Mark42

The Shimano Hyperglide Freewheel (MF TZ07) is on two of my bikes. One bike is about 10 years old and that freewheel has never failed. Three other bikes have the newer Tourney Freewheel MF TZ21 and all three failed (seized) within a year or two doing mostly street and rails-to-trails riding.

I have a few questions:

1) Is the MF-TZ07 really a better freewheel than the MF-TZ21?

2) Why is the MF TZ07 listed as a HyperGlide freewheel when it doesn't have HG in its model number?

3) Why can't I find the MF T07 freewheel for sale anymore?

4) What made the MF TZ07 a better freewheel than the nearly identical MF TZ21?

5) Why doesn't Shimano list any MF-HG freewheels on their website under tech docs anymore?

Thanks,
Mark.

xenologer

Marketing, Progress, and Planned Obsolescence

nfmisso

1. no
2. Ask Shimano.
3. Shimano chose to discontinue it.
4. see 1 above.
5. They chose to stop.

I find Sunrace freewheels to be of better quality than Shimano freewheel offerings.

You might want to try lubricating the freewheel with light oil.

Mark42

Thanks! I respect simple straight forward answers!

But you have to admit there are 07 FW around long after the 21s bite the dust. I'm suspecting they chose to save money be eliminating a dirt seal, or cheaper ratcheting mechanism, etc because they seize up.

Funny, now you can buy HG freewheels like this https://www.amazon.com/Shimano-MF-HG...mano+freewheel , but they are not listed on Shimano's web. Go figure.

maddog34

here... buy this one... or a cheap one that won't hold up as long under heavy/frequent use....Realize that freewheels are outdated tech., very complex to manufacture, and only a few bikes are now sold with them, new...

NIB Simplex freewheel,cassette 7 speed 14/28 L'Eroica | eBay

or this one...
Regina Extra NOS 80's Syncro 7 Speed Freewheel 14-28 Campagnolo Compatible RARE

even back when these were "new", they were expensive... like, 45-70, and up! in 1980 dollars, of course...

i assumed yours is a 14-28.... run a search on Ebay for your gear range, and shop.

the reason the tourney FW's don't last very long is use of too little, and low quality lube.

70sSanO

In a nutshell, Shimano 7 speed freewheels today are throwaway products. I have no doubt your older freewheel is better. You can also look at other manufacturers such as Sunrace or DNP, but they are not high quality either.

Any older 7 speed Shimano freewheel will work, it doesn't have to be hyperglide. If you find an old Shimano 600 or Dura Ace it will last longer. eBay is where you might find a decent used one. I have a bike with a freewheel and I am using a Sachs Aris (LY9x) from the 90's. It indexes with Shimano shifters.

Or just buy cheap ones and replace them often.

John

hermanchauw

1) Is the MF-TZ07 really a better freewheel than the MF-TZ21?

Not necessarily. As mentioned by the rest, the quality of the lube matters.

2) Why is the MF TZ07 listed as a HyperGlide freewheel when it doesn't have HG in its model number?

Doesn't matter.

3) Why can't I find the MF T07 freewheel for sale anymore?

Have you checked in taobao.com?

4) What made the MF TZ07 a better freewheel than the nearly identical MF TZ21?

The lube probably, as above.

5) Why doesn't Shimano list any MF-HG freewheels on their website under tech docs

Too old maybe.

Btw, i recommend you switch to 8/9/10 speed freehub wheels. Cassettes are much more easily available and freehub axle is more supported (ie stiffer, ie stronger, ie durable) than threaded 7 speed axle.

buck1973

They are listed on Shimano's site. Click on Line-up Chart and any Tourney or other low end line such as A050 and you will find them. For example:

2017-2018 SHIMANO Product Information Web

Alternatively, from the following page, you can download a pdf file for the specifications of the complete Shimano line for any given year from 2004 to 2017:

2017-2018 SHIMANO Product Information Web

hokiefyd 

That's interesting -- most mass-market freewheels today are sold with a 14T sprocket as the smallest one -- this has a 13T. I've never seen this freewheel choice before -- thanks for the link.

HillRider

How about: Marketing, Progress and Replacement by Superior Technology.

joejack951

Only a few bikes? Perhaps you are referring to bikes sold in bike shops and that would make your statement true. But for department store bikes, which make up the bulk of bikes sold in the US at least, most are still being shipped with 7 speed freewheels assuming they have multiple gears. For bikes that likely won't see 100 miles in their lifetime it really doesn't matter what they have back there.

u235

I have a hybrid that was my primary bike until recently. Mine have never siezed, they just get wobbly and noisy. I've had some last a few hundred and some last a few thousand. I ride a lot of mud, water, and dirt and at one point I was a clyde. I have an older MTB from the last 90's with a 7 speed and although I've haven't used it much in the last 10 years and it sits under a cover outside, it is still going. My thought... I've taken one apart and cleaned out the dirt and relubed but in reality, they are only $15-18 to replace.

70sSanO

It is good to put "Replacement" and "Superior Technology" together because that is definitely the case. While I wouldn't recommend old technology, there was a time when freewheels, and more specifically freewheel cogs wouldn't wear out for years. Now there are actually forum threads on how to squeeze out a few more miles out of paper thin components.

Freehubs are a superior design. I'm just not sure there's more fun riding from having more thinned out gears. I guess the exception would be a wide range cassette.

John

fietsbob

IRD, Merry Sales/Soma say they make better freewheels. Sachs-Malliard Aris Were better freewheels..





...

Dave Mayer

First off, freewheels come on likely 90% of bike sold globally - to date.

Freehubs, although superior technology, are more expensive to manufacture, and in the end, for 7 and less speed drivetrains, freewheels are good enough. And for the vast majority of riders, even fussy roadies with first-world 'needs', a 2x7 drivetrain offers enough gears and gear range.

As to freewheels, the Shimano TZ21 and HG37 freewheels are two of the great bargains in cycling, and are good enough for the vast majority of cyclists over a wide range of conditions.

There are some vintage freewheels that were made somewhat more precisely than the current inexpensive Shimano units, but they featured primitive cog profiles that shifted very poorly (basically anything French or Italian), and they used inferior removers that are now hard to find and strip easily.

70sSanO

Ummm... My LY9x Sachs Aris freewheels use a standard Shimano freewheel tool, same as my Dura Ace freewheel. Not sure how much crisper it can shift than my 7 speed Dura Ace index shifters to an XTR rear derailleur to the Sachs, but everything is quiet and silky smooth. Maintenance is easy by unscrewing cog 1 and 2, and the freewheel body has an oil port. And if I need to, I can send it off to the Freewheel Spa and have it rebuilt.

As for the newer Shimano freewheels, I have heard that a Shimano freewheel lockring tool supposedly exists, but I just haven't tracked one down. Then again since they are throwaway components, I guess there is no need for maintenance.

John

Dave Mayer

I have at least 20 pounds of Sachs 7 and 8 speed freewheels plus a few dozen spare cogs. Never use them because TZ21 freewheels are significantly lighter, and the HG cogs shift somewhat better than the chisel-shaped Sachs cogs.

Plus for the price of a single replacement Sachs cog on Fleabay, I can buy a whole replacement TZ21 unit.

BTW: Dura-Ace 7-speed shifters are in no indexing way compatible with XTR rear derailleurs. The issue is not cog spacing, but a fundamental mismatch in cable pull requirements versus derailleur actuation ratio.

Barabaika

What about the Evo freewheels?
They look better with the nickel plating and are even drilled.
The Shimano freewheels on Niagara are the cheapest.
https://www.niagaracycle.com/categor...els/multispeed

70sSanO

Yes it is cable pull but they are compatible if you know what you are doing to get around it. A well known simple fix.

As for cogs, they are more expensive, and so are the freewheels. The teeth on the cogs are thicker and last longer. But the best part is that I can customize them since they come apart like old freewheels. For me being able to run a 30t/32t without a Megarange jump is more important. Won't find that with Shimano, Sunrace used to offer it.

I'm not suggesting that everyone go out and buy these old freewheels, but I have used newer Shimano and also Sunrace freewheels and not only do the not hold up, I can't customize them. I made a tool to remove the Surace lockring, but the newer ones are on too tight. So if you have a little used 30t cog you can't transfer it to a new freewheel.

John