I have googled and not found the answers to my questions:

I have a used Ultegra crankset I'd like to use. It came to me with ruined chainrings, so I replaced them inexpensively with RaceFace rings from Nashbar. Now I need a Hollowtech BB.

1. Are there different models and years? I ask because I see there is a Hollowtech II, so I assume there was a first series. I don't have the cranks in front of me, but I'll see if there's a model number on them.

2. I'll need the BBT-9 tool, right?

3. Also, I don't have the bolt that goes on the end of the spindle and presses the left arm on. I do have the pinch bolts. Where can I get that bolt?

Thanks.

"Hollowtech I" was also known as "Octalink" and was a larger diameter hollow spindle splined cartridge-type bottom brackets (BB-5500/03 and BB-6500/03) and used with FC-5500/03 and FC-6500/03 9-speed era cranks. It used the same BBT-2 Park tool as earlier square taper cartridges.

Hollowtech II is the current external bearing bottom bracket (BB-5600, BB-5700, BB-6600, BB6700, etc.) used with cranks having the spindle built into the drive-side crank arm and the nds arm clamped to the other end using splines and pinch bolts. The installation tool for the bearings is indeed Park's BBT-9 or Shimano's TL-FC32.

The "bolt" that presses the nds arm on is just a externally threaded plastic cup that is tightened not much beyond snug with the other end of the BBT-9 tool or Shimano's TL-FC16. That bolt should accompany the crank but maybe your LBS has an extra you could use.

Shimano BB-R60 11 Speed Cups (Ultegra 6800/105 5800) - Bottom Brackets - Ribble Cycles This the current Ultegra level BB. Works for 10 and 11 speeds. As you can see, they are cheap. Any of the other Hollowtech II will work if you prefer a different color. Shimano Crank Arm Fixing Cap (each) - Chainset Spares and Accessories - Ribble Cycles This is the fixing cap, as they call it.

The BB-R60 has smaller diameter external splines than the earlier HTII cups but comes with an adapter ring to allow the use of the BBT-19 and TL-FC16 tools. If you do get a BBT-R60 and want a specific tool, Park Tool's BBT-59 is the one.

It (i'm guessing ) is the bearing pre load cap. External Bearing BB took that sort of Idea from threadless headsets .

so it snugs up side to side play, then you tighten the bolts on the left arm ?

Any god LBS should be able to order one, you can also get aftermarket alu versions, check out eBay for thes

https://www.aliexpress.com/item/Hot-...9-5cbe33aeb774

I checked: the arms are marked 6600/6603, so I take it that means I can use the easily obtained Hollowtech II unit. Thanks.

yep, just a proper locating device to set the sideplay of the spindle... people over-tighten them if they get a wrench on them... the park tool has a THUMB KNOB that spins on the handle of the tool.... LOW TORQUE is all you need....

tighten the two clamp bolts in even stages, too....