What Type of Bottom Bracket Do I Have?

[techsupport]

Hi,

I need some help identifying what type of bottom bracket my bike has, it is a Shimano Hasa R5 2015 and in the specs of the bike it shows - BOTTOM BRACKET: NECO CH-51 Cartridge Type

I am looking at a crankset that comes with bottom bracket and my 2 options are:

Shimano 4600 BB Cups (34/35/4500 double/triple)
OR
Shimano BB-RS500 BB Cups (Tiagra 4700)

My first guess was Shimano 4600 BB Cups (34/35/4500 double/triple)

Thanks!

[find_bruce]

It is not clear to me what you want.

If you are replacing the bottom bracket & keeping the crank, the NECO CH-51 Cartridge Type is a square taper, pretty much like a Shimano UN55

If you are replacing the crank, you need a bottom bracket that suits both your frame, which will be 68mm English thread, and the new crank.

There is, as far as I am aware, no difference between a 4600 & 4700 bottom bracket

[techsupport]

It is not clear to me what you want.

If you are replacing the bottom bracket & keeping the crank, the NECO CH-51 Cartridge Type is a square taper, pretty much like a Shimano UN55

If you are replacing the crank, you need a bottom bracket that suits both your frame, which will be 68mm English thread, and the new crank.

There is, as far as I am aware, no difference between a 4600 & 4700 bottom bracket

Here is a link to the page, when you configure options asks for either of those 2 bottom brackets. The Bottom bracket comes with the http://www.ribblecycles.com/au/shimano- ... groupset-1

[A_P]

of the 2 choices, one of them will likely be for italian thread BB.

[find_bruce]

A_P wins the prize - the first option is "Shimano 4600 BB Cups (34/35/4500 double/triple) Ital " - ie Italian thread. You want the second option "Shimano BB-RS500 BB Cups (Tiagra 4700)" which should be English thread. Personally I would send them a message to confirm that the second option is English thread

[Duck!]

There is, as far as I am aware, no difference between a 4600 & 4700 bottom bracket

Not so. Like the higher-spec models trickled down from 9000 Dura-ace, the RS500 (4700-level) bottom bracket has a smaller external diameter and corresponding low-profile bearings, along with improved, lower-friction seals compared to 4600. The critical dimensions of assembled width and internal diameter are unchanged.

[techsupport]

There is, as far as I am aware, no difference between a 4600 & 4700 bottom bracket

Not so. Like the higher-spec models trickled down from 9000 Dura-ace, the RS500 (4700-level) bottom bracket has a smaller external diameter and corresponding low-profile bearings, along with improved, lower-friction seals compared to 4600. The critical dimensions of assembled width and internal diameter are unchanged.

So mine is the 4600?

[Duck!]

No, yours is a square taper internal cartridge.

[techsupport]

No, yours is a square taper internal cartridge.

Will either bottom bracket fit on my frame? 4600 or 4700

[Duck!]

Yes, just be sure to get the English thread version.