YST Threadless bottom brackets
 

I've done some searching and I'm seeing mention of chamfering being required with them. But most of the posts saying that are 2+ years old. Is that still true?

I've also read a little about chamfering, but I'm having a hard time visualizing how it works. Anybody care to offer maybe a better explanation?

Is chamfering something I could do myself? Would I need special tools? If not, how much does it cost to have done?

The reason I ask is because I stripped the threads on my bb and am looking into a threadless bottom bracket. The YST bb is only $20, but if I'm going to have to spend $40 or more on special tools or having a shop do chamfering, then I may as well go with the threadless bb from VO for $60.

Harris Cycles [Sheldon Brown] indicated that they quit carrying the YST because of quality issues.

Concur - stay AWAY from YST BB's. You might as well take your $20 bill and flush it down the toilet.

Get the VO BB or a Mavic threadless BB.

-Kurt

Ah, thanks for that advice, but a little late in my case. I put one on my Lambert. I did not need to do anything to the shell; I just installed the thing and it was done. No problems to report.

I got fed up with their BB system on my Viscount as well. I buzzed the BB shell mitering clean, and threaded it Italian.

-Kurt

IIRC, no special prep is needed for the YST unit, but as others have noted it is not well made either. The Mavic BB is superior, but requires chamfering to install. Make sure your LBS has the proper tool before buying a Mavic BB. EDCO made a threadless BB cartridge with eccentric cups to hold it in place, but they have not been made for many years now. The new Velo-Orange threadless cartridge looks promising, though.

Ok, I'm glad I didn't order one last night then.

I can't find any Mavic ones in my brief search. Do they work the same as the VO ones?

how long have you been using this yst bb? It's not going on a high dollar bike, so it doesn't need to be top of the line. If I were to go with the one VO sells, I will be paying as much for a bottom bracket as I did for the whole bike.

I paid $50 for a frameset and $60 for a VO threadless bb - and I'm very happy with it. I'm keeping the bike so the investment was worth it.

I put the bike together only a couple months ago, and have probably ridden it less than 100 miles; I doubt it will ever get more than 10 miles from home (I have other bikes for that!). So my good luck, so far, is not necessarily an endorsement for the quality of the BB.

I see. While this bike isn't high dollar, it's the nices one I've got and will likely see the most use. I should probably go for the higher quality BB.

My take on the YST threadless BB
 

https://cimg1.ibsrv.net/gimg/bikefor...fce7bf3886.jpg
https://cimg2.ibsrv.net/gimg/bikefor...e60dcb3a38.jpg
https://cimg3.ibsrv.net/gimg/bikefor...a48ceadb08.jpg
In the BB shell of one of my bikes, the non drive side thread is broken while drive side one is fine. In the past I have installed BB-UN55 type BBs using epoxy. While epoxy is highly reliable, it can be a pain to deal with. So I thought I would buy a threadless BB this time around. I opted for the YST threadless BB as it was reasonably priced. Having used it, I find the YST one to be of poor design. The fit is based off a fairly small tapered section close to the ends of the BB. The tapered part squeezes into the frame and provides the fit. This means that the contact between the frame and the BB occurs only on the interface between the tapered part on the BB and shell of the bike. Should any of the parts deform even sligthly, the component will probably come loose. The velo orange BB seems to be of a better design, in that regard. If you decide to go with the YST, make sure you use some thread locker while installing it.

Always check the alignment of the BB after installing a threadless one. The guidance provided by a threadless shell is much less reliable than if it were threaded. The threadless BB may end up very slightly crooked, even if the fit appears good. Incorrect alignment is best detected with the crank and chain mounted. Poor alignment will cause the chain ring to engage the chain at an angle instead of in a straight way.