Hollow Tech Bottom Bracket Bearing Replacement

[T_Dog]

The price of Shimano BB bearings keeps going up, and the after market versions don't last very long so have been putting in my own stainless steel bearings. The 6805 bearings used are fairly common and you can get them on Ebay as well.

Process for doing it is below. If you use a propane torch or an electric heat gun to heat up the housing, the bearings pop out quite easily as the aluminum housing will expand at a higher rate than the steel bearings. Make sure you wear a leather glove and hold the housing with a rag to avoid burns.

http://www.mountainbikerides.co.uk/fettling/24-drivechain/35-shimano-hollowtech-ii-bottom-bracket-bearing-replacement.html

Cost for the two bearings should be about 300 baht, versus 1600 plus for the Shimano OEM part.

[rhythmworx]

Hollowtech is known for its problems.

I would say replace the whole crankset with something better, but that would also mean chain and cassette which would be costly.

Not anything I can offer here.

P.S. (just checked) same price as they go for in UK .

Edited April 20, 2014 by rhythmworx

[T_Dog]

Hollowtech is known for its problems.

I would say replace the whole crankset with something better, but that would also mean chain and cassette which would be costly.

Not anything I can offer here.

P.S. (just checked) same price as they go for in UK .

I like the Hollowtech system as it is so easy to work on. Would be curious to know what other systems you are referring to as a replacement.

[rhythmworx]

I wanted to put an XTR crank on my bike a few years back but after researching there were too many reports of clicking/grinding and short bearing life, I just stuck to the old square taper design in the end.

I was originally thinking a Chris King bottom bracket, and presumed that would mean everything else would need changing to suit but I just had a look and they make a fully compatible Hollowtech II replacement.

The downside is it cost's 5x more than a Shimano BB but is guaranteed for 5 years, they have good reviews. You can also re grease without disassembly.

[CobraSnakeNecktie]

The Chris King bb's are work of art and precision. Probably good for 10+ years of service but not cheap.

Why mess with the bearings if a new Shimano BB70 costs less than 1k baht and lasts a few years? Chitawat and Sept-19(bkk seller) on ebay stock them.

Usually its just the non drive side that wears out. If someone is wearing them quickly then my guess is adjustment mistake or water accumulation in the BB shell. Might need to drill a hole in the shell for drainage etc.

I abuse the heck out of mine with high mileage and hard climbing and they just last and last.

[T_Dog]

The Chris King bb's are work of art and precision. Probably good for 10+ years of service but not cheap.

Why mess with the bearings if a new Shimano BB70 costs less than 1k baht and lasts a few years? Chitawat and Sept-19(bkk seller) on ebay stock them.

Usually its just the non drive side that wears out. If someone is wearing them quickly then my guess is adjustment mistake or water accumulation in the BB shell. Might need to drill a hole in the shell for drainage etc.

I abuse the heck out of mine with high mileage and hard climbing and they just last and last.

Yeah, water is a real killer on bottom brackets of any kind. I find that the Shimano units are not very well sealed, unlike the bearings I put in myself that have shields that are very difficult to remove. We have had quite a few "full immersion" rides up here in the last few years! Tried to post a pic but getting an Upload Error from ThaiVisa's server.