Step 1
Remove your cranks and current BB if applicable. Thoroughly clean your frame’s bottom bracket threads using isopropyl alcohol and a clean rag.
Bottom Bracket User Manual
Contents
Installation Step-By-Step
Step 2
Apply a layer of grease to the threads on both bottom bracket cups. Additionally add a swab of grease to the o-rings on the center sleeve or mating surfaces on the cups.
Step 3
If using shell spacers slide them onto the cups now. Shell spacers should really only be used to be able to use a wide spindle crank on a narrow frame BB width. See our spacer selection guide for more help on choosing spacers.
Step 4
Thread the drive side (right) cup into the frame with the shell attached. Make sure the orientation on the shell is correct (R marking on the sleeve is facing the drive side cup), and that the shell is fully seated in the cup (if the shell is off kilter it can get crushed when installing the other side cup). The drive side cup is left-hand threaded, so will tighten when turned towards the rear of the bike.
Step 5
Tighten to 50Nm using the correct sized BB tool and a torque wrench. WT 24mm Spindle BSA: 44-16 Tool. WT 29mm and 30mm Spindle BSA: 46-12 Tool. WT T47 Internal: 52-16 Tool.
Step 6
Thread the non-drive side cup into the frame. This cup is right-hand threaded, so will tighten when turned towards the rear of the bike.
Step 7
Tighten to 50Nm using the correct sized BB tool and a torque wrench.
Step 8
Apply a layer of grease to the inside of both bushings and their contained o-rings.
Step 9
Slide any necessary spindle spacers on the crank spindle as you install your cranks. Use supplied spacers to remove side to side play from your system and to achieve your desired chainline. See our guide on spacer choice for best practices on this process.
Step 10
Install the non-drive side crank arm and confirm there is no play.
Bottom Bracket Spacer Guide
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Install the bottom bracket. Follow our install guide for proper instructions. If you are replacing an existing bottom bracket on your bike, best practice is to mimic your existing spacer setup with the supplied Wolf Tooth spacers. If necessary, use this guide to help make any adjustments to the setup.
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Install both cranks with no spacers, tightening down fully. Installing the cranks facing the same direction will simplify the next step.
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Center your cranks, aligning them with the chainstays. They should be spaced approximately evenly with at least 3mm of clearance to their respective chainstays.
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Determine approximate spacer width. On each side use a ruler, caliper, or simply hold spacers up to the spindle. If using an adjustable preload spacer, fully compress it first.
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Remove the cranks and install the spacers before reinstalling the cranks
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Check for any lateral play, and double check the clearances. Ensure clearance between the crank arms and frame as well as chainring clearance to the frame. At least 3mm is recommended.
Calculating Exact Spacer Width Required
Preface:
Setting up your bottom bracket and cranks to achieve the correct spindle width and chainline requires some tinkering and patience. As much as we hear the word “standard” in the bike industry, the word unfortunately doesn’t hold much weight. Multiple factors and dimensions go into bottom bracket and crank setup, many of which are controlled by parties that are independent of each other.
Goal:
The goal when setting up your bike is to remove any play the crankset has in the bottom bracket and to position the crankset to achieve the recommended chainline for your bike and groupset.
Definitions: What are the key factors/dimensions that will have an impact on BB/Crank setup?
A. Bottom Bracket Shell Width
-The distance between the outside faces of the bottom bracket on your frame
-Controlled by the frame manufacturer
B. Bottom Bracket Thickness
-The distance between the outermost face of the bb cup and the face that contacts the frame
-Controlled by the bottom bracket manufacturer
C. Crank spindle Width
-The length of your spindle when both cranks are installed, or distance between the contact faces
-Controlled by the crank manufacturer
D. Chainline
-The distance between your frame centerline and chainring centerline
-Based on your bike’s rear hub spacing there is a chainline recommended for optimized shifting, drivetrain lifespan, and minimized noise
E. Chainring offset
-The distance from the chainring mounting surface to the edge of the chainring’s wide tooth
-Controlled by the chainring manufacturer
1. Gather Information
Measure your frame's bottom bracket shell width
This is most easily found with a caliper, but a ruler can work as well.
BSA threaded bikes commonly have widths of 68, 73, 83, and 100mm
T47 Frames commonly have widths of 68, 73, 86, and 92mm
(T47 frames with widths of 68mm or 73mm require an external cup while 86mm and 92mm require an internal cup. Wolf Tooth does not currently make T47 External Bottom Brackets)
Measure the thickness of your bottom bracket cups
This is most easily found with a caliper, but a ruler can work as well.
Wolf Tooth BSA cups have a thickness of 11.1mm
Wolf Tooth T47 cups have a thickness of 2.5mm
It’s important to note that some bottom brackets have removable seals or end caps. If they are required for assembly, you need to measure from the outermost face of this cap to the frame contact face for an accurate measurement.
Measure the spindle width of your crankset
This is most easily found with a caliper, but a ruler can work as well.
If your crankset requires the use of a preload ring, measure the length from the inside of the preload ring while fully compressed.
2. Determine Required Spacer Width
The information you just gathered will allow you to do a quick calculation to determine how much space you will need to fill with spacers to remove any spindle play.
If the number is positive, you now know how much distance you need to fill with spacers
If the number is zero, no spacers are required
If the number is negative, your crankset may not be compatible with your frame and bottom bracket*
*If the number is only negative by a millimeter or two it will likely work just fine, most cranksets have enough flexibility to accommodate a few millimeters of BB width difference. This comes with a warning though, the more negative this number gets the less engagement your crank will have with the spindle which can lead to compromised strength and retention. Cranks coming off can lead to severe accidents.
Determine Spacer Configuration
Skip this step if your configuration does not require spacers. If you are well-versed in chainline and crank clearance you may also choose to skip these calculations.
What is the recommended chainline for your rear hub? Does this align with the recommended chainline of your groupset?
If the recommended chainline of your groupset does not align with your rear hub size it is very likely you will need a different offset chainring to realign them
Insert the drive side of the crankset into the bottom bracket until it bottoms out and measure the chainline.
This can be measured with a ruler or a caliper. The Wolf Tooth Pack Wrench has a convenient chainline measurement feature as well.
*Chainline is a bit harder to measure for two-by systems as the true chainline falls somewhere in between the rings
To find the width of spacers required for the drive side of the crankset subtract this measurement from your recommended chainline.
If negative, you likely have a chainring that doesn't have enough offset to achieve the desired chainline.
If more than the total spacer width required, your chainring likely has too much offset.
The required non drive side spacers can be found by simply subtracting driveside spacers from overall width of spacers required.
Wolf Tooth Bottom Brackets come with spacers both for the spindle and for the exterior of the cups.
In an instance where you may be using a wider spindle crankset on a frame that has a narrower bottom bracket width (MTB crankset on a road or gravel bike) you may decide to use the shell spacers to essentially make your frame bottom bracket into a wider standard. Two 2.5mm shell spacers are included to make this conversion.
It is not advised to use the shell spacers if your frame width is already on the high end of the adjustable width (73mm for BSA or 92mm for T47), as using the shell spacers would effectively make your frame’s BB width wider, meaning the o-ring seal between the shell and cup will not be active.
Ultimately what combination of spacers you choose to use to remove play in the spindle is up to you and what works best for your build.
4. Sanity Checking
Now that you know what spacers theoretically should go where, it’s time to make sure everything works out in the real world.
*If you are using shell spacers you will need to remove your BB cup and reinstall with the spacers on before proceeding to the next step.
Slide the drive side spacers onto the spindle and install through the bottom bracket.
It’s important to check your chainring clearance to your frame here. If you don’t have at least 3mm of clearance between your frame and chainring you might need to consider either shifting spacers from the non drive side to the drive side (if possible), getting a chainring with less offset, or getting a smaller chainring.
Slide the non drive side spacers on before installing the left crank.
Tighten down the system and ensure you have no play. If you feel any looseness, reinstall with an additional 0.5mm or 1mm spacer to remove it. Or if your crankset system has a preload ring, turn it to remove play.
Measure your final chainline and make sure it is approximately right for your hub spacing and groupset. Adjust as needed.
Dimensions and Details
