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-   -   Bent fork, broken heart (http://www.bikeforums.net/folding-bikes/876170-bent-fork-broken-heart.html)

Brimstone 03-05-13 02:12 PM

Bent fork, broken heart
 
3 Attachment(s)
Hi everybody.

Yesterday I hit an SUV which pulled out in front of me from a business driveway near a busy intersection. I was hauling a small load of groceries...saw it coming, braked...but could not stop in time. I tried to to turn and take it sideways but ended up with my front wheel wedged between his tire and bumper. Might have been OK at that point but...he instinctively began to back up and mangled my front wheel before I could get him to stop.

So. Today I did damage assessment on my Dahon '08 Mu XL Sport. Front wheel, taco'd to un-salvageable. Front rack strut slightly bent. Generator hub hard to turn...probably toast.

Here's the bad part. Both front fork blades appear torqued symmetrically about an inch to the rider's left. Don't see any frame damage; headset looks OK and steering turns smoothly.

What to do? Can they be reliably straightened? Can they be replaced? I sent a message to my usual bike-drug pusher Thor.

http://bikeforums.net/attachment.php...hmentid=302669 http://bikeforums.net/attachment.php...hmentid=302671 http://bikeforums.net/attachment.php...hmentid=302672

Oh my. Oh my.

Call Me Al 03-05-13 02:26 PM

The poor thing. Me and my Mu are feeling your pain.

brakemeister 03-05-13 03:01 PM

I send u an email .... need to get a fork, which shouldntbe a problem, have the wheel in stock
darn.. is the driver paying for it ? after all he was moving :-)
Best Thor

Boudicca 03-05-13 03:20 PM

Lends new meaning to the term folding bikes. That wheel definitely looks folded.

badmother 03-05-13 06:11 PM

That sucks! Be happy it is not a broken neck :thumb:.

zebede 03-06-13 12:13 PM

Yes, some forks can be bent back to original place in all planes....Every safety conscious person, Bike mfg, Bike shop will tell you NO don't do it.. But if personal economics drive you, you can make your own judgement as to the soundness of your own repair.

I have fixed my own steel forks (Raleigh Twenty) with a little tweak (measure, measure, measure). It was my judgement that it took considerable force with levers to tweak back into place there fore I rode it with confidence.

HOWEVER....If I my bike cost what your bike did (nice bike) I would buy a new fork.

Brimstone 03-06-13 04:46 PM

Update
 
2 Attachment(s)
Thanks everyone for the support and advice.

I researched straightening forks last night, learned a few things. yes shops are reluctant to do it though some seem to specialize in that. More common in motorcycle shops, some of which have special tools for this job. This post from "miamijim' was particularly helpful:

"2. Legs. The legs can be bent to either the side or back or a combination of both. If your front wheel looks 'tilted' to either side when looking at it from the front chances are the legs are bent to the side. Simple fix...grab legs and pull. If your wheel looks 'twisted' or appears to out of alignment with the crown (crown and stem are aligned but wheel is off center) one of the legs is bent back. Easy fix....grab leg and pull."

http://www.bikeforums.net/showthread...ight=bent+fork

Most discussions were about steel frames. Apparently aluminum is easier to bend but easier to weaken after bending, especially if there is a visible or palpable 'crease' in the metal. I learned that a bike can be suspended upside down by strings attached to the wheels, and if it hangs with the wheels in line the frame and forks are likely straight. I learned that a dowel inserted straight into the hole in the bottom of the fork crown will run straight down between the fork arms and serve as a rough gauge of true-ness. Several recommend using a length of steel pipe as a lever.

So. Today I took another good look at the thing. No creases. I sat down and put the wounded beast in my best submission hold, gripped one fork arm and put some pressure on it in the direction of true. Nothing. I increased the pressure, felt nothing. I thought about how a couple of years ago the city repaved the now six-lane street where my accident occurred, how they put in NO bike lane and how there was NO convenient parallel low traffic route and that there are tons of bikes on the sidewalk along that street. How they approved a mini-strip mall at the busy, dangerous intersection on that street where my accident occurred, how I have no choice but to ride on the sidewalk against traffic there, how difficult it is for drivers to get into and out of that place.
I got really angry. I pulled really hard. I felt the thing move! Eventually I got things somewhat straight. Here is the result:

http://bikeforums.net/attachment.php...hmentid=302843 http://bikeforums.net/attachment.php...hmentid=302844

I think there may be a bit of lean to the rider's left remaining; however I took her for a test ride and, other than some looseness in the handlepost, everything seems OK. I did the recommended "hands off" test (OK not completely hands off as I have never been able to do that safely with small wheels) and did not detect any pull. Rode to the LBS where the mechanic who would not touch it was somewhat impressed. I'll probably still get a new fork from Thor just to keep him in business. I'll revisit by fork tweak after a few more days of riding and perhaps adjust. How's it look in the photos?

Here's my total loss so far: One wheel destroyed, rim gone, spokes and dyno hub maybe salvageable with a rebuild. Fork damaged. Front light/reflector gone. Plastic horizontal water bottle cage broken. Handlepost loosened.

The driver was apologetic and gave me a lift home (ain't folders great?). He left me with his card, and offered to pay for repairs. Technically the accident was his fault, he should have yielded to traffic on the sidewalk he was crossing. In Florida it is legal to bike in either direction on the sidewalk.

However I place the blame for this accident squarely on the traffic planners who were apparently oblivious to bike traffic when they expanded this street. I avoid riding on the sidewalk, especially against traffic. But there was no feasible safe way to avoid it on this trip. The driver was occupied with oncoming traffic and not looking to his right where I came from. I am normally very, very conscious of this driveway as I know drivers are distracted there. However on this occasion I suppose I was distracted by dodging the dude blocking the sidewalk by waving one of those huge signs advertising one of the businesses in the strip mall. As soon as I ducked past this guy, the SUV appeared in front of me and I could not brake in time.

I am undecided how much of the repair I will ask the driver to pay. He does not seem like a rich guy.

Thanks again to everyone for the help.

BassNotBass 03-06-13 07:22 PM

Quote:

Originally Posted by Brimstone (Post 15348279)

Every time I see this photo I envision the wheel with clock hands mounted at the hub and draped over the edge of a stone altar or withered tree branch la Dali.
If the forks were steel I would be somewhat cautious about cold setting them. However since they are aluminum I wouldn't trust them. Maybe I'm just 'Chicken Little' and over cautious but I've experienced the results of fatigued alu and don't trust a cold reset at all, even at the slow speeds that bicycles travel. My intention isn't to be the harbinger of some disastrous fate, because I really hope that the forks weren't tweaked enough to be weakened by a cold reset, but I hope this works out for you... although I personally wouldn't take the chance.

Joe Remi 03-06-13 07:27 PM

Hmm..that's an interesting result. I recently purchased an old Peugeot folder off the Ebay, and it arrived with the fork bent to the side. I didn't feel much like going to the hassle of arguing about it with the seller (a very nice person who I doubt had a clue about the problem), so figured I would get a frame guy to fix it. It hadn't occurred to me to try it myself. That old steel is thick, and the bike will never be used to bomb down a big hill, so I think I'll give it a shot.

jur 03-07-13 01:47 AM

I would also haul away to try and fix it. it is useful to measure things as good as you can. Bike frame alum is amazingly hard. Use a pipe over the fork tyne for more control. When all looks good, ping it and listen for off-sounding sounds.


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