on with the last three on a carrier? Could then mix and match 7 speed cogs onto 6 speed wheel body perhaps.

…. Edit, but if you can’t crack the carrier, then you’re stuck with the big final step…..

 

[bikeworkshop]

Really if you want custom sprocket choice with crisp indexing, you need an hg freehub wheel.

An old hub is worth pennies, and it's not rocket science to swap a hub out if the flanges match.

Get a 130 width hub, I'd assume your frame is 126 but you can almost certainly spread that.

Then you can set it up 6 speed with some work on the spacers.

Job done.

 

[doctor-bond]

True, but I’m devoted to the Dura Ace/Mavic set I’m running, so am just musing on possibilities. Will man up on 26x28 for now.

Just for info, in case anyone else falls down this rabbit hole, shimano did do a traditional (no carrier) freewheel with hyperglide cogs, Tourney MF-HG22, but you’d be hard pressed to find any uphill ratios for it:



Here’s a bare 600 freewheel body showing how the cogs slot on: