Anything better than praxis?

hubcap

Hi all, I'm getting a frame that has a PF30 bottom bracket but want to run an Ultegra chainset in it, is there anything better than using the praxis converter?

I would be happy to use something that fits in the frame and allows the use of a shimano threaded bottom bracket as I've always found these to be excellent but, and it's a big but, I obviously want to avoid any creaking.

Therefore is the praxis the best option as I've read that they tend not to creak if correctly installed?

Thanks.

shmooster

My Praxis is a bit creaky, but from what I read before buying it, they were the best option.

My LBS fitted it, but it was a bit of a rush job and they didn't fully torque it up. I subsequently tightened it which made it creak less, but never been 100% right.

thomasmorris

I have a wheelsmfg in my BBright (very like PF 30 but offset) where the bearing takes 24mm cranks with no shim / reducers / converter. Works really well.

Basically, you have adapters (e.g. Wheels MFG), shims that reduce the inner diameter to accept the smaller shimano axel (24 mm verus 30mm). These slot in to the existing BB bearings. The benefit is they're cheap if you already have a bottom bracket in there which takes a 30mm axle (~£25). They're also easy to install as they just slot in ahead of your cranks. The downside is using converters introduces another interface that could creak, on top of your PF30 shells which are already prone to creaking.

Frame - pressed aluminium cups - bearing - converter shim - axle.

You then can also buy BBs for PF30 that have bearings that fit 24mm cranks without the need for reducers / shims / converters (eg race face here). There is less chance for creaking here as you have one less interface. However, obviously you have to buy a complete bottom bracket and install it (and remove the old one).

Frame - pressed aluminium cups - bearing - axle.

Better still are bottom brackets (as made by rotor, praxis, wheelsmfg etc.) that don't just press fit into the frame (two independent cups), but screw together. This ensures the bearings are aligned, and doesn't require as good an interface fit to hold solid. The downside is these are the most expensive and as above you'll need to completely remove any existing BB and install this. They're easier to install than standard press fit (obviously you need the bb wrench).

Frame - screwed aluminium shell - bearing -axel.