3T Strada sub 6kg goal with cable disc and mechanical shifting

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takolino
Posts: 325
Joined: Sun Nov 13, 2016 9:11 am
Location: USA, SF Bay Area

by takolino

First post of a bike here on WW. I’ve been getting a lot of great info here so thought I’d share my current project bike.

Just a little background first. I’m a mid 50s guy who got back into bicycling in my mid 40s. I used to ride MTB recreationally in my youth. I live in the bay area and try to get up OLH at least once a week and get to the coast a few times a year. It didn’t take long before weight weenies got to me and I’ve built up several titanium and carbon bikes, some hitting sub 5kg. (Litespeed Ghisallo, Addict, Supersix)

So on to the current project. This is actually my first aero bike. Being a weenie, I’ve been avoiding the heavier frames until now. It seems there are more choices for lighter weight frames and components including some disc brake stuff. The wide aero rims from Lightbicycle, for example, are amazingly light. I was able to build up a WR50 wheelset with extralite hubs to 1252g, a perfect match for the Strada.

The unique aspect of this build will be the brakes.
In pursuit of lighter weight, I decided to go with cable actuated hydro disc. I thought about going with Di2 9170 because I really like the compact hoods but the weight savings over Sram hrd are diminished for a 1x setup.The big battery and cables for just the rear derailleur didn’t appeal to me either. So this will be a Sram Red mechanical build.

Running cables in a modern carbon disc frame means you have to run cable housings all the way through the frame. So I got a bit obsessed with cable housing weights. With the addition of mechanical shifting, housing weights really impact the build. After getting some grams/meter specs, I realized that I needed to eliminate the housings inside the frame. Otherwise, it won’t be much lighter than a 9170 build. Using jagwire KEB and LEX housings, I’m saving around 80g. That does not include the foam tubes to eliminate rattles. Two foam tubes that came with the Strada weigh 40g.

So, has anyone run cables without housings inside a carbon disc frame? Love to hear what others have done. My approach will be to 3d print cable guides with teflon tube liners. For the Strada, I’ll need one at the head tube and one just behind the bb. Maybe I’m being a bit anal? Can you just let cables run over bare carbon? The thought of cables grinding into the carbon scares me. The friction will probably be annoying too.

I’ll be testing the internal cable setup first before I get fully into the build. I’ll post my findings and some pics soon. Build list will be coming too.

by Weenie


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Klaster_1
Posts: 1376
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Location: Paphos, Cyprus

by Klaster_1

@takolino welcome to Weight Weenies :beerchug:

Do you plan to list the parts? Given the weight, your wheels are probably laced to either Ti or Berd spokes, right? If Berd did you go with SPD-3 hubs? A while ago, I made a not very well researched 1x mechanical front spreadsheet and it's a wash at best, what of the values are way too off?
Annotation 2020-08-16 105132.png

takolino
Posts: 325
Joined: Sun Nov 13, 2016 9:11 am
Location: USA, SF Bay Area

by takolino

Hey @Klaster_1, thanks for the warm welcome. I was very impressed with your Hongfu 1x disk build. You opened my eyes to the possibilities of using 9170 for a lightweight build.
Yes, I will post the parts list soon.

The WR50’s are Insanely light for 32mm wide 50mm rims right? The wheelset is based on plain old Aerolites and Extralite SPD3 f/r plus veloplugs. My WR50 flyweight set came in at 398g/408g. I just weighed the wheels with veloplugs now: 665.9+580.1=1246g Slightly lighter than my calculations. I’m very happy with the weight although I have yet to ride them. I’m hoping they are not too fragile. My current lightest clincher build was based on Reynolds Attack/Extralites/CXRays weighing 1173g including rim tape. No surprise since they are narrow and shallow.

I agree with you about the weight comparison between a 9170 brake system and a cabled disc setup with Juintechs. I did consider 9170 initially. But if you add the battery, junctions, cables and the rear derailleur, it adds up to a heavier total weight. I’m saving around 130g compared to the stock 9170 levers, 9150 calipers and Di2 parts. Even with RX4, I think the cable build comes out slightly lighter.
By the way, what kind of pads are those? They are super light. Can they be used for the Juintech GT?

takolino
Posts: 325
Joined: Sun Nov 13, 2016 9:11 am
Location: USA, SF Bay Area

by takolino

Here's my preliminary build list. I weighed all the components that I have in posession on a digital scale. I have most of the parts on this list. Still trying to figure out internal routing and eliminating cable housings inside the frame. More to come...

Frame 3T Strada M RTP, painted 959
Fork 3T strada M fork uncut 410 will remove around 5cm
Headset G.W. headset 58
Spacers carbon cone, spacers 50mm 35
Bung and Cap Extralite bung, Tune cap and bolt 11
seatpost clamp 3T Strada wedge 30
Seatpost 3T Charlie 240 Darimo possibly save 100g...waiting
Seat Selle Italia SLR Tekno 85
Bar Ebay Aero integrated drop bar stem 343 Aeolus RSL bar stem combo 281g
Bartape Lizard Skins DSP 2.5mm 50
bottle cages and hardware one ebay carbon and alu bolts 20
Cables brake/shift cables and housings 121
Brakes Juin Tech GT-F F/R, pads, bolts 328 Cooma pads suggested by Klaster_1 save around 28g
Rotors Ashima Ai2 rotors F/R, Ti bolts 160
Rear derailleur Sram Red Wifli Rear Derailleur 166
Crankset Clavicula SE compact 170mm 304
Bottom Bracket FSA pressfit bb 77
Chainrings fibrelite 40t 33
Chainring bolts generic chainring bolts 10
Chain chain kmc x11sl 230
Shifters Sram Red double tap levers, gutted 260
Cassette 3T Bailout 9-32 220
Wheels:
hubs Extralite Cyber F/R SPD3 212
Spokes Aerolite spokes 223
Rims LightBicycle WR50 806
Inntertubes Continental Race Supersonic 100
Tires conti Grand Prix 5000 28 470
Skewer/TA thru axles 57
Pedals Look Keo Blade Ti axle pedals 190
Polar/garmin/computer mounts 3D printed phone/light mount 38
Tape/glue veloplugs 4
total grams 6250

Changes in blue should bring the total weight closer to 6kg goal.

Spoiler alert:
Updated build list below as of Oct 2020 after modding Charlie seat post.
Sub 6kg achieved! :beerchug:

Code: Select all

3T Strada M cable/hydro	
	
3T Strada M frame RTP+paint	959
3T strada M fork cut		370
headset				66
Integrated Aero  bar PuraRaza	330
Sram Red double tap  levers	260
Sram Red  Wifli Rear Derailleur	166
3T Bailout 9-32			220
bung and cap			30
Bar tape			80
Selle Italia C59		63
3T Charlie modded		130
seatpost collar			30
bottle cage and bolts		20
Juin Tech GT-F F/R +ti bolts	304
Ashima Ai2 rotors F/R +ti bolts	160
LightBicycle 50 clincher disk	800
Extralite Cyber F/R disk hubs 	212
Aerolite spokes			223
veloplugs			4
conti gp5k 28			470
tubolito tubo road		80
thru axles			50
brake/shift cables, guides	121
Look Keo pedals			190
Clavicula SE compact		304
chainring bolts			10
fibrelite 40t			33
FSA pressfit bb			77
chain kmc x11sl			230
total grams			5992
Last edited by takolino on Thu Nov 05, 2020 6:35 am, edited 2 times in total.

tonytourist
Posts: 1385
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Location: 90039

by tonytourist

I think you'll struggle with routing your cables through the frame without full housing, friction would likely be very high too due to the bends caused by the TT cable routing. I really like my Strada but it is definitely on the fat side of the scale!

takolino
Posts: 325
Joined: Sun Nov 13, 2016 9:11 am
Location: USA, SF Bay Area

by takolino

tonytourist wrote:
Mon Aug 17, 2020 3:07 am
I think you'll struggle with routing your cables through the frame without full housing, friction would likely be very high too due to the bends caused by the TT cable routing. I really like my Strada but it is definitely on the fat side of the scale!
Among aero framesets, actually, I think it's not to chubby. I got the RTP version and it came in a little below the claimed weight at around 940g. I was hoping it would be sub 900g but oh well. 3T claims 970g for the medium team frameset.

I agree the internal routing without housings won't be easy. My plan is to fabricate internal guides. If I succeed, I can save around 83g compared to Jagwire KEB SL and LEX SL. Plus, I would still need to add the foam sleeves to stop the rattles which weigh around 40g for two sets. It's a WW project for sure!

takolino
Posts: 325
Joined: Sun Nov 13, 2016 9:11 am
Location: USA, SF Bay Area

by takolino

So here's a quick diagram to illustrate my internal cable routing plan below. I need to fabricate two cable guides, one at the toptube and one behind the bottom bracket. I have ferrules that will work for the entry and exit points. I took some imprints of the internal surfaces and created a CAD file so I can 3D print some prototypes. I'll post details of the guides soon. So far, I think it will work.
cable-routing.jpg

Ten8ious
Posts: 3
Joined: Thu Oct 23, 2014 12:34 am

by Ten8ious

I just built up a Strada with mech and thought the same thing about the need for full length housing and whether internal stops could replace it. I suspect a really easy solution would to run one peice of housing from the BB through the say to the RD and make a simple "stop" where it exits the frame. At the front end a similar single piece from the shifter through to the bend in the downtube with a stop on the metal peice where it enters the frame would probably work a treat although you only end up saveing housing = the length of the downtube.

What I would really like though is a stem with a cable exit above the top cap (kind of Pro Vive style but for both for the shifter and rear brake hose) to really clean up the front end.

easyv
Posts: 209
Joined: Thu Mar 26, 2020 12:11 pm
Location: USA, Bay Area, CA

by easyv

takolino wrote:
Mon Aug 17, 2020 4:39 am
tonytourist wrote:
Mon Aug 17, 2020 3:07 am
I think you'll struggle with routing your cables through the frame without full housing, friction would likely be very high too due to the bends caused by the TT cable routing. I really like my Strada but it is definitely on the fat side of the scale!
Among aero framesets, actually, I think it's not to chubby. I got the RTP version and it came in a little below the claimed weight at around 940g. I was hoping it would be sub 900g but oh well. 3T claims 970g for the medium team frameset.

I agree the internal routing without housings won't be easy. My plan is to fabricate internal guides. If I succeed, I can save around 83g compared to Jagwire KEB SL and LEX SL. Plus, I would still need to add the foam sleeves to stop the rattles which weigh around 40g for two sets. It's a WW project for sure!
Agree! Reason I bought a 3T Strada last year was because compared to all the other aero bikes that came out last year like the Venge, S5, SystemSix, etc., it was actually at a decent weight and, after a test ride, didn't feel like the ride was going to beat me up like some of the super stiff aero bikes out there.

Nice build list!

I'm in the process of upgrading my own bike -- which came with SRAM Force 1 and currently weight 7.4kg -- so was curious to see what you were going to hang on the bike to get sub 6kg. Based on my own calculations as to my potential upgrades, getting to about 6.6kg isn't too difficult. But the remaining 0.6-0.8kg is going to require some significant weight weenie parts (i.e., Darimo seatpost if and when they get around to finishing that mold, Darimo / THM cockpit, Berk or Gelu saddle, THM Clavicula SE crankset, Speedplay Nanogram Zero, etc.).

easyv
Posts: 209
Joined: Thu Mar 26, 2020 12:11 pm
Location: USA, Bay Area, CA

by easyv

Ten8ious wrote:
Mon Aug 17, 2020 6:02 am
I just built up a Strada with mech and thought the same thing about the need for full length housing and whether internal stops could replace it. I suspect a really easy solution would to run one peice of housing from the BB through the say to the RD and make a simple "stop" where it exits the frame. At the front end a similar single piece from the shifter through to the bend in the downtube with a stop on the metal peice where it enters the frame would probably work a treat although you only end up saveing housing = the length of the downtube.

What I would really like though is a stem with a cable exit above the top cap (kind of Pro Vive style but for both for the shifter and rear brake hose) to really clean up the front end.
Let me know what you find on your last point. I've been searching for the same thing and, unfortunately, due to size of the fork steerer tube and upper headset, the 3T Strada isn't compatible with the potential 3rd party systems out there for internal wiring (FSA ACR, Deda DCR, etc.). Best solution I have found thus far, though I haven't yet pulled the trigger on either, is to get either a Specialized Aerofly II or 3T Aeroflux LTD aero bars which have cables exiting right next to the side of the stem so that at least the routing looks cleaner, even if still external.
Last edited by easyv on Mon Aug 17, 2020 8:37 am, edited 2 times in total.

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Klaster_1
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Location: Paphos, Cyprus

by Klaster_1

takolino wrote:
Sun Aug 16, 2020 11:35 pm
By the way, what kind of pads are those? They are super light. Can they be used for the Juintech GT?
These are Cooma Ex Plus pads, available for multiple caliper brands. Initially, I had to grind Shimano pads down, but the manufacturer was very kind to make Hope compatible pads at my request too.

Ten8ious
Posts: 3
Joined: Thu Oct 23, 2014 12:34 am

by Ten8ious

easyv wrote:
Mon Aug 17, 2020 6:34 am
... 3T Aeroflux LTD aero bars which have cables exiting right next to the side of the stem so that at least the routing looks cleaner, even if still external.
I went with the Ergonova and Apto stem for now. I agree, the Aeroflux exit would be way better as the Ergonova dumps the cables out the bottom adding an extra bend. I have no doubt 3t could make a combo that is perfect... not sure why they havent yet!

Look forward to seeing the build. I almost went with Red + mech/hydro brakes but ended up using Ultegra R8020 as an interim while I sort out gearing etc. Ultimately I think a cabled 12 speed is the way to go for the bike, just got to wait for the right product (a campy/sram mullet while possible just felt wrong)

takolino
Posts: 325
Joined: Sun Nov 13, 2016 9:11 am
Location: USA, SF Bay Area

by takolino

Ten8ious wrote:
Mon Aug 17, 2020 6:02 am
I just built up a Strada with mech and thought the same thing about the need for full length housing and whether internal stops could replace it. I suspect a really easy solution would to run one peice of housing from the BB through the say to the RD and make a simple "stop" where it exits the frame. At the front end a similar single piece from the shifter through to the bend in the downtube with a stop on the metal peice where it enters the frame would probably work a treat although you only end up saveing housing = the length of the downtube.

What I would really like though is a stem with a cable exit above the top cap (kind of Pro Vive style but for both for the shifter and rear brake hose) to really clean up the front end.
I like your practical approach to saving weight for internal routing, Ten8ious!
I agree, the cables entering the frame at the top kind of annoyes me too. It also makes internal routing more complicated. If they just did the normal thing, i.e., cable entry on the down tube, I wouldn't need internal guides at the front.

I looked at the Pro Vive stem you mentioned. I get the idea. The Pro Tharsis may have enough room for shift and brake cables but it's also a bit heavier. Giant took it a bit further with the Propel and Defy by putting all the cables over the top of the stem. Cool concept, but to me, it looks a bit complicated and kludgy. It has flaps on the sides to give cables clearance to rotate. Reminds me of the Madone brake flaps.

takolino
Posts: 325
Joined: Sun Nov 13, 2016 9:11 am
Location: USA, SF Bay Area

by takolino

easyv wrote:
Mon Aug 17, 2020 6:27 am
Agree! Reason I bought a 3T Strada last year was because compared to all the other aero bikes that came out last year like the Venge, S5, SystemSix, etc., it was actually at a decent weight and, after a test ride, didn't feel like the ride was going to beat me up like some of the super stiff aero bikes out there.

Nice build list!

I'm in the process of upgrading my own bike -- which came with SRAM Force 1 and currently weight 7.4kg -- so was curious to see what you were going to hang on the bike to get sub 6kg. Based on my own calculations as to my potential upgrades, getting to about 6.6kg isn't too difficult. But the remaining 0.6-0.8kg is going to require some significant weight weenie parts (i.e., Darimo seatpost if and when they get around to finishing that mold, Darimo / THM cockpit, Berk or Gelu saddle, THM Clavicula SE crankset, Speedplay Nanogram Zero, etc.).
Thanks, easyv!
Glad to hear the Strada worked out for you. I'm looking forward to finishing and riding it.
I've already invested in the Clavicula SE. I'll keep emailing Darimo. There's a new semi lightweight aero integrated bar but it's also pricey. Bontrager Aeolus RSL bar stem combo. Supposedly around 280g for a 40cm. Ironically, the Chinese bar/stem combo I bought on ebay seems to be its clone but it's a bit heavier, around 340g. So with the Darimo seatpost and the Aeolus bars, I may be able to get a bit closer to 6kg.

by Weenie


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takolino
Posts: 325
Joined: Sun Nov 13, 2016 9:11 am
Location: USA, SF Bay Area

by takolino

Klaster_1 wrote:
Mon Aug 17, 2020 7:51 am
takolino wrote:
Sun Aug 16, 2020 11:35 pm
By the way, what kind of pads are those? They are super light. Can they be used for the Juintech GT?
These are Cooma Ex Plus pads, available for multiple caliper brands. Initially, I had to grind Shimano pads down, but the manufacturer was very kind to make Hope compatible pads at my request too.
Thanks! I'll definitely check these out. Another 28 grams saved!
I just need to figure out which pads are compatible. From the looks of the Juintech pads, they look like Shimano d02s for the Saint. Can anyone confirm?

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