Could anyone point me in the right direction that is the minefield of bike standards!

I want to convert Tarmac SL4 to house a shimano chainset, currently the frame is OSBB and the chainset thats in is BB30, any opinions on shims/adaptors etc?

thanks in advance

A praxis works bb converter should do the job. Upgrade are the UK distributor so most LBS should be able to help.

https://praxiscycles.com/product/shimano-conversion-bb/

yeah I saw that seems like the best solution, although I was looking at some shims too for the time being for ease and cost

what would be the pros and cons of a new shell rather than some adapters?

Is OSBB the same as PF30? ie not threaded? If it is there are shim type adaptors like the sram one that are much cheaper and you then use standard HT2 bbs. I’ve been running a PF30 to HT2 sram adaptor on a hardtail for a year. All ok, more or less, but recently it looks like its pulling out slightly on the driveside. On my list of jobs to investigate and reset it. So maybe not as good as a praxis one, but much cheaper.

Well from what I gather (without spending too much time researching) is that my BB is PF30 and the BB thats installed is BB30 which I guess I need the adapters to convert to HT2.

or the praxis solution which I will probably do eventually (because seems more solid solution) which is Spesh PF30 to HT2?

not sure if I am missing something, but I plan to get the adaptors short term see how they fair up

I run an SL4 frame (roubaix) and hollowtech cranks.

I looked at the options when I was specing it up and they are as follows;

1- use the adapter cups that came with the frame to widen out the BB area to allow the fitting of a hollowtech crank. This was what I started with (unintentionally, more of which in a bit) and it creaked straight out of the box. It was removed and re-fitted but the creak never went away.

2- Praxis works. Silent running unless you go BB deep in water, then you will need to pull it out of the frame and re-grease it and all is good again. I now use this option and have been very pleased with it.

I should have had praxis works from day 1 but the LBS didn’t put the praxis BB with the parts when they were building the bike up…. so I used the spesh solution. But my experience of the cups does seem normal when you look into it. The praxis kit isn’t cheap but it does seem to offer an excellent solution, and their customer service dept is excellent if you have any questions.

cheers guys I now have a good in-depth solution to go at, invaluable advice

much appreciated

KCNC and wheels MFG also do converter bb’s

I used Wheels Mfg adapters to fit an Ultegra chainset into my Tarmac SL4. These are just push-in nylon reducers but I’ve had no trouble / noise at all.