SHIMANO 7-Speed Tourney Bicycle Freewheel - MF-HG37

This MF-HG37 looks fairly well made despite belonging to the Tourney product line. All of the sprockets are threaded directly to the body, unlike the OEM Shimano freewheel that it replaced. The original Shimano freewheel that came with my bike had the two largest sprockets riveted like outriggers to the fifth largest sprocket. I also note that this MF-HG37 is made in Singapore, while the crummy Shimano freewheel that came with the bike was made in mainland China.Gearing is 13 - 15 - 17 - 19 - 21 - 24 - 28.The MF-HG37 is probably the best choice if your bike is equipped with a seven speed freewheel. Unfortunately, that's not saying a great deal because the field is so limited and low end since Sun Tour went out of production years ago. Basically, you only have two choices in the Shimano lineup: this MF-HG37 and the MegaRange. The MegaRange has a too-large 14T high gear and a goofy jump to its 34T low gear. Regardless of your choice, the metallurgy in the sprockets is mediocre and you can expect the smallest sprockets to wear out and start jumping. Alternatively, you can go with the DNP lineup for better gearing arrangements but at the cost of a fragile body assembly and even lower quality sprockets.The conventional wisdom had been that freehubs (together with their cassettes) would become nearly univeral. Freewheels were expected to disappear except on Wal-Mart level bicycles. That hasn't happened, and you can still find lots of Treks and Motobecanes with seven speed freewheels instead of freehubs. Those freewheel equipped bikes can be fairly pricey at the LBS if they come with a good frame and otherwise good components. Shimano needs to recognize that there's a market for better quality freewheels.I'd really like to see Shimano re-introduce a freewheel that deserves to be in the Altus product line. Better metallurgy is a must, at least in the smallest sprockets. A 13T to 32T option would be appreciated. Nothing currently available rates five stars.

I hate that I am saying this, but its true... it arrived nicely packaged, seemed to be of good quality, but after installation (with proper tools and procedure) it became apparent that I received a bad one. Freewheel was knocking- literally knocking with every pedal revolution. apparently the cone bearings in the freewheel were set too loose, and there's no way to adjust without special tools. very disappointed...

I bought this 13-28 because I couldn’t tune the stock 14-28 that came stock on my Walmart bike. I also wanted the 13 to eliminate some of my spin outs. After Installing this freewheel, my bike shifts cleaner and the derailleur stays adjusted. I used the park tool freewheel removal tool made for Shimano to remove and install both units. I have this paired with a KMC chain and I’m very pleased.

I bought this for my 29inch. 21 speed ironhorse Walmart bike. The gears and chain totally worn out. Probably 7000 miles. Im changing the chain lube due to this mileage. Going with a wax based product. My mileage is mostly stop and mostly go 20miles a day. This gear set has 13 low gear teeth and i put 50 up front. 170mm crank. Hopefully i can get 10K or more out this set. Its kind of easy to change. Just had to buy the right wrenches i added a pic of the 2 tools

Only about three months in, the hub seal (the ring with the two little holes inside and below the lockring) managed to unscrew itself. This should absolutely never, ever happen with a new freewheel. At $20 it is barely worth the trouble to return, and the seal is overlapped by the cogset so that pin spanners don't fit, so to attempt a proper repair means acquiring a lockring wrench and dismantling it. Economically the best option is to toss it and find a better one, or better yet switch to a freehub/cassette.This is so ridiculous an issue that I've downgraded my review to 1 star.

Replacement for a worn-out SunTour freewheel on an early '90s Specialized MTB I use for commuting, errands, and around-town riding. (Note that this is a freewheel and not a freehub/cassette--know the difference!) The spacing doesn't work perfectly with the SunTour indexed shifting but it's close enough. Not an exact replacement for the SunTour that was on there, which was 13-30T, but I don't miss the lowest gear since I mostly ride on flat roads anyway. Nice that it saved me the expense of converting an older bike to using a freehub in the rear; I'd likely had to have had a custom wheel built as this older bike uses 26" rather than 29" wheels.

Shimano MF-HG37 (13-28T 7 speed)I bought an inexpensive Genesis GS700 bicycle from Wal-Mart (made by Kent), and it came with a cheaply made Sunway drivetrain. I managed to crack the smallest sprocket on the freewheel while climbing hard on an uphill bridge. I inspected the original freewheel and identified the tool I needed to remove the freewheel (Park FR-1), and proceeded to replace the assembly.The Shimano HG37 is well made, with all of the sprockets cut properly and nothing wobbling or bent out of shape. It also felt somewhat lighter and also looks more aesthetically appealing. Once installed, I took the bike out for a spin and immediately noticed smoother and quieter shifting while the freewheeling ratchet sound also changed.It was easy to install and I had to use a bench vise with the FR-1 tool to remove/tighten the freewheels.Overall: 5/5 stars, extremely well made replacement freewheel. It's not an Ultegra or Dura-Ace freewheel/cassette, but it sure as heck beats the cheap parts used on department store bicycles. I kind of wish I could find a 7-speed freewheel with a 11-tooth sprocket.