Well, yeah. Is it a problem? No.

Here's a question that I think is interesting: steel has a fatigue limit, but, for practical purposes, do steel frames have a fatigue limit? I do not know the answer but my hunch is NO. The steel-is-real fanatics refer to the fatigue limit of steel to insist that steel frames will last forever and that aluminum frames will break five years in. I'm pretty skeptical that fatigue limit is all that relevant to any frame of joined metal tubes. But I don't know.

Basically, what I'm saying is, of course fatigue is a real thing, but aluminum frames are sufficiently overbuilt to easily account for it over a lifetime of use, and it's probably a mistake to think steel frames aren't subject to it. And it doesn't matter if they are or not. So there's a silly long mostly off-topic answer for a simple question.

I think it is, but I also think it takes mega miles to show up. My CAAD9 has been through three iterations of Rouge Roubaix and hasn't flexed apart...yet, anyway.

I'm hesitant to buy a used caad because of the aluminum fatigue thing. carbon, no problem, because it can stand infinite stress cycles due to the thermoelastic nature of its epoxy resins, so long as it's not cracked.

out of curiosity, can aluminum be heat treated multiple times? the thing that leads to fatigue is the molecules sliding past each other, and not moving back. heat treating, which I think is done to all 6061 aluminum, allows the molecules to migrate to a more stable lattice. Can this be done on a used aluminum part, and prolong its life?

How used is it? There are early 2000s versions still kicking around quite happily. Methinks you might be overthinking this.

you're right, I need an engaging job to help me think less about useless stuff.

Agree 100% - My guess is that apart from damage (and the occasional defective frame), the average rider will expire before the frame does.

Besides, getting new bikes is fun. Who the heck wants to keep bikes forever :lol:

Carbon delaminates. In theory the infinite fatigue life of steel vs finite fatigue life of aluminum is correct
In practice, how well the welds are heat treated makes orders of magnitude more difference. Since bike frame design is dominated by stiffness rather than stress, you're not going to see that much difference in fatigue life between materials.

And all that's without even going into things other than materials that make much larger changes in fatigue life, cycles to failure isn't linear with increases in stress, heat treat grade makes a difference, alloys make a difference.

Tl;dr other things are much more important than game material.

So many myths out there on frame material. "Carbon fails without warning," not necessarily true. "Steel bends, it doesn't snap," but the classic failure mode of a steel frame at a stress point is that a crack grows slowly and almost invisibly over time, until it abruptly opens up and the tube comes apart. Take it all with a grain of salt. I've had a used aluminum mountain bike with a huge dent in the chainstay. Never a problem.

Is it true that if you crash a Ti frame it actually gets stronger?

lol tkp I almost spit out my fruit shake!!

Every ride.

One. SRAM. Like we were discussing. I'd love a 9000 SRM but the SRAM SRM does everything I need it to do for a grand. The Stages is on my seldom used rain bike. I don't commute anymore. The route is too dangerous during commuting hours. No good way to get there and back. I would if I could.

if [MENTION=99188]tetonrider[/MENTION] is going to constantly shill for SRM, he should be required to note that he sells SRMs in his signature. It's only fair.

I'd settle for a 9000 SRM for a grand. :)

right--but apples to oranges. you didn't get a new Sram SRM for $1k; if you are open to refurbs and used ones, you can get a Shimano 9000 for cheaper. you might be pleasantly surprised what i could get you a new shimano one for (with a pc8)--not that you need one in your line-up.



we have, like, 10 people who post here, and i'm pretty upfront. responding to direct questions is not shilling. i happen to have a pretty solid set of experience with a bunch of power meters and a history with using them; some people find it helpful. hell...even you have come to realize a bunch of things that i've said are true that you initially disputed/resisted.

anyway, it's a discussion forum. i'll share my experiences.

for the record, i hook up people i like with power meters at a price they otherwise couldn't afford so they get something that is much better for them in the long-run. i don't go around doing it for everyone and anyone. AND....i can and have sold power meters from 5 different manufacturers, but i naturally steer people to the products i believe to be superior. my history of posts reflects a solid amount of balance in terms of actual experiences.

i could be wrong, but most here (and you if you are honest) know that to be true. speak up if it isn't the case, and it is easy enough for me to stop participating/contributing info in these threads.

i'm pretty honest about trade-offs; every power meter has one, and some have many.

Wrong!

Anyway, if you're being honest you should put it in you signature. Or find someone to trade an SRM for a thicker skin.

I don't really care. I'm happy you happen to sell the best and totally-not-overpriced power meters. God knows the terrible data from powertaps, stages, and quarqs, mixed with wrong FTPs and blended in inferior head units keeps everyone from getting to Cat 1.

Serious, relax, it's a joke.

calm down. you seem pretty charged up.

thanks, as always, for your insight and for telling everyone what they should consider a good or bad value. interesting but not surprising, that you happen not to know current pricing. i just learned the new pricing this morning.

not everyone needs and SRM. not everyone's needs match a stages, either. understanding trade-offs is all that matters.

"the riivolution" got you mad?

good times..

anyway, those power tap "p1" pedals are out - anyone used em?

still waiting on their crank-based power meter.

For me, there isn't a perfect power meter on the market; the Pioneer seems to be on the right track but its a tad bit off too. I'd love an SRM, but it doesn't have left / right data, which is important to me. Twice I've had issues that threw one legs power off and I was able to troubleshoot the issue. Heck, I'm curious to see if my left leg power drops after my crash.

I'd love to see a PM where it tracks power in various points (some do) and goes into .1 recording for a small periods of time so you can track small details of your sprint....


[MENTION=74778]mattm[/MENTION] I've been lurking on ST for reviews of the Powertap pedals; from a usability perspective it is the best on the market (Vectors are more a pain because of torquing). No torque required, just need a Hex wrench to install. We'll see how it everything else stacks up....if its solid that may be my next big purchase.

I am interested in the P1 question as well. Shopping for a TT bike and I'll need reliable power on it. I was assuming I'd just get a second SRM because I've already had a lifetime of data issues with my Stages meters. But I can get the P1 pedals for maybe $700ish less than the SRM. Can't decide if $700 is worth being a guinea pig for something new that may turn out to not work for me.

I don't get your joke. Are you selling rocket7 or d2 now?

self-awareness not a strong suit in this one.

other than a curiosity during rehab, L/R hasn't (yet) been shown to be of much use for training purposes. lots of examples there that have been beaten to death.

i wish i had L/R data before/after breaking my femur, but it would not change anything for me on the bike. have you seen anything that shows there is something actionable? everything i have seen, to date, shows that imbalances exist in all of us and vary based on intensity...and have no impact on overall performance (i.e., "correcting" an imbalance does not mean someone will make more power).

genuinely curious if you have data.

totally agree there is no perfect power solution--none without trade-off. there's always hope that the next one will be the best one, though.

PT has a good rep but their hubs had issues in the field before getting to the current, more refined iteration. nice to see some new products coming out. that is ALWAYS good for the industry.

hey, heath pack.....i just got new pricing this morning. maybe check with your dealer about it. (no idea what you were quoted on the SRM.)

basically every power meter that has come out has had issues. it's just the nature of the game. some are more severe than others. you are right to ask the $-savings-vs-guinea pig question.

i don't yet know this about the P1 but a question you may want to ask is whether it can be calibrated by the end user. PT hubs can, at least, be checked by you (5' process)--though they cannot be updated.

some designs have had decades to mature (PT hub, SRM spider), so fewer/no unknowns.

Alright I have a question. What is the essential difference between an SRM and a Quarq? They seem to be the two most 'similar' devices in terms of construction (Power is measured through the spider in a very direct method). Are their strain gauge configurations different? Do they use different types of sensors? SRM has an element of perfectionist design from what I can see, is that what accounts for the price premium above a quarq? or are there hardware differences aswell? (Aside from the simple fact that they are made by different companies and use different components)