I’m putting together the parts for a titanium gravel build with GRX Di2. I know this won’t be cheap, but I started thinking about the bottom bracket. The frame takes a standard BSA threaded BB and I can get an Ultegra one for $17, Wheels Manufacturing for $100, or Chris King (non ceramic) for $170 I think.
On the one hand, I want to have top quality stuff on this build but on the other I’m not worried about chasing grams or spending money where I don’t need to.
Do you think there’s an advantage to premium bottom brackets for an average rider? Thanks!!
I’d go with the Wheels version, I’ve had the good luck with the one in my gravel bike. Shimanos are OK but seem to wear faster. Chris Kings are really nice but historically they seemed to have fairly high drag. Zero data here just personal experience.
To note that Shimano cranks do seem put an uneven load on the BB system. All of my Shimano cranks in years past wears out the non-drive side much faster. FWIW.
CK tends to pack their bearings in a specific type of way where it appears as though they have higher drag when you do the “spin test”, but they are designed to have load in the system and the drag actually lower at operating temperature.
That being said, I don’t think the extra 70 is worth it compared to Wheels.
I went ceramic on my new build, but only because I did get a deal. I’m told they do wear quite a bit longer than standard so I figured the durability would be worth the difference in price and not having to teardown and replace. I agree with the above poster that the Wheels Manufacturing products are a good buy for the money. I went with another company by our mechanics feel the Wheels Mfg. are really nice.
For a gravel build, my top priority would be how well they are sealed. And reviews for how long they last. But then we don’t have gravel, we only have slightly drier mud.
@FrankTuna Ultegra is famously an unreliable choice for a gravel application. All things crankset/bottom bracket are off the table.
For gravel, I would pick either the Enduro stainless (stainless steel races & balls, angled contact, great tolerance, larger balls). Or hawk stainless with CX seals.
DEFINITELY NOT CERAMIC. 5x the risk for a couple hundred milliwatts of performance. Not worth it.
If I was going to pick a Shimano bottom bracket for gravel I would go down their price chart, not up. Do they still make a Tiagra bottom bracket?
Wheels MFG use Enduro bearings. See this helpful table:
Sounds like you might want their 440C Stainless Steel bearings (or XD-15 if your budget extends that far). Unless you want to service the bearings every 6 months, avoid Ceramic Hybrid.
If you already have the BB cups, it can work out quite a bit cheaper to just source the replacement bearings and have your LBS swap them out.
Also take a listen to the Cycling Tips Nerd Alert with the Founder of Enduro bearings:
ABEC 3 is not a bearing type. It’s a concentricity/runout spec that applies to many different types of bearings, including angular contact.
AC bearings are designed to take load both radially and axially (inline with the spindle). Deep groove radial bearings primarily take load radially, although they can sustain a small amount of axial force.
Not sure why they’d offer both types. You’d think as a manufacturer, they’d know which is better in this application.
I was getting circa 7,000km out of Ultegra BB.
My current Hope BB has 34,000km on it (including 2x 1000km+ Audax).
The Hope BB cost a bit more, but I think it has paid for itself relative to replacement Ultegra BB over that time.
The only thing I’ve done with the Hope BB is to remove, clean and regrease the face and refit.
Very confused on the abec -3 and angular contact option as well for the issues you illustrated. Theoretically opposed angular contact bearings can be preloaded to create an extremely rigid joint but not really seeing a point in a bottom bracket. It would make more sense in a headset.
For BSA? Just get a Dura Ace one and remove & replace as needed - takes 10min total. No other BB will gain you anything, except CK (bling).
All the fancy BB are there for the following reasons:
Fancy bearings that do things slightly better for the first 100miles or so.
Fancy bearing mounts for press-in BBs. (for press in, I like BB-Infiniti w/ their ABEC7 bearings; I don’t like the spin-together because they mess the paint on the BB shell; I don’t like the super expensive ones because they aren’t any better).
Given you’re buying quality stuff, the difference is the grease, seal, and fitment. The grease and the seal cost about 1w; the lack there of is for single-use / short term bearings. Ceramics can get away with lighter grease, but they destroy their perfection quicker because the ceramic balls are harder than the race (with steel, they are much closer in hardness). The fitment is something the basic BSA design better than the molded carbon/fancy AL pressin designs.
This is probably close to correct Hawk Racing: Bottom Bracket Study The unloaded would show the basic seal /grease/fitment drag. (Side note - Interesting that the SRAM GXP is 1w better than the Shimano. .4w seal/grease as seen in the unloaded graph. I’m guessing because one of the bearings doesn’t have any side load or the different size bearings allow for some fitment room that helps under load.
BSA bottom brackets are also press-in, but they are pre mounted in cups, so they rely on the bike’s BB opening to be correct. It’s usually correct because it is just a round metal tube. A Shimano BB is $32, will test within .5w fresh of the best you’ll ever find NEW, will test BETTER than the best after 300 miles (because the better seals and bearing wear), and will last just as long as any other BB.
I think DA and Ultegra are mostly the same here, but they use smaller bearings than the cheaper or older ones. This sounds like a small weight savings thing. The DA uses better seals (in the new 9100 version) overall. The Ultegra/105 SM-BBR60 ones uses better seals than the older version supposedly. That study doesn’t show much difference over the two types. You might want to go for the RS500 for a more durable bearing at a 20gr penalty.
I’m not a big fan of Wheels Mfg’s seals. They’re probably great, but I don’t like them because they don’t stay put when you remove the crank (which isn’t really a problem).
