Bottom Bracket Selection Guide
Kill That Creak!
I recently got a call from a customer who said, "I installed a BBInfinite module and my bike is still creaking. What do I do now?" The good news was that, even though his creak was never the bottom bracket, he still made the right choice in going with BBInfinite to enhance his performance and increase durability of his bottom bracket over time.
That said; he was not the first guy to still have a creaking issue after installing a BBInfinite module, simply because the bike creak resided elsewhere. There are many reasons why your bike creaks. Sounds propagate through a carbon frame in strange ways, resonating at one end when the cause was at the other. Full suspension mountain bikes, be they alloy or carbon, are, without a doubt, creak prone. If a creaking bike is 100% new, you should still go through this entire procedure step by step. New bikes are the most common creakers out there. New means nothing. Don't assume the guy who built it "must've done this" or "checked that". Even if they're the best mechanic in town, they are still human and make mistakes...and assumptions. Because of these realities, I suggest you:
- Ensure skewers are tight. If they are of the ultra-light, titanium variety, I don't care if---insert renowned, highly respected, boutique maker's name here---makes them, find some regular steel Shimano, Mavic, or Campy skewers to use for this testing procedure. If you have trick, fancy, super-light, Ebay-sourced skewers, throw them away before they fail and hurt you. Sorry guys...it's true.
- Remove the fork. Remove and clean the headset bearings, grease the contacts (the angled portions), and reassemble. If they're bad, change them. Apply the proper amount of preload to the headset and torque the stem binder bolts according to manufacturer's procedures and specifications. Grab a handful of front brake with one hand and pinch the headset cap with the other, bridging the gap between the cap and the frame with your thumb and forefinger. Now rock the bike back and forth, fighting the front brake. If you feel even the slightest movement between the headset cap and the frame, there's something wrong. Find out what it is and fix it.
- Ensure handlebar face plate is tight.
- Twist seat, bearing down on it with your body weight. If it doesn't creak, remove it and check that the post has been "slash cut" at about 45 degrees, with the angled cut towards the back. Lube with carbon paste and reinsert. Torque seat post binder to spec.
- Remove rear wheel. Ensure cassette has proper spacers if it's a 10 speed Shimano road cassette. Shimano 10 speed road cassettes generally require a 1mm spacer, which should be used along with the spacer Mavic includes with their road wheelsets. Some Sram cassettes require spacers as well. Check and make sure all is right before moving on.
- Torque cassette lock-ring to 40nm. If the wheels have some miles on them, make sure the cassette doesn't "wobble" or have play in it. This can mean that your freehub has excessive wear, something common to high mileage Mavics where the plastic freehub body slip-ring has worn excessively. This is also a common area for shifting performance to suffer on 11 speed bikes, causing mis-shifts, ghost shifting, and generally inconsistent rear shifting. The 11 speed Shimano systems are very sensitive to this, just like the 11 speed Campy systems have been for years.
- Check spoke tension. Bladed spokes creak, especially if they are straight-pull. J-bend spokes are less likely to do this because they resist twisting, but if under-tensioned, anything will creak. When bladed spokes slowly twist over time, they present edges against any spoke they cross over. This edge digs into the other spoke as the wheel is loaded and unloaded with each revolution. I call this "cricketing" because it is reminiscent of the titular insect's stridulation.
- If it's a full suspension MTB, go through and properly torque every suspension bolt. Don't go nuts, man, they're alloy and you might break one. Find out the proper torque and use a torque wrench.
- Make sure every pivot moves freely. Loosen the rear shock to do this easily. Rear shock bushings go bad and are easily replaced.
- If there is a suspension fork in the mix, pull the front wheel off and flex the stanchions towards each other slightly. I've had my share of creaky stanchions lately. The cryo-fit joints where the upper stanchions press into the crown can come just loose enough to creak when twisted, which is basically every stinking pedal stroke. This one has stumped many a great mechanic, so be advised.
If everything is done, and checks out, go for a ride. Bike still creaking? Now:
- Swap out rear wheel. Get one from a bike that's not creaking if you don't have a spare bike wheel set. If you have a 10 speed bike you can use one from your buddy's 11 speed bike and vice versa. You're just going around the block. It'll work. Just stay in the middle of the cassette to avoid dropping a chain into the spokes or onto the chain stay. That would be bad.
Go for a ride. Bike still creaking? Oh boy:
- Now it's time to swap out the crank for another one of the same type. Yes, cranks can creak. Even Shimano ones. The one you swap with doesn't need to be the same brand, per se, just the same type. A 30mm spindle (Rotor) can be swapped with a 30mm spindle Sram, and an FSA Gossamer 24mm spindle crank can be swapped for a Shimano one, and so on. Don't forget to adjust the derailleur.
Now go for a ride. If your bike is still creaking you might have a crack in the frame. Take it in for a professional diagnosis to determine what is really going on. If the creak was the crankset all along, check out our article about bike crank creaking for details on how to address it.
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