Juin Tech GT

Discuss light weight issues concerning road bikes & parts.

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bobones
Posts: 336
Joined: Mon Aug 12, 2013 11:19 am

by bobones

Does anyone have success running these on fully integrated setups, such as on newer Factor O2 VAM?

Mr.Gib
Posts: 4637
Joined: Fri Mar 18, 2005 4:12 pm
Location: eh?

by Mr.Gib

bobones wrote:
Wed Dec 01, 2021 3:17 pm
Does anyone have success running these on fully integrated setups, such as on newer Factor O2 VAM?
Even if you could get the cables in place, I don't think it would be a good idea. The tight bends would lead to serious cable drag. It is possible that a frame/bar combo with gentle routing might work but I doubt it. I know it won't work on a Factor O2 and that's not even fully integrated. The bend from the entry at the top of the head tube down to the down tube is just too tight.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

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Steve Curtis
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by Steve Curtis

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PoorCyclist
Posts: 542
Joined: Wed Dec 07, 2011 1:26 am
Location: California's country side

by PoorCyclist

Got these Yokozunas. I'm only doing the front brake conversion so did not want to buy a pair of GT-Fs. Comes with metal cable which is very hopelessly stiff, it may steer my bike to one side. Rotor have removable air scoops about 150g, before a centerlock adapter. I was thinking of keeping the scoops to avoid rotor warping.
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bobones
Posts: 336
Joined: Mon Aug 12, 2013 11:19 am

by bobones

Mr.Gib wrote:
Wed Dec 01, 2021 10:31 pm
bobones wrote:
Wed Dec 01, 2021 3:17 pm
Does anyone have success running these on fully integrated setups, such as on newer Factor O2 VAM?
Even if you could get the cables in place, I don't think it would be a good idea. The tight bends would lead to serious cable drag. It is possible that a frame/bar combo with gentle routing might work but I doubt it. I know it won't work on a Factor O2 and that's not even fully integrated. The bend from the entry at the top of the head tube down to the down tube is just too tight.
Thanks, I was sure the standard O2 would've worked because of the external routing, but it seems trickier to find a suitable frame for cabled discs than I had thought.

Do you think an Aethos frameset has suitable routing for the GTs or is anything with rear cable entry on downtube going to be OK?

DaveS
Posts: 3559
Joined: Fri Mar 24, 2006 1:26 pm

by DaveS

I wouldn't use cables on a fully integrated bike. My rear cable enters the down tube and comes out on the inside of the chainstay about 20cm ahead of the rear axle or 10cm ahead of the caliper. That works, but I still align the caliper before attaching the cable.

takolino
Posts: 264
Joined: Sun Nov 13, 2016 9:11 am
Location: USA, SF Bay Area

by takolino

bobones wrote:
Thu Dec 02, 2021 12:53 am
Mr.Gib wrote:
Wed Dec 01, 2021 10:31 pm
bobones wrote:
Wed Dec 01, 2021 3:17 pm
Does anyone have success running these on fully integrated setups, such as on newer Factor O2 VAM?
Even if you could get the cables in place, I don't think it would be a good idea. The tight bends would lead to serious cable drag. It is possible that a frame/bar combo with gentle routing might work but I doubt it. I know it won't work on a Factor O2 and that's not even fully integrated. The bend from the entry at the top of the head tube down to the down tube is just too tight.
Thanks, I was sure the standard O2 would've worked because of the external routing, but it seems trickier to find a suitable frame for cabled discs than I had thought.

Do you think an Aethos frameset has suitable routing for the GTs or is anything with rear cable entry on downtube going to be OK?
The Aethos is not a great option for the Juin tech although I think someone here has made it work. The required proprietary front flat mount adapter makes it challenging to mount the brakes. You have only a few millimeters of clearance for the mounting bolt head so you'll need to grind down a hex bolt and find a thin wrench. Brake line exits are a bit close to the mounts but if you use smooth cables, it should be ok. Small frames may not have enough room in the rear triangle.

Mr.Gib
Posts: 4637
Joined: Fri Mar 18, 2005 4:12 pm
Location: eh?

by Mr.Gib

IMO there are two basic requirements to be able to use Juin Tech GT:
1. For both front and rear the cable exit port must be at least 14cm from the dropout (center of the thru axle hole). This assumes that the exit port is on the inside of both the fork leg and the chain stay which is pretty much all internal frames.
2. The rear brake cable entry into the head tube must be in line with or very close to in line with the head tube junction with the downtube. Entry directly into the downtube can also work.

Note that the 14cm works with GT but may not be enough for the Juin Tech F1 due to the cable stop on the F1 caliper being an additional 1 cm closer the cable port. Also note that my dimensions are based on using Jagwire Pro Cable housing which is fairly stiff. Yokozuna cables are even stiffer and would require more distance to make the bends. Although the Yokozuna cables probably give the best performance due to their stiffness, the top stuff from Jagwire performs so well that most people probably would not notice a difference and it is much easier to work with.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

bobones
Posts: 336
Joined: Mon Aug 12, 2013 11:19 am

by bobones

takolino wrote:
Thu Dec 02, 2021 2:07 am
The Aethos is not a great option for the Juin tech although I think someone here has made it work. The required proprietary front flat mount adapter makes it challenging to mount the brakes. You have only a few millimeters of clearance for the mounting bolt head so you'll need to grind down a hex bolt and find a thin wrench. Brake line exits are a bit close to the mounts but if you use smooth cables, it should be ok. Small frames may not have enough room in the rear triangle.
Interesting, thanks. Here is a diagram of the Aethos front mount from this article. Can you please explain the problem in regard to fitting the Juin Techs?

Image

bobones
Posts: 336
Joined: Mon Aug 12, 2013 11:19 am

by bobones

Mr.Gib wrote:
Thu Dec 02, 2021 4:33 am
IMO there are two basic requirements to be able to use Juin Tech GT:
1. For both front and rear the cable exit port must be at least 14cm from the dropout (center of the thru axle hole). This assumes that the exit port is on the inside of both the fork leg and the chain stay which is pretty much all internal frames.
2. The rear brake cable entry into the head tube must be in line with or very close to in line with the head tube junction with the downtube. Entry directly into the downtube can also work.

Note that the 14cm works with GT but may not be enough for the Juin Tech F1 due to the cable stop on the F1 caliper being an additional 1 cm closer the cable port. Also note that my dimensions are based on using Jagwire Pro Cable housing which is fairly stiff. Yokozuna cables are even stiffer and would require more distance to make the bends. Although the Yokozuna cables probably give the best performance due to their stiffness, the top stuff from Jagwire performs so well that most people probably would not notice a difference and it is much easier to work with.
Great information, thanks very much.

takolino
Posts: 264
Joined: Sun Nov 13, 2016 9:11 am
Location: USA, SF Bay Area

by takolino

The Juin Tech brakes are slightly non-standard in that it's positioned in the 140mm mounting point of the standard flat mount plate so the upper mounting bolt is further from the caliper body and the hex socket can be accessed. When you mount it to the Aethos flat mount adapter, the upper mount bolt is closer to the caliper body and becomes blocked so you can't use a normal hex socket bolt.
Screenshot 2021-12-02 011640.jpg

bobones
Posts: 336
Joined: Mon Aug 12, 2013 11:19 am

by bobones

Got it, thanks!

pmprego
Posts: 1661
Joined: Mon Jan 21, 2019 3:16 pm

by pmprego

bobones wrote:
Thu Dec 02, 2021 10:55 am
Got it, thanks!
Yep, a friend made it work but it was a pain in the rear... The aethos proprietary adaptor makes it very very troublesome to work with the juin tech. He had the "luck" to have access to a machined bolt but even there it came with compromises. I'd not recommend it.

bobones
Posts: 336
Joined: Mon Aug 12, 2013 11:19 am

by bobones

Yes, I have given up with this for now. I had originally ordered a Factor O2 rim brake frameset in their off-season sale, but then had second thoughts about the colour and cancelled it thinking I could use the GTs with a matte black O2 VAM disc frameset that was a very good price. I then toyed with the Aethos idea as the cable path looked better, but luckily enough this thread has kept me right on that front too! I'm going to stick with rim brakes for now and have ordered an old school Focus Izalco Max Di2 frameset instead, which is the most boring of all the framesets I have considered (Arc8 Escapee and Time AdH being the others), but it is cheap(ish), light and by all accounts is a great ride.

by Weenie


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Ritxis
Posts: 873
Joined: Fri Jun 01, 2012 3:00 pm
Location: San Sebastian

by Ritxis

Juintech F in my Felt FR fork...rear i use TRP Spyre
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