Are bottom bracket spacers necessary?
If you need to use a bottom bracket mounted chain guide or derailleur, then you’ll also need to remove the innermost 2.5mm spacer on the drive side – so a 68mm or 83mm shell will have one drive side spacer and one non-drive side spacer, while a 73mm shell will need no spacers at all.
Where do the spacers go on a bottom bracket?
For a bottom bracket shell width of 89.5mm, insert the 2.5mm spacer into the right hand side (between the frame and the right hand adapter). Use the inner cover. bottom bracket shell, it should be installed with the inner cover sleeve to prevent possible contamination.
What are BB spacers for?
Bottom bracket spacers are used to adjust the spindle position to add extra clearance, or to fine tune chainline. For example, if your inner chainring is too close to the chainstay you can add spacers to move the crank outward just a bit. They are really great if you want a perfect chainline on a fixed gear bike.
What is an octalink bottom bracket?
Octalink Bottom Brackets. This system, designed by Shimano, was the first successful alternative to the older square taper. The Octalink system uses a larger and stiffer spindle with eight splines. The splines provide a greater contact area between crank and spindle for a stiffer interface.
How do I know what size bottom bracket I need?
To find out the size of bottom bracket needed, measure the inside of the bottom bracket shell in your frame, it will be 73mm, 70mm or 68mm. Some older frames may have Italian threaded bottom brackets, instead of the more modern English.
How many spacers should I install on my bottom bracket?
A 68mm or 83mm bottom bracket shell needs two of the 2.5mm spacers on the drive (chainring) side and one 2.5mm spacer on the non-drive side. If your bottom bracket shell is 73mm wide, you only need one 2.5mm spacer fitted to the drive side.
Where do you put a spacer on a super boost bike?
If your bike has Super Boost hub spacing (157x12mm) and a 73mm shell then you’ll need a 4.5mm spacer on the left-hand side of the crank axle, a 9mm spacer on the right-hand side of the crank axle and no spacers on the bottom bracket.
Do you need spacer on bottom of GXP?
Much like GXP, you don’t need to add any spacers to the bottom bracket if you have a 73mm shell, but you will need to add a 4.5mm spacer to the right-hand side of the crank axle, unless you’re using a chain guide, in which case a 2mm spacer is required instead, along with a 2.5mm spacer on the right-hand side of the bottom bracket.
How big should my bottom bracket shell be?
You should now know how wide your bottom bracket shell is. For a threaded bottom bracket, there are only three common sizes; 68mm, 73mm and 83mm. If your bottom bracket shell measurement isn’t very close to one of those, you’ve probably measured it incorrectly – or something very odd is going on with your frame.