Shimano HG51 8-Speed Cassette

Perfect Fit and Easy Installation The Shimano Alivio CS-HG51 8-speed cassette was a direct replacement for my old Shimano Altus CS-HG31. It fitted perfectly on my existing hub with no compatibility issues, and I installed it myself without any problems After installation, shifting feels crisp and smooth thanks to Shimano’s HyperGlide technology. I primarily ride in the higher gears (smaller cogs), and yesterday I put it through a tough test with a 61-mile ride—no skipping, no noise, and flawless performance throughout. In my opinion, it passed with flying colors! I commute 18 miles daily on my bike, mostly using the higher speeds, which puts a lot of wear on the smaller sprockets. My previous CS-HG31 cassette wore out quickly—after just a few months, the chain started skipping on the overused cogs. The HG51 is from Shimano’s higher-tier Alivio group (with chrome plating for better corrosion resistance compared to the Altus’s zinc phosphate finish), so I’m optimistic it will last significantly longer under the same riding conditions. Overall, this seems like a worthwhile upgrade for daily riders looking for reliability and longevity. I’ll update if needed after more miles, but so far, highly recommended!

Quick Notes: - Great quality cassette that’s light in weight.(I didn’t put it on a scale but just holding it I could tell it weighs less than 1lb.) - Easy to install you just need a chain whip or an old chain and some gloves (is what I use) and a Shimano freewheel remover to take off your old cassette and just the freewheel tool to install the new cassette. - Can take a lot of force being applied to it without any chain slippage. - Up shifting (high toothed gears) is as smooth as butter and has the smoothest down shifting (lower toothed gears) that I’ve experienced out of any cassette I’ve used. - Becomes super shinny again when cleaned with simple degreaser. - I would recommend this cassette to anyone looking to replace or just upgrade their current cassette. Full Review: I’ve used this cassette every day for 3 weeks now and have put a few hundred miles on if so far and I’m very pleased with its performance. I installed this cassette in less than ten minutes including setup. To replace a cassette you will need a chain whip and a Shimano Freewheel remover. It’s worth noting that if your cheap like I am you can just use an old chain and hold it with some gloves to prevent the old cassette from moving when removing it. The chain isn’t needed when installing the new cassette just the freewheel tool. If you are unsure of how to change a cassette look it up on YouTube or take it to your local bike shop or if I get 5+ comments asking about installation I’ll make a video of how to replace a cassette but there already tones on YouTube if you are unsure of what you are doing. Now about the performance of the cassette up shifting on this cassette is like most others its butter smooth but much to my surprise this cassette dramatically improved the ease of my down shifts it almost never slams into any gear the only gear slam I notice is going from 28T down to 24T and I assume the 32T to 28T is probably the same but I’ve haven’t had to go into 32T yet in a real world ride. Every other down shift though is very smooth it is important to note that in order to get smooth shifts it’s not just the cassette that matters but your derailleur and shifters as well. My personal set up is a Shimano Acera M360 derailleur and Shimano Acera SL-M310 Shifters. The next cassette I order though will probably be a 11-30T simply because I’ve climbed some pretty steep hills any only ever felt the need to go to 28T but if you are new to mountain biking you will probably want to get a 11-32 just to make sure you can climb any hill. You can also really crank out the power on this cassette and not have to worry about chain slippage, which is great if you like doing burst power workout rides like me or if you are on the heavier side and looking for a quality cassette to go with a bike that you can use for some basic exercise. But the best part of this Cassette is by far its durability with scratch resistance. When you clean your bike after a long off road venture that gets everything covered in mud just spray some degreaser on your cassette and spray it off with a hose and it will look brand new again. I have no problem recommending this cassette so anyone its fairly inexpensive and the performance is miles ahead of any of the cheaper cassettes that really makes this cassette worth spending the extra 10 bucks on. --*If you have any questions please leave a comment and I will try and respond as soon as I can, but I have a job and things to do so please don't expect a response immediately.*

Great price, and exactly what I was looking for to complete my vintage build.

Shifting with this cassette seems much better than with the aftermarket cassettes I've sampled on the same bike. I marked it five star because it works great, and is a good value. In the category of "easy to install" I gave it a 4-star, because it would be impossible to call it 5-star easy given the fact that swapping cassettes requires two bike-specific tools (a cassette chain whip wrench, and a cassette socket), plus a torque wrench. If you work on bikes enough to have those tools (as I do), then yeah, it's 5-star easy. For everyone else, it's not until you go pick up those necessary tools. I marked it 3-stars for light weight, because it's not. It's exactly the weight that you would expect of a mid-tier Shimano cassette. Dura-ace would be 5-star light. Ultegra and 105 would be 4 star light weight. This one is 3-star light. And low end cassettes would be 2-star light. Sure, it's pretty light, but it's not "wow, I'm giving this 5 stars!" light. The shifting is good, the chain runs well over all the cogs without skipping, it's just what it should be if you need a replacement 8-speed cassette. I also like the gearing range; 11-32. That goes well with my hybrid bike that has a 28/38/48 chainset in front. It would be even better if I had a 9, 10, or 11 speed drivetrain, but we pick cassettes to match our shifters, derailleurs, chains, and chainsets. And 8-speed is what I've got. In that category, this is about as good as you can get.

Perfect

Fit perfectly and works great! I like the range that is both higher and lower than the 7-speed that I replaced. The gear progression is nice.

I rubbed enough grease off my old cassette to see it is marked HG-50 on the lockring and the cassette is sort of a bronze color. This HG-51 is more like a chrome finish. Maybe this HG-51 is a newer and/or better version of my original equipment HG-50? Anyway, my main problem with my old drivetrain (around 3,500 miles) is sort of a grinding sensation with noise only when using the 8th cog (11 teeth) with either my middle or big chainring. It got a lot better after I put on a new chain and new chainrings, but it was stilI noticeable. I rarely used the 8th cog on my old cassette, so can't figure why that cog only would be worn enough to give me grief while the rest of the cassette cogs ran smooth as silk in silence. But maybe it was poorly machined or maybe it's just that total smoothness on an 11-tooth cog is asking a little much. UPDATE - admittedly I have only done 20 miles on this new cassette, but my impressions: 1) mounted easy enough using a chain whip and sprocket tool. 2) my original HG 50 was more quiet on cogs 4-7 but not the smallest 8th gear. It was really grinding then skipped a tooth once after I put the new chain on a few weeks ago. This new cassette got rid of the 8th gear issues almost 100% but it is not as smooth as gears 4-7. Maybe the 11-tooth 8th gear was bad on my original cassette. Why? No idea, I rarely used that gear even on the street because with only 11 teeth, when on the big front ring I had to stand up and pedal to maintain a pace even on flat ground. I primarily used cogs 4-7 and again, those were still quiet and working well with the new chain and front chainrings. But people said with 3,500 miles and a noisy worn chain, do the chainrings, chain, and cassette, so that I did. Bottom line maybe this new cassette needs to work a while with my new chain to smooth things out. I'll see. Shifting thru the gears up and down is fine, but my old cassette was not giving me any grief on shifting either. I'll update further at maybe 100 miles.

I've got a 2003 GT Palomar I've been on a journey with during it's resurrection. You can find my reviews and learn more about the journey and parts I've bought through my reviews. Please know this is an old school bike with front and rear derailleurs and is 21 speed. I thought I finally had the GT where I wanted it, but decided I wanted a lower 1st gear ratio for trail riding. I built this GT for both road and trail riding with a 22-32-42 Shimano Crank Set and an 11-28 7 speed Shimano HG cassette. Which gave me a 1:1 first gear ratio. When I found out my rear derailleur could handle an 8 speed cassette, I bought this 11-32 to drop first gear below 1:1. I also bought a Shimano 8 speed Revo Shift to match the front derailleur, as they had been performing perfectly for me in the bikes current configuration. I installed this cassette and Revo Shift, then dialed it in. They work just as smooth as the 7 speed cassette and shifter I removed installed. Now, I still have my 42-11 high road gear ratio as well as my 22-34 Trail gear ratio and 24 speeds to choose from.