tandemraw

We've just started to enjoy a new Landshark tandem. At some point, I'll do a full writeup of the new bike for those interested, but here's a quick summary:

All carbon fiber frame with titanium S&S couplers
Whiskey road disk fork with thru axle.
Lightning cranks
Ultegra di2 11 speed shifting. 50-34 front, 11-36 back. Works great without needing a Roadlink or other modification.
Dual disk brakes. TRP Hy/Rd. 180 rotors front and back.
Bodyfloat suspension seatpost for stoker.
HED Belgium+ rims, 32 hole, with DT Swiss 240 hubs.
Gates timing belt.

Overall the bike is amazing, and quite an upgrade from our 15 year old coupled Comotion, which we've ridden happily and trouble-free in many parts of the world. It's 15 lbs lighter, handles delightfully, and also seems much more efficient climbing. We were initially nervous about going from the old 3x9 speed with a low gear of 28 front - 32 back to a low gear of 34-36, but some combination of lighter weight and greater efficiency is seeming to make the low gears feel equivalent while climbing.

Needless to say, the Landshark detailing and paint job is fantastic also -- the bike looks great.

Anyway, here's my question, as I'm new to disk brakes. When we ride casually with only modest hills, the brakes work great -- powerful and quiet. Each time after we do a significant descent though, some noise develops in the brakes. The problem is resolved if I wipe the rotors clean if isopropyl alcohol, but then recurs after the next significant descent. Fyi... our team weight is 295 lbs, and we are relatively fast descenders, so I have not been hammering on the brakes.

Perhaps my bedding technique isn't appropriate -- I've been trying about 20 slow stops with each brake. Perhaps the the pads aren't the best choice -- they are simply the default pads that came with the brakes. As far as I can tell, brake alignment is correct. The same issue is happening on both brakes.

Any advice would be appreciated.

Thanks,

Ron

Tandem2

I had the same issue with organic pads, a change to semi metallics got rid of most of my noise.
Alcohol is a great rotor cleaner, but strips away that pad material you have so carefully put in place during the bedding process which explains the momentary silence but diminished effectiveness of your brakes.

akexpress 

I don;t know what rotors you are using but one piece rotors are noisy after they get hot. Two piece floating rotors like Hope V2 tend to be much quieter. they may get noisy while hot but get silent again after cooling. Shimano Ice tech rotors are also quiet but there have been reports of them melting the core (we did in Europe along with 2 other tandem teams).

mtseymour

I agree with Tandem2 that repeated use of isopropyl will lengthen the bedding process. Perhaps you should start by checking and cleaning the brake pads. Then do 5-10 hard stops (not slow stops) in a safe area. If the brakes still squeal, then your pads may be contaminated (eg. finger contact, oil). Our experience is that the Hy/Rd are quiet even after long, steep descents (8-12% grade). Since the TRP can use Shimano M525/M515 pads, it's easy to try other pads.

I don't know which rotors you're using but they can make quite a difference. We're happy with the Shimano Ice-Tec rotors but Avid & Hope should work well too.

Please post some pics because the Landsharks usually look pretty sharp.

tandemraw

I'll try what you suggest of cleaning the pads and then trying hard stops. If I have to replace the pads, do you have a brand/material to recommend? The rotors are TRP-25 2 piece centerlock. Thanks for the suggestions.

Pictures coming soon.

Ron

twocicle

Hey Ron,

Looking forward to seeing some pics of your new Landshark. The paint schemes I've seen of his creations can be wild and interesting. Our tandem is nude which we would not change, but from an artistic point of view Landshark has done a bunch of masterpieces.

On the front of our tandem we have the Whisky No.9 thru axle fork + 180 rotor with no brake squeal or howl whatsoever. Our main differences from yours is with the use of Shimano Deore/XT level hydro caliper plus either ICE RT99 or Hope V2 Floating rotor... neither make any noise with resin or metalic pads.

If you are using plain one piece steel rotors, then you might have better success trying out some alternate rotors. If you want to try a ICE rotor and your hub is a 6-bolt variety then you would need a RT86 (Centerlock rotors like the RT99 Freeza are not an option).

mtseymour

There many good options for brake pads. The most obvious are the Shimano M515/525 pads. They're widely available and work well. The Swissstop Disc 15 and EBC CFA327 (Green) are also good candidates. I prefer the organic pads to the metallic/sintered pads because they're quieter. The metallic pads are more durable, esp if you ride in wet or muddy conditions.

You should check if your TRP rotors use the Centerlock or 6-bolt mounting pattern. I prefer Shimano's Centerlock interface because it's lighter and more secure. However, it's incompatible with non-Shimano parts and requires an adapter if you want to use a Centerlock disk hub with 6-bolt rotors (eg. Avid, Hope). Of more relevance is that drilled rotors (eg. TRP-25) are usually less powerful than slotted rotors (eg. Shimano RT99). Compare the two models to see the design differences. If you have Centerlock hubs, then the RT99 would be a good upgrade.

gracehowler

Not to confuse, but I found organic pads to be much quieter than metallics!
R

twocicle

Not a ton of definitive info out there, but here is an interesting read (https://roaddisc.wordpress.com/) concerning resin vs metallic pads on the Shimano RS785 brakes. I wish the author had posted heat data taken at more locations than just the pad cooling fins. However, you can observe the IR color differences in the rotors where the resin pad test have the rotor a bright yellow/orange vs the metallic pad test show the rotors look much cooler even though his data indicates the metallic pad cooling fins are much hotter.

Other than noise and heat, durability of metallic/sintered pads is indeed known to be superior than organic/resin. No way would I try a long & steep decent with resin on the tandem (and I'm light on brake usage).

One further observation, apparently the Giant Defy Advanced Pro 1 is/was spec'd with a TRP 2-piece rotor (6-bolt, not Centerlock). As such, it does not have the Shimano ICE Tech Freeza RT-99 rotor. So whatever heat data is provided, may be quite different with the RT-99 rotor Shimano specs for use with these brakes.

Source:
https://road.cc/content/review/136548...d-sl-road-bike

mtseymour

Good article.

It's worthwhile to try different pads with a specific caliper/rotor combo. For most setups, resin pads will be quiet and powerful. The metallic pads are more durable in wet conditions but are slightly noisier. Regardless of the pad, I would avoid the TRP drilled rotors. The Shimano and Avid slotted rotors (eg. RT-86, RT-99) are more powerful.

Don't emulate the author and bed-in and test the disk brakes when following a car down a steep descent. It's safer to accelerate on flat ground and brake hard. Repeat and try gentle descents until your brakes are dialled-in.

twocicle

Considering that use of resin pads may cause higher rotor temperatures, if using any of the Shimano ICE rotors (steel/AL sandwich) that may be a recipe for melting the rotors, especially when braking with tandem mass. The ICE rotor AL core is known to melt in some usecases.

Also, resin pads will fade badly and burn away with high heat loads. The article does not seem to discuss those issues. We have had plenty of tandem teams reporting the need to replace resin pads (of various mfr) just half way down Mt Ventoux.