12 January, 2015

Building a Bike From the Frame up - Bottom Bracket

by Igor

We've done a bunch of write-ups in the past that were mainly oriented towards accessories (fendersrear racks, and chainguard), but with the increased number of frames going out the door everyday, we've had home mechanics asking questions about assembly and component selection for their new bike. Perhaps it's your first frame/fork build or you just need a refresher of the basics. To help out, we're going to start a small post series devoted to installing our components on our frames. Today, we'll tackle installing a bottom bracket.
All of our current frames use a 68mm English/ISO threaded bottom bracket shell. This measurement is from flange to flange and is the most standard bottom bracket shell currently used for steel road, city, and touring bikes. You can find parts and tools in any bike shop around the world (a real plus for touring/rando folks) with pricing and quality ranging from basic loose ball bearing to custom high end ceramic bearing. All of our bottom brackets use sealed cartridge bearings for durability, water resistance, and installation simplicity.

Many road and mountain bike manufacturers have gone to a "press fit" or "drop in" style bearing for their carbon or aluminum frames for various reasons including perceived stiffness (pie charts and line graphs), proprietary design (to keep you using one crankset), and cost savings in manufacturing (no need for thread tooling!). The two most common issues associated with this "new" style is creaking and shell sleeves delaminating from the frame (this ruins the frame). The last thing I want on a tour is to hear a creak going through my mind when I'm trying to get 40 winks after a several days worth of riding.
To install a bottom bracket in your new VO frame, all you need is a bottom bracket tool, wrench (adjustable or ratchet), grease (Park waterproof in a tube is my favorite), and a phillips screwdriver.

As mentioned in a previous post, all of our frames come prepped from the factory. The bottom bracket shell has been faced (flanges are on parallel planes) and the threads have minimal (if any) overspray. Run your finger along both flanges of the shell to confirm that there is no dust or contaminants. If you find something, a bit of fine sandpaper can knock it off.
Our frames use a cable guide under the shell that is secured by a screw. It is usually flush with the inside of the shell, but it's good habit to back it out a bit to make sure the screw doesn't gouge your new bottom bracket during installation.

Put a good sized dab of lube on both the drive and non-drive side threads of the shell and spread it on. Do the same for both bottom bracket cups.
Non-drive side is right hand threaded
Drive side is left hand threaded
For normal English threaded bottom brackets, (when looking at the flange from their respective sides) the drive side screws in counter clockwise (left threaded) and the non-drive side screws in clockwise (right threaded). I install the non-drive side a couple turns first then install the drive side.

Note: If you have something besides English threading, check Sheldon Brown's cribsheet for your threading and compatibility: http://sheldonbrown.com/cribsheet-bottombrackets.html


Installing the non-drive first makes lining up and installing of the drive side cup easier. Now that the drive side is threading, tighten it down all the way. Torque wrenches can be surprisingly imprecise so I go to one barely audible grunt (~60Nm). Install the non-drive in a similar fashion. Clean up any excess grease and screw the cable guide back in. You're done!
What do you want to see next? Brake lever selection? Gear ratios for touring? Handlebar nuances? Let us know in the comments.

We also have a Bottom Bracket Basics tech info page: http://support.velo-orange.com/#bbarticle.html

25 comments:

Anonymous said...

I would be most interested in handlebar nuances and selection, thanks for the informative blog!

CV said...

Great post ! How do I know which bottom brackets are compatible with a crankset ? Or viceversa :/

Wes Ewell said...

Great! Just as I'm putting the finishing touches on my Camargue build, you finally post instructions. ;-)

bsimon said...

Is the red on the BB threads locktite? I'm referring to the picture where the threads are being lubed. I'm in the habit of lubing threads that have locktite, but am wondering if I'm alone in this practice.

Corey L said...

How can the shell have been faced if there's still red paint on the mating surface?

Aaron said...

I've been thinking a lot about tour gearing. I'm seriously considering doing a half-step setup with an 11-34 9-speed cassette in the rear and 46-42-24 on the front.

VeloOrange said...

@bsimon,
There is a thread locker applied to the cups from the factory, but I still use grease for installation and water resistance.

@Corey L,
The frame is prepped before paint. This is the most important part. We have found no discernible difference in bearing alignment with or without wet paint. If your frame is powder coated, it may be better to scrape the shell as the layer is thicker than wet paint.

Anonymous said...

Thank you. I would be interested in a blog post about trail and head tube angle. For example, why is a bike with less trail better for carrying a front load.

Mark Holm said...

The bottom bracket is the lowest point in the frame. It is very likely that water will accumulate there eventually. Smearing a liberal coating of the thickest, most water resistant grease you can find on the inside of the shell is a good idea. Note that Park Polylube, because it uses polyurea thickener rather than lithium soap, may be more water resistant than general purpose "lithium" greases. Old fashioned cosmoline, or something similar, might be even better.

Mark Holm said...

Aaron,

Shimano's 12-36 9-speed cassettes have more even ratio steps between cogs than the 11-34 9-speed. The average in both cases is near 15% per cog, but the variation between steps is greater with the 11-34. That said, I'm using 11-34. It's fine for my purposes. If you use a Shimano Deore (9-speed, not 10) style RD with a Total Capacity of 45, you can get away with the 12-36 because, even though it gives a total range of 46 with the chainrings you specify, I know from experience that these RD's can handle a total range of 47. Chain length has to be right, but the traditional instructions will get you there.

Anonymous said...

I've adopted the habit of using small tubs of the blue grease for servicing Penn fishing reels. After unsuccesfully trying to procure bike grease from a couple local shops (none of them had any for retail or were willing to sell any quantity from the back of the shop?) it occured to me the Penn stuff I already had is formulated to withstand salt water fishing so why wouldn't it work for lubing/sealing a BB, brake posts, seatposts, stems, etc.? It's readily available from local tackle shops and gets the job done. My last overhaul I generously applied to the entire BB assembly

Corey L said...

Boat trailer wheel bearing grease works well, too. You can buy it in small tubs at most auto part stores.

Pete said...

Handlebar nuances would be great. I am also interested in "truing" wheels.

Anthony C said...

Im so happy you're doing this series! I needed it when I was building my first (non track) bike ever! Loving my new Campeur!

Aaron said...

Mark Holm,

11-34 is fine for me too. I already have one, so that's money I don't have to spend. With 26" wheels the 34t cog and 24t chain ring will provide an 18 inch gear. I think lower than that and I'm better off just pushing the bike.

Anonymous said...

Setting up center pull brakes

Anonymous said...

I find a drain hole to be advantageous in a bb shell. Plenty of bikes don't have them and years later when the bb is replaced the inside is full of rust. If your frame doesn't have a drain hole in the bottom take a 4-5mm drill bit and drill one as close to centre as possible (avoiding the cable guide and inside of the threads) and at the lowest point. Water will always get in - through the seat tube and breather holes - a drain hole gives it a way back out.

drew said...

I'd like to read your handlebar nuances and lever selection post; would you consider a post on shift lever selections, too? A post or posts addressing a few of VO's ideas on overall cockpit set-up, covering all of these would be really cool. Perhaps illustrated with views of VO handlebar/controls set-ups you folks have put together, on bikes you build and bikes you ride?

CMC SanDiego said...

I would love to learn more about gearing/touring gear ratios. I hope to be able to assemble/build my own dream touring bike in the near future.

Anonymous said...

Yes, gearing please! I've been reading more about it and started using Sheldon's gear calculators to get specs on gearing for some of our existing bikes for comparison. As I'm about to build up a Camargue for my better half to accompany her over-geared roadbike with a "standard road triple" I'm very curious to see something on gear rations from the VO perspective.

RoadieRyan said...

Love it -keep the "building a bike from the Frame up" series coming!

AaronPrice said...

A wonderful visual gear calculator is by Dirk Feeken at www.gear-calculator.com. It really makes it easy to see the gear spacing and best crossover points between chainrings. I myself am a fan of very close gearing in the most used part of my range. My current setup is a 14-27 9-speed cassette put together from a 14-25 and a 12-27, grafted together at the 19-21 jump they both have (which maintains the smooth Hyperglide shifting): 14-15-16-17-18-19-21-24-27. I currently have this paired with a standard 53/39 crankset, but on my new build it will have a cyclocross crankset set up with 46/34 to lower the gear range.

Mark said...

Great article. What about how to install the crankset now as a follow on

Andy said...

A medium strength thread locker, such as LocTite 242, (when applied properly) will all but completely seal the threads of a bottom bracket eliminating any fear of corrosion. It will also have the added effect of preventing the BB from working loose so you can get by with the appropriate amount of torque (usually ~34-48nm, depending on brand) to ensure you don't damage your BB or frame.

Also, a correctly calibrated torque wrench, when used properly, can not be "imprecise".

jonathansmith68 said...

Looks like this post might need to be updated now that the Piolet is available and according to the Piolet product page, takes a bottom-bracket intended for a 73mm bottom-bracket shell. I did have a quick question regarding your frames and their BB shells. Is it safe to assume that Camargue has a 68mm wide bottom-bracket shell? I'm just curious since the Piolet kind of reminds me of a disc-braked version of the Camargue, although I know that aesthetically, there are many more differences than that. Thanks!