Bicycle Mechanics - Fork bent backwards=replacement advice (pictures included)

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jmonsw21
11-09-10, 08:49 PM
So I'm riding a 49 cm Windsor Timeline and managed to get hit by a car yesterday. This is my commuting bike and I've put almost 1k miles since August.

My fork got bent back and although it works fine, it gave me more aggresive handling which I'm not interested in for commuting. There was once no toe overlap and now there is= no track standing or making u-turns.

It has two decent cracks in the paint from the bending back so I know I'm going to need to replace it. I emailed bikesdirect to find out how much a replacement would run me but under the advice of someone on the forum, I'd like to know what else I should look into getting besides the stock fork from BD. I don't really want to spend too much considering I'll probably need to take it to a bike shop to get the top cut down to size.

The bikesdirect website doesn't give much specs, and I'm not sure if they were affected from the crash, so I don't know if I should just measure myself. The fork runs 700 x 32c wheels (I have a 700 x 23 for now because my other wheel is too out of true to be fixed) and has a 1 1/8" steerer. I'm looking to keep the fork steel considering its for commuting. Anybody want to send me some recommendations? I have the 49 cm frame.

This is what bikesdirect.com says about the fork:
Windsor Custom Drawn Triple Butted and Tapered 4130 Cromoly Aero Road
Drilled for road brake, 1.125 inch steerer

As for the geometry,
SEAT TUBE C-T 49cm
SEAT TUBE C-C 46cm
TOP TUBE 514mm
WHEEL BASE 998mm
STAND OVER 29.7"
CHAIN STAY 405mm
H/T ANGLE 72
S/T ANGLE 75

Here is the stock picture of the bike and a picture of it now.
http://i56.tinypic.com/eq2k4m.jpg
http://i52.tinypic.com/w0589e.jpg


operator
11-09-10, 09:21 PM
You need to buy any 1 1/8" threadless fork. It probably won't be the same colour. It'll probably run around $30-$100 for steel. And around $100+ for carbon legs/AL steerer. Fork install, with cutting should run you about $30 or less at your LBS.

svdodge
11-09-10, 09:51 PM
I'd be very careful about riding on that fork, you never know when it might fail.

On the plus side, when you get a new fork you could make (or have someone else make) some bicycle fork bottle openers (http://www.flickr.com/photos/svdodge/sets/72157624357197644/) like I have made. It's a cool way to keep what would be trash and make it useful.


Thumpic
11-09-10, 09:58 PM
you need to check your front wheel very closely also.....cracks; bent spokes; etc.......catastrophic failure = catastrophic injuries....

jmonsw21
11-09-10, 10:07 PM
you need to check your front wheel very closely also.....cracks; bent spokes; etc.......catastrophic failure = catastrophic injuries....

I'm not currently riding that front wheel, I put in my front wheel from my old Raleigh road bike.



Operator, thanks for the info on the prices.


Can anybody give me specifics on what kind of sizing I would need on the fork to get a similar rake to what the stock fork has and can fit 700 x 32?

DannoXYZ
11-09-10, 10:34 PM
What is the reach on your brakes? The fork is slightly longer than a lot of 700c road-forks in order to clear the tyre. The pads are at the very bottom of the slots. Or even easier, what's the distance from the brake-mounting hole to the dropouts?

http://www.sheldonbrown.com/rinard/images/forkdim.gif

Read up on how fork-length changes handling: http://www.sheldonbrown.com/rinard/forklengths.htm

Also how rake & trail are related and how they affect handling:
http://davesbikeblog.blogspot.com/2007/05/trail-fork-rake-and-little-bit-of.html
http://www.dclxvi.org/chunk/tech/trail/


BTW - bicycle and motorcycle terms are often confused, however, they are not interchangable. Bicycle head-angle is motorcycle rake. Bicycle rake is motorcycle offset. Trail is the same for both.

San Rensho
11-10-10, 08:34 AM
Check the frame. A hit that hard probably bent it. Check especially for kinks, bends in the downtube and top tube near the head tube. If its kinked, its toast.

fietsbob
11-10-10, 11:08 AM
Turn it around backwards and crash into the same thing at the same speed.:P

Doohickie
11-10-10, 11:40 AM
I'd be very careful about riding on that fork, you never know when it might fail.

Bah. Here's what you do: Take the wheels off the bike, put the fork between the rungs of a ladder, and pull on the back of the bike to straighten your fork. If you apply the force at the rear of the bike frame, your force is magnified (less force required by you, therefore it is very controlled). I did this on a '84 Nishiki and got the fork pretty much back to perfect geometry, and it was worse than yours (I couldn't steer past the downtube). I rode it like that for 6 months until I got a new bike. If that's a steel fork, it won't fail. You still need to replace it, but it should be fine to ride temporarily.

EDIT: What I'm suggesting is essentially the same as what fietsbob said, only with more control over the forces applied.

Doohickie
11-10-10, 11:47 AM
Check the frame. A hit that hard probably bent it. Check especially for kinks, bends in the downtube and top tube near the head tube. If its kinked, its toast.

Yeah... here's what the Nishiki looked like after I crashed it:

Frame damage:
http://i42.photobucket.com/albums/e341/Doohickie/Bicycle08/th_Picture215.jpg (http://s42.photobucket.com/albums/e341/Doohickie/Bicycle08/Picture215.jpg) http://i42.photobucket.com/albums/e341/Doohickie/Bicycle08/th_Picture219.jpg (http://s42.photobucket.com/albums/e341/Doohickie/Bicycle08/Picture219.jpg) http://i42.photobucket.com/albums/e341/Doohickie/Bicycle08/th_Picture221.jpg (http://s42.photobucket.com/albums/e341/Doohickie/Bicycle08/Picture221.jpg)

Fork after accident (front tire can't steer past downtube):
http://i42.photobucket.com/albums/e341/Doohickie/Bicycle08/th_Picture011-2.jpg (http://s42.photobucket.com/albums/e341/Doohickie/Bicycle08/Picture011-2.jpg)

After straightening fork:
http://i42.photobucket.com/albums/e341/Doohickie/Bicycle08/th_Picture209.jpg (http://s42.photobucket.com/albums/e341/Doohickie/Bicycle08/Picture209.jpg)

Doohickie
11-10-10, 11:49 AM
One last thing about the fork: Check with your LBS before ordering online. Ask them how much to cut the tube, then ask them how much it would cost to buy the fork there; maybe they will cut the tube for free, plus you won't pay shipping for buying it online. If it's cheaper or about the same, you might be better off just getting a fork from the LBS.

JohnDThompson
11-10-10, 12:12 PM
I'd be very careful about riding on that fork, you never know when it might fail.

On the plus side, when you get a new fork you could make (or have someone else make) some bicycle fork bottle openers (http://www.flickr.com/photos/svdodge/sets/72157624357197644/) like I have made. It's a cool way to keep what would be trash and make it useful.
You could also make it into a wheel truing stand.

jmonsw21
11-11-10, 12:03 AM
Thanks for all of the suggestions, I actually know someone who's on a local forum and has a fork straightening tool. Anybody know about that? He wants $40 for fixing it without a gaurantee of 100%, what do you guys think? Haha, he's on this forum too so he might find me asking about his price. Would I be better off trying the ladder thing myself? If so I'd need a little more specifics. When you say fork between the rungs of a ladder you mean:

http://i51.tinypic.com/fc75sz.jpg

?

Deanster04
11-11-10, 04:45 AM
Take it to an old school LBS or bike builder in the area. There is a special tool that was made for adjusting a fork back to the original shape and measuring the results to get it close to perfect. Also, an experienced person can "feel" the metal as they bend back the fork and can tell you if you need a new fork. Over the years I have had to bend forks back into alignment and used the tool that a friend has. I have tried the homemade solution and the fork is never quite right. EBay can be a good place for used steel forks.

jmonsw21
11-11-10, 08:31 AM
Take it to an old school LBS or bike builder in the area. There is a special tool that was made for adjusting a fork back to the original shape and measuring the results to get it close to perfect. Also, an experienced person can "feel" the metal as they bend back the fork and can tell you if you need a new fork. Over the years I have had to bend forks back into alignment and used the tool that a friend has. I have tried the homemade solution and the fork is never quite right. EBay can be a good place for used steel forks.

I actually know someone who's on a local forum and has a fork straightening tool. He wants $40 for fixing it without a gaurantee of 100%, what do you think?

Doohickie
11-11-10, 08:42 AM
Thanks for all of the suggestions, I actually know someone who's on a local forum and has a fork straightening tool. Anybody know about that? He wants $40 for fixing it without a gaurantee of 100%, what do you guys think? Haha, he's on this forum too so he might find me asking about his price. Would I be better off trying the ladder thing myself? If so I'd need a little more specifics. When you say fork between the rungs of a ladder you mean:

http://i51.tinypic.com/fc75sz.jpg

?

Not quite. One rung goes just in front of the fork crown (or near the fork crown); the next rung goes behid the back of the fork toward the dropouts, then just lift up on the back of the frame. You're not putting a linear load (straight pull like in the diagram), you're putting a rotational loade on the fork. The point of leaving it attached to the frame is to give a huge moment arm to magnify the rotational force. You can either do it as pictured or flip the bike upside down. You might need another person to hold the ladder steady so it doesn't tip.

http://www.bikeforums.net/attachment.php?attachmentid=177755&d=1289491234

177755

Shimagnolo
11-11-10, 11:03 AM
Fork after accident (front tire can't steer past downtube):
http://s42.photobucket.com/albums/e341/Doohickie/Bicycle08/Picture011-2.jpg

OK, I know they say toe overlap isn't a big deal, but that is just too much.:roflmao2:

fietsbob
11-11-10, 11:18 AM
seen a few mechanics slam the bike down, by the wheel, back to front.
to give it the Newtonian equal and opposite force treatment..

on mostly Kids bikes when parent was not wanting to just buy the child a new bike..

Mild steel has some Ductility , fortunately, to last long enough, the short period of time before they outgrow it ,
or rationalize and budget a replacement.

Chombi
11-11-10, 12:55 PM
If that's a steel fork with a "unicrown" (crownless design), it should be a good candidate for repairing by cold setting, as long as the welding at the stemm look undamaged by the accident.. If it's aluminum, forget it, just buy a new replacement fork as it will be too dangerous to try and bend it back because cracks can develop when you bend it back or it might be there already from the accident. That's just how Aluminum behaves when you bend them too much.
Ideally, you should have a knowledgable mechanic or frame builder do the cold setting, but if that's just not available to you, you can try and do it yourself...at your own risk, of course......

chombi

Thumpic
11-11-10, 03:33 PM
seen a few mechanics slam the bike down, by the wheel, back to front.
to give it the Newtonian equal and opposite force treatment..........................................

you've never seen a "mechanic" do that :eek:; maybe a total rank newby. Or maybe they just didn't think it through. I'm a home trained shade tree, and even I know what a ridiculous and dangerous repair attempt that would be. I hope it wasn't your kid's bike. :)

op......Why don't you just contact the mfg for a replacement or their suggestions for a replacement?

cny-bikeman
11-11-10, 03:51 PM
A couple questions unrelated to the tech issues - How did the accident happen, was a police report or insurance report made, and who is paying for replacement?

maddmaxx
11-12-10, 05:35 AM
One more thing to check that I haven't seen mentioned. Did the force that bent the fork "ovalize" the head tube and does the headset still work properly?

Doohickie
11-12-10, 08:50 AM
A good thing to check, but the head races can take a lot of force without bending.

echo
11-12-10, 09:07 AM
Turn it around backwards and crash into the same thing at the same speed.:P

Now that's funny! :P

jmonsw21
11-13-10, 05:21 PM
I did email Bikesdirect and they said:
I'm sorry to hear about you and your bike getting hit. I hope you're ok.
Unfortunately, we don't have any forks here that will work as a replacement for yours. All of our road forks are designed for skinnier tires and shorter reach brakes. I don't have the rake specs but you want a fork that will accept up to a 700 x 40 tire and a long reach brake(55-73mm reach) like your tektro 556 brakes. I would see if Surly makes a fork that will match these dimensions.
Good Luck,
Matt at bikes direct
So does anybody want to take that into consideration in helping me find a fork, although I am thoroughly considering taking it to this guy with the fork straightening tool. A new fork will probably cost me $100 and thats more than double the $40 even if I'm getting something new and more reliable. Also here's a video of the wheel


UPDATE: Bikesdirect told me they have forks from Kilo TT WT in black and the guy will sell me one for $50. I don't mind it being black, as long its a suitable replacement.

Can anybody who knows how to crunch these numbers tell me if I'll be toe overlap free? I hate having to time my turns when I'm turning into my house or wherever I am going.
Fork Length:
Inches / mm
14.8 / 375.0Fork Rake:
Inches / mm
1.5 / 38.0

Bezalel
11-13-10, 06:42 PM
you haven't provided enough numbers to determine if there will be overlap. I would need the following numbers:
Wheelbase
Chainstay Length
BB Drop
HT Angle
Fork Length (old and new)
Fork Rake (old and new)

I don't see any reason to deal with BD unless they are willing to sell you the same fork (or at least guaranty that the Kilo uses the same fork geometry).

LarDasse74
11-13-10, 06:47 PM
UPDATE: Bikesdirect told me they have forks from Kilo TT WT in black and the guy will sell me one for $50. I don't mind it being black, as long its a suitable replacement.

KiloTT has a 1" steerer tube, you need 1-1/8. Also, road or TT frames that can accomodate tires bigger than 28mm are rare. I would be terribly surprised if the kiloTT has the necessary clearance to fit your 32mm tire. And a fork that fits fatter tires is generally longer, so the KiloTT fork is probably shorter than your stock fork and will change the geometry of the bike. If it were to fit. Which it won't.

jmonsw21
11-13-10, 08:10 PM
KiloTT has a 1" steerer tube, you need 1-1/8. Also, road or TT frames that can accomodate tires bigger than 28mm are rare. I would be terribly surprised if the kiloTT has the necessary clearance to fit your 32mm tire. And a fork that fits fatter tires is generally longer, so the KiloTT fork is probably shorter than your stock fork and will change the geometry of the bike. If it were to fit. Which it won't.

No, we're not talking a Kilo TT, we're talking a Kilo TT WT which is meant to fit wide tires. The WT also takes a 1 1/8" steerer tube. Here's the geometry of the bike which I had posted before but forgot to repost with the question.

SEAT TUBE C-T 49cm
SEAT TUBE C-C 46cm
TOP TUBE 514mm
WHEEL BASE 998mm
STAND OVER 29.7"
CHAIN STAY 405mm
H/T ANGLE 72
S/T ANGLE 75

I don't know the fork dimensions unfortunately because I think the bend probably altered them and bikesdirect doesn't have any for my bike (they do for the TT WT).

M_S
11-13-10, 08:16 PM
This fork should also work well:

http://www.google.com/#q=salsa+casseroll+fork&hl=en&sa=X&pwst=1&prmd=ivs&source=univ&tbs=shop:1&tbo=u&ei=LlTfTNS4PIyisAOc47SGCw&oi=product_result_group&ct=title&resnum=1&ved=0CB4QrQQwAA&biw=1366&bih=667&fp=8d8dc79919fbb9a2

Don't bend it back. That fork is effed. Yeesh. Not worth the 50-100 bucks saved.

Doohickie
11-13-10, 08:50 PM
When I talked about bending the fork back, I was recommending a temporary fix pending the OP getting a new fork.

M_S
11-13-10, 10:25 PM
I recommend not riding it at all, temporary solutions can promote procrastination of replacement until the fork snaps at the crown.

jmonsw21
02-18-11, 02:03 AM
Just to add some closure, I finally did get that fork from Bikesdirect. Was a perfect fit, installed for only $30 at my local shop and they switched to a different brake lever for me too. There's no toe overlap so I'd say its practically identical geometry. Only difference is the fork is black. Here's a pic.

http://i51.tinypic.com/ndlqud.jpg