DScience

I am building a new bike using a Wabi Classic frame, and plan on using SRAM Omnium crankset and bottom bracket. I emailed Richard at Wabi and he said there is no need to face/chase the BB, it's ready to build. I also called a LBS and asked them how much they charge to face/chase a frame. They told me that they haven't had to do that to a NEW frame in over 10 years, and it's normal to install BB with paint on the face. Below is a few images of the BB. Do I need to have this faced/chase to use the external GXP bb from the SRAM? Or should I try to install anyway.

I've read differing opinions on the forums, so what are peoples opinions now? Is my LBS full of it, lazy?

Also real quick, i'm putting a new build together and will have a lot of questions. Would it be better to do a build log and if so where should that be located?

HillRider

Your LBS isn't being lazy, just truthful and honorable. They could have made money by doing the job for you but told you it wasn't necessary. Also. if the builder says it isn't needed, it isn't needed.

I've installed external bearing bottom brackets (Shimano) on three bikes, including a Surly Pacer which is not a boutique frame. All three installed easily with no alignment problems or any binding.

AnkleWork

You received definitive, authoritative answers but you ask here. What a bizarre world view.

You don't think there's anything wrong or you would have just test fitted the BB, right?

Just curious: are you going to continue to ask anonymous random strangers until you get the answer you want? You really don't need permission to do what you want.

shelbyfv

Yes, it would be a good idea to keep all your questions in one thread. Next time you have a question, start a new thread titled "Wabi Classic build" or something and keep adding to it. Post pics, seems like it will be an interesting project. Good luck!

DScience

Thank you. Can I ask you something: if this is the case, why are there people who say you MUST have the BB faced/chased? Is it just differences of opinion?

Man you are kind of an *******.

Listen, I am not a child. I'm new to building bikes and i'm trying to learn all I can. I've searched the internet, talked to people, and I have gotten different opinions. I do think something may be 'wrong' because when I feel the face of the BB it doesn't feel completely smooth.

Just because two people told me something doesn't mean it's FACT. So these sources are definitive just because they sell and fix bikes? If you aren't going to provide any instructive information, just don't post.

edit: the reason i'll continue to ask anonymous random strangers questions is because some are kind and provide good, unbiased information. I don't necessarily trust someone who also wants my money.

shelbyfv

My understanding is that with cartridge bottom brackets facing became less of an issue than it had been with the older loose ball type of BB because the cartridge kept both sides aligned. With Hollowtech II and other outboard systems there could, in theory, again be an issue. Apparently, in practice, current production methods are adequate and the need to clean up BBs is uncommon. Additionally, you cannot know if the mechanic knows how to do this or maintains the tools properly so you are taking a chance. Better to leave it alone unless it binds or is obviously misaligned.

noglider 

It wasn't even necessary to chase and face most of the time. It was done as an extra precaution. the idea was that it could help but couldn't hurt. That it couldn't hurt was not true. First, it wears down the very expensive tools. Second, it could be done badly, such as shaving off too much material, which narrows the BB shell. Worse, you could bugger the threads as they say in Britain.

DScience

Thanks, this all makes sense. The LBS I called had to verify they even had the right equipment.

Yea the main reason I became concerned is because I read on several threads from this forum of people using the GXP bb with the omnium and having issues. Peoples opinions were that it could have been user error, i.e. not facing/chasing the bottom bracket and thus an uneven surface causing issues.

Because this is my first build, I figured why not take every step to ensure it's done correctly.

That also makes perfect sense. Some of the "home remedies", which i'm sure you're aware of, is using a razor blade to remove all the paint from the frame. With this method theoretically you shouldn't remove any metal from the frame. Is this also unnecessary?

I guess what i've been contemplating this whole time is if I should have looked into a sealed BB such as a campy record pista, thus avoiding the external (possibly POS GXP) of the Omniums.

mconlonx

I'd not bother with a square taper or other cartridge BB, but I'd consider it if I were going to install an external BB... and then shrug it off if both the mfg and LBS tell me it's not necessary. If it started eating external BBs at an accelerated pace, I might be bothered to do it when replacing one.

HillRider

The NEED to face and chase bottom bracket threads pretty much dates back decades when neither the bb shells nor the tooling was as good as it is now and the alignment had to be cleaned up after manufacture. Most newer frames don't need either.

jason_h

I don't see any reason to chase the threads on a BB shell if your cups thread in fine without requiring any excessive force to do so. That said, some frame makers don't mask off the BB shell when they paint the frame. Trying to install cups into a BB shell with threads filled with clear coat is a futile endeavor. I might be wrong, but I would guess Wabi masks off the threads when painting based on their response, and as such you don't need to chase them.

As for facing, the BB shell on a quality frame should already be square to the threads. If there is paint on the edges of the BB, it wouldn't hurt to scrape it off with a razor blade if you have a BB that interfaces with the ends of the BB shell. The proper solution though, if you haven't bought the Omnium crank yet, is to get a Phil Wood BB and an ISO or JIS taper compatible crank, as Phil BBs don't require the BB shell to be faced.

zukahn1 

+1 There shouldn't be an need to recchase threads unless there bad on anything. If everything threads fits the threads are good not needed chasing in shops is an arcane practice dating back to the not so well done stuff of a 100 years ago.

AnkleWork

Except that you didn't accept the LBS' advice even though it was opposite of what could have made money for them. The manufacturer couldn't make money either way and you didn't accept their word either. You are looking for something very different from advice.

DScience

Thanks for the advice, I ended up installing the BB and it seems to be on good. There is no play with the crank, and it spins smooth. I appreciate the information!

noglider 

Jeez, I didn't know getting extra advice was such a bad idea. It's a fair point that the maker and the shop are probably right, but asking isn't so bad, as proven by the nice, further-in-depth explanations here.

FBinNY 

The answer depends on whether the BB shell is already 68mm wide with a flat concentric surface. That's what facing is intended to achieve, so it it's there already there's no need to do more to it.

Brazed lugged frames need the BBs faced somewhere along the production line because the cast or pressed shells were shipped rough and over-wide. This allowed extra material to be removed and the distortion that happens during building to be corrected.

TiG welded frames use BB shells that are machined tubes which are cut to length with faced ends on the lathe. They're already spot on, and welding doesn't cause end-on distortion, so there's no reason to rework them.

There is some legitimate opinion about the need to remove or reface the paint surface. IME the paint layer is usually thin and uniform enough to leave, but if I saw something suspicious I might do a light pass just to remove any high spots.

BTW-the best answer is that of the builder. He knows his craft, what he's done, and what's left to be done. His reputation depends on that. Given that the builder has the inside track, his opinion trumps all others.

bradtx

+1

Brad

fietsbob

Has been before.. Name Italian Frame builders shipped out frames fully finished with paint , but expecting the dealer to do the final prep,
which included using their own frame tool Kit (ala Campagnolo's) to do the chase, face the frames ,
before build up with Components of customer's choice..

FBinNY 

I'm always surprised when folks trust information from strangers on the internet over that of folks with documented expertise. I understand the need for reassurance, but remind you that there's plenty of misinformation out there, and you have little basis to sort the wheat from the chaff.

Also, while there's never harm in asking and trying to gain some knowledge, you have to understand that specific information trumps general information. So if you're asking and planning on taking action on the advice, remember that the only one with specific information is the builder. Everyone else is only speaking generalities.

Imagine you're at a stream and thinking of wading across. You've researched and the stream has an average depth of only 2 feet, and the weather's been dry so all looks good. However, there's an old man there who says he lives along the banks, and the depth now is 8 feet because they opened a dam spillway upstream yesterday. Do you cross based on general info, of act on the specific info?

As a general rule, the right answer to any technical question should begin "It depends....." because it always does.

SquidPuppet

+2

It gets old after a while. Often times posters are scolded for not doing enough research. Then when they come here to gather as much information as possible, (do research) they are scolded for that as well. Makes no sense.

DScience

Thanks!

I agree about this and I don't doubt Wabi Cycles. Another thing to note is that I also had a issue with my headset, and when contacting him about that he stated that he must have missed that error from the factory. Thus I thought it was possible he missed the BB as well.

The BB appears to be flush with the frame, although the BB face wasn't totally even. Also using a caliper it measured about 68.1 - 68.2 mm, not 68mm. If I ever got a new BB I will probably take the paint off.

1. what makes you think I trust people on the forums? I am accessing information from multiple channels, but your assumption that I am "believing everything I read" is unfounded.

2. I disagree that I have little basis to filter out the garbage.

3. Thanks for the tip, it makes sense to me. In order to provide some more insight, can you lay out several possible explanations for what facing a bottom bracket would "depend" on, as you say? Basically you are saying that the answer to my question "Should I face this BB", is that it "depends". What does it depend on? Why not list all the things you can come up with so someone like me can make a more logical decision on whether or not facing the BB is justified. (Not that i'll trust you )

FBinNY 

I make no assumptions on that score, I was simply thinking out loud about the processes people use.

Strictly your call, but you're asking a specific question on something with wide differences of OPINION, and so I would suspect that you didn't know, and therefore further wonder what basis you'd use; sounds plausible, popular support/voting, vibes? Don't answer, that was simply rhetorical.

I already offered a qualified answer to just that early on. Use whatever means you have to judge whether it's a good answer or not. It's your bike, and I'm not invested in it or the builder in any way. In the end you'll do what you think is best, whether it's right or not because that's how things work.

DScience

Thanks again for the help!

noglider 

Ooh, pretty!