# what size bottom bracket?



## feh (Mar 8, 2007)

I have a Motobecane Record purchased in 2007. It has the ubiquitous Kinesis 7005 aluminum frame.

Anybody know what size bottom bracket it takes? Thanks!


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## frdfandc (Nov 27, 2007)

That is an open ended question to a point. Kinda of like "what size tires do I need".

But I'll try and expain.

Bikes currently on the market (including those that are a few years old) are one of 2 kind.

1. English threaded frames or Italian threaded frames. 

2. The Bottom bracket shell is either 68mm wide or 73mm wide. This needs to be measured to be 100% sure.

3. Spindle length of bottom bracket if its not external bearing style. Most double cranks are 109.5mm or 110 mm. Triples are normally 118mm.

Your Moto is probably the English threaded with a 68mm shell. 

Now the type of bottom bracket is dependent on the crank set itself. If its the new external cup style like the new Shimano Ultegra 6700, then its just getting the correct threaded cups. But if its an internal cartridge style, then it is matched to the crankset itself. The easiest way to determine the length of this is to remove the BB and look on the body of the BB cartridge. Should have a sizing on it, something like 68x110 or 73x118.

That should give you an idea in which head direction you need. 

Now the next question is why do you think you need to replace the bottom bracket?


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## SilverStar (Jan 21, 2008)

It would help also if you could tell us what kind of crankset you're running...someone might be able to narrow it down without you dismantling everything.


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## feh (Mar 8, 2007)

It's an FSA triple. Square taper, sealed cartridge.

I've got this ticking noise, once per crank revolution, that I think is coming from the bottom bracket. Of course, I'm not positive, but I've tried to eliminate all other possible sources.

It has 4000 miles on it; how long are inexpensive BBs expected to last?

Thanks folks.


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## wim (Feb 28, 2005)

If it's an FSA "Vero" triple, it takes a Sugino BB-7420 square taper sealed cartridge BB with a 116 mm spindle. You most likely need the 68 mm shell width, but measure your frame BB shell width to be sure. (AFAIK, BB-7420s come in another shell width as well).

Should last more than 4,000 miles. Ticking often comes from the BB-frame interface, not from wear. Wear usually shows up as rough and noisy spindle rotation.


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## feh (Mar 8, 2007)

wim said:


> If it's an FSA "Vero" triple, it takes a Sugino BB-7420 square taper sealed cartridge BB with a 116 mm spindle. You most likely need the 68 mm shell width, but measure your frame BB shell width to be sure. (AFAIK, BB-7420s come in another shell width as well).
> 
> Should last more than 4,000 miles. Ticking often comes from the BB-frame interface, not from wear. Wear usually shows up as rough and noisy spindle rotation.


I've already removed the BB and greased all contact points. I'm wondering if it's a problem internal to the BB.

BTW - I think the crank model is "RPM"; at least, that's what it says on the inside of the crank arm...


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## wim (Feb 28, 2005)

feh said:


> BTW - I think the crank model is "RPM"; at least, that's what it says on the inside of the crank arm...


Hm, I'm getting confused now. "RPM" is not "FSA," and I didn't know that FSA made an "RPM" model crank. But RPM brand stuff is made by TH Industries, which is probably making cranks for FSA as well. So there is an FSA > RPM connection. If you can find your crank at the link below, you'll see what BB it needs. As said, easiest would have been to read the label off your BB or measure your BB when you had it out.

Does the ticking always come at the exact same spot in crank rotation? 


http://www.thindustries.com.tw/prod_rpm.asp


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## frdfandc (Nov 27, 2007)

Make sure that its not your pedals or chainrings. Also see if the front derailleur cable isn't hitting the crank arm as it rotates. It will cause a ticking noise, once per revolution, always in the same location.


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## feh (Mar 8, 2007)

wim said:


> Hm, I'm getting confused now. "RPM" is not "FSA," and I didn't know that FSA made an "RPM" model crank. But RPM brand stuff is made by TH Industries, which is probably making cranks for FSA as well. So there is an FSA > RPM connection. If you can find your crank at the link below, you'll see what BB it needs. As said, easiest would have been to read the label off your BB or measure your BB when you had it out.
> 
> Does the ticking always come at the exact same spot in crank rotation?
> 
> ...


I removed the BB - it's 68x118. Thanks everybody.


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