Road Cycling - Frame flexing

How can you tell if your frame is flexing? I'm hearing something that I haven't heard before and it's mostly only on climbs, especially the steep ones where I pump harder. I can't figure out if it's coming from my frame or what, but I'm fairly sure thats where it is, but can you can hear the frame flexing? Is flexing a bad thing for a bike frame?

Flexing can be real bad if it's aluminum! If AL is flexing you got a short period of life left. Most bikes your not going to hear the frame itself flexing unless it's carbon because carbon will give a creaking sound. Steel and TI both will flex (the degree of which depends on how it was built and materials used), but with these materials the frame could last a life time since flexing has no real effect on those materials especially the TI.

You can tell if your frame is flexing when you climb a steep grade and your really hammering it, the chain will rub the front derailleur ON BOTH SIDES. Also when your hammering it the chain slips gears in the back-BUT that could also be due to an adjustment being not quite right.

The strange sound could aslo be your cleats creaking in the binding.

Could also be your bottom bracket. Just a thought.

Just getting an AL frame to flex does not imply it's on the verge of failure. AL does not have a fatigue limit such that if you subject it to stresses below said limit it will never fail; this much is true. The reality is that most riders will never subject the material to enough cycles at sufficiently high stresses to cause failure. There is much misinformation out there on this topic and many people could benefit from reading a materials engineering text. If AL is so prone to failure, why do nearly all manufacturers provide a lifetime warranty on their AL frames?
As was mentioned before, if you're riding clipless pedals check that everything's lubed up. Might be worth checking your bb as well. I recently experienced a new noise that was due to loose chainring bolts.

I do use clipless pedals, what part of them should I lube? And forgive my ignorance, what is the bottom bracket?

As far as clipless noise, I lube contact points on pedals and cleats with a silicone grease stick or just spray Pam on pedals and cleats. WD 40 also works okay.

The bottom bracket (BB) is the spindle/bearing mechanism that the crankarms mount on. That area of the bike experiences more stress and flexing than any other. Particularly under hard climbing or sprinting.

Consequently, the BB is often the source of creaking noises that occur when pedaling hard. But, too, lots of times the creaking that is blamed on the BB turns out to be coming from the seat post, or as happened to me recently, the seat rails(!). If your seatpost is well greased, it shouldn't creak. Does the creaking go away or change when you stand and pedal?

Waldo; misinformation is coming from the manufactures of AL bikes. I reported this information before which is something I knew about for years and had a friend experience it. But now even a professional bike industry publication has came out and admitted that AL may not be the best choice for long term use, take a look at VeloNews Buyers Guide edition dated june 10th, 2003 and see page 42. If you want I can copy the text for you, just ask. And lifetime warranties don't mean anything, if that was the case than Colnago would be a junk bike due to it's 1 year warranty and Sears bikes would be better than Colnago due to their lifetime warranty! So lets not measure a bikes worth by it's warranty.

Chain rub. If on your hard effort your chain is rubbing against the fron derrailleur (you could hear it too), your frame is flexing. It has nothing to do with the materials. It is the frame design. Even your very expensive Ti frame can flex. Flex is not good because your effort is not translated to the foward movement of the bike.

My frame is aluminum, and it's about 3 years old. I bought it off of a racer. It's a Trek 2200. So if something happens to this frame to where it cracks or something, what kind of material should I look for in a new frame?

Take it to the LBS the creeking could also be your headset, pedals (not the cleet) seat, or seat post.

as far as steel or AL, get what works best for you I had my heart set on steel but as I am 6 feet tall and weigh any where between 175 and190 over the course of a year all the steel frames I rode flexed badly, skeptically I test road a Cannondale R600, and it was perfect for me, great fit, no flex, smooth ride, nice components, and its bright orange/yellow. I will let every one know when and if it fails

BTW is there any data about how many steel vs AL frames fail in the real word or is all just theory

The creaking can come from the cleat platform interface. Use a wax based lubricant or engine oil with contains additives that adher to teh cleat and pedal platform.
I find Spray and cook frying pan lube to quite brilliant as well.

And lifetime warranties don't mean anything, if that was the case than Colnago would be a junk bike due to it's 1 year warranty and Sears bikes would be better than Colnago due to their lifetime warranty! So lets not measure a bikes worth by it's warranty.

Warranties mean a lot. If these "greedy" manufactures are trying to gain as much profit as possible, why would you offer a lifetime warranty on a bike that is going to fail in 5 years under heavy use?

From a business point that doesn't make any sense at all, you'd be better off having a customer come in a purchase a new bike every 5 years and making more profit than replacing things under warranty. This happened with a niche (yet popular) Sony product, it originally had a 3yr warranty, then they lowered it to a 2yr warranty. Why? Because there was something like an 80% increase in warranty claims in that time frame. And instead of a huge customer backlash, people kept buying them, people brought them in for service, etc. On the other hand the cost to the manufacture for a new frame is relatively small, so maybe they just eat the cost.

I do agree though that the time frame of a warranty doesn't indicate quality at all, as you mentioned a Colnago with a 1yr warranty is a great bike compared to a lot of bikes with lifetime warranties.


BTW is there any data about how many steel vs AL frames fail in the real word or is all just theory

I'm sure somebody has real world data, but anything we read on here is more anecdotal than anything. The numbers don't mean anything without a baseline to start from. I mean, if the bike shop sold 90% Al bikes it would be expected that he would see more Al bikes fail than anything else.

Andrew

Interesting thread. I might have this issue too.

Yesterday for the first time I heard a noise while hammering a climb. It was coming from near my F. derailleur and I thought it was my chain.

I'm a 130lb rider on a small Giant TCR Carbon and thought that at my smaller size and the rigidity of a smaller frame I wouldn't have this issue.

Maybe my legs are just ungodly powerful...

Or not.

Ok Ajay, I understand what your saying, what I was saying is that just because it has a lifetime warranty does not mean it is amoung the best bikes on the market. Most, if not all, European bikes come with only a 1 year warranty, is that making the logical jump in conclussion that all European bikes are not well made. Or places like Sears can put a lifetime warranty on their bikes should also makes us conclude that the Sears bike is better than any European bike? Warranties are just sales tactics; Hyundai car company boast a 7 year 100,000 mile warranty the best in the industry, is this an indication the Hyundai therefore is the best car in the world? And remember AL frames are the least expensive material to make into a frame, so if a bike shop, say Cannondale since their made in the USA thus labor cost are higher, makes a frame for $100, in 8 or so years you break the frame that Cannondale sold you for $500 (frame only here) and they replace it...their still ahead. If you have one of those Trek AL's made in China the cost for those frame are about $35. So of course the bike company can afford to replace the frame, but their also betting that most people will never use the warranty!!

Granted AJAY, I would prefer a lifetime warranty, in fact I have one, but the warranty is not why I bought the frame, I bought the frame because it meant my specifications at the time. But how good is my warranty now that Trek no longer even makes that type of frame anymore? I cannot demand them to make me the same frame so how are they going to settle it? Apply the value of my frame towards another? BIG DEAL, I would want the same frame and since that would be impossible I would buy something else-so much for the lifetime warranty. My next bike I am seriously considering a Colnago Master X-lite or a Tommasini Tecnos, neither carry a lifetime warranty.

Ok Ajay, I understand what your saying, what I was saying is that just because it has a lifetime warranty does not mean it is amoung the best bikes on the market. Most, if not all, European bikes come with only a 1 year warranty, is that making the logical jump in conclussion that all European bikes are not well made. Or places like Sears can put a lifetime warranty on their bikes should also makes us conclude that the Sears bike is better than any European bike? Warranties are just sales tactics; Hyundai car company boast a 7 year 100,000 mile warranty the best in the industry, is this an indication the Hyundai therefore is the best car in the world? And remember AL frames are the least expensive material to make into a frame, so if a bike shop, say Cannondale since their made in the USA thus labor cost are higher, makes a frame for $100, in 8 or so years you break the frame that Cannondale sold you for $500 (frame only here) and they replace it...their still ahead. If you have one of those Trek AL's made in China the cost for those frame are about $35. So of course the bike company can afford to replace the frame, but their also betting that most people will never use the warranty!!

You have to look at it from a business point of view. Hyundai offers a 10yr/100,000mi warranty because the public percieves the cars as being unreliable, so they are trading service profit for more sales (and actually last year Hyundai was in 2nd place in terms of reliability behind Toyota according to JD Powers). This is all done to enhance/repair their brand image.

With companies like Trek and Cannondale, that excuse doesn't work. To the "average" consumer they are both considered to be top of the line brands (we're talking about consumers who have never heard of Colnago, Pinerello, Tommasini, etc) with top notch brand image. They don't "need" to offer the lifetime warranty anymore to get sales. Why do they do it? Probably to continue offering a strong brand image, to keep selling as many bikes as they can make, etc. Colnago doesn't need to do that, they aren't a "mass-market" bike, they do things the "Italian" way on their terms, and they sell as many as they can make as well (but at much lower numbers).

But basically yes, a warranty is just another sales tool, but not at the expense of a company losing money. IF Al frames are really so fragile they need to be replaced every 4-6 years you can bet that they wouldn't come with lifetime warranties. That would be business suicide to have your business plan call for the replacement of the one piece you supply to be replaced every 4-6 years for free. And you're right, warranty hardly ever is an indication of quality on a product, but does give an indication on how the manufacture stands behind their products. I can't remember if it was here or on another forum where somebody who had purchased a nice carbon Colnago frame had a failure about 2 months after the warranty expired. Everybody knew it was a defect (and a very rare one at that), the LBS said so, the distributor said so, etc...and I think he only got a replacement because the distributor replaced it and not the manufacture (for fear of losing a small bike store chain with good sales).


Granted AJAY, I would prefer a lifetime warranty, in fact I have one, but the warranty is not why I bought the frame, I bought the frame because it meant my specifications at the time. But how good is my warranty now that Trek no longer even makes that type of frame anymore? I cannot demand them to make me the same frame so how are they going to settle it? Apply the value of my frame towards another? BIG DEAL, I would want the same frame and since that would be impossible I would buy something else-so much for the lifetime warranty. My next bike I am seriously considering a Colnago Master X-lite or a Tommasini Tecnos, neither carry a lifetime warranty.

On the warranty claim a typical manufacture would replace the frame with one of equal or greater value. Or assign a "value" to it and let you decide what to do (ie if you wanted to upgrade to the next model frame). That value would be a replacement value, or a value to get the same or better in today's dollar (and not a "market" value). Of course not every manufacture will do that, some will balk at somethings to keep the bottom line as tight as possible, etc but will usually cave.

Andrew

You may need to tighten your crank arms. They will creak when the bolt is loose. If you do not tighten it you may round the spindle out or hammer it enough to cause it to constantly loosen up. It is supposed to be done to a specific torque setting, but if you can turn it with a normal allen wrench that is more than likely your problem. Check it out. ;)

Originally posted by froze
Waldo; misinformation is coming from the manufactures of AL bikes...lifetime warranties don't mean anything, if that was the case than Colnago would be a junk bike due to it's 1 year warranty and Sears bikes would be better than Colnago due to their lifetime warranty! So lets not measure a bikes worth by it's warranty.
While I'm sure that Velonews has some good research to back their statements, I've seen many more carbon frames fail than AL (and I would be curious to see where they got their info, off I go to find the article). All I have to go on is my personal experience at the shop and a background in mechanical and materials engineering.
I beg to differ with you on the warranty issue. It would be foolish for a company to give a lifetime warranty on a product prone to failure in a short period of time. Even with your argument about it not being an economic issue for a company, the negative publicity would do them in. As an aside, having witnessed the testing Specialized puts their frames through and knowing that they just changed their warranty from 5 years to a lifetime warranty, I am inclined to trust that they know the limits of the material (though engineering background helped sort out the sales guy's b.s.). I think folks are smart enough to know that a warranty is not an assurance of quality, anyway.
This being said, this is not an issue that will be settled anytime soon, certainly not in this forum.

Originally posted by Waldo
While I'm sure that Velonews has some good research to back their statements, I've seen many more carbon frames fail than AL (and I would be curious to see where they got their info, off I go to find the article).

I'm curious to see this article too. The problem is that people assume that there are problems, and then it gets perpetuated, and suddenly everyone believes it.

There are very few creditable sources saying that AL bikes have failed.

But I'm waiting for the name caller to PM me with a phone number to the bike shop that has all the failed Al frames.

I've asked 8 bike shops in San Deigo.

There's been 2 failures. One after a car crash (the guy bent it back himself).

One was a suspect weld.

Kind of makes you want to raise the BS flag.

Wow! Some folks are really paranoid about AL fatigue failure. If an AL frame had fatigued to the point of cracking (the only mechanism by which the frame alone could "creak," total failure would be almost immediate.

Almost certainly, your creaking is due to something else. Creaks can be hard to track down and are annoying. Here's a list of the "usual suspects."

Seat rails/seat post creaking--junction not greased.
Seat post/seat tube creaking--junction not greased.
Handlebars/stem creaking--junction not greased.
Stem/headtube creaking--junction not greased.
Shoe cleat/pedal clicking--worn cleat.
Pedal/crank arm clicking--not greased.
Bottom bracket/bottom bracket shell clicking--not greased.
Bottom bracket railroad track sound--bearing worn or misadjusted.
Pedal bearings tapping--bearings worn or misadjusted.


In addition, make sure the noise is in sync with your cadence. Otherwise another likely candidate could be lose spokes that rub against each other when stressed.

Dave

Oh yes, almost forgot,

Lose chainring bolts (clicking sound).

Good luck finding that irritating creak,
Dave

hayneda is right. You will need to use process of elmination to find the creak. It may drive you nuts for a while, but you will eventually find it. I always seemed to develop more creaks after a good long ride in the rain.

Did you say how heavy you are? What size chainwheeels?

Some flex is inevitable, especially on "big" chainrings, the "ye old bike shop way" or inspecting frame flex has to do with, standing your bike's front wheel against a wall in a corner.

Put the cranks at 3 and 9 o'clock "level" --- get on the bike and stand on the forward pedal and bounce to inspect the amount of flex.......

But then you guys all knew that.....

The other one you might check, silly as it sounds, is proper wheel alignment in the front fork. We had a lady bring in a Ti bike (notorious for creaking problems at the bb, as we all now) that was making some noise. We could not duplicate the noise, she kept getting progressively more mad, and so on it went. Finally, we figured out that she wasn't getting her front wheel aligned properly in the fork and that was the source of the noise.
Beyond that, what hayneda said is the way to go.
Oh, and I haven't been able to find that article so if anyone has it and can send it my way that would be swell. Got another cracked OCLV frame today...

creak sound may be caused by cracks, loose mechanical members - both dynamic and static.

loose bolts and nuts cause this. not just that, "loose thread"/or damaged thread causes creaks too. but they are hard to detect until they actually fail. its not really the damaged thread that is making the noise but the what the bolt is actually holding in place. Say the creaks are caused by a two objects rubbing at high friction with minimal movement -- very hard to detect.

i have blamed several components before (when i had this)...
BB, Crank Arms, Headsets, and my frame. It turned out to be my seatpost being loose -- cant detect the seat post move... but the "bolt" holding the seat post was at the correct tension. after taking it apart -- i noticed that the thread was slightly damaged. after replacing it, everything was ok! well, this is just an example.. i felt like sharing..

now if you think its the frame, check the headtube and BB first. then check you stem and fork.

so much concern about frame material, man....... sounds like trying to pick fly poop out of the pepper grinder. Titanium rules!

titanium and carbon is good...

don't forget.. steel is good too, just a bit heavier..

Well, to comment on aluminum bikes. I am a large rider (190 when I am on the light side) and I like a stiff frame.

I have been riding Cannondales for years now. I have put over 30,000 miles on 3 Cannondale frames now - a Black Lightning, a CAAD 3 and a CAAD 4. I am a pretty high mileage cyclist. I ride pretty fast (I have done a number of 20 mph centuries) and being large and putting on miles, I think if aluminum frames fail much, I would see it.

OK the CAAD 3 (or whatever they called it failed). The thing had a weird set up. Instead of the rear triangle going to the hub, it went to the chain stays about 3 inches short of the hub and they flattened the chain stay and drilled a hole in the center. The chain stay snapped right where the dern hole was. It was like it was designed to fail there. Cannondale gave me a new frame (CAAD 4) no charge. The other 2 frames never showed any signs of failure and I got rid of them when all the components started to fail.

Really 30,000 miles is about 10 years of riding for most riders and most riders don't keep a bike that long. And even then, they probably will not see a failure. The one that failed on me was at a design flaw which Cannondale did not repeat. I did keep the Black Lightning around to loan to friends who visited me and all said that it was a great bike because it had superb acceleration and handling. So I think even a 30,000 miles, the Black Lighting probably had a lot more wear in it.

I used to think the same thing about components. I recall shimano had a component (I think it was a bottom bracket) that tended to go at 10,000 miles. Then I realized that it really was not a problem because very few riders ever put that many miles on a bike.

So I would suggest that if you get an aluminum bike, you will probably never put enough miles on it to get it to fail. And if you do, most manufacturers have a warrenty on the frame and you will just get a new frame for free.

I was able to virtually eliminate "creaking" or "snapping" sounds from the bottom bracket area of my Schwinn Aluminum Comp (Walmart Special) by removing my seat post and water bottle mount screws and spraying ACF 50 (aircraft corrosion resistant compound) into the frame tube interior in such a way that it seeped into the unwelded interior areas of the tube joints. Apparently there is relative motion of the tube adjacent to the welded joints so the trick is to apply a suitable penetrating lubricant and allow gravity (or capillary action) to draw it into just the right spot. Probably any penetrating lubricant will do, WD40, One-lube, etc. I am going to experiment with a mixture of Marvel Mystery Oil and moly-disulphide powder next. If weight is not an issue you can pump your frame full of moly-disulphide chassis grease. Do not use hypoid gear oil though because the extreme-pressure additives will cause every fastener it comes in contact with to come loose......................no matter how much you tighten them!!! (smells bad also)

Dennis D'Inzeo

You can tell if your frame is flexing when you climb a steep grade and your really hammering it, the chain will rub the front derailleur ON BOTH SIDES. Also when your hammering it the chain slips gears in the back-BUT that could also be due to an adjustment being not quite right.[/QUOTE]

If your frame is flexing that much, then you're too heavy for the bike. Some guys are just plain big (others are too fat today, unfortunately). A friend of mine back in the 80s was a top rider in my area who won many races both road and crit, but at 6'5" and 230 lbs twisted every bike he tried until he got a custom-made Cuevas (local NYC builder) with Reynolds 531 tubes that were custom drawn at the factory just for him (IOW, a heavier frame).

Now (sadly) I guess an aluminum frame is the way to go if you're that big. But Ti is pretty rigid too. I don't know about the other brands, but my "brand X" is extremely rigid. I have a titanium bike (brandless TST factory frame) and a steel bike (Colnago Tecnos). I'm 5'11" 165 lbs and I can't bend the Ti frame. It's incredibly rigid and and comfortable at the same time, and just flawless in every category, and (with Bontrager race wheels) the most efficient piece of machinery I've ever ridden, but strangely souless and uninspiring at the same time. . . the Tecnos, on the other hand, does flex a bit, even though the frame (with steel fork) is quie a bit heavier. . . but the joy of riding this bike more than compensates: I actually ride faster with the Tecnos because I'm almost always happier on it.

An important consideration for all those "gram-crackers" out there. ;) that that

where did you find this old thread?:D

where did you find this old thread?:D
by searching clipless + lube..... haha....... :D

by searching clipless + lube..... haha....... :D
now, I expect you to reply to this post in ANOTHER five months time :)

Will a persons weight (220 lbs.) be one of the causes of creeking?