Sram gxp bb

Discuss light weight issues concerning road bikes & parts.
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Boshk
Posts: 311
Joined: Wed Jul 19, 2017 2:59 am

by Boshk

Stupidly I got my lbs to install the standard sram gxp bb to my new C60 (bb86) with Quarq pm. Going mechanical is easy, I can thread the cables around the gxp which has a sleeve.

If I want to install di2, is there anyway around it?
Can the junction box fit in the Seat tube, is it even viable?

If the sram gxp needs to be removed, it's pretty much trash right?
Colnago C60

jlok
Posts: 730
Joined: Tue Jun 30, 2015 3:30 am

by jlok

you need a new one if you remove the PressFit GxP bb. SRAM original one is cheap so don't worry. You may save the bearings tho, maybe it could prove useful in the future.
Giant Propel Advanced SL Disc 1 / BMC TM02 < Propel Adv < TCR Adv SL Disc < KTM Revelator Sky < CAAD 12 Disc < Domane S Disc < Alize < CAAD 10

by Weenie


alcatraz
Posts: 1342
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

If you aren't a very powerful rider putting crazy high torque on the bb then some retaining compound of some kind on the cup should be enough to secure it adequately.

You only need to remove one side in order to remove the tube.

Doesn't the c60 have a sort of guide under the bb you can undo?

Before changing cables in the future you could get yourself some thin clear pvc lining that you slide over the old cable. It takes the cables place temporarily.

/a

Boshk
Posts: 311
Joined: Wed Jul 19, 2017 2:59 am

by Boshk

jlok wrote:
Wed Mar 28, 2018 1:48 am
you need a new one if you remove the PressFit GxP bb. SRAM original one is cheap so don't worry. You may save the bearings tho, maybe it could prove useful in the future.
thanks
alcatraz wrote:
Wed Mar 28, 2018 4:37 am
If you aren't a very powerful rider putting crazy high torque on the bb then some retaining compound of some kind on the cup should be enough to secure it adequately.

You only need to remove one side in order to remove the tube.

Doesn't the c60 have a sort of guide under the bb you can undo?

Before changing cables in the future you could get yourself some thin clear pvc lining that you slide over the old cable. It takes the cables place temporarily.

/a
yea it does, I believe its called a T47 and Enduro does a T47 bb to replace the Colnago one but its pretty expensive. One of the LBS said I could do that, replace the whole bb with Enduro one and use an enduro adapter for GXP but it all seems $$$ and complex.
The C60 should be fine according to quite a few guys on this forum as long as the LBS doesn't damage it.
Colnago C60

Attermann
Posts: 271
Joined: Sun Jan 05, 2014 11:04 pm
Location: Denmark

by Attermann

no the colnago is called ''T45'' :)

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Calnago
Posts: 6743
Joined: Sun Nov 07, 2010 9:14 pm

by Calnago

I'm not sure what you're doing now. Is it a mechanical drivetrain or are you going electric. If it's mechanical, I don't know what you're talking about with wrapping cables around the "sleeve" etc. The cables come out the slot and get routed through the external cable guide which is screwed onto the underside of the BB shell.

If it's electric then yes, you need to hook everything up before you install the bottom bracket. If you've just pressed in a GXP adapator in the existing Threadfit Cups, then I would think you might be able to remove them and reuse them (it's new, right?). Delrin cups and all? You can also replace the existing Threadfit cups with something else, and much more expensive, but I dont' think I'd bother.

@aclatraz: Although I've never tried it, the routing of a liner sleeve all the way through the C60 or other internally routed colnagos prior to the C64 is unnecessary and I'm not sure it even would work because of the size of the opening where the cables enter the downtube at the headtube lug. I think it would be very difficult to guide the liner through that hole, or if it's even big enough. Plus, with the large slot in the downtube you don't have to... you just run the cables in and pull them out the slot at the bottom bracket. The C64 is another matter, and the use of inserted sleeves when replacing cables is pretty much mandatory. You just remove the cable port on top of the downtube where the cables enter allowing easy acccess to the sleeve. Without the temporary sleeve, once everything is installed it would be impossible to route a new derailleur cable without removing the entire crankset, but with the sleeve it's a breeze.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

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IrrelevantD
Posts: 359
Joined: Sun Nov 29, 2015 5:47 pm
Location: Near DFW Airport

by IrrelevantD

I'm going to assume, like Calnago did, that you're asking about running internal wiring through the frame without removing the BB. Every frame being different, I couldn't speak to if this is possible on a C60, but I was able to do it on a Giant Propel without removing the BB using floral wire to fish it through the frame, then tying the e-Tube cables to the wire to pull it back. It was a colossal PITA, but it can be done. That being said, unless it's going to cost you more than $40-50 to replace the BB, I'd just assume its going to need to be replaced. I ended up replacing mine with a Wheels Mfg. BB that was pretty easy to remove and re-install.

Using small neodymium magnets attached to thin flexible wire might also work, and might be a better idea if you go forward with tryign to fish it through without removing the BB.
* There is a 70% chance that what you have just read has a peppering of cynicism or sarcasm and generally should not be taken seriously.
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Calnago
Posts: 6743
Joined: Sun Nov 07, 2010 9:14 pm

by Calnago

For sure if you’re going to start messing around with routing electrical systems, then one of the cable routing kits with magnets and rubber sleeves etc is the best investment you can make. Park Tools has a good one. There are others. Can’t believe I struggled around with fishing and shaking things for as long as I did before finally getting one of these kits. Helps with a lot of internal mechanical routings as well.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

Boshk
Posts: 311
Joined: Wed Jul 19, 2017 2:59 am

by Boshk

Calnago wrote:
Wed Mar 28, 2018 3:55 pm
I'm not sure what you're doing now. Is it a mechanical drivetrain or are you going electric. If it's mechanical, I don't know what you're talking about with wrapping cables around the "sleeve" etc. The cables come out the slot and get routed through the external cable guide which is screwed onto the underside of the BB shell.

If it's electric then yes, you need to hook everything up before you install the bottom bracket. If you've just pressed in a GXP adapator in the existing Threadfit Cups, then I would think you might be able to remove them and reuse them (it's new, right?). Delrin cups and all? You can also replace the existing Threadfit cups with something else, and much more expensive, but I dont' think I'd bother.

@aclatraz: Although I've never tried it, the routing of a liner sleeve all the way through the C60 or other internally routed colnagos prior to the C64 is unnecessary and I'm not sure it even would work because of the size of the opening where the cables enter the downtube at the headtube lug. I think it would be very difficult to guide the liner through that hole, or if it's even big enough. Plus, with the large slot in the downtube you don't have to... you just run the cables in and pull them out the slot at the bottom bracket. The C64 is another matter, and the use of inserted sleeves when replacing cables is pretty much mandatory. You just remove the cable port on top of the downtube where the cables enter allowing easy acccess to the sleeve. Without the temporary sleeve, once everything is installed it would be impossible to route a new derailleur cable without removing the entire crankset, but with the sleeve it's a breeze.
Me either actually :?:

Still riding my XR3 and the front derailleur is super smooth now.....plus no time to build the C60 yet.

If I go mechanical, its easy, I already threaded fishing lines into the frame around the pm and bb.

I was referring to di2 installation with the 'normal' sram gxp bb....got the answer already, I cant squeeze the tiny di2 junction box around the bb and into tube, I have to remove the bb.
If the sram gxp bb didn't have that internal sleeve , just 2 cups pressed in like the ultra-torque's, I could home install the di2, but now I'll have to remove pm, punch out the gxp bb and bin it, route the di2 stuff, reinstall new gxp bb......not that big a deal in the big scheme of things....$50 inc installation fee.
Colnago C60

by Weenie


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