Truvativ Euro-Threaded BMX Bottom Bracket Adapter for American Cranks

john zook: I saw a tutorial video of a guy using this bottom bracket adaptor in a vintage Schwinn road bike. He removed the one piece crankset and original bearing cups, slid this adaptor in the bottom bracket shell and tightened the bolts. Worked perfect. So I purchased one to use on an old Sears Free Spirit I am restoring. Out of the box it looked to be a nicely built product. When I removed the bearing cups from the frame I was restoring, I noticed the bottom bracket shell was not a piece of tubing, but a piece of flat steel rolled into a circle. Well, sort of a circle. I'm sure when the bike was built in 1973 it was a lower quality frame. So the bottom bracket shell was not cut from a piece of tubing like most bikes. They had rolled flat stock into a circle, then added another thicker piece of flat stock to the inner diameter to add strength. It wasn't perfectly round, and the additional piece inside was thick and not very round at all. When I tried to test fit the BB adaptor, it did not fit at all. Long story short, it took days of grinding, turning parts in a lathe, grinding more, cutting and generally trying everything possible to get the adaptor to fit the frame....

United States on Nov 24, 2023

Raymond M. Dunne: I used this to convert an American shell bottom bracket on a BMX bike to a mountain bike style sealed cartridge bottom bracket. Works well but you also will need 9/16" threaded pedals and a mountain bike style chain ring versus the standard BMX sprocket that you need with a proper BMX 3 piece conversion kit. I went this way because I already have all the parts from mountain bikes so it was more economical for me. It installed very easily and the bottom bracket also installed very well. Good product for this type of use.

United States on Oct 03, 2023

ぽんdeらいおんぽんdeらいおん: 変換アダプターとシェルにグリス塗布してシェルに圧入。この際、プラスチックハンマー等でアダプターを均等に入れていくのだが
この時、左右のアダプターが決まっているので適当にやると二度手間になる恐れがあるので要注意！
まずネジの頭が入る方のアダプターが左、ネジの受け側が右になるようにセットして行う。
（アダプター内側のネジ山向き→左側が正転、右側が逆転になればOK）
最後に3本のネジを締めなければいけないので、２つのアダプターの穴位置がズレない様慎重に入れていく。

そこだけ注意すればOK、最後にネジ山にもグリスを塗布して締め付ければ装着完了！

Japan on Jun 26, 2023

Samuel R.Samuel R.: Insert is 51.3mm, I had to grind the bottom bracket a bit to fit the adapter and used a bearing race installer.

Very happy with the product.

Canada on Jul 03, 2022

Julian FriasJulian Frias: Muy buen producto, fácil de instalar, buena calidad y ensamble perfecto. Muy recomendable.

Mexico on Mar 13, 2021

Romans5Romans5: Like others have pointed out, if your bike's chainstays or downtube protrudes into the shell of the bottom bracket (see picture #1), you are going to have to modify this adapter. I was installing Shimano Claris cranks which require the BB-ES25 bottom bracket which is threaded. If I had cranks that were compatible with a square tapered bottom bracket, then I could have gotten the Sunlite conversion kit and not worry about all the protrusions in my BB shell. Unfortunately, I was basically stuck with this style adapter. Here's how I made it work.

1. Identify the drive side and non-drive side of the adapter. They are not interchangeable. As you will see later, I took great pains to get things aligned, so having to remove and re-install it is not going to be a fun task. I screwed the adapter onto my uninstalled BB and marked the sides "D" and "ND" with a Sharpie. See picture #2.

2. There are three long screws that are used to pull the other side of the bracket into the shell. With all the various protrusions inside the shell, there was really only one configuration where all three screws don't hit something and make it to the other side. See...

United States on Sep 10, 2018

JoeyJoey: Did this operation on a Schwinn traveler that I've been riding fixed gear. Normally the problem that people are encountering is a raised area within the bottom bracket that forces you to file or grind the cup adapters so they will fit flush within the bike. Luckily, I didn't have this problem. The adapters fit with no gap and no filing. However, the problem I did have is that my bottom bracket is a few mm to narrow for the the adapters to accommodate the cartridge bearing I bought. It's a Shimano cartridge with a 68mm shell (I believe this is the narrowest they make). Now, the total width of my BB with the adapter cups was around 71.5mm, but the cups are machined with insets that hold the bearing in place, and my best guess is that this brought the width down to around 65. Bottom line is that fully tightening the bearing into the cups left a few mm of threads outside the adapter, which maybe isn't the biggest problem but I wouldn't risk it. They make spacers to solve problems like this. I was doing the operation at my local non-profit bike co-op type place, and a quick look around found me a few. The one I used is about 4mm thick you can see it on the non drive...

United States on Feb 17, 2018

Tim: Habe einen coolen Rahmen bekommen der allerdings mit angeblich "Euro BB" ausgestattet war. Musste lange recherchieren und war mir bei der Bestellung am Ende noch immer unsicher ob dieser der richtige ist. Hat jedoch bestens gepasst. Der Adapter muss wirklich mit viel Kraft eingefügt werden. Ich empfehle Schraubzwingen zu verwenden. Am Ende werden beide Seiten gegeneinander verschraubt um sicheren Halt zu gewährleisten. Ich habe trotzdem Buchsenkleber verwendet, um wirklich keine Gefahr einzugehen!

Germany on Oct 02, 2016

vh: Lightweight, exact dimensions, easy to install.

United Kingdom on May 25, 2016