Bottom Bracket Selection Guide
Cervelo Soloist T47A BBRight System
The all-new Cervelo Soloist road bike boasts a T47 version of BBRight, which was first introduced by Factor in the Ostro Vam under the “BBcorrect” name. To clarify: BBRight T47 is the same as T47A and BBcorrect. Our 1-piece, hub-style bottom bracket threads into the asymmetrical Cervelo frame easily, boosting stiffness while maintaining bearing alignment for that incredible BBInfinite spin and performance you’ve come to expect. And of course, the system is dead quiet. BBInfinite is here to optimize your performance and solve the bottom bracket creaking and squeaking that’s ruining you ride. BBInfinite delivers the most efficient spin performance of any BB system out there. Faster and creak-free? Absolutely, with BBInfinite.
Watch how BBInfinite T47 outperforms the competition
BBInfinite's Speed Formula
In the video we introduce the new T47 One Piece bottom bracket for this Cervelo Soloist, which just came out.
We are going to do a before and after comparison to the factory bottom bracket and we're going to show you how much better a BBInfinite bottom bracket can perform in the same bike.
The factory bottom bracket is made of multiple pieces. (Pictured Right)
Compare that to our bottom bracket. (Pictured Left) Our bottom bracket uses a one piece design has perfect bearing alignment just like the front wheel hub. We will show you how this one piece design will make you faster.
What is T47A?
Before we discuss the install, I want to get into some details about T47A which is also known as BBRight T47 which is also known as BBCorrect. Confused? Factor introduced this a while ago and they called it BBCorrect but it is basically a 77mm asymmetric T47 bottom bracket.
Is a 1-Piece bottom bracket really lighter?
The first thing that we want to compare is product weight. Our one-piece hub style BB comes in at 99 grams, that's as it would be installed in the bike.
The factory bottom bracket that we removed from the Cervelo Soloist weighs 162 grams, that’s all the parts and pieces to run a Shimano crank.
Our T47 bottom bracket, even though it is one piece, unlike the factory bottom bracket which is multi-piece, is still considerably lighter.
A is for Asymmetric
In T47A the “A” stands for asymmetry or asymmetrical, this is the same idea that is used in the BBRight standard from Cervelo.
Next lets compare BBright as a press fit with BBRight as a threaded system.
In the picture below you can see that if this was inside the bike as a press fit, this module would be hidden because it's inside the bike and this nose would be sticking out. The reason for that is that the asymmetric bottom bracket shell itself on the bike.
Taking a quick look the bottom bracket shell itself, you can see the bottom bracket is actually offset to the non-drive side. Observe how this non-drive side chain stay is so much thicker than than the opposing chain stay on the drive side. That's because the offset is designed to extend 11mm to the non drive side. This extends a traditional 68mm bottom bracket shell to 79mm.
The reason the nose of the module extends out past the frame is because cranks like this Shimano Dura Ace crank are not asymmetrical they need to be in the bike symmetrically on the center line of the frame. We need to have that offset built into the bottom bracket. Otherwise the Q Factor will not be balanced.
Something to Consider
Another detail about our T47 one piece bottom bracket is it's also a the same exact unit that would fit in a TREK or any 86.5mm T47 or as it is otherwise known as T47 internal. In this configuration this DS ring would basically be on there just like this because that the full width of that bike is 86mm.
Crank symmetry in an asymmetric frame
This Cervelo Soloist road bike bottom bracket is 77mm. When the bottom bracket is in the bike it will actually extend out on the drive side to form that offset that's necessary. Hopefully we've cleared up some of the misunderstandings around the T47 and T47A standards.
T47A Installation Simplified
We will be installing our T47A DirectFit Shimano product in this Cervelo Soloist road bike, once this product is installed we will install the Shimano Dura Ace crank.
To begin the installation we're going to grease this up. Some people might want to put something like Teflon tape on the bottom bracket itself, you can do that if you want but that's not required. Retaining compound is not required just grease.
The delrin ring, in case you guys didn't know, goes on the drive side. We install this delrin ring with hand torque, using the polymer socket that comes with the T47 bottom bracket. The tool is included with all our T47 bottom brackets. Just slip over that ring and like I said we're just going to tighten it all the way. Remember this is left hand thread.
The drive side is right hand thread. It follows in that old kind of BSA English threaded format even though it's a king size as in Chris King size, because Chris King is the one that has invented T47 it was his brainchild.
Next we want to put a little bit of Grease on the inside of the Ring here. Try to be nice and neat with the grease okay.
Next we're going to install the bottom bracket from non-drive side. Install this direction marked on the product helps keeps it simple. We're going to give it a little a little push to get the nose started and then it's ready to engage some threads.
You can use our BBInfinite 16 Notch tool this works on all of our all of our BSA threaded stuff no matter what. Even with all of our Italian bottom brackets too. The tool also works on our our T47 external bottom brackets and it works on this tool right here which gives us a nice interface. Now we can use our 3/8" ratchet tool. This is your same exact format as a park tools BBT 69.2.
As you begin tightening we're going to start to see something happen. You will begin to notice the bottom bracket is poking out of the drive side. As I mentioned earlier, this forms that offset that is necessary for the BBright.
I have set the torque wrench to 22 foot-pounds. This torque wrench does not read in newton meters, this is 30 newton meters equivalent. We're just going apply torque and it's done it when the wrench breaks away at 22 foot pounds which is 30 newton meters which is the torque spec for this bottom bracket. You're done.
Installing the Shimano Dura Ace crank
It's time to install the crank. Begin by putting a little bit of grease on the top hats which is what we call them. The inserts that go inside the bearing and convert these 6805, 25mm internal diameter bearings into 24mm with a nice tight fit and also this is a nice feature unlike this Factory one which has 24mm bearings.
Without these inserts, the irreplaceable Shimano steel spindle is going to be up against this steel bearing. This is a major source of creaking. I have no idea why people keep doing this. There's a reason why Shimano does the top hat style like this which insulates the steel from the steel with the polymer. Shimano does it because they don't want it to creak the reason we do it is because we don't want it to creak. If the spindle bearing interface is steel on steel it's going to creak and cause corrosion and it could cause wear. Like I said you cannot replace the spindle on a Shimano crank, once it's worn down much past 24mm it's no good.
Whenever you're changing between bottom bracket systems always look on the back sides of these spindles because you see how this dust cover is stuck on here. This is on here because the grease is holding it on, that could actually look like it belongs there. That's actually the seal from the old system that's going to add two millimeters to your chain line offset and you would be chasing your tail wondering why I can't adjust my front derailleur because the crank is now two millimeters or more further out than it's supposed to be. So make sure the crank is stripped down all the way before you go ahead and put it in the bike.
Whenever I do an assembly of anything, I like to do little intermediate checks. So I will pop the crank arm on here and make sure that the plastic tab is popped down. I do a quick spin with the crank just to see how things are starting to look. If you're at this point, just starting to put the crank together and something already isn't working right you need to stop. The bottom bracket should be spinning awesome because it has zero preload on it of any kind. To finish the install I adjust the axial position of the non drive crank arm to set the correct stance. Once the stance is set the bearing should be spinning freely and all axial movement and play is gone. All that is needed is to torque the two crank arm fixing bolts to 12-14Nm and the install is done. It many be necessary to adjust the front derailleur at this point. It is also a good idea to double check the pedals for appropriate torque.
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