Growtac Mech Disc

[reuben]

Well, the incoming Kona Sutra LTD is flat mount disc only, so I succumbed to <cough> progress, which can sometimes be synonymous with throwing in the towel in order to achieve a greater goal. Intentionally losing the battle in order to win the war. Knuckling under.

[NHAero]

That's a deal, bad timing on my part, ordered mine 2/28!

So today I did a typical 21 mile loop and worked in a short spur up Peaked Hill, about 1/3 mile with 11% average grade, so I could test the brakes coming down. They really work well. I'm not sure if in a blindfolded test (which I am not willing to do down this hill ) I would know if these are hydros or not.

I'm really stoked because I want to travel with this bike and adjusting these brakes is really easy, and there is no worry about popping the pistons or needing to bleed, or getting them set so they don't rub once the calipers are unbolted from the fork for travel.

[gcartelli]

Originally Posted by NHAero

That's a deal, bad timing on my part, ordered mine 2/28!

So today I did a typical 21 mile loop and worked in a short spur up Peaked Hill, about 1/3 mile with 11% average grade, so I could test the brakes coming down. They really work well. I'm not sure if in a blindfolded test (which I am not willing to do down this hill ) I would know if these are hydros or not.

I'm really stoked because I want to travel with this bike and adjusting these brakes is really easy, and there is no worry about popping the pistons or needing to bleed, or getting them set so they don't rub once the calipers are unbolted from the fork for travel.

Happy you pulled the trigger! shame about the sale timing but fortunately you're content with the components.

[NHAero]

Everyone who has reviewed these has noted that the rubber plug on the outboard pad adjuster goes AWOL pretty fast. I noticed that the hole is tapped. I called VO and they told me it is for an M4, but he was adamant that M4 only has one thread pitch, and when looking for them online it appears they can be coarse 0.7 or fine 0.5 pitch. Anyone know which for these brakes? Would like to plug the hole with a buttonhead screw.

[NHAero]

Heard back from VO and they say the pitch is 0.7mm.

One build tip, learn from my mistake - moving the bike in the basement, I turned the bars all the way to the right. The rear brake pinched closed! I realized that even though this is a full housing installation, there's a break in the housing at the connector where the 5mm housing from the bars meets the 5.5mm housing out to the caliper. So the upper housing can pull on the cable when the bars are at their extreme. So I need to put a slightly longer piece of cable housing at the bars.

[NHAero]

New screws instead of rubber plugs

[rockdude]

Originally Posted by NHAero

New screws instead of rubber plugs

Thanks for sharing. The only drawback on these was I was sure the rubber plug will fallout sometime soon, this resolves the issue. What length did you use?

[NHAero]

Originally Posted by rockdude

Thanks for sharing. The only drawback on these was I was sure the rubber plug will fallout sometime soon, this resolves the issue. What length did you use?

The threaded length is 6mm. Hex key is a 2.5mm.

[donevwil]

NHAero, thanks for the thorough review. I'll be installing a set in a few weeks and the tips on replacing the plug and, especially, the installation of the funky housing connector/adapter will help. What is the purpose of the connector anyway, i.e. why the need to jump from 5mm to 5.5mm mid housing run?

I do wonder if anyone has tried these with standard (non-compressionless) housing?

[NHAero]

Originally Posted by donevwil

NHAero, thanks for the thorough review. I'll be installing a set in a few weeks and the tips on replacing the plug and, especially, the installation of the funky housing connector/adapter will help. What is the purpose of the connector anyway, i.e. why the need to jump from 5mm to 5.5mm mid housing run?

I do wonder if anyone has tried these with standard (non-compressionless) housing?

Great question on the standard housing. I dunno, and since they ship with a lot of housing I decided to do what they said first I have compressionless housing on the Litespeed, now converted back to flat bars with BB7s, and those brakes work great with that housing.

The compressionless housing they supply is very stiff and would be hard to get up along the bars and into the shifter. I don't think the connector is a horrible idea, but now I know to provide a little extra housing.

I liked the brakes enough to order another set on sale, and I'm going to try them out on the Bingham, which has internal routing within the DT (only). It looks as though the compressionless housing Growtac provides is maybe a couple of 0.001" larger than the Jagwire brake hose on the Bingham, so I am hoping that getting the Growtac housing inside the DT won't be a 1/2 a day shot to hell!

[donevwil]

I am running Yokozuna Motokos and Reaction cables/housing on a frame with internal DT routing, it's definitely a snug fit. The caliper's housing tension adjuster is in an awkward position for IS mount orientation and the stiff housing. No real issues with the braking other than how the housing eats paint on the tight bends. Hoping these provide a better option.

[Hilltopwalters]

I got to test out a customer's bike today that was equipped with some Growtacs. Definitely liked them and will be sourcing a pair soon.

[NHAero]

Originally Posted by donevwil

NHAero, thanks for the thorough review. I'll be installing a set in a few weeks and the tips on replacing the plug and, especially, the installation of the funky housing connector/adapter will help. What is the purpose of the connector anyway, i.e. why the need to jump from 5mm to 5.5mm mid housing run?

I do wonder if anyone has tried these with standard (non-compressionless) housing?

My second pair are at the PO. I'm thinking that maybe I'll see what my stock of standard brake housing looks like, and once I swap the shifters, mount the caliper and maybe just run a length of housing, not internal, so it's reasonably quick, and see what the rear brake feels like. Certainly don't need as much power at the rear brake as the front.

[XXtwindad]

I haven’t read through the whole thread, but I’m intrigued. For someone (me!) who doesn’t bike pack, rarely does centuries, and is not mechanically inclined, what is the advantage of Growtacs or cable actuated disc brakes?

[NHAero]

Originally Posted by XXtwindad

I haven’t read through the whole thread, but I’m intrigued. For someone (me!) who doesn’t bike pack, rarely does centuries, and is not mechanically inclined, what is the advantage of Growtacs or cable actuated disc brakes?

I'd think less for you than for me. On the performance side, I expect hydraulics will remain the gold standard. Also, you, Lavi, and Donevwil are all larger humans than me, so sheer braking power may matter more, and it's possible you might detect more of a difference between braking systems than a 140 pound rider.

On a day to day basis, on the occasions I put the bike in the car, I have to remove the front wheel and remember to put the spacer in between the pads so I don't accidentally hit the brake lever and pop the pistons. On a longer term, I don't have to worry about bleeding, and there is a lower chance of the pads getting contaminated by the brake fluid (mineral oil in my systems). So I'm not urging everyone to run out and buy these, we each have our own priorities.