supernova87a

Hi all,

On a new Ti road bike from Litespeed, I have the option to request at the time of purchase a T47 bottom bracket, which I understand is a threaded BB and the main reason I'd want to do this is to preemptively avoid a future press fit BB creaking issue that can happen over time. (Default bike comes with PF30 BB)

(I am not super knowledgeable on this mechanical issue or religious about the BB topic as I gather some people are, but after reading/watching videos about it, I at least understand what the issue is).

However, it's another $250 to get this option, and not to say I'm cheap but I don't feel like spending yet more on something if I'm not going to run into this problem for a long time. Or if it's cheaper to fix the problem when it does come up some day.

Can you give me opinions about whether to go for this option? My current logic is, if it were so disadvantageous to have a press fit BB, why would bike manufacturers offer it? But maybe it's like printer cartridges, you pay less up front, but pay for it later.

Thanks!

chaadster

There a few things getting mashed up here, so let’s start by saying No, it’s silly to pay extra for BSA.

Now, creaky BB is very unlikely to be a problem with a new Litespeed Ti frame because metal machining is accurate. Creaking is caused by imprecision in the BB bore spec, and is almost exclusively an issue in carbon fiber construction, and results pressfit BB’s cannot overcome it.

Next, T47 is not a pressfit BB anyway, it’s threaded.

The benefit of T47 is that it’s oversized, and better suited to making stiffer frames and fitting various crank spindle diameters. It’s better than BSA in this regard.

Litespeed are saying, essentially, that they prefer to work to modern standards but will accommodate silliness if you pay them to do so.

supernova87a

Thanks --

Not sure if I'm reading your reply right, maybe you can confirm, their using modern standards is the default option that comes with the bike, and paying them extra for the T47 is the silliness?

This is what the spec of the bike says: "PF30 bottom bracket, with T47 bottom bracket upgrade available"

nomadmax 

There's no way in the world that I'd buy a new bike or frame set with ANY kind of press fit BB, AND, I wouldn't pay extra for a threaded one. Lynskey still builds with a BSA threaded BB and they don't charge extra for it.

datlas 

I am surprised the default is a PF. Would want a threaded BB, but the old standard BSA is fine. Is that an option??

Sy Reene

T-Lab does PF as well for their Ti bikes. I think I've heard that for them this accommodates the down and seat tube sizes/shapes better and more stiffness for the frame? Here's their comparison photo of pf vs BSA.

datlas 

Nothing better than a PF vs threaded BB discussion. I accept that a properly done PF is viable, but it gets complicated in a hurry.

Bah Humbug

T47 is likely the option because it's the same dimensions as BB30 or whichever it is, but threaded. This will let them do the same external welding, whereas BSA is smaller as seen above.

eduskator

It would cost less than 250$ to fix a creaking issue if you ever have one... Never personally had one so I can't tell, but servicing a BB is not that expensive. You could also very well have a creaking issue with a threaded BB...

Litespud

I would. Other posters have pointed out that the precision fabrication of Ti addresses the less precise fabrication of CF that results in many of the problems associated with press-fit BBs. However, threaded has been a rock solid approach forever, and T47 combines the stiffness advantage of oversized BBs with the reliability of threaded. How often do you buy a new Ti frame? Do it once and do it right.

supernova87a

Thanks, I'm back (morning) and just want to clarify for everyone reading, the default model comes with PF30, and is offering a T47 for $250.

I guess the cost of this is because they need to take an extra step to drill the precision threads and then measure, verify, rework it if needed (but still it feels like $200 more than I would expect). I mean, ok, every part bike related is $200 more than you expect...

And I get that it's a nice insurance against future PF issues. I guess I'm on the fence about whether it's worth it. Even on my current bike I'm not that bothered by various hiccups/noises, but maybe with such a nice bike I'll start to get more discriminating!

ThermionicScott 

That comparison is entirely irrelevant to this thread.

deacon mark

I am a long time bike mechanic do my own work. I personally would avoid a bike with a press fit. It I still have the choice I am going BSA threaded BB without a doubt. My Habanero was almost 40k in and the original Shimano BB60r BB and 6800 cranks spin like a top without the chain. No creaks, no wobble, never had any maintenance. If the system is broken the don't fix it.

Bah Humbug

No, it shows why the option is T47 instead of BSA.

himespau 

BSA is not an option because they use the oversized BB shell. OP has the choice between PF30 and T47. That's it. Not sure why people keep bringing BSA into it. $250 seems like a massive amount of money just to put threading into the same shell that they were going to use anyway, but I have always had a thing for threaded as well.

supernova87a

Not that this is an important consideration, but why would Litespeed do this? Just an upsell opportunity, given that people are willing to pay? I read into it, if they offer a standard PF by default, they deem it a good enough experience for their product, even if you do not buy the threaded option?

Iride01 

Do you see yourself changing to different cranksets a lot with this new bike and DIY'ing them yourself?

If so, maybe the T-47 makes sense for you. However if you are just worried about all the doom and gloom that's gone around about pressfit, then you need to realize that more people don't have doom and gloom stories to tell. However the ones with negative experiences probably show up more to complain.

Compared to just plain old stories of BB issues with any kind of BB, pressfit doesn't really seem to be a overwhelming majority of them.

supernova87a

Thanks --

No, given that I have been relatively happy with my current old Trek 5500 bike for so long, and I"m not a diehard racer or bike mechanic myself, I doubt I would be upgrading my bike with every new possibility that comes out over future years.

Rdmonster69

I would get the T47 and pay the loot. I looked at a Litespeed before I bought my Dpmane. I would have got the T47 in a heartbeat because how often are you getting a custom build like this. As it is my Domane has a threaded BB I went with a threaded BB on the mountain bike I ordered. I like being able to work on things easily and a press fit does not allow me to do that like a threaded BB does.

Bah Humbug

I do assume they're comfortable with their default PF BB, though Trek was until they decided that was a mistake and reversed course. From Litespeed's perspective, it's not hard to tap some threads into the shell and make some money if the customer wants, even if they (LS) don't think it's necessary. Why refuse? The sleazy thing would be if they constantly pressured you to get it threaded to spend it by implying the default would be unreliable; if that were the case in that hypothetical then they should just do it on all of them.

Dave Mayer

Sigh.. all current bottom brackets are press-fit. So even if you buy something threaded, the 2 cartridge bearings at the core of the BB have been press-fit into their BB shells. Even current BSA-threaded square taper bottom brackets are press-fit, as the carts are press-fit in.

I've worked on bikes since the 70's and have serviced hundreds of BBs. I have several bikes with the old (BSA, Italian and even French) threaded and several with the newer standards, of which BB86 is my favorite. BB30: not so much.

If you select a frame builder with decent manufacturing tolerances, press-fit is fine for the life of the bike with zero issues, and overall it results in a lighter and stiffer solution.

chaadster

I see you edited the OP from what you originally stated, so I don’t know the silliness is, but I have my suspicions.

In any case, it’s probably best for you to just go with whatever the standard Litespeed spec is.

supernova87a

Thanks, all, for all this information!

Rdmonster69

My Chris King BB was just a bunch of parts. Nothing look pressed in anywhere. There were 2 separate shells that threaded into the BB.

The Origin 8 and Shimano's I put in a few recent rebuilds meet that description.

Dave Mayer

Precise language: your Chris King BB was not a 'bunch of parts', but consisted of 2 cups which threaded into the bike frame. In each of those cups, there was a single cartridge bearing that had been pressed in. Your bottom bracket spindle is in contact with and rotates with the inside of each cart.

So your BB is press-fit. Similarly all current BBs are press-fit, regardless of maker or BB specification.

A threaded BB setup does not prevent BB problems if either the threaded BB shell, or the BB itself is out of out of spec. I've seen several frames that were threaded out of spec, and rapid BB wear and creaking resulted.