On Friday, April 16, 2021 at 1:08:52 PM UTC-7, Mark cleary wrote:
The local bike shop needs a mechanic they called me about doing some work for them. They knew I could build wheels and repair them and the manger of shop knows me. Well I go in to discuss things and they said most all the work they do is on disk brake bikes. That surprised me although they are a Trek Dealer. They definitely need a wheel person the shop manager is the only one who can really rebuild a wheel and probably my take only he could true them decent. That sounds pretty off for a Trek shop.

Then I told them I happen to have Shimano 6800 and was good with Shimano and Campy/Shram I did not work on much but not hard to figure out. They seem cool to the fact that I would figure it out pretty quick. But the guy mentions my 6800 is old stuff hard to get parts. I told him I road Titanium and still always want BSA thread BB on my bikes. He laugh but agreed at least TI was good and nothing wrong with rim brakes. I was just totally surprised they find 6800 old? Do folks ever ride bikes for a few years before buying another or junking?

Finally I told him I could not tell him if I wanted the job until after the weekend. He wants 3 days a week 10-6pm. I cannot do weekends the deacon works. Then the wild thing I am discerning if I want to pursue the priesthood with further study. If the Bishop gives me a dispensation on some formation requirements.....then? I don't want to work 3 days.

Finally I guess if you buy a bike it is outdate after 2 years? Granted mine is 4 but wow I was taken back by what he said.
Deacon Mark
All of the upper end Shimano are disk brakes as of 2021. They also changed from that crappy BB90 to T47 which is a threaded version of the BB90.

Shimano disk brakes are EASY to work on and the things you need to know is how to install them and how to bleed them. One time and you are set for life. They have video's that show you how to do it all and it is so easy that I looked at a video and did a completely bike in 20 minutes. And that was slow compared to what a shop worker could do after a couple of times.

The hard things: 1. there are a dozen or more bottom bracket standards and they are ALL different and have their own peculiarities. BB386 is normally 30 mm shaft diameter which is used by several crank manufacturers but is also available in 24 mm for Shimano cranks or 24/22 mm for SRAM crap. You coat the outside of the BB in non-seize compound and you place the largest side of the BB on the power side. You need two 52mm tools that are made by Park Tool to insert them properly.

BBright is the standard of Cervelo and it is for 30 mm cranks shafts only. It is narrower than most and is ratherr silly in my mind.

They made other such as a BB30 which is supposed to be a 30 mm crank shaft diameter. I haven't worked on one of these but I believe that it is a standard BB but set up for push in bearing meaning that the crank shaft itself is narrower then standard.

Campy makes an Ultradrive which puts some cups in a normal BB shell but the bearings are part of the crank and the shaft has a 25 mm diameter.

At the bottom of it all - because carbon fiber requires a lot of area to become strong enough not to break, they worry about aerodynamics. Because Steel tubing is so comparatively much smaller in diameter Aerodynamics on anything other than the wheels is unnecessary. The increased speed of the carbon bikes is because they are lighter so pros ride them. When you have a full time power of 450 watts, you are going up hills so damn fast that you HAVE to have a superlight bike to be competitive.

For Joe Average rider that puts out 150-200 watts FTP it matters very little. You are simply going too slow for weight and aerodynamics to make any difference, Aerodynamic deep section carbon fiber wheels have absolutely horrible rim braking though Campy pads improves that somewhat. Put disk brakes on it and the brakes go from dangerously inadequate to dangerously overadequate.

There ARE aerodynamic aluminum wheels available. They are only 40 mm deep but again, who is it that is going to have enough power for it to make a difference? The pro's are sponsored so they aren't going to change to aluminum wheels.

But rim brakes on aluminum wheels is where it is at. You can still brake too hard and crash, but you have to work at it.

Other than disk brakes on MTB's which are a whole lot harder to bleed, there is really nothing to worry about.