TRP TTV revisited

Triathlon Forum
1

Well, since our tri bike’s launched in Sept., we have received a lot of positive feedback, as well as some criticism. One of the biggest complaints is about the TTV brake, which is probably one of the most commonly spec’ed brakes for tt/tri bikes today. Some spoke of it with utter disgust, it seemed, saying it’s weak, unsafe, and useless.

That said, I have been riding a prototype V for quite some time, and the TTVs have served me quite well. Especially when I had my Campy Eurus on, the braking power was, dare I say, on par with or at least close to my trusted Campy Record brakes. The power was clear and well defined. Maybe I could use a bit better modulation, but there was no question about stopping power.

In addition, its design in principle is no different than V brakes on mountain bikes, which require much more braking power than triathlon bikes. V brakes have served mountain biking very well for years and are continuing to do so. So why is the TRP TTV such a POS in many people’s eyes?

The answer, I believe, lies in the fork blades, as the pivots are rooted in the forks and when engaged would push against the fork blades for counter-force. Therefore, forks on MTBs are much more solid for the brake lever to push against, compared to the super thin blades on some of the latest tri bikes. Fortunately the fork blades on our bike happen to be of a reasonable thickness, so the braking power seems rather decent.

Any thoughts appreciated.

BTW, this discussion is not mean to address the drag added by the brake cable, which isn’t huge anyway.

2

The problem is not so much the power of the brake, or modulation…those are are affected by setup and user savy (or lack thereof). As you say, these types of brakes have been used for quite some time on mtb forks and cyclocross forks, and the brake arms are shorter, thereby lessening the force that could cause problems for the fork via distortion. In addition, with the extra layup in those areas, the carbon is engineered to address those added forces. The problem that I see is that you are taking a very sleek design; one that has been lusted over since softride first came out in '89ish and made its way to the zipp 3001 and has had an almost religious following, whose members have watched technological advancements and have been mentally putting every single one on their beloved ‘ideal bike, if I were king’. I say this, because it is what I have done as well; and why my criticism was centered around the cable routing which left a nagging stray hair sticking out on a brand new haircut. I can completely understand the reasons which you have provided for making it this way, but that will not make it meet the expectations which have risen to an almost unreachable level due to the time this design has been sitting around for many people to make ‘ideal’ in their mind’s eye. So…I think the brakes are fine, they are just not what I would want to see on that bike; and paying that much for not meeting my personal expectations would lead me to not purchasing the bike; despite being the closest to ideal currently available.

Stephen J

Oh, and I sitll think that you missed the boat by engineering OUT most of the suspension in the bike. That is what would have set it apart from the rest of the superbikes. Now it is an updated version of the Trek y-frame, rather than an updated titanflex/softride/zipp.

3

Thank you for your input, Steve – I can see your point of view. I do want to limit this discussion mainly to the TTV brake though. Honestly I think people see others say “TTVs are weak and useless” and then just follows without asking or thinking why. The truth is, if you have a solid fork, TTVs can provide very good braking power.

As for the V, I realize many of the design choices have evoked polarized opinions, and that’s OK.

4

My bike (Argon 18 E116) has TRP TTV brakes front and rear. I’ve found they have good stopping power, no matter if I’m using my training wheels with aluminum braking surface or race wheels with the carbon braking surface.

That said, working on the brakes, more so the rear, is a PITA. Switching between wheels, I need to change out the brake pads. If I wasn’t running Q-Rings, I’d have to remove the crank in order to accomplish this. I’ve also noticed one side of the rear brake hinge has caked up with salt remnants, causing it to not move, which ends up pulling the wheel to the side when the left side of the brake engages the wheel. This requires me to dismantle the entire rear brake to clean and put back together.

Honestly, I really, really like the Argon frame, but when shopping for a new tri frame in the future, on top of the list will be bikes that are not running TRP TTV brakes. Plain and simple, I want stopping power and easy serviceability, not one or the other.

5

I believe that the reason why many people dislike the TTV is because using it behind the fork almost always creates a large loop of cable that spoils the look and aerodynamics of the front end. As far as I know, the only bikes to hide the behind the fork brake cables are the Fuji Norcom and the Cannondale Slice RS. And even when the cables are hidden, the brake arms usually protrude from the sides of the fork a bit, and the clamped end of the cable still sticks out a bit. Overall it is not an absolutely terrible solution, but I see it as a suboptimal one in a world with the Tririg Omega, Magura RT8TT, and other fully integrated options becoming more common.

6

Why not use a top-notch, conventionally-mounted, self-contained brake (like an eebrake, which has gotten nearly universal raves) on your new bike? The eebrake is a good choice because it has a nice aero cabling profile, has out-of-this-world weight and performance, and its standard centerbolt mounting still allows people to switch it out if desired. If you want super aero, you can make a carbon brake cover for that area on the fork and under-BB area, like cervelo, felt, and others.

Greg @ dsw

7

I personally have no issue at all with the brake’s stopping power.

It’s all about the cable routing, the associated drag (which is not tiny enough to ignore on a top aero bike), and the visual appearance… of not just the cable housing in the wind but also the transition from the fork to the frame.

I can understand why you did what you did, because using an off the shelf fork certainly makes things easier… but even in that case there might be better options… like just putting a Tririg Omega on the front.

http://www.slowtwitch.com/articles/images/7/80667-largest_FalcoBike2.jpg

8

One option that I will be exploring with this frame is dealing with the front brake cable routing.

I fully believe that the cable could be run down the hollow section running in front of the head tube, and then shot toward the brake with a standard 90 degree rigid brake noodle. The outside diameter of that is only about 2.5mm, so the holes drilled would be quite small. Then you just run it out the back of the fork with a flexible noodle and you’re good.

Only thing you need to change about the build (other than the drilling) would be using a rear brake on the front as well as the back. That gives you the ability to hide the entire mechanism.

Chris

9

As I failed to drag the topic back to the original point about braking power… LOL… yes we have thought about that as well and are experimenting a few things. This could mean front brake on the right.

10

I personally have no issue at all with the brake’s stopping power.

It’s all about the cable routing, the associated drag (which is not tiny enough to ignore on a top aero bike), and the visual appearance… of not just the cable housing in the wind but also the transition from the fork to the frame.

I can understand why you did what you did, because using an off the shelf fork certainly makes things easier… but even in that case there might be better options… like just putting a Tririg Omega on the front.

I just don’t understand using a brake with a big noodle out the side instead of something like the TriRig Omega or even a TRP T920. Center pull with no cable noodle off to the side. If you’re doing custom cable routing, rather than a retro-fit, just do it. Get that cable outta the wind!

11

if that were my bike i’d replace the fork with a Cervelo FK 26 or a Felt Bayonet and put a TriRig Omega on there.

I assume that stem is a Pro Missile stem… good cable routing options for an Omega.

12

I fully believe that the cable could be run down the hollow section running in front of the head tube, and then shot toward the brake with a standard 90 degree rigid brake noodle.

Actually thinking you could make a custom noodle out of a piece of SS tubing that you could run all the way to the brake arm.

13

Yes. I have done this with aluminum, but it was not as nice as I would like. I filled the tube with sand and then put several bends in it, which generally came out well. SS should hold it’s shape better, though you’d still want something inside to prevent crushing.

Chris

14

My bike (Argon 18 E116) has TRP TTV brakes front and rear. I’ve found they have good stopping power, no matter if I’m using my training wheels with aluminum braking surface or race wheels with the carbon braking surface.

That said, working on the brakes, more so the rear, is a PITA. Switching between wheels, I need to change out the brake pads. If I wasn’t running Q-Rings, I’d have to remove the crank in order to accomplish this. I’ve also noticed one side of the rear brake hinge has caked up with salt remnants, causing it to not move, which ends up pulling the wheel to the side when the left side of the brake engages the wheel. This requires me to dismantle the entire rear brake to clean and put back together.

Honestly, I really, really like the Argon frame, but when shopping for a new tri frame in the future, on top of the list will be bikes that are not running TRP TTV brakes. Plain and simple, I want stopping power and easy serviceability, not one or the other.

Is there a guide for how to change the rear brake pads? I’m in the same boat, and the mechanic swapped pads for me the first time. Have a Quarq with Sram rings, so I’m assuming I’m going to have to take the crank off?

15

If you cannot access the bolt for the brake pad with the chainrings on, then yes, you’ll need to remove the crank. Then you have the fun of pulling a tiny metal pin out of the brake pad holder to remove the brake pad, and possibly having to file your new brake pads in order to push the pin back in once they are in the holder.