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Bottom Bracket with easy bearing change

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nonameguy

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Discussion starter · #1 ·
I want a bottom bracket as cheap as possible with easy bearing change for my hollowtech ii crankset with thread not pressfit. Shimano bb have 6mm thickness and is almost impossible to find quality bearing. I looked the praxis works bsa but the 24mm id is again hard to find. I want to put quality bearing like skf nsk etc so the bb will last forever. I dont want to put 7mm thick bearing in my current shimano bb because it need a lot of work to fit propely.
 
#7 ·
I have a Chris King threadfit 24 BB on my 2016 Santa Cruz 5010. Installed the BB in 2016 and the bike has over 20,000 miles since then. All I've done since new is keep the BB area clean with an air gun maybe once a month (or less) and wash the bike maybe twice a year). I take the cranks themselves out once a year during my pivot service and clean and grease the spindle and BB too. NOTHING with the actual bearings though. Too this day, the BB is perfect. No need to change out bearings.....

I just built up a new Blur 4 for next year and immediately purchased a Christ King headset and BB upon purchase and installed. Same thing when I bought a new Orbea Terra gravel bike last May 2021 (ordered October 2020). I have over 1500 miles on that too in 2021 and zero service needed to the headset or BB bearings. All the gravel bike sees is dirty, dusty air too.
 
#8 ·
Not in English, but it doesn't matter. Skip to about 2:35 if you already know how to remove the BB and watch how easy it is. Do be a bit careful as the plastic covers are fragile, especially after a few years, but it really is that simple. I haven't looked at the newer/slimmer versions (MT800 and newer), but have done this to the old XT and it works great.
 
#9 ·
nonameguy said:
I want a bottom bracket as cheap as possible with easy bearing change for my hollowtech ii crankset with thread not pressfit. Shimano bb have 6mm thickness and is almost impossible to find quality bearing. I looked the praxis works bsa but the 24mm id is again hard to find. I want to put quality bearing like skf nsk etc so the bb will last forever. I dont want to put 7mm thick bearing in my current shimano bb because it need a lot of work to fit propely.
Click to expand...
If you have the older style bearing cups, or GXP cups, the bearing outside diameter is 37mm for a 7mm wide bearing.

Shimano used a 6805 bearing (37x25x7) plus the cap to bring the inside diameter down to 24mm to match spindles. A enduro 37x24x7 bearing can be pressed in and not require the cap. There are other reduces to get down to 22mm for GXP cranks.

Most threaded BSA aftermarket bearings are just cups to hold 37mm OD bearings. You can replace the bearings with any brand that fits. 6805 if you have caps, 37247 if you don't. Use AC bearings for Shimano cranks. Not critical to use AC for GXP as they don't have a preload system.

Getting the bearings out can be a challenge. Banging them out works. This tool makes it easy. Bottom Bracket Bearing Puller (Wind-Out Type)
 
Discussion starter · #10 ·
My last shimano bb52 bb last 2 years and 3000km. Nothing. Now I have the same no issues for now but I want just new quality bearing not new bb

drjos said:
If you have the older style bearing cups, or GXP cups, the bearing outside diameter is 37mm for a 7mm wide bearing.

Shimano used a 6805 bearing (37x25x7) plus the cap to bring the inside diameter down to 24mm to match spindles. A enduro 37x24x7 bearing can be pressed in and not require the cap. There are other reduces to get down to 22mm for GXP cranks.

Most threaded BSA aftermarket bearings are just cups to hold 37mm OD bearings. You can replace the bearings with any brand that fits. 6805 if you have caps, 37247 if you don't. Use AC bearings for Shimano cranks. Not critical to use AC for GXP as they don't have a preload system.

Getting the bearings out can be a challenge. Banging them out works. This tool makes it easy. Bottom Bracket Bearing Puller (Wind-Out Type)
Click to expand...
I have replaced my bb in June 2021 so it have 6mm thick bearings.

noapathy said:
Not in English, but it doesn't matter. Skip to about 2:35 if you already know how to remove the BB and watch how easy it is. Do be a bit careful as the plastic covers are fragile, especially after a few years, but it really is that simple. I haven't looked at the newer/slimmer versions (MT800 and newer), but have done this to the old XT and it works great.
Click to expand...
Im do this every year but again not last long.
 
#14 ·
mnpikey said:
I have a Chris King threadfit 24 BB on my 2016 Santa Cruz 5010. Installed the BB in 2016 and the bike has over 20,000 miles since then. All I've done since new is keep the BB area clean with an air gun maybe once a month (or less) and wash the bike maybe twice a year). I take the cranks themselves out once a year during my pivot service and clean and grease the spindle and BB too. NOTHING with the actual bearings though. Too this day, the BB is perfect. No need to change out bearings.....

I just built up a new Blur 4 for next year and immediately purchased a Christ King headset and BB upon purchase and installed. Same thing when I bought a new Orbea Terra gravel bike last May 2021 (ordered October 2020). I have over 1500 miles on that too in 2021 and zero service needed to the headset or BB bearings. All the gravel bike sees is dirty, dusty air too.
Click to expand...
+1 for Chris King. Just built my Transition Scout with CK headset and BB because i never want to mess with it ever again
 
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#15 ·
Thustlewhumber said:
+1 for Chris King. Just built my Transition Scout with CK headset and BB because i never want to mess with it ever again
Click to expand...
+1 from me too. Sram were lasting 3 months, shimano xtr was a year, the cheapest from wheels engineering (closeout blemish unit for $12.50) lasted 6 months.

I am beyond 4 years now on ck bb and the bearings are so smooth you can't feel that they're moving. I bought an aftermarket grease tool and flush the old grease with automotive zirc gun twice a year. You don't need to replace bearings if you can flush the dirty grease out of them. I didn't believe it would work but it does.

Edit: Because before you get excited about swapping in new bearings... price them out first - they're not cheap.
 
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