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Old 12-09-13, 04:07 PM   #251
twocicle
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Originally Posted by Werkin View Post
I contacted TRP in the U.S. with a few questions including how the Stop Sell notice effects consumers. They have not formulated a plan at this point. The person I spoke with shared some of their considerations, but it's only speculation till the official announcement.

The design fault is not the same as the carbon arm failure. As I understand, the way to avoid the potential failure mode is to use the outboard pad adjustment screw/bolt to set initial pad gap and compensate for pad wear, rather than with the barrel adjuster.
I called TRP directly too. I have more confidence now (at least for the alloy armed version), knowing that the problem would occur only by drastic user maintenance error and not by product failure such as breakage.

It will likely be a few weeks out for replacement calipers. I decided to hang on to my NIB Spyre and then have it swapped directly from TRP.

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Old 12-09-13, 06:35 PM   #252
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It's official recall

http://www.trpbrakes.com/news_detail.php?nid=140
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Old 12-10-13, 02:39 AM   #253
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Honey Bees have been having trouble lately too ..
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Old 12-10-13, 04:58 AM   #254
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I cannot see what advantage adding hydraulics to the system would bring, except for causing maintenance headaches. People's reports of their experience with the HyRd brakes certainly hasn't changed my opinion on this yet.

Even on my MTB, I use a fully mechanical setup - Avid BB7 MTN brakes with SD7 levers, standard brake housing, and Avid rotors - simply awesome stopping power with very little finger effort, and good modulation (for some reason, this is easily better still than any disc brake setup I've achieved with drop-bar levers). Again, who needs the headaches of hydraulic systems, even on MTBs?
Both tandems, Ventana and Co-Motion run BB7 Mountain calipers, Avid discs and Avid Ti levers. The braking is robust on both. While we prefer flat bars on both machines, this is what allows the BB7m on the Co-Motion.

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Old 12-10-13, 12:44 PM   #255
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____________________________________________________________________________________________________



The over-rotation dislocating the balls is different than carbon melting(?) and cracking causing over-rotation. The crux of it is what is TRP's one report of brake failure in this manner. They've got another report of failure? If the over-rotation-ball-dislocation problem is fixed, does the carbon cracking/melting on the SLC get fixed as well, but discretely?

It reads better about some over-rotation dislocation than "The brake cable actuator arm that we made out of carbon to save 8 grams can melt (duh) and crack, leading to sudden and complete failure."

I queried on the TRP Facebook whether the one report of failure was on a Spyre, or Spryre SLC.

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TRP Brakes Ritterview, my understanding is the problem is irrespective of carbon vs aluminum
Which doesn't answer the question.
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Old 12-10-13, 03:20 PM   #256
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As I understand, the way to avoid the potential failure mode is to use the outboard pad adjustment screw/bolt to set initial pad gap and compensate for pad wear, rather than with the barrel adjuster.
That statement is consistent with their recall notice. If you tighten the brake cable (undo the cable bolt and pull it more taught, not letting the arm return to its resting position) and/or use the barrel adjuster to a very large degree, it would affect the travel path of the arm. Their bulletin states that if the arm is moved enough, it will "dislocate". So it does make sense.

I'm still on the fence as to whether I'll be sending mine back. Still haven't even installed it on bike yet.
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Old 12-10-13, 04:37 PM   #257
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I just got off the phone with a TRP rep.

I have an idea of the exact nature of the problem, so I'll share.

The dual pistons are actuated via "ball and ramp design" (not entirely sure what that means). That mechanism breaks down in some fashion when the angle of the rotating caliper arm is sufficient.

Let's say the rotating caliper arm is able to travel a total of 30 degrees. At its resting position, with no cable attached, let's call that angle 0. The maximum angle the rotating arm can achieve is up until it bumps up against the "fixed arm" that holds the caliper's barrel adjuster. If the barrel adjuster is screwed all the way in, the rotating arm might actually bump up against the tip of the barrel adjuster since that tip protrudes a bit past the "fixed arm". Let's call the angle at which the rotating arm bumps up against the tip of the barrel adjuster 30 degrees. If you unscrew the barrel adjuster a bit, presumably you can get the rotating arm to travel up to, let's say, 32 degrees (at which point its rotation is limited by that "fixed arm" that holds the barrel adjuster).

The problem, according to how I understand it, happens at some point when the rotating arm exceeds a certain angle. That angle (based on discussion above) might be 25 degrees, it might be 30 degrees, or it might be 31 degrees. At such an angle, the ball and ramp design that actuates the dual pistons begins to fail in some manner. It sounded like this critical "angle of failure" is very close to the angle at which the rotating arm actually bumps into the fixed arm holding the barrel adjuster.

So, the design flaw is really that either:
1. The ball and ramp mechanism is flawed in that achievable high angles are not supported by the ball and ramp or
2. The fixed arm holding the barrel adjuster is too far away, allowing the rotating arm to traverse an angle that is too large.

In my opinion, there are two ways to solve this issue. We could address #1 and replace the ball and ramp design, allowing for a greater angle or rotation, or we could move the fixed arm holding the barrel adjuster to prevent such a great angle of traversal by the rotating arm.

In any case, it does sound like the angle at which this problem occurs will be very unlikely - it would require a very thin rotor and/or very worn pads, and the cable adjustment would be such that the "resting position" where you let go of the brake lever would have the rotating arm settle in a position significantly away from 0 degrees, as defined above.

However, considering that perfect design is always an ongoing process (implying that any particular part is very likely to never have a perfect design at any point in time), instead of sending the old part in for a new one, I have come up with another solution that is perhaps a bit more elegant and requires less effort by parties involved.

The solution I might adopt is to use some "cable donuts" on the cable section between the rotating arm and the barrel adjuster. The idea behind this is that the rotating arm's movement would be limited by these cable donuts before the critical angle of failure was reached.

These are the kinds of donuts I'm talking about:

http://www.jensonusa.com/Jagwire-Cable-Spacer-Donuts
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Old 12-10-13, 05:59 PM   #258
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Actually if you use a helper spring, the spring will compress such that it will limit the travel when all the coils are touching...solving 2 problems with 1 fix. I would still rather have an inherently robust design and a stronger return spring. Did TRP state that they had a fix and replacement units?


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Originally Posted by Rambetter View Post
I just got off the phone with a TRP rep.

I have an idea of the exact nature of the problem, so I'll share.

The dual pistons are actuated via "ball and ramp design" (not entirely sure what that means). That mechanism breaks down in some fashion when the angle of the rotating caliper arm is sufficient.

Let's say the rotating caliper arm is able to travel a total of 30 degrees. At its resting position, with no cable attached, let's call that angle 0. The maximum angle the rotating arm can achieve is up until it bumps up against the "fixed arm" that holds the caliper's barrel adjuster. If the barrel adjuster is screwed all the way in, the rotating arm might actually bump up against the tip of the barrel adjuster since that tip protrudes a bit past the "fixed arm". Let's call the angle at which the rotating arm bumps up against the tip of the barrel adjuster 30 degrees. If you unscrew the barrel adjuster a bit, presumably you can get the rotating arm to travel up to, let's say, 32 degrees (at which point its rotation is limited by that "fixed arm" that holds the barrel adjuster).

The problem, according to how I understand it, happens at some point when the rotating arm exceeds a certain angle. That angle (based on discussion above) might be 25 degrees, it might be 30 degrees, or it might be 31 degrees. At such an angle, the ball and ramp design that actuates the dual pistons begins to fail in some manner. It sounded like this critical "angle of failure" is very close to the angle at which the rotating arm actually bumps into the fixed arm holding the barrel adjuster.

So, the design flaw is really that either:
1. The ball and ramp mechanism is flawed in that achievable high angles are not supported by the ball and ramp or
2. The fixed arm holding the barrel adjuster is too far away, allowing the rotating arm to traverse an angle that is too large.

In my opinion, there are two ways to solve this issue. We could address #1 and replace the ball and ramp design, allowing for a greater angle or rotation, or we could move the fixed arm holding the barrel adjuster to prevent such a great angle of traversal by the rotating arm.

In any case, it does sound like the angle at which this problem occurs will be very unlikely - it would require a very thin rotor and/or very worn pads, and the cable adjustment would be such that the "resting position" where you let go of the brake lever would have the rotating arm settle in a position significantly away from 0 degrees, as defined above.

However, considering that perfect design is always an ongoing process (implying that any particular part is very likely to never have a perfect design at any point in time), instead of sending the old part in for a new one, I have come up with another solution that is perhaps a bit more elegant and requires less effort by parties involved.

The solution I might adopt is to use some "cable donuts" on the cable section between the rotating arm and the barrel adjuster. The idea behind this is that the rotating arm's movement would be limited by these cable donuts before the critical angle of failure was reached.

These are the kinds of donuts I'm talking about:

http://www.jensonusa.com/Jagwire-Cable-Spacer-Donuts
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Old 12-10-13, 06:10 PM   #259
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I believe the use of the auxiliary return spring was related to the Hy/Rd, not the Spyre. The recall does not affect the Hy/Rd. Use of an extra return spring on the Spyre would seem (in my opinion) like overkill, since the spring tension on the stock Spyre caliper seems to be very great especially as the rotating arm begins approaching the barrel adjuster.

As to the date of when they would have replacement units, the time frame stated was 2 to 3 weeks.
When I mentioned mid-January it seemed like a "yes".

If you want to replace your Spyre unit, the procedure is to email them using the email provided on the bulletin. If you call them they will probably tell you to use the email (as they told me over the phone).
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Old 12-10-13, 06:27 PM   #260
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Actually, now that you bring up the spring issue, without having disassembled the Spyre it seems to me that it uses kind of a "leaf spring" for the return action, as opposed to a coil spring. As a consequence, it would seem that the "return force" caused by the leaf spring would grow very quickly as the rotating arm rotates to actuate the pistons. It seems that this force would grow much quicker than if the mechanism were to use a coil spring. Therefore, if someone is using the Sprye with very worn pads and/or a very thin rotor, it seems that the braking force needed at the brake lever would be abnormally high. I think a much more preferred adjustment of the system would be to move the pads outwards as they wear, so that the "normal" spring tension in the return mechanism would be felt at the brake lever.

I guess this is yet another reason why the situation outlined in the recall is unlikely - someone mechanically inclined would notice that the hand brake force is too great and would attempt to solve the problem by moving the brake pads outwards.
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Old 12-10-13, 07:08 PM   #261
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More info and detail from Cyclocross Magazine. The article states that a report has been filed with CPSC, however, said report is not yet available at the CPSC website. The greater detail here shows that the recall problem (distracted-balls-from-ramps) is distinct from our problem (cracked-carbon-actuator-arm). The question is, whether the one report of failure is ours. If it is, this suggests that having found two problems, TRP found it parsimonious to classify our cracked-carbon brake failure into the distracted-balls-from-ramps category.

TRP Recalls Spyre and Spyre SLC Mechanical Disc Brake Calipers

Itís certainly early days for road and cyclocross bike disc brakes, and today TRP Brakes joins Shimano and SRAM as the third company to recall select models of their disc brake calipers. All TRP dual piston Spyre and Spyre SLC disc brake calipers are affected, with no injuries reported, but TRP is issuing a voluntary recall on all Spyre calipers. Full recall notice below.

Voluntary Recall Notice

Tektro USA/TRP Brakes has issued a voluntary recall notice for customers and retailers to stop riding and stop selling Spyre and Spyre SLC mechanical disc brake calipers. We have also filed a report with the CPSC in accordance with their guidelines. We have identified a specific condition that could result in failure or one or both of the brakes when installed on a bicycle.

The Spyre caliper uses a dual piston design in which ball bearings move within opposing ramps. We have discovered that in a specific scenario, the balls can be forced from the ramps if the actuator arm is fully activated to its stop with excessively worn or no pads installed.

The effect is that the one or more of the balls can jump from its position within its respective ramp, resulting in a reduction or loss of braking force. The recall applies to approximately 4000 brake calipers sold from April 2013 to December 6, 2013. There has been one reported incident of a single caliper brake failure with no injury or property damage.

Customers are asked to take their Spyre or Spyre SLCís back to the original place of purchase or to contact Tektro USA/TRP Brakes Customer Service to arrange a return shipment. All Spyre and Spyre SLC calipers will be replaced free of charge.

Tektro USA / TRP Brakes
688 W. Amidan Drive, 4X-1
Ogden, UT 84404
877.807.4162
info@trpbrakes.com
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Old 12-13-13, 01:20 PM   #262
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Conversation with TRP today is that the new version in fabrication right now and comes out in a couple weeks. The new version has larger ball bearings and longer ramp so that they do not fall out if the arm is over rotated. TRP was only able to produce this effect in the lab by removing the pads entirely. While the one customer instance was reportedly produced with pads in place. You can limit the potential for this happening by regularly adjusting the pad gap with the adjustment screw on the side of the brake. The one that tightens the pad spacing. However, the recall is free, including shipping, and the new version is available soon. I am sending mine back in for replacement. My Spyre is on the bike seasonally, so right now is good for me to return.

The cracked SLC arm is thought by TRP to be tandem related, although as has been noted in this forum that a brake lever induces no more force when on a tandem versus a road bike, and certainly no more force than a mountain bike lever. TRP was silent on this question today when I made that point again. In any event, the warranty is void if the installation is noted to be on a tandem. I don't assign any malice on TRP part for having a recall on undersized ball bearings, separate from the SLC cracked arm. The two failures seem unrelated.
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Old 12-13-13, 02:50 PM   #263
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The amount of force that can be put into the brakes via the brake whether a single or a tandem if both are at a stop is the same. However, the amount of force that a brake lever can be put into a brake when they are moving is different. The brake on a single will take much less force to lock up the wheel(max force) than a tandem. So I can see that as a reason not to warrantee.


That being said, every time I work on my brakes I test tehm to the maximum force I can apply while on the stand so really they do need to be stong enough to take that force.


However, the force applied on a tandem may be at a higher heat that the brakes are not tested at for a single. In this case it would seem they failed with a combination of heat and brake pressure.
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Old 12-13-13, 05:48 PM   #264
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Ritterview (Will), were you using Campy levers and a BPB (brake power booster) when you had the Spyre SLC installed?

Combining a BPB along with disconnecting the front brake (re: carbon rims) for long descents, may be the recipe for failure of the SLC carbon arm. The BPB would produce something like the ultimate death grip (and heat load?), perhaps beyond whatever TRP spec'd during their lab tests.

Not making excuses for TRP though. My preference is to have the assurance of a large safety margin built into a product... not be near the limit.

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Old 12-13-13, 06:04 PM   #265
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The BPB is actually a Brake Power Reducer as it is used to up the cable pull and actually reduces the leverage ratio.
It does allow you to "take up" or pull more cable.
Using the BPB on the lightest setting (highest input hole) works well with the Avid disc calipers and Shimano STI combination. Allows the lever to not bottom out which in turn allows more squeeze. Too much ratio change like if you use a Travel agent goes too far which makes the lever feel like wood and has no power due to not having enough mechanical advantage any longer. The light setting on the BPB strikes the right balance.

Last edited by stevoo; 12-13-13 at 07:21 PM.
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Old 12-14-13, 12:11 AM   #266
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Originally Posted by twocicle View Post
Ritterview (Will), were you using Campy levers and a BPB (brake power booster) when you had the Spyre SLC installed?
The really nice thing about the Spyre has been that I've been able to dispense with the BPB. Even with the Campy levers there is engagement within just a centimeter or so of lever pull. As the brake pads wear, this degrades, so that on a longer or hillier ride there may be the need to adjust the cable.



I think the tandem related factor to our brake failure was heat degradation of the carbon arm. The thing is, half-bikes are not immune, as there are no particular shortages of clydesdales, that might be prone to riding brakes all the way descending steep hills and with much smaller rotors. Ours won't be the only SLC Spyre that gets hot.

What would happen is the clydesdale would make a long descent riding mainly say, the front brake. The brake heats, the carbon degrades and the actuator arm cracks. The cyclist would continue to squeeze the front brake, but with no power. So he would then ride the rear brake. Which would heat up, the and then the rear actuator arm crack. Now there are no brakes. It that rider has a GoPro going, the video would get a lot of hits.
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Old 12-14-13, 06:39 AM   #267
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This entire topic of the cracked arm is now just a bother to read.

The oem tells you it is not tandem rated, there was a failure when used on a tandem. If you want to use it, like so many other things we use on these bikes that are not tandem rated, you take your chances.

Complain about the failure if you like, but according to the oem of the brakes, you basically brought a knife to a gun fight.

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Old 12-14-13, 12:14 PM   #268
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^^^ PMK, for years Avid was saying the same thing... BB7 != tandem rated && void warranty. AFAIK, that still holds true.

Anyone who says a broken carbon caliper arm is strictly due to usage on a tandem is, to put it mildly, kidding themselves. I am 100% certain the problem could be reproduced on a single road or mtn bike.

It will be interesting to see if TRP implements any changes to the caliper arm's weak point along with this ball bearing recall fix.

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Old 12-14-13, 01:41 PM   #269
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In regards to to the Avids, I will defer that to the guidelines used by Alex of MTBTandems.com. Alex is a very conservative tandem dealer that will only sell tandem rated equipment. The Avid BB7m series is something he uses in the builds of Fandangos and Ventanas.

After visiting their website, they are pretty proud of their testing the mechanical / hydraulic brake system with a disc that was glowing red. Not sure about how much heat soak the components saw, but they claimed no failure.

TRP is Tektro, and my experience with Tektro, though not with every product they make has always led me to consider them second tier.

Hope you find the glory in the TRP. But similar to your spider failures on the cranks, if you live and ride equipment that close to the edge you basically have a works bike. And with it comes a works bike maintenance requirement.

Best of luck with it.

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Old 12-14-13, 04:32 PM   #270
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the TRP part of the company is trying to continuously develop hot new Racing parts.

the rest of the company ships containers of conservative design stuff .
to the big multi brand assembly factories


From my brief read of the recall issue is when the user lets the pads
wear too thin the ball bearings in the mech that turns the lever motion
rotating the pressure ring, the balls fall out of place..

so one supposes they are back to the CAD, drawing board
to improve the retention for those who Ignore the pad wear.

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Old 12-14-13, 08:24 PM   #271
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In regards to to the Avids, I will defer that to the guidelines used by Alex of MTBTandems.com. Alex is a very conservative tandem dealer that will only sell tandem rated equipment. The Avid BB7m series is something he uses in the builds of Fandangos and Ventanas.
Means nothing concerning the position you were making about formal "tandem rated" brakes, but does appear to agree with "use as appropriate" common sense. Either way, dodging facts by deferral. Nice.

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Hope you find the glory in the TRP. But similar to your spider failures on the cranks, if you live and ride equipment that close to the edge you basically have a works bike. And with it comes a works bike maintenance requirement.
PK
Not us. Response seems something of a deliberate slight.

I recall a post/photo provided by Ritterview that showed a FSA crank spider failure achieved by a very high powered (ie 3KW) male race team in AU. As seen in the photo, they also used only a single chainring with the chainring bolt heads interfacing directly with the carbon spider arms. Likely a poor install to begin with. These cranks are designed to be sandwiched between two chainrings, not have the minimal surface area of a bolt head putting immense pressure on an extremely small area.

Cheers.
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Old 12-14-13, 11:42 PM   #272
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Means nothing concerning the position you were making about formal "tandem rated" brakes, but does appear to agree with "use as appropriate" common sense. Either way, dodging facts by deferral. Nice.



Not us. Response seems something of a deliberate slight.

I recall a post/photo provided by Ritterview that showed a FSA crank spider failure achieved by a very high powered (ie 3KW) male race team in AU. As seen in the photo, they also used only a single chainring with the chainring bolt heads interfacing directly with the carbon spider arms. Likely a poor install to begin with. These cranks are designed to be sandwiched between two chainrings, not have the minimal surface area of a bolt head putting immense pressure on an extremely small area.

Cheers.
Sorry, it was turbotandem with the broken spider.

All the best with your caliper.

PK
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Old 12-15-13, 10:58 PM   #273
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This entire topic of the cracked arm is now just a bother to read.

The oem tells you it is not tandem rated, there was a failure when used on a tandem. If you want to use it, like so many other things we use on these bikes that are not tandem rated, you take your chances.

Complain about the failure if you like, but according to the oem of the brakes, you basically brought a knife to a gun fight.

PK
Am I complaining about the failure? I switched out the cracked carbon-armed SLC for the aluminum-armed Spyre, and blamed myself for not realizing that carbon isn't what you want to have on a critical brake part on a tandem, as it will get very hot and degrade. So, I think it has been learned thereby to avoid the Spyre SLC on a tandem, but I still think that the Spyre is a good brake, and better than the Avid BB7.

My concern now is not for tandems but for the much more numerous singles, if the Spyre SLC is continued. Where there are many riders, some are going to be clydesdales nearly the weight of a tandem team, and so when the one tandem with a Spyre SLC fails within a few months, it should mean something for the hundreds and eventually thousands of singles with Spyre SLC's. The tandem is the canary in the cage, as it were. As far as I can tell, TRP looks over, sees the dead canary and shrugs, saying "Oh, that's just the canary...its a bird, which is different." I don't think that's wise. Even now, there is no weight limitation on the Spyre SLC. Whatever mechanism TRP might posit regarding the failure that is tandem-specific must involve team weight. TRP never asked us our team weight (292 lbs). If weight has something to do with it, and 292 lbs. is proven subject to failure, then a weight limitation of 250 lbs (?) should be in order. Don't you think, PK? Or is that complaining?
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Old 12-15-13, 11:35 PM   #274
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With a team weight of 292# the tandems weight should be factored in, with maybe (4) 750ml water bottles, tool kit, up into 330/335 lbs. range.

Last edited by Bad1; 12-15-13 at 11:48 PM.
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Old 12-16-13, 03:04 AM   #275
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With a team weight of 292# the tandems weight should be factored in, with maybe (4) 750ml water bottles, tool kit, up into 330/335 lbs. range.
A 300 lb rider could also easily get to a total weight of 330 lb with a mid-range bike, some bottles, accessories, and saddle bag. And what about the 280 lb guy who uses the bike for commuting and puts a rack and pannier on the back? Then there is the 250 lb guy who puts it on his loaded touring bike in the mistaken opinion that the most expensive model in the range will give him the best braking.

Personally, knowing about this issue and that TRP are not doing anything about it, I wouldn't recommend the carbon-armed version to anyone, regardless of their weight.
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