New Trek w/ T47 BB

[FIJIGabe]

Sure, it isn't the Emonda we had been expecting, but Trek just announced their first T47 equipped bike: The Crockett.

https://bikerumor.com/2019/06/05/crocke ... -brackets/

The Dauphine starts this week, so maybe the Emonda will debut then (heard rumors of more aero shaping, ala Tarmac).

[TobinHatesYou]

I don't think the Emonda an update until next year. The 2020 Domane was delayed, likely because of a last minute decision to change from BB90 to T47.

[nickf]

I'm betting just alloy frames will get T47.

[Calnago]

I'm betting just alloy frames will get T47.

I think that might be a reasonable guess, as it would be a fairly easy change to make. But it would be nice if they made the change across the board, even in their carbon offerings, although that would add to the cost of production and significant manufacturing changes. Production schedules are not weeks or months, but more like years. To suggest there is a “last minute” change as significant as moving from BB90 to T47 is ludicrous. If a new carbon Domane comes out with T47, it was not due to a “last minute change”. It had been in the works for some time.

[TobinHatesYou]

Design changes happen up until the last few months typically. Specialized identified a problem with the SL6 disc, it got delayed a few months. Allied swaps in different inserts into the same mold to accommodate different head tube lengths. Custom carbon builders use similar inserts to give the customer the BB standard they requested. AFAIK the carbon Trek BB shells are still for the most part a modular piece, molded separately and bonded to the DT, ST, chainstays. A late revision is not out of the question and a plausible reason for a several month delay. <-- This is a bike they are going to sell for 3 years. They'd rather delay the release by 3-4 months than release a BB90 version interim only to release a T47 version less than a year later.

[MichaelB]

Agree with Tobin - the discussion may have been going for a while with pricing and design etc, but the chnage can be done pretty quick in the end. The moulds are designed (or should be) with maximum flexibility for changes in key areas like dropouts, bearing interfaces and the like.

[silvalis]

Sigh. 85.5mm non-standard T47 bb

[Calnago]

Tobin’s talking as if he actually has some experience in manufacturing. I don’t know, maybe he does, but I suspect his knowledge mostly comes from whatever he could google up on the subject.
And I’m saying I don’t know up front here, but has Trek actually publicly announced a release date for a new Domane? Again, maybe they have. I haven’t been following that closely. But if they haven’t, then there’s no basis on which to say something is “delayed”. And delaying the release of something last minute due to a late discovered design flaw is a lot different than delaying something because you just want to make one more change. There is always “one more”, or several, changes you could have made, but at some point the design process is closed, and those changes get incorporated into the next version.

[pdlpsher1]

Sigh. 85.5mm non-standard T47 bb

Haha. I just read about this now. So Trek has created a modified version of the T47. But it appears that the only difference is in the bearing cups....the bearing spacing is still the same. So you could still put your favorite T47 BB in the Trek frame.

I have the Chris King T47 BB. I've taken the cups out many times to service the bearings and I never had any issues with installing or removing the cups.

https://cyclingtips.com/2019/06/trek-t4 ... -brackets/

[silvalis]

They made a thicker flange on the BB and narrowed the shell appropriately. And are saying that the preload adjusters on cranks are good enough to take up the slack if you throw a regular sized t47-86 in (and hence end up with, eg, an 85.75mm bb).

Except we all know that trek's BBs aren't of the best tolerance, so i'm sure if this rolls out across all models we will no doubt hear of outliers. Time to stock up on wavy washers?

[Calnago]

The T47 spec is mostly referring to the bore size and the thread pitch, you could vary the shell width by a good margin and still be able to have cups that would fit virtually all cranks available. As for tolerances, even if we agree that Trek’s tolerances aren’t perfect, that would have no bearing on their ability to produce a good T47 BB. After all, the T47 insert, however they implement it would have to be either an alloy sleeve or two alloy cups, like Colnago’s T45. And therein lies the advantage, the tolerances that they can manufacture to are so much tighter and easier to achieve with alloy than carbon, hence the reason for going this route in the first place. Perhaps they might, if they do, and I hope they do, implement this in their entire range of bikes. We’ll see. If they do, that would send a very strong signal to the other big manufacturers that perhaps it’s time for them to do the same. The T47 spec is really nothing more than making a bigger diameter threaded BB shell like we were used to in the days before all the pressfit stuff. It works. And works well. It’s easy to maintain and install bottom brackets. No need for retaining compounds and various presses. Yes, it would be welcome.

[TobinHatesYou]

Always with the Google shit. Don't you have something better to do than be a boring ass troll? I called the BB switch months ago while you remained skeptical, what more do you want? What could I possible "Google" here? The fact that frame pieces are molded separately? As I mentioned just a couple posts ago, molds are not only modular, but individual molds can be modified with inserts. I mentioned Allied because I asked Sam Pickman in person how they build both the high stack and normal versions of the Alfa with "one set of molds."

Besides everyone knows most carbon "monocoque" frames are made up of several pieces that are later bonded together.

Trek has three options...I already mentioned this.

1) Release a BB90 version now and wait a whole 3 year update cycle before they release a T47 version.
2) Release a BB90 version now and release a T47 mid-cycle update within a year.
3) Make the change to T47 now.

The Domane should have been released at P-R. It missed that window. Trek has not rolled out 2020 versions of the current Domane with eTap or Force AXS. This should be proof enough that a new Domane should have broken cover by now. They're not going to delay the announcement anymore than they have to.

[DartanianX]

The new Domane is the same shape as the e version announced earlier this year.

From everything I’ve been told. New BB standards are being rolled out and the non standard T47 is a mute point.

Regular T47 bbs will fit, just with spacers to accommodate the narrower shells.


Sent from my iPhone using Tapatalk

[TobinHatesYou]

The new Domane is the same shape as the e version announced earlier this year.

From everything I’ve been told. New BB standards are being rolled out and the non standard T47 is a mute point.

Regular T47 bbs will fit, just with spacers to accommodate the narrower shells.

Yo, but did you GOOGLE that? Kidding of course.

[TobinHatesYou]

Time to stock up on wavy washers?

Wave washers will totally sap like half a watt, man.

The preload adjuster has plenty of capacity and like other threaded BBs, you could just add a 1mm spacer or two .5mm spacers between the shell and the cups depending on where you want the chainrings to line up.