Folding Bikes - Broken Xootr Swift

Hey, tried a search and couldn't find anything, so preemptive apologies if this has been raised already. I just had a Xootr Swift fail on me catastrophically.

http://img.photobucket.com/albums/v689/eddiebrannan/IMG006011.jpg

I just wrote the company, and I'm attaching what i wrote, as it's easier than retyping it, but my question for the forum is; has anyone else had a similar experience?

Hi there,

Just wanted to let you guys know about a catastrophic failure which just happened to my Xootr folder. First of all, I want to stress that I converted the bike to singlespeed, which I believe contributed to the problem, so I am not trying to press this as a warranty issue, but simply to let you know what happened, for your information and reference.

As you know, on this bike the seat stays cross the seat tube, GT style, and they sheared ahead of the point at which they intersect. I was stationary, pushed off from a standstill and suddenly felt it give. I had pushed off with the right foot and the rear of the bike just rotated counterclockwise around the seatpost.

The entire rear triangle is connected to the rest of the bike solely at the pivot point of those rear stays and the top tube. The upper and lower parts of the seat tube are separate, and the seatpost is the only thing that links them, and it does so passively, not actively. The bike was designed to have a derailleur, which would have absorbed some of that rotational torque, but nonetheless you may wish to keep this in mind: in the absence of a downtube, the fact that the seat tube is designed to be in two unconnected parts (ie with nothing keeping that lower part in alignment with the upper other than the stays—the lower quick release does NOT hold the assembly sufficiently fast), means that all of the pedaling torque is applied at that particular point, around the downtube and onto two of the thinnest tubes on the bike, which is precisely where the failure occurred.

As I say, this email is for your reference. The bike is terrific (I miss it!), but in retrospect it does have a fundamental design Achilles' heel in the lack of linkage at the intersection between the upper and lower half of the seat tube, with only two quick releases and the seat stays holding the bike together at that point. The seat post is simply a spindle, essentially, and tortional forces meet very little material. For sure it may have held out longer with the derailleur in place, but I still advocate beefing up those seat stays, as they are all that connects the rear triangle to the front of the bike.

Please excuse the shoddy cellphone photo. I only had my Blackberry on me when it happened, but it's pretty clear what occurred nonetheless. However I can shoot hi-res images should you need.

http://www.bikeforums.net/showthread.php?t=286609&page=3

just scroll down the page, there's a post by kb5ql (http://www.bikeforums.net/member.php?u=63370) on his broken swift, with photos.

Happened with mine. They sent me a replacement. I have since sold it and am on a Bike Friday. I posted about it. It's probably on page 289 of the swift folder thread ;)

I converted the bike to singlespeed, which I believe contributed to the problem...

The bike was designed to have a derailleur, which would have absorbed some of that rotational torque

in the absence of a downtube, the fact that the seat tube is designed to be in two unconnected parts (ie with nothing keeping that lower part in alignment with the upper other than the stays—the lower quick release does NOT hold the assembly sufficiently fast), means that all of the pedaling torque is applied at that particular point, around the downtube and onto two of the thinnest tubes on the bike, which is precisely where the failure occurred.



No experience with your bike but just judging from your post I see a few things their engineers may get a chuckle at when they read your letter.

I fail to see how converting a bike to SS would contribute to the problem - deraileurs don't 'absorb' much torque or much of anything other than chain slack. The underside of the chain and deraileur has very little stress applied to it aside from when you're shifting gears. There is probably the same stresses applied to a frame if the drivetrain has a deraileur vs. internally geared rear hub vs. single speed.

I'm guessing the seat tube is part of the strength of the frame when it is in place which is why it might be flimsy without it?

Edit: If the seat tube was solid it would defeat the folding mechanism.

I assume it was Al not steel.

oh well pardon me for my naive speculation, bontrager, and thanks for setting me straight without a shred of superciliousness.

i am not sure what you mean about the seatpost being "solid," and i certainly never suggested in any way that it should be. just that there ought to be something locking the upper and lower parts of the seat tube in alignment so that there is no danger of the lower part being subjected to rotational forces under pedaling. could be something as simple as a "male" protrusion on the upper piece that engaged with a female slot on the lower (or girl on top, as preferred), locking the pieces in alignment, without preventing it from folding.

and since it broke when i was riding it it's obvious that the seatpost was inserted, so your flimsiness point is irrelevant.

and since their ****ing bike just broke on me i fail to see anything for xootr's engineers to be amused at.

so what were the other things that you and they were chuckling about?

Bike frames of all types fail, that's just how it goes. That's why most bike manufacturers offer frame warranties with fairly long terms, e.g. Xootr's "lifetime frame warranty to the original owner." Aluminum frames in particular tend to fail quickly and with little warning.

Keeping in mind that I am not an expert frame-builder: I agree that it is unlikely the SS conversion caused this problem, nor is it likely that the hinging setup is to blame. There are enough Swift frames in use that if it was a structural issue, that frame design would have been updated or abandoned years ago.

If anything, given the spot of the break, my first guess is a bad weld. Next guess would be that you had a frame with the narrower tubes, an issue which has been subsequently fixed.

There have been several of these same failures. It seems to be a weak point in the design. I inspect mine from time to time at those spots.

it is not a weld issue. the welds didn't fail. the stays broke ahead of the weld. it is tube failure.

The fact that the bottom seat clamp did not hold tight was probably the primary cause for the failure. In the literature that comes with the bike, it is explicitly stressed that the seatpost is an integral part of the bike frame and should not be replaced with anything inferior; failure to have both seat clamps tight will absent the primary strength member from that part of the frame. So your statement that the seatpost holds the parts of the seat tube together "passively" is incorrect. It is part of the design that the seatpost and seat tubes become a unified strength member.

With the seatpost not tight at both clamps, the frame is highly stressed at those welds and the result is those tubes fail over time. You might imagine the situation without a seatpost at all: The seat stays will experience all the stress of the rider weight at the welds. And this will happen with or without torque around the seat tube.

Bummer. However, I still think you should pursue a replacement irrespective of the fixie conversion.

the lower quick release was tightened as fully as it could be, but it was not tight enough to prevent play. you would imagine that even after the break, you could clamp the qr tight enough so that the rear of the bike would ot fishtail while being walked home. that however was not the case, and even set as tight as possible the rear was still moving. this is simply a case of more force required than a quick release is capable of generating.

as i said, that could be remedied with a simple protrusion from the upper or lower assembly that mates with a recess in the other, locking them in alignment.

It's a shame. Interesting trying to understand why it failed though. I know how you feel as my rather cheaper Merc failed about an inch below where the seat post enters the main frame member. I hate that it is broken, but I have ridden it quite a lot.

Hope they fix you up with a replacement frame.

If the bottom seat clamp did not clamp hard enough to prevent play, that's a manufacturing defect and it likely led to the failure of the frame. The seatpost clamps *need* to be really tight; that's the main thing that holds the bike together.

My first Swift had a similar problem with its seat tube, although I raised it with Xootr before it had a chance to fail. I understand that they've had some tolerance and quality control problems with the Taiwanese firm that manufactures the frames. They very graciously replaced mine, no questions asked. I suspect they'll do the same for yours.

As you predicted I received a very graciousl email this morning promising a full replacement. Excellent policy, excellent company.

I also further examined the frame, and it is impossible to get the lower qr to fasten down tight enough to hold the seatpost correctly. i couldn't even bet it tight enough to prevent up and down play, let alone rotational.

As you predicted I received a very graciousl email this morning promising a full replacement. Excellent policy, excellent company.

I also further examined the frame, and it is impossible to get the lower qr to fasten down tight enough to hold the seatpost correctly. i couldn't even bet it tight enough to prevent up and down play, let alone rotational.

Well, then there is the problem.. my lower clamp will secure the seatpost from rotational movement by itself, as will the top one .. when you get your new bike, and if you haven't already done so, make sure and lube up the Q/R's so you don't get a false tightness reading... also, RickyBales on this forum races his Xootr and suggests upgrading the stock Q/R's to higher quality units.. might be worth a look..

As you predicted I received a very graciousl email this morning promising a full replacement. Excellent policy, excellent company.

I also further examined the frame, and it is impossible to get the lower qr to fasten down tight enough to hold the seatpost correctly. i couldn't even bet it tight enough to prevent up and down play, let alone rotational.
Great result! :) The lower seat clamp and/or the mismatched tube diameters is definitely the problem. The booklet states that the rider must make sure both clamps are individually tight enough to prevent any movement at all.

To improve clamp performance, clean the sliding surfaces of the QR lever, and put on a drop of Boeshield T-9 or other suitable lube - it makes a huge difference to the clamp performance.

I don' like the QRs on my Xootr Swifts so replaced them with normal metric bolts. I don't expect to fold the Swifts fast anyways: but I do fold them. I usually had tightness issues with the neck-fork connection.

Great bikes and company regardless of the QRs.

The QR on my Onza Mini bike are the best I have found so far. I have replaced my Dahon handlebar stem with them. Sorry no picture as camera broken. These might be worth trying. They are effective due to the fact they are 2"-3" long. I have emailed Onza today them to see if I can get some, or get a link where to get them. Else long lever mod?

1+ on lubing your quick releases. It open and closes smoothly after some lubrication. I have considered using regular bolts, but it is nice to have the fold ready in case of any emergency. By the way, I tried rolling the Xootr while folded last time and it worked great.

xootr emailed that they're shipping the replacement out today. excellent company, excellent service.

i may well replace the qr with bolts. i don't need to fold the bike and it'll be nice not to have to remove the seatpost when locked up.

it'll be nice not to have to remove the seatpost when locked up.

If you have any insert left that goes bellow the frame could you can drill a hole towarsd the bottom of it and put a tiny padlock through it, than leave it on the bike.

I couldn't deal with the stock QRs, lube or no lube-- it just took too much muscle to get them tight enough.

An alternative to metric bolts is to find some enclosed-cam QRs. Sheldon explains why they're better than the other kind here:

http://www.sheldonbrown.com/skewers.html

I found some Kalloy ones for cheap on JensonUSA.com. They're definitely better than the stock ones, although they're still kinda crappy. I wish I could find some as good as the ones that ship with Shimano hubs. Shimano doesn't seem to make them in a shorter length for seat clamps.

Hey, this is no joke. I'm concerned about this and my Swift. I weigh more than you, too. Something like this can happen at high speed or in traffic, whatever. Now i am reminded why I never wanted an aluminum bike before.

They just recalled 20,000 Treks, Cannondales and Norco (whatever that is) bikes. Report this to the US Consumer Products Safety Commission! Here is how to do it:

http://www.cpsc.gov/talk.html

Bicycle Recall Affects 20,000 Trek, Cannondale, and Norco Models

By David Goguen on May 20, 2009 12:12 PM | No TrackBacks

Over 20,000 bicycles and bike frames are being recalled because of different defects that can cause riders to lose control and crash, the U.S. Consumer Product Safety Commission (CPSC) and the bicycle companies announced this week...


http://blogs.findlaw.com/injured/2009/05/bicycle-recall-affects-20000-trek-cannondale-and-norco-models.html

three working days later.

http://img.photobucket.com/albums/v689/eddiebrannan/box.jpg

I've posted this on the Swift thread but as it has been mentioned here forgive the repeat. I wanted to "upgrade" the Q/Rs on my Swift and have just fitted some Salsa Q/R seat bolts. The threaded shafts appear to be thinner than the stock bolts. Has anyone tried them and had problems?

"three working days later."

Well, they're happy you're not suing them.

There seems to have been a number of very serious Swift bike frame breaks posted here, like this one, but if you guys don't report it who will know, and there won't be a possible recall until someone gets killed, huh?

There seems to have been a number of very serious Swift bike frame breaks posted here, like this one, but if you guys don't report it who will know, and there won't be a possible recall until someone gets killed, huh?
A handful of anecdotes on a web forum does not indicate a massive or systemic problem. (Heck, if that was a reliable indicator, every carbon fiber frame would've been pulled from the market years ago...) This is the first time I've heard of anyone having problems closing the QR's on a Swift. I have no doubt if there was a major issue, Swift would issue a recall.

And again, any frame can fail for a wide variety of reasons. That's just how it goes with bicycles.

"And again, any frame can fail for a wide variety of reasons. That's just how it goes with bicycles."

Not really. I've been riding bikes all my life, and raced them at one time, too, and I never had a frame failure, and I don't expect it to be "just how it goes with bicycles" when i'm barreling downhill and hit a bump or something. They wouldn't tolerate that sort of thing in cars - like the frame or some critical component breaking every now and then for no particular reason.

At least two critical Swift frame failures have been documented on these boards, right? What percentage of Swift owners in the world post here? How many critical frame failures occurred in those Treks, etc., that were recalled? How many are supposed to be acceptable?

Here is the form that you can fill out to report an unsafe product to the USCPS (probably the only government agency that serves a useful function). You do it right online. Doesn't even cost you a stamp. Maybe save some cyclist's life. Maybe even yours.

https://www.cpsc.gov/cgibin/incident.aspx