D shaped forks and Giant TCR

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leadoutforbeer
Posts: 6
Joined: Tue Feb 23, 2021 1:03 pm

by leadoutforbeer

By pure luck I got gifted giant tcr sl disc frame but it's missing a fork. The idea here is to try and get it internally routed. I'm aware that regular round fork with internal routing will not work as upper bearing ID is 32,8mm. Had the idea just to get a regular fork with 1 ¼“ steerer but in that case I would have to drill it and reinforce it. Do not have a huge issue with that but the problem in this case could be related to amount of slack in the system and general maintenance.

The second idea that I would like to explore is related to D shaped steerer tube forks. I do not know any brands that sell it aftermarket but BMC has one (well 2, the old and new design for Teammachine SLR01), Factor, Colnago….

I would like to know what are dimensions of those D shaped parts to figure if it can actually fit the upper bearing of the TCR. I do not mind even using the bearing for non SL TCR as it will be for a female rider at around 50kg so stiffens is not an issue.

K4m1k4z3
Posts: 339
Joined: Sun Nov 05, 2017 1:33 pm

by K4m1k4z3

The 2023 Propel comes with a D-shaped fork. Might be able to figure something out with a 2023 Propel stem and some 3D-printed spacers.
Attachments
Propel 2023 headset.jpg
'24 S-Works Tarmac SL8 RTP - soon™
'22 Tarmac SL7 Expert | Ultegra R8100 | Alpinist CL / Custom Rapide CLX 2x60
'19 Diverge E5 Comp
'18 Epic HT Comp Carbon WMN
'18 TCR Adv Pro 1 Disc

by Weenie


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Aeo
Posts: 668
Joined: Wed May 25, 2016 2:06 am

by Aeo

titic wrote:
Fri Jan 29, 2021 3:22 pm
Just build up my TCR last week 8)
S size with Ultegra 8070 Di2
Quarq Dfour power meter
Roval CLX50 wheelset
Giant SLR integrated one piece bar
Hide all cables into handlebar :mrgreen:

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titic wrote:
Sat Jan 30, 2021 1:25 pm
Knightyboy27 wrote:
Fri Jan 29, 2021 4:10 pm
titic wrote:
Fri Jan 29, 2021 3:22 pm
Hide all cables into handlebar :mrgreen:
How?? any photos of the process?
Forgot to take photos when I build it~
But you can see how cable go inside the steerer
Image


And https://www.bilibili.com/video/BV1Ji4y1G7eg
Giant TCR Adv Pro Disc '17 · BH Lynx Race Evo '19 · Seraph GR029 '21 · Canyon Inflite AL '14

leadoutforbeer
Posts: 6
Joined: Tue Feb 23, 2021 1:03 pm

by leadoutforbeer

K4m1k4z3 wrote:
Tue Aug 23, 2022 6:12 am
The 2023 Propel comes with a D-shaped fork. Might be able to figure something out with a 2023 Propel stem and some 3D-printed spacers.
That crossed my mind but shape of the crown section would stick out as a fin

@Aeo
That method is my last resort. But would love to avoid it if possible.

jih
Posts: 596
Joined: Fri Jan 29, 2016 12:54 pm

by jih

Is that a slot cut into the steer tube, and a Giant AirCap top cap support in place of a bung? Any reinforcing around the cut?

StiffWeenies
Posts: 613
Joined: Sun Feb 28, 2021 3:39 pm

by StiffWeenies

Converting the '17-20 and '21-23(?) TCR Advanced SL/Pro (OD2) to fully internal routing can be done. You can also use the TCR Advanced (OD1) but you'd need to change the headset to accept the new OD2 fork. This method can also be used to convert the '15-16 (PM, QR) and '17-18 (FM, TA) Defy Advanced SL/Pro (OD2) and Advanced (OD1). Ditto for the Liv Langma and Avail counterparts of TCR and Defy.

Here's what is needed:
1. electronic groupset, preferably semi-wireless or wireless
2. hydraulic brakes, hydromechanical and mechanical won't work with all the cable bends
3. '19 or '20 Defy Advanced Pro (OD2) fork, '21 and beyond switched back to external routing. Make sure that the fork is from the Advanced Pro as the standard Advanced is OD1. Propel forks theorectically work but it'll be quite ugly and I'm not sure if they'll fit right at the headtube/fork crown.
4. hollow expander, either Giant AirCap (OD2) or Elilee (OD2 & OD1 versions)
5. OD2 compatible cockpit that supports true ACR style front fork hose steerer routing, either Pro Vibe Evo or Rollingstone Classic 2.0 (not 1.0!!)

Here's how it works:
1. There is absolutely no need to cut holes in the steerer, holes cut from the factory are reinforced so cutting an unreinforced hole at the most stressed part of the fork is just playing a dangerous game.
2. The stock '19-20 Defy and '18-22 Propel forks have a factory cut hole at the back of the steerer ('23 Propel switched to the front). These two bikes' internal routing work by using the hole to route the front brake hose from the caliper to the steerer hole where it'd leave the fork to exit out of the frame in an opening behind the headset.
3. Because the TCR has no such behind headset opening, you have to creatively re-use the fork steerer hole for another purpose. Instead of routing the front hose out of it, you route the rear brake hose into the hole along with your Di2/EPS wire should you require it. The front fork hose stays internal and doesn't exit the fork at this point.
4. Together with the front brake hose, the rear brake hose and electronic wire will all exit at the top of the steerer. This is where true ACR style fork hose routing comes into play (as implemented on Bianchi and Cinelli) where the fork hose comes out of the steerer and into the stem. Here, two hoses and a wire are passing through instead of just one. This is also why OD2 is needed, as regular OD1 size ACR expanders can fit just one hose (except for Elilee's which is bascially impossible to get outside of China). You will be stuck with the Giant AirCap and its weird gluing installation method which is not ideal.
5. Now that the hoses and cables are fed into the stem, you will route and assemble the cockpit as one would on any other bike.

Sample pics from Tieba:
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Last edited by StiffWeenies on Wed Aug 24, 2022 4:38 pm, edited 5 times in total.

Maddie
Posts: 1532
Joined: Tue Oct 17, 2017 5:44 am

by Maddie

Great info, thanks for sharing

js
Posts: 1003
Joined: Tue Nov 18, 2008 9:57 pm
Location: Canada

by js

I own a Defy Adv Pro. I never liked the cables entering behind the stem, but I hadn't yet occurred to me to re-route them so the front cable stays in and the rear feeds out the reinforced opening in the fork.

I can't say I enjoy the look of these taller stems, but it might be worth pursuing at some point. It's just so clean!

Thanks for the detailed share.

leadoutforbeer
Posts: 6
Joined: Tue Feb 23, 2021 1:03 pm

by leadoutforbeer

@StiffWeenies

Thanks a lot for your detailed guide. One of the plans was to modify existing fork with the entrance on the back and then reinforce it with additional plug that would go entirety of the steerer. But knowing that defy fork does the same without any modifications is great. Is defy fork the same axel to crown length and rake (rake seems to be 5mm higher) as TCR?
I'll machine my own glue in plug to avoid Giant one. Now need to figure out if there are any ACR style stems that work with 1 1/4" steerer tube. Getting 11cm long and 36cm wide integrated ACR style cockpit seems to be an impossible mission.

StiffWeenies
Posts: 613
Joined: Sun Feb 28, 2021 3:39 pm

by StiffWeenies

leadoutforbeer wrote:
Wed Aug 24, 2022 12:24 pm
@StiffWeenies

Thanks a lot for your detailed guide. One of the plans was to modify existing fork with the entrance on the back and then reinforce it with additional plug that would go entirety of the steerer. But knowing that defy fork does the same without any modifications is great. Is defy fork the same axel to crown length and rake (rake seems to be 5mm higher) as TCR?
I'll machine my own glue in plug to avoid Giant one. Now need to figure out if there are any ACR style stems that work with 1 1/4" steerer tube. Getting 11cm long and 36cm wide integrated ACR style cockpit seems to be an impossible mission.
FSA/Vision ACR stems are 1-1/8" only and the opening in the Pro Vibe 1-1/4" stem is only large enough for a single Di2 wire.

You could try this Parlee top cap on any conventional 1-1/4" stem but the routing will be very ugly.

No idea on the fork geo

leadoutforbeer
Posts: 6
Joined: Tue Feb 23, 2021 1:03 pm

by leadoutforbeer

StiffWeenies wrote:
Wed Aug 24, 2022 12:50 pm

FSA/Vision ACR stems are 1-1/8" only and the opening in the Pro Vibe 1-1/4" stem is only large enough for a single Di2 wire.

You could try this Parlee top cap on any conventional 1-1/4" stem but the routing will be very ugly.

No idea on the fork geo
For the vibe stem you mean brake hoses plus one di2 cabel or just di2 cabel and hoses would hacve to be routed outside?

StiffWeenies
Posts: 613
Joined: Sun Feb 28, 2021 3:39 pm

by StiffWeenies

leadoutforbeer wrote:
Wed Aug 24, 2022 1:21 pm
StiffWeenies wrote:
Wed Aug 24, 2022 12:50 pm

FSA/Vision ACR stems are 1-1/8" only and the opening in the Pro Vibe 1-1/4" stem is only large enough for a single Di2 wire.

You could try this Parlee top cap on any conventional 1-1/4" stem but the routing will be very ugly.

No idea on the fork geo
For the vibe stem you mean brake hoses plus one di2 cabel or just di2 cabel and hoses would hacve to be routed outside?
The Vibe stem (1-1/8" version pictured) has this little channel for the Di2 wire, no room for the two hoses
Image

js
Posts: 1003
Joined: Tue Nov 18, 2008 9:57 pm
Location: Canada

by js

You could also use the Contact SL Stealth Stem from the Defy and then modify the plastic top section that goes over the cables.

Image

That would give you the 1-1/4 size, a bit of space for cables up top and assuming you're okay with a bit of arts and crafts (certainly on a less scary scale than working on steerer tubes!), you should be able to get a fairly clean look overall by trimming the second half of the cap.

I recall Michael Schar used to run a Defy stem on his Propel. It's hard to find any great still shots of it without his arms blocking, but it looked way better than the Propel set-up!!

Image

StiffWeenies
Posts: 613
Joined: Sun Feb 28, 2021 3:39 pm

by StiffWeenies

js wrote:
Wed Aug 24, 2022 4:24 pm
You could also use the Contact SL Stealth Stem from the Defy and then modify the plastic top section that goes over the cables.

That would give you the 1-1/4 size, a bit of space for cables up top and assuming you're okay with a bit of arts and crafts (certainly on a less scary scale than working on steerer tubes!), you should be able to get a fairly clean look overall by trimming the second half of the cap.

I recall Michael Schar used to run a Defy stem on his Propel. It's hard to find any great still shots of it without his arms blocking, but it looked way better than the Propel set-up!!
It'll look like this


by Weenie


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js
Posts: 1003
Joined: Tue Nov 18, 2008 9:57 pm
Location: Canada

by js

Right - but if you went a bit custom on the rear part of the top cover, you could drop the extended length and have the cables going into the steerer, instead of the ports behind the stem.

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