aMTBer 20T Chainring 64 BCD MicroDrive

20 teeth = smooth torque with finesse to climb anything effortlessly. I LOVE IT High quality stainless steel is tough, long lasting and does not rust. Light filing of aluminum crank was needed for chain clearance. VERY HIGHLY RECOMMENDED

I wanted to try out this idea. I was first disappointed because being steel, it is very heavy. Probablytwice the weight of my aluminun 48t ring. I did not order the spacer because I thought the spacer frommy old 24t would work. It doesn't really, it gets squashed and deformed to an extent. So maybe youwant to order the spacer at the time you order.On my test run, I rode up a mountain called Mt. Wilson near LA. The vertical climb there is quite challenging.Could only be slightly happier with the performance of this ring. It was a little noisy but the climb was mucheasier than I'd ever had it before. By the time I reached the peak, I had a lot of energy left, which I neverbefore experienced (in other words, normally I'd be half dead)Rear cassette: 11-34tNow this happy experience was frustrated when I upgraded my chain and cassette. Well, the cassette wasn't really a problem.Here's the problem: highs and lows. The teeth on this ring are longer and sharper ("My what sharp teeth you have, granny!") and the valleys between the teeth much lower than most chainrings you meet. The height of the teeth and sharpeness appear to actually very slightly slow down the physical engagement of the chain and also create the additional noise I earlier mentioned.This added height might also very well create more resistance that add to the wear and tear.The height of the teeth is really not much of a problem compared to the depth of the valleys between teeth. The full effect of this really depends on your chain. Using my old chain, there was no problem - KMC 9sp, light but not SL. But when I upgraded to KMC SL 9sp, the hollow kind, all Hell broke loose.The newer chainlinks must be ever so slighly longer because the links rest lower in the valleys than my old chain. This is a complete disaster because when that happens, the chain actually rubs and becomes elevated by, on one side, the mounting bolts and on the other side, the crank bolt hole structure. What happens then? The chain does not engage at slope induced forces. I mean, when you're going uphill, the chain slips entirely. After installing the chain, I was going to do the Mt. Wilson trail but could not even begin it, I got maybe a 20th of the way before I had to turn back.The problem is not with the chain but the design of the chainring. Beware if you are using a higher end chain. I went ahead and made modifications to my bike however. I grinded down both the mounting bolts and the crank hole molding. I also reduced the sharpness of the chainring's teeth. Just a little.Now everything works and it's not nearly as noisy as it was.Summarize design flaws:#1. The valleys between teeth are way too low. Or, maybe more importanly, the base of the teeth should be wider.#2. There should be a recessed area in which the bolts are driven. Slightly more expensive versions have this recess and it is very important. Without it, depending on the chain you use, the chain could ride on the bolts and not engage when you need it most.If you don't mind doing a little modifying, this chainring can work for you. It's now working fine for me. In the future, I will probably buy a higher end titanium version and hopefully, the titanium version will not have the design mistakes of this model.10 years later. No, no! I no longer have it! It lasted several years and I was real happy with it. (I had plenty of 24s and 22s laying around so I never bought another 20t) These ten years later, I'm again searching for a 20t and wow, here it is. I did not recognize my own review until I saw "Mt. Wilson" Hey, that's the mountain I ride up! ...oh.I only gave this chainring 3 stars. That wasn't very nice. It deserves 4 or 5.But I'm not buying it again just yet. when I bought it last time it was only about 7 bucks or so. I think... Now they want nearly $40! I'm not sure if that's a good deal at this time. It's starts to look more practical to upgrade my hub to XD or other so I can get a greater compensating range. Personally, I'd rather just get the 20t but I must be practical...

I.installed this on a 7 speed and didnt have the need to file down the bolts. I think a 7 speed chain is wide enough that it does not run the inner bolts. Aside from that this chainring is probably a little overkill on the trails. I don't have to use the last gear on the back. It is awesome to be able to climb with a little more ease with this 20t. I came back to review in hopes to order another one but see that is out stock. Bummer and thank you, and please stock this asap!Edit:I mentioned earlier about not having to make any modifications. However, when I changed the cassette the chain started to catch on the inner chainring bolts. I took a dremel and grinded the bolts until it was smooth and flush with the surface of the middle chainring. Now the chain does not catch and all is well again. I since then ordered a second granny gear.

I've used this 20T chainring for just over a year now. So far, very good. With it, I now have a 20-32-44T triple crank combined with an SRAM 11-34T cassette. The chain is an SRAM PC951; so I'm running a 9-speed. It is smooth shifting, smooth running, and exhibits no chain suck so far (meaning the teeth aren't worn down too much). Not only have I gotten a lower low, I have also gotten a lower RANGE of gears (4, to be exact) below 25.4 gear-inch, which is the lowest gear on the middle chainring (32T). I use this 20T to pull a 30-lb dog trailer with a 55-lb Chow Chow up a hill that is 1/3 mile long with a 13 percent grade at its steepest. I could do that in my younger days with the 22T, but it was a chore. Now, at age 68, my quads are thankful for the 20T! My wife is complaining about her knees biking uphill, so I guess I will be converting her bicycle soon.

Read all the reviews and decided to give it a try. At 69 years young the prospect of achieving a gear ratio that was kinder on the legs was enticing. Now to achieve perfection it takes some simple modifications. A die grinder with a stone was my weapon of choice. A quick study made it clear what was required. Reshaping the mounting towers took only a couple of minutes with minimal material removed. The gear it self is a perfect fit. The end results is way better than expected. Shifting is smooth and quiet and that hill I used to kill myself going up is no longer a problem. Very pleased with this product . If you are not mechanically inclined I am sure your local bike shop could help.

Was not for 9 speed. Must be for 8 speed.

Works great if you are on the heavy side. Be aware it needs to file and adjust a few things for the chainring to work

You will need to be committed to this modification. It will take some machining to work correctly. if you're handy, for the price it is the way to go. It will help with the really steep sections. I rarely use my 2 lowest gears now. Only for the "holy crap you can ride that?!" Hills. I would only recommend this on a 3x10 system.