HELP - BB60 sizing - English or Italian

[Joffey]

Hi

Seen another thread on this but an answer was never found. I have checked Sheldon Brown as well but it doesn't seem to show B'Twin bikes or Shimano 105 5800.

I have a B'Twin Mach 720 (built in France I believe) and need a new bottom bracket. The old one only has these markings on it:



It would appear to be a Tiagra BB form what I have read online so an Ultergra / 105 BB60 will fit lovely. Problem is I do not know if it is English thread (68mm) or Italian (70mm).

I have measured the hole in the frame that the BB goes in and it seems to be 68mm so is it likely that the English thread will be the one I need?

Yours, hopefully, Joff :-)

 

[Tim Hall]

68mm and 70mm refer to the width of the shell. So, as you say, measure the hole and away you go. The 1.37 x 24 is how the British thread is defined anyway, and one of the bearings will be left hand thread whilst Italian thread is (a) bigger and (b) both cups are right hand thread. Get the English one.

 

[Joffey]

Excellent, thanks very much!!!

 

[Yellow Saddle]

He he.... I see you had some fun attempting to pop out the seals to see if you could coax the bearing back to life.

 

[Joffey]

He he.... I see you had some fun attempting to pop out the seals to see if you could coax the bearing back to life.

Yeah!! Saw a guy doing it on YouTube and it looked simple. I broke it first go! Pretty shocked the bearings went after 365 miles.

 

[Yellow Saddle]

Yeah!! Saw a guy doing it on YouTube and it looked simple. I broke it first go! Pretty shocked the bearings went after 365 miles.

Which one went, the left one?

 

[Joffey]

Which one went, the left one?

Yeah. Sounded like it was the right one until I took it apart and checked the bearings.

 

[migrantwing]

Yeah!! Saw a guy doing it on YouTube and it looked simple. I broke it first go! Pretty shocked the bearings went after 365 miles.

Use something like a Stanley blade, or similar next time. The thinner, the better