maartendc

Hi there,

My bottom bracket on my road bike needs replacing, but I've never done this before. My expertise on bike mechanics is pretty basic, but I can adjust and install a derailleur, service the freewheel and bearings on my rear wheel, change tires, adjust brakes, etc. So I'm not a complete novice.

Its a BMC SLC01, with Dura Ace 7800 crankset. From what I gather I need:
- a Dura Ace english threaded 68mm bottom bracket such as this: Shimano Dura-Ace SM-BB9000 Bottom Bracket | Competitive Cyclist
- I'll also need a bottom bracket tool: Bottom Bracket Tool | Park Tool

Any other specific tools I need?


Should I try to replace the bottom bracket myself? Or should I leave it to the experts? I am looking to save some money by doing it myself, but is there a big chance of me doing something wrong in the process? (I also need to buy the tools involved, so I guess the savings are negated right there, but I could learn something in the process).


Thanks!

jonpear6

This first time for you I would take it to the LBS and ask if you can watch. Note what they do and do not grease, clean, etc. Most any LBS will let you watch. From then on do what you are comfortable with.

HillRider

Doing a job once that requires specialty tools is indeed not a cost savings compared to having a shop do it. However, once you have the tools (and learn how to use them) subsequent jobs are a lot cheaper.

Marcus_Ti

How do you know your BB is shot?

Further what year frameset are we talking? Odds are you do NOT have a threaded BB 68mm BB. It is probably BB86 or some such.

Phlorida

Take a look at the instructions on the Park Tool website and see what your comfort level is. If you are willing to buy the tool there really isn't much to it.

mstateglfr 

I am forever amazed that bike shops allow for this as it takes business away from them.
Keeping people in the dark is not the solution, but teaching them so they dont come back seems counterintuitive.

jimc101

If it's a 7800, that's from a time before BB86/press-fit were so common, so it most likely a HT2, which are probably the easiest BB's going to user service, all you need is a Park BBT-9 and a Hex key for the crank arm

JohnnyCyclist

Your mechanic skill level is about the same as mine. No-brainer decision for me: I'd take it to the LBS. I don't have the specialty tools or knowledge.

For me, this task would need to be done very rarely, so I personally wouldn't ask to watch-and-learn.

spdracr39

Do it yourself it's not that difficult and mistakes are a learning experience for next time. Just take your time and pay attention to the order all parts come off and replace them the same way.

trailangel

It costs extra to watch

FullGas

as long as you're willing to invest in the appropriate tool, swapping out a BB is pretty easy.

https://www.youtube.com/watch?v=xZNJM1Hi7jc

dsbrantjr

It is called "customer service".

There is more to staying in business than extracting every possible cent out of your customers; if they sense this is your approach they WON'T come back.

Treat them right and with respect and they WILL come back.

mstateglfr 

Completely agree that service brings people back.
I frequent a couple shops almost exclusively because of knowledgeable employees who are helpful. dont charge for a handful of brake cable caps. Dont charge for pulling off a stuck pedal that even a vice couldnt extract. Its appreciated and they do good work, so I go to them.
What you say applies for sure.

Showing a customer how limit screws work(referencing another thread) is a benefit because the customer can do it and not bring the bike into the shop in the future since thats an adjustment that would be made right then and there and probably not charged. That provides the customer with knowledge, shows them the shop cares and is helpful, and also saves both parties time in the future.

But not everything is that way nor should it be.

jimincalif

Piece of cake with the right tools and online videos.

Banzai

HT II is so simple, a caveman can do it. It's one of those designs that makes you wonder why it wasn't thought up first, it's just that elegant.

Don't sideload the bearings by overtightening the "dust cap", and you'll be golden. That end-cap is for bearing pre-load tension, and should basically be finger-snug, just so there's no play. Actually clamping it down will side-load the bearing, and cause clicking and grinding.

Everything else is entirely self-explanatory. Nashbar makes a wrench for the bottom bracket that is perfectly adequate.

rm -rf

Bottom bracket bearings seem to be a "consumable" item these days, maybe every few years. So it might be worth learning how to swap it.

If my crank seems rough or noisy, I'll take off the chain (I have a Sram quick link). Then remove the crankset. BUT--make sure you know how to put the crank back on correctly and adjust the bearing pre-load. You may need a tool for the preload end cap. It's not hard, but the adjustment method depends on the crankset.

I don't remove the bottom bracket. With the crank off, I can turn the inner bearings by hand, and feel for roughness. Both sides should feel smooth and turn easily. If either side grinds, I'll replace it.

~~~~~~~~~~~~
Adapters can be difficult

My bike has a pressed-in "PF30 to threaded" adapter for Ultegra cranks. It's nylon, including nylon threads for the adapter. I found it quite tricky to screw in the new threaded aluminum bottom bracket without cross-threading. (I think the LBS may have cross threaded, backed out, and reinstalled, which mangled the fine adapter threads a little.)

Jarrett2

If it's anything like a SRAM GXP, go for it. Dead simple to do.

I did my first one last week during a build it was was really easy.

ptempel

I say buy the park tool and have at it. Full steam ahead! BB service is a good thing to learn and yours looks really easy to replace. Just check Shimano's online info for the specific BB you have. Some BB's specify a torque so that and any other info is good to know beforehand. Mine are the older ones requiring the big splined tool with another to hold it on. Still not a big deal once I had the right tools. To be honest, you probably could get away with a channel lock plier and a rag. But nothing beats the right tool and its only $27-30 online.

fietsbob

buy the tools the Bottom Bracket Tool | Park Tool

+ 3/8 drive breaker bar/ ratchet to get it off & a torque wrench to put it back on.. I'd get a 1/2'' torque wrench + a 1/2 - 3/8 adapter to be mid scale

Tight enough spec with a 3/8 torque wrench is just past the scale peg.

torque wrenches .. 1/4, 3/8 & 1/2" drive each have their own range.

skimaxpower

The BB9000 would work fine. It's very nice and very light. You can use any shimano "hollowtech 2" bottom bracket though. There are cheaper options than the Dura-Ace model.

I prefer the Park BBT-9 tool over the one you linked to. It's cheaper, comes with an appropriately sized handle making it difficult to over-torque, and it includes the tool to tighten the pre-load cap.

This is an easy repair with lots of good documentation online. I say do it yourself.

maartendc

Thanks for the helpful comments guys. I think I'm going to do it myself! It does look pretty straightforward watching some Youtube videos on it.

Thanks for the tip, I will try that Park Tool BBT-9, looks like the one they are using in this helpful video too: https://www.youtube.com/watch?v=KGzCHGjTDRM

Thats good to know: Would this bracket work as well?: Shimano Ultegra 6800 Bottom Bracket Cup Set BBR60

What would be the difference between the Ultegra and Dura Ace? The claimed weight is the same.. would the Dura Ace be more durable?

skimaxpower

^ The Ultegra BB weighs 8 grams more and is half the price. They are both equally compatible with your crankset. You pick.

noglider 

Only perform this service if you're sure you need it. Cartridge bearings don't need care until they need replacement. They need replacement when they stop working. If yours works, leave it alone.

@mstateglfr, I've worked as a shop mechanic and was generous with knowledge. I taught customers up to the point that they wanted to listen. Some want to learn a lot; some don't. If I teach them too much, they end up not using the knowledge, but they appreciate the way I've treated them. They become loyal. If they get in over their heads, it's not my fault, and I was always there for them anyway, whether I taught them or not. So it's better to err on the side of teaching them too much rather than too little.

dr_lha

I have that BBR60 BB on two bikes, and it's a great BB, light and of high quality construction. I doubt the Dura-Ace is significantly better, but both are low cost items, so you won't be massively out of pocket going for the DA version.

One thing to note about the BBR60 is that it requires an adapter to work with the BBT-9 tool, as it is smaller than previous Shimano BSA bottom brackets. The adapter takes the form of a plastic insert, that goes into the BBT-9 and reduces the size of it. I own two of these adapters because they came with the two BBR60 BBs that I have purchased.

dksix

I would think anyone who can change pedals and has access to YouTube can replace this BB. IIRC, one side is left handed thread the other is standard, same as pedals.