# help



## pcorr79 (Oct 15, 2012)

Hi, i'm new to road bikes,got the first one in march.i have a compact but i now want a 53/39 so i need to know what type of BB i have so i can buy the right crank but still be able to fit the compact if i want to. i have a 2012 giant defy 1. i looked on the giant website but is only says its a shimano press fit but it seems it should have some numbers in the title.
does anyone know what BB i have?

cheers
paul


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## JasperIN (Oct 25, 2010)

Believe it's a Shimano BB71
Bottom Brackets up! The Shimano SM-BB71 Road Press Fit Bottom Bracket is a middle of the range complete press-fit bottom bracket assembly kit for Shimano HollowTech II and two piece road cranks. It comes with an inner cover for 86.5mm BB shells.

Key Features:

The cups are made from a fibre reinforced polymer material which reduces the risk of frame noise or sustaining any damage to your frame.
This set includes left and right hand cups and an inner cover.
Sealed cups keep out dirt and water maintaining a long lasting, smooth running, maintenance free BB which is ideal for those not wishing to get their hands dirty through maintenance.
For use with a BB shell width of 86.5mm on road bikes.
Designed for a 41 mm cup diameter.
A press-fit installation system allows for hassle free easy installation.
You may wish to contact the bicycle brand (frame brand) manufacturer if you have a question in regards to BB specifications or assembly conditions.


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## pcorr79 (Oct 15, 2012)

thanks jasper, thats what i was looking for.

cheers
paul


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