Tandem disc brake pad material?

[LittleWheelsandBig]

My stoker’s Santana tandem’s rear disc brake is the main rear brake and it is a TRP Spyre (same pads as Shimano M515, etc.). I should be able to lock up the rear wheel if riding it solo but no dice. I cleaned the 250mm rotor properly with no improvement.

What is the preferred pad material for disc brake tandems? This is for an audax tandem with confident middleweight descenders (no dragging the brake, little luggage, two blokes) and mostly on undemanding terrain. I am leaning towards organic pads for modulation and quietness but would prefer some real-life knowledge to theory.

Last century I experienced several disc brake overheating failures on a MTB tandem and sintered was the only option to avoid killing brake pads seemingly every ride but technology has hugely advanced since then.

[L CC]

Ours are sintered but we're heavy.

[thing1]

I find e-bike pads work well. There used to be some great deals but always hard to find again. The only ones reliably available over the years are
Swissstop 15 Disc E
https://www.swissstop.ch/brakepads/discbrakes/disc15/disce/
I probably wouldn't consiy anything else for the tandem now.

but technology has hugely advanced since then.

True, but unfortunately the santana 250mm rotor is stuck in last century. There's no way you'd need such a huge and heavy lump with modern tech but updating the Santana to this decade is probably not viable.

This thread Reminds me I have acquired a calfee with soggy Hy/rd disc calipers I need to make road worthy before summer alpine cycling begins.
 

[LittleWheelsandBig]

The Santana has just been swapped to 2x11 STI from 3x9 STI this week. I am having some trouble getting the R7000 front mech working properly but the rear gears work fine. The latest Shimano front mechs are not very intuitive. Updating is often more fun(!) than I prefer.

[FifeingEejit]

Have you tried some of the Kevlar based compounds?
The pads being M515 should mean there's a good range of availability from the likes of Superstar and Epic

[LittleWheelsandBig]

I haven't tried anything up till now as it isn't my tandem. But as captain, I prefer better performance than the current sub-standard rear braking, so I am making a change. If so, I might as well pick something that doesn't come apart at Mach 5.

The only cycles with disc brakes that we have in the house perform well on Shimano resin pads but HK is very light, so they aren't very stressed and last a long time. The stresses on tandem brakes are quite different.

[thing1]

The Santana has just been swapped to 2x11 STI from 3x9 STI this week. I am having some trouble getting the R7000 front mech working properly but the rear gears work fine. The latest Shimano front mechs are not very intuitive. Updating is often more fun(!) than I prefer.

Ah yes. Did you drop £130 or whatever it is on the bespoke front mech seat tube clamp bracket that has just the right spacing for this to work?

Edit - this one
https://www.santana-tandem.com/zubehoer/index.php/de/schaltungen/umwerfer/4115-detail

Maybe only required for di2?
I hate front mechs

[LittleWheelsandBig]

No, there is a more complex clamp-on fitting that includes a flat plate to allow the R7000 cable tension adjustment bolt to bear against. I will have another go at it later this week.

[sojournermike]

No, there is a more complex clamp-on fitting that includes a flat plate to allow the R7000 cable tension adjustment bolt to bear against. I will have another go at it later this week.

I’m think there are two relevant bolts on the new Shimano front mechs - a support bolt that keeps the mech parallel and which, may, not be required if you have a clamp on adapter, and a tension adjust bolt that operates by pushing against a ‘cam’ in the mech itself. The best way to adjust the tension seems to be to set it up according to the destructions and then fiddle until it works properly. To be honest it would be better if you also had an online cable adjuster as well…

Not trying to teach you to suck eggs!

[FifeingEejit]

I haven't tried anything up till now as it isn't my tandem. But as captain, I prefer better performance than the current sub-standard rear braking, so I am making a change. If so, I might as well pick something that doesn't come apart at Mach 5.

The only cycles with disc brakes that we have in the house perform well on Shimano resin pads but HK is very light, so they aren't very stressed and last a long time. The stresses on tandem brakes are quite different.

aye, I've no experience of discs on a tandem, the self-energising canti's on the tandem iroiromono and i occasionally ride are very different from what I'm used to on solo but manage to stop our excessive mass pretty well (with most of the excess being in my saddle); reckon we were around 200kg all in last time.

My MTBs are set up with superstar sintered front, kevlar rear but that's a hangover from getting brake longevity balanced against my lack of technical skills and pissing off the riders who could do the tech but couldn't ride fire road for toffee in 24hr races in the scottish autumn/winter, even at 75kg I was a heavy rider. (and I'm quite a bit more than that now).

[LittleWheelsandBig]

You are absolutely correct SM. I actually knew what I what looking at and what they are supposed to do but used the incorrect terms for the screws.

I understand T1. The chainline on a Santana tandem is usually pushed out further than normal but the cranks and BBs were also replaced when the gears were, so I need to measure chainlines, Q-factors and suchlike to understand what is going on. Currently it is running Shun (never heard of them before) crossover cranks supposedly on BB30 BSA threaded BBs (which sounds contradictory) with a SRAM spline interface (assume Power Spline but not sure). My feet definitely feel like they are further apart than I am used to but I might be able to get away with the same cleat setting.

[thing1]

When we first got the Santana I put pedal spindle extenders on one of my other bikes and it helped adapt my legs to the wider Q of the Santana pedal cranks. Now I'm used to them I can swap back and forth between different bikes with different pedal separation without really thinking about it.
Lmk if you'd like to borrow the extenders to put on another bike.

[sg37409]

Is the increased Q all driven by the 160mm rear hub ?
Whats the actual difference in Q as a result ? I reckon I'll have a difference across my bikes, and on the tandem where I use flats and trainers I often see my left foot further out that my right (which isnt even tight up against the crank)

[LittleWheelsandBig]

Yes, Santana went to 160mm OLD for stronger rear wheels and used 73mm BB shells. The wider BB shells allowed wider-spaced and bigger chain-stays and a bigger bottom tube to be fitted in pursuit of frame stiffness. The chainwheels needed to be pushed out to clear the chain-stays and nominally to line up with the cassette. Normal road triple/ tandem chain line is around 45mm, Santana is about 60mm, so the front mech needs to sit further out, otherwise it can’t shift over all the chainrings.

Sensitivity to Q-factor is very individual. Some folk don’t notice and ride anything interchangeably. Others are delicate flowers and get sore knees from big alterations, particularly when going wider. As a rider’s stance widens, usually their feet point outwards more and their cleats need to be adjusted to match. I am one of those flowers.

[iandusud]

I've only just seen this thread so maybe coming in a bit late. I use DiscoBrake Ceramic Pro pads on our Spyre on the back of our tandem. They seem to lack initial bite but then (presumably as the heat up) are very effective, and seem to last well. I use the back brake extensively. We tour fully loaded with camping gear, often in hilly terrain, so need good brakes.   

[thing1]

I've only just seen this thread so maybe coming in a bit late. I use DiscoBrake Ceramic Pro pads on our Spyre on the back of our tandem. They seem to lack initial bite but then (presumably as the heat up) are very effective, and seem to last well. I use the back brake extensively. We tour fully loaded with camping gear, often in hilly terrain, so need good brakes.   

Thanks for this. I bought some yesterday which arrived today so installed a set in the rear of our new-to-us Calfee. Quick test ride this evening to bed them in all looks good so far. Off to the Alps next week so will get some descent decent on them!
I was trying to install some random Gorilla sintered pads I had in the spares box but they seemed too think and left no gap for the disc to insert. Or, I'm just crap at retracting pistons on hy/rd calipers lol. I did bleed the brakes too all seems good.

One thing, the discopads website has like a million different compounds and no simple comparison table. Once you buy some, you find they do post a handy summary comparison (skewed by marketing needs I'm sure, but still instructive) on the back of the packet....

https://photos.app.goo.gl/2FSNpcCZywYVehxT6

[Lightning Phil]

They have it in their FAQ page

https://www.discobrakes.com/?s=0&t=10&q=compounds&