I bought a 39T ring to replace the stock little ring on my 52T/36T crankset. I live in an area with lots rolling terrain, and the 39T ring helps me hit the gearing sweetspot without inefficient crosschaining. I run a 11T-28T cassette and never feel undergeared on hills. Shimano says the 39T is only for use with the 53T ring, but mine works fine with the 52T; I've ridden this setup almost daily for ~2 months and only dropped a chain once due to bad shifting/pedaling technique.
After 11,000 miles and a couple of chain replacements another chain was due, wearing to .75%. That was more than my original front chain rings could bear and I was slipping on my large ring after the new chain was installed. I replaced my rings with these and no more slipping. In fact, what surprised me was the decrease in noise. It was remarkable. These are not cheap but they're genuine, in stock, and shipped right away. It was well worth it.
BTD sent me the wrong Shimano Ultegra Large Chainring for my 2017 TREK Madone 9.0 even though I requested BTD to confirm compatibility prior to ship. Post purchase, I was unable to talk to anyone thus all communication was via email. After several exchanges over several days, BTD admitted they do not have the ability to confirm compatibility in a pre purchase environment. I was told to use a Dremel tool to modify the chainring Shamino Ultegra received to "make it work". As a rider who averages 5,000 miles a year, I will never use BTD again for my cycling product needs.
My bike had a compact set, which was just a little too low for my fast bike. I like spinning fast on my inner ring, but with a 34 tooth Id have to almost cross chain to go my normal speed. I bought a 36, and it is perfect. Now I can keep it more in the middle of my cassette and spin away. Good quality, worked perfectly swapping the 34 to the 36, with a 50 outer.
Needed a replacement 6800 big ring after going too long between chain replacement and wearing out my old one. BTD had it in stock. I couldn't be happier with the service and price. My fav on line bike shop.
Came stock on the bike so just a maintenance purchase but really it's Shimano Ultegra, works fantastic with Di2. Original parts lasted a long time so no disappointments there. Smooth quiet and reliable.
one might think and expect that the 46 tooth ring would be a direct, physical replacement for the stock "outer" on an fc 6800 crankset.....surprisingly it is not.....an extra kit is required to attach it, bringing the total cost for the single 46 tooth ring to more than $xxx....even worse is that the extra kit looks odd because it alters the smooth lines of this otherwise wonderful crankset............the inner ring sizes are reasonably priced so i kept those......free shipping is a nice touch......beware the 46t......it shouldn't be listed with this product without a few emphatic caveats or asterisks