bradcycles

My wife and I just went to ride our recently completed Calfee Tetra tandem this past weekend. In the build list we agreed with Calfee (Mike Moore), we specified 203mm rotors for the rear hydraulic disc brakes. We noticed that they built it up with 180mm rotors instead of 203mm rotors.

What are the tradeoffs between the two different sized rotors? I'm upset they built it up in a way different than what we agreed and never told me or got my approval before building it that way. They are planning to ship it out today to Portland (where I live), but I want them to change it back to the 203mm rotors we agreed upon, unless there is some really compelling reason that I should stick with 180mm rotor.

bradcycles

This is the email Mike Moore just sent to me explaining why they changed the spec (but notice explaining why he didn't get my approval):

"The frame is not compatible with hydro road brakes and 203, Craig and Rob have discovered. They've just informed me we're not shipping any more tandems with 203 installed. They make noise, owing to flex. I can ship 203 that you can install and test if you like. Tandem is already packed, on the way. I'm out of office, back tomorrow morning. Mechanical and 203 is ok, not as strong as hydro."

Ritterview

First its that the frame is discovered to not accommodate 203 mm, then its that 203 mm is noisy due to flex.

It'll be interesting to see if future tandems with the braced seat-chainstay are sporting 180 mm or 203 mm.

joe@vwvortex

With the new rotors like Ice-Tech which have an aluminum spyder - they don't flex any more than smaller rotors - and if they did it would be too minimal to detect. Sounds like they messed up and are now try to cover it up with some excuses.

twocicle

re:
"The frame is not compatible with hydro road brakes and 203, Craig and Rob have discovered."
and
"Mechanical and 203 is ok, not as strong as hydro."

Strange.

I could see having a fork not accepting a 203 rotor, but IMO the rear of any tandem should always accept a 203. That they specifically say hydro compatibility is an issue may have more to do with the high amount of power generated by these hydro calipers and resulting high torque levels. It's not that a 203 is needed for stopping power with these calipers, but it is usually still needed on a tandem to handle the higher heat sink loads.

We have a fork that accepts up to a 180 rotor and I would not ever put a 203 on a fork with these hydraulic brakes and is that could overpower the fork blades. Historically the rear has always been a safe place to use a 203 rotor, so I guess with the hydro brakes it has reached the point of becoming become too strong in this case.

On top of that, since the ICE Tech rotors can be melted, limiting to a 180 size for the rear may mean other rotors like the Hope V2 are a better option.

uspspro

That's strange...

- I was running the SRAM road hydro with 203mm and there was some noise but not too bad.
- Now I am running the Shimano road hydro with 203mm, and it was making a very crazy resonant vibration sound... like sending a violent buzz through the frame, it was basically unusable.
- I just swapped to the XTR metal compound brake pads, and these things are super CRAZY powerful!! ... I heard the noise a couple times on our first ride with them, but they seem much much better (the noise was less often, less violent, and they may not yet be fully bedded-in)

But this has me thinking now. Perhaps something needs to be done to run hydro 203mm on the rear of a Calfee road tandem?

B. Carfree

Technical issues aside, that's a total customer service failure.

Ritterview

Who's to expect customer service when purchasing a >$10,000 custom-built bicycle?

akexpress 

We have about 700 miles on 203mm rotors on the RS785 hydraulic brakes on our frame with the new added strut and have not had any issues. They have been noisy a few times on a hard braking descent but quiet down quickly after they cool. There has been some mild vibration but nothing of concern and it has abaited over time. It appears that the frame will accommodate a 203 rotor it is just that Calfee no longer recommends it with these brakes. I am more concerned with melting the rotor as we have done that in the past with a Hy/Rd brake. I am going to put on the 203mm Hope V2 rotor as it has been my rotor of choice for a couple of years now on some big descents. My customer service has been great although slow at times but always dealt with any problem fairly. These brakes are powerful and the resin pads do seem to wear quicker then expected and I am moving to the semi metallic pads.

bradcycles

We were shocked they did this without getting our approval beforehand. This was one of four major customer service failures by calfee so far.

uspspro

Ak:
Which rotors are you using now? Are they solid? I wonder if the floating pads plus the floating rotor is too much movement? I also wonder about any harmonics introduced by extra fins hanging off the pads

bradcycles

We only rode it for 3 days. They shipped it out today to oregon where we live, without changing it to the 203mm rotors as agreed.

This was in the build list sent by michael moore and agreed to by me:

Front Brake Shimano R785 (newest) 180mm rotor N/A $0
Rear Brake Shimano R785 (newest) 203mm rotor N/A $0
Rotors Shimano Rotor for Disc-Brake, SM-RT98, XTR, L 180mm (front) 203mm (rear) w/Lock Ring 180/203mm rotor N/A $123

The bike was built with an extra strut to handle increased power of hydro brakes

twocicle

Brad, lucky you having 3 days riding the new tandem. Linda & I have yet to get ours on the road due to both with injuries. I'm sitting here with a full arm cast

A number of us have new builds with thru-axles, and I wonder if harmonics differ at all from QR dropouts because there seems to be significant diff in the amount of material at the dropouts between these two types, plus the added stiffness of the thru-axle integration.

What was your impression of the Calfee?
Also, refresh me on the fork/rake and resulting handling?

bradcycles

The Calfee felt great - a big improvement over our old Santana. The frame felt light and stiff. We got the TRP thru-axle fork, as the Whisky fork was no longer available, and my understanding is that there are no other thru-axle fork options. The handling feels significantly different than the Santana we have, but overall feels pretty good (maybe slightly twitchy).

bradcycles

Here is further input from Michael Moore at Calfee:

"Feedback from clients is a mixed bag - some report brake noise/shuddering - some do not. As such, Rob has informed me (yesterday) that we can't deliver tandems with hydro/203mm rotors installed - that is no longer an option. After delivery, folks can do as they like - install/test a 203mm rotor, for example. We'll need to update our order form w/180mm rear disc brake option - currently only describes 203mm and 10". Of course, I expect that Craig will solve for this in the near future. "

Has anybody else heard this from Calfee?

twocicle

Looked up your build info... https://www.bikeforums.net/tandem-cyc...fee-build.html. I'm dealing with one arm, so a bit handicapped.

The M/S frame w/47mm rake should be perfect. We have the 49mm Whisky, but no team test ride yet. With the TRP fork your tire clearance should be very good.

I believe brake noise/shuddering results will vary on a case by case basis with diff frame sizes, dropout types and components (hubs, adapter brackets, pads, etc), but it could also be their extended Ti IS mount tongue contributes to the issue with this particular brake caliper & rotor. Craig is good at figuring out these new issues as they arise.

oldacura

I am reading this thread with interest since we are considering getting a Tetra. When I spoke to Mike at Calfee he suggested to me that disc brakes were 1) More expensive, 2) heavier and 3) an unnecessary complication. I was leaning toward rim - caliper brakes. Mel at Tandems East was encouraging us toward discs. We have never really had any issues with our current rim - V brakes. Sometimes they squeal but this is usually due to brake pad material transfer to the rim. Once that is cleaned up, they are quiet.

Given all of the above hassles with disc brakes, why the strong appeal?

twocicle

you asked for this same info in the Di2 & Discs thread. seems to be answered. need a repeat? best to start your own thread AFTER searching prior topics. plenty of existing discussion on disc vs rim brakes.

I bet there is more background to the story than indicated. If you said you anticipated riding mostly flat to average terrain, then sure, rim brakes could be sufficient. However, Calfee wouldn't steer you away from discs if you said you where headed up Mt Ventoux for example.

uspspro

This is more of an "early adopter" type of setup.

Get a TRP Spyre or Avid BB7 and some EBC gold pads, and a regular 203mm rotor and you most likely have no issues, and plenty of power.

I had the BB7 + EBC gold + Hope V2 203mm for a long time, and it worked without any issues... the only pain was having to keep the pads close to the disc.

Some of the rides I do had me wanting more (if possible). >10% AVERAGE grades for more than 1 mile, etc... The Bay Area is full of these steep climbs (not super long, but long enough to tax the brakes, and increase the "pucker factor"). Another favorite spot for us is the Eastern Sierra. Stuff like the top portion of White Mountain Road and Onion Valley Road are pretty gnarly on a tandem.

reburns

FWIW, here's my take: although rim brakes have quite a few advantages over disc brakes, discs shine in two areas: 1) they will not heat your wheel rim on a long steep descent, thus no risk of blowing a tire off the rim due to excessive temperatures 2) they are more effective when wet

Other ways to address issue #1 involve using a 3rd brake as a drag brake, either a drum or disc. For #2 , the issue is that your tires also are less effective in the wet, so the effect on safety is questionable.

oldacura

Your'e right. I did bring up the same question in that thread and several have partially answered my question. However, I don't think my basic question has been answered with respect to brakes: All else being equal, will disc brakes (cable or hydraulic) stop a tandem in a steep descent with tight switchbacks with fewer adverse consequences than caliper/rim brakes?

Some people adopt a new technology because it is clearly superior. Some people adopt a new technology because it is cool or thought to be the way of the future. Sometimes a new technology can be both.

In reply to reburns: Because of where we live and when we choose to ride, we almost never ride in wet conditions so wet rims have never been a problem for us. However, for those who do frequently ride in the rain, this would be a major advantage.

Dean V

We have blown off a tyre twice on steep technical descents with rim brakes. So I have a preference for discs on such rides as it isn't good to be braking from 50mph+ and then laying the bike into a corner at still considerable speed wondering if the tyres are going to stay on!
For less extreme terrain I still prefer rim brakes though.

Carbonello

I've been watching the discussion of disk brakes for a couple years now. A couple local teams get horrible noises and shuddering with their disks. I'll keep waiting till the early adopters get it sorted out. My Santana with Sweet 16's will accept a rear disk brake (instead of the occasional Arai Drum) when I decide the time is right.

akexpress 

Ok I'll give you my/our take. Perspective first 40 + years of significant riding with a number of years of club racing both road and mountain biking. Tandeming for 7 years and about 18,000+ miles in that time. Do all my own wrenching and building of bikes including some internal DI2 conversions. Team weight about 330 and we ride in mountainous terrain and hilly country the majority of the time with very seldom long days of flats. We have done Mt Ventoux, Arthers Pass in New Zealand and many other European descents and climbs on the tandem. Arthurs Pass had a number of stokers in tears due to the steepness and exposure so it is intimidating. We started with front DuraAce caliper and Avid BB7 rear disc and 203mm rotor. The descent on Mt Ventoux melted the red plastic locking adjusting rings on our BB7 and every other one on the other tandems. The win zips went thru an entire set of pads the one bike with rim brakes had a terrified stoker whom sprayed water from the bottles on the rim all the way down. Bengal brakes had no issues really. This started my quest for better brakes for the tandem. I have now had Bengal (actually a pretty good simple brake), Hy/Rd mechanical hydraulic ( doesn't self adjust for pad wear but good at the beginning of use) my go to rotor is the Hope V2 floating rotor. We melted a Shimano Ice tech rotor in Germany on a 17% descent (as did another team). We put the first generation 10 speed Di2 hydraulic on last year before an Italy trip in the rear only and really liked the power and modulation. When we had a new frame built this year we decided to go full in with the new 11 speed and RS785 brakes and I think they are the best brakes we have used by far although we have not yet had a chance to do a major descent with them. My wife now warns me when she is riding without hands to do something as I can throw her off the bike with these brakes as they are that powerful. They are kind of a pain to bleed with the long hose to the rear caliper but you only do that once. I would be uncomfortable using them on a non thru axle front fork due to the power. We are presently using 180 front rotor and 203mm on the rear on our Calfee tetra. I am again trying the XTR Icetech rotors to use the full system integration but will probably return to the Hope rotors as they cannot melt. BTW we use an alternating braking technique and do not use the discs as drag brakes. We are not afraid to go fast and 50 mph is not out of our comfort zone. I now never have to worry about blowing off a tire due to rim heat from rim brakes. If you ride mostly flat or rolling terrain they are probably over kill. YRMV

oldacura

Thanks for all the info. I really appreciate other's experience and well-reasoned perspective. We've never done Mt Ventoux or ever ridden in NZ or the Alps (and likely never will). Maybe the mountains in Colorado are tamer than these roads. We've ridden most of the paved mountain passes in Colorado including Trail Ridge Road and Mt Evans (highest paved road in north America). We also climbed & descended Mt Haleakala on Maui. For some of these descents we used an Arai drum - others not. I think it brought peace of mind though I'm not sure we ever "needed" it. Most of the mountain roads here are not that steep but long with big sweepers. Plenty of time between tuns to allow the rims to cool (mostly). When speeds get above 40 MPH, air drag can absorb a lot of energy.

So, for our purposes, maybe rim brakes are enough. I like the fact that the forces on the wheels & frame are symmetrical and that the front wheel doesn't have to be dished.

I will continue to gather info and opinions. For almost all equipment decisions on a tandem, there is no objective "better". Cost, weight, complexity, speed, smoothness, quietness, reliability, bling, etc.. What is most important to one isn't necessarily to another.

Thanks.