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Old 08-05-14, 08:07 PM   #1
Caliper
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Schwinn Passage possible bent fork

So, last weekend I saw an ad for a project bike for sale. Frame looked about my size, and he only wanted $40 (of course, it's missing wheels, saddle and seatpost one of the brake levers, and the derailler hangar was bent but it's a project bike, right). Turns out it's a 1986 Schwinn Passage, so the Tenax tubing should be a nice improvement over the True Temper tubes on the Traveler I've ridden since before high school (moving from a 23" to 25" frame should be nice also!).

I really want to ride the bike, and have the missing parts to make it rideable but I'm noticing that the fork legs bend back slightly before curving forward. I made a jig to hold the fork and measure the offset and I'm getting about 32mm of offset which seems pretty low and calculates out to something like 77mm of trail at the ground. I'm pretty confident in the offset measurement, at least +/- a mm or two, but was expecting to see something more like 45-55mm? Does this sound like a bent fork? I don't see any cracked paint, and both legs are very even so I'm curious if maybe this is just how it was made? I can't find a fork offset number online for this model so wanted to check before trying to straighten things just in case they are straight already.
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Old 08-05-14, 08:48 PM   #2
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pictures ?
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Old 08-05-14, 09:07 PM   #3
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Straight edge, down through the stem bolt, through the middle of the fork crown, down the fork leg. If it deflects behind the straight edge, its probably bent. A yard stick or a long lever works well.
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Old 08-05-14, 09:16 PM   #4
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Pic of the fork.
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File Type: jpg IMG_20140805_230542_914.jpg (91.5 KB, 73 views)
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Old 08-05-14, 09:25 PM   #5
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Bent
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Old 08-05-14, 09:40 PM   #6
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How long is it ? I have a Tange Cro Mo fork off of a Nashiki Prestige if you need a fork?
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Old 08-05-14, 09:42 PM   #7
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Never mind. Too short for your 25 inch frame
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Old 08-05-14, 10:07 PM   #8
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Bent
I was afraid so. Anyone know the correct fork offset for the Passage to straighten it to?
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Old 08-05-14, 10:20 PM   #9
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That fork is seriousluy bent at the mid point indicating a near fatel crash. I would double check everything on the bike before I road it and would just pass as a whole. Sometimes bent is just bent.
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Old 08-06-14, 05:33 AM   #10
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How long is it ? I have a Tange Cro Mo fork off of a Nashiki Prestige if you need a fork?
In case someone else has one that would fit... The steer tube is 242mm (9.5") with the top 30mm threaded. Looks to be about 390mm axle-crown with the canti bosses 295mm from the axle. Oh, and something more than 32mm rake, haha.

Almost looks like the Nashbar CX fork would fit, but I'd like to keep it threaded, not threadless... Any ideas what sort of offset this bike should have on the fork? What did the Voyageurs use in the mid-80's? Tips on straightening this fork?
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Old 08-06-14, 07:06 AM   #11
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Got a frame that had a similarly bent fork a few years ago. After finding no damage to the top/down tubes, I straightened the fork with the bubba method of using two wood blocks, body weight, measurements along with thorough inspection. Still have and ocassionally ride the old '83 Trek. Have changed the rake on several others as well. Never had a failure of the forks. Have also straightened high end airgun barrels using this same method. Manufacturers and pro shops use specially designed presses but employ the same principles. Eventually bought a Park subframe and fork straightening tool that has advantages in some areas.
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Old 08-06-14, 01:07 PM   #12
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When it's the blades themselves that are bent, it's easier to straighten them. If the bend involves the crown/crown race area, it's really tough to get it bent back right so your headset will align correctly. I can't tell for sure where your fork is bent but I fear the latter case. I had a fork like that once and tried to straighten it by clamping the blades/crown in a wood vise and using a long piece of pipe to bend the steerer back. I could bend it, but never could get it right.

People have posted diy fork straightening jigs - maybe do a google search for that and see what you get.

Small alignment errors will translate to either burned up headsets or wanky steering, and without a pro jig or a really good diy one, it may simply be easier to find another fork.
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Old 08-06-14, 01:53 PM   #13
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When the frame has a bent fork but no wheels, it is fairly obvious why it doesn't have wheels now... trashed in the crash. And even if there is no obvious severe damage to the frame itself, why start with this frame to build from??? To fix and finish the build you will have spent a good bit on it. You could pick a different frame and fork in good condition and spend on it. In the end you would be well ahead. General recommendation; if the fork is bent then run, don't walk away from it!
/K
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Old 08-07-14, 07:00 AM   #14
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When the frame has a bent fork but no wheels, it is fairly obvious why it doesn't have wheels now... trashed in the crash. And even if there is no obvious severe damage to the frame itself, why start with this frame to build from??? To fix and finish the build you will have spent a good bit on it. You could pick a different frame and fork in good condition and spend on it. In the end you would be well ahead. General recommendation; if the fork is bent then run, don't walk away from it!
/K
Just curious, what sort of indications would one look for in frame damage here? There is no cracked paint or bending/warp[ing of the top/head/down tubes. Around here there is a serious lack of quality bikes available. CL is full of old Varsity's and Walmart bikes for crazy prices. Anything lugged has ebay pricing (may as well buy a new bike...)
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Old 08-07-14, 07:07 AM   #15
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[MENTION=374587]Caliper[/MENTION]-

Are you going to combine the Voyageur and Passage?

I think the Passage is a really awesome bike- and if there's no damage to the frame and the Voyageur fork works on it you're going to come out with a sweet bike. IMO, I'd choose the 86 Passage over the 83 Voyageur, and the Voyageur fork is an upgrade for the Passage.
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Old 08-07-14, 07:12 AM   #16
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Old 08-07-14, 08:29 AM   #17
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Pic of the fork.
To me it looks like the blades are slightly bent between the crown and the offset curve. If the blades don't show any wrinkling/buckling of the tubes and the crown brazing isn't cracked anywhere, I'd be very tempted to straighten them using member Ken Sibley's clever technique.

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Old 08-07-14, 11:19 AM   #18
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I was afraid so. Anyone know the correct fork offset for the Passage to straighten it to?
The fork offset on the 1986 Passage isn't specified in the specifications published in the '86 catalog. However, the head tube angle (HTA) is specified as 72.5 and the wheels are 27" (630mm BSD) and the tires are 27" x 1-1/4", so given a typical 27" fork crown to axle length, a 40mm fork offset would yield 65mm of trail and a 45mm offset would yield 59mm of trail.

My own personal sweet spot for trail is around 60mm, so I'd try to bend the blades to get somewhere in the 43mm - 45mm offset range.
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Old 08-07-14, 11:54 AM   #19
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To me it looks like the blades are slightly bent between the crown and the offset curve. If the blades don't show any wrinkling/buckling of the tubes and the crown brazing isn't cracked anywhere, I'd be very tempted to straighten them using member Ken Sibley's clever technique.

That looks like a great method - thanks for posting.
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Old 08-07-14, 12:03 PM   #20
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That looks like a great method - thanks for posting.
Thanks, but I'm just the messenger. KenNC (Ken Sibley) came up with the idea.
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Old 08-07-14, 12:30 PM   #21
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Just curious, what sort of indications would one look for in frame damage here? There is no cracked paint or bending/warp[ing of the top/head/down tubes. Around here there is a serious lack of quality bikes available. CL is full of old Varsity's and Walmart bikes for crazy prices. Anything lugged has ebay pricing (may as well buy a new bike...)
Caliper; There are lots of threads on the various Bike Forum sections dealing with how to tell if the frame is bent. Recommend search and see if any resonate with your thinking. I suspect that they cover all the possibilities including hidden damage that doesn't appear to the eye. Over some 40+ years of mucking with bikes and also building a fair number of frames, I have seen only a few frames fail after a bent fork was replaced, but the number is not zero. My normal recommendations for a completely safe post-frontal-crash scenario would be to do diagnostic things (after all I am an engineer) that exceed the replacement cost of the typical frame thus replacement is normally suggested. It comes down to your situation and comfort level.

On the topic of forks, I am usually willing to put on a used fork only if the bike is of significant C&V value. For most cases, I just look for a new one that looks about like the bent one, has the correct measurements and use it. The retail market is flooded with new replacement Chromoly forks in the $30 to $60 range (look on Amazon, Ebay, or Nashbar to scope the availability). Over the last 4-5 years I have bought 6 new forks and not a one was inadequate in any way.* Likewise over the same period I have bought 4 used forks to match up to "special bikes" and only 1 of them was found to be acceptable for use (bent, cracked, rusted out, not right metal, etc.). The numbers lean to the new ones but admittedly the sample size is too small for decent statistics.

Please post your progress and final outcome.

/K
*I did have an issue with two Nashbar chromoly touring forks, circa Feb 2013, which had the low rider rack braze-on's installed a 1/2 inch too low on the fork blades. But it was easier to just bend/mod the planned racks a bit to match the fork than wait for Nashbar's next years production run from Taiwan). Other than the off braze-ons, the forks were beautiful and very well made. These are the ones Nashbar sells to go with their $99 aluminum touring frame (which I also found to be excellent). If anyone has one of these forks and needs info on the rack mod, PM me to let me know and I can send pix, etc.
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Old 08-07-14, 02:37 PM   #22
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The 1986 specifications indicate the Passage fork has hi-ten blades whereas the Voyageur has chromoly blades. Both forks are Tange.

Hi-ten has a lower yield strength than chromoly, so depending on the blade wall thickness the hi-ten blades might be more likely to bend from a front end impact than chromoly blades. The bend in the OP's blades is pretty minor, and could be cold set back to the original offset with minimal risk assuming the blade tubing isn't rusted, dented or wrinkled and the crown brazing is solid. JMHO.

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Old 08-07-14, 02:54 PM   #23
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It'll buff out.
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Old 08-07-14, 03:50 PM   #24
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@Caliper-

Are you going to combine the Voyageur and Passage?
No, pretty sure I'll keep the Voyageur complete, plus the Passage uses canti brakes anyways so it doesn't make sense to break up a perfectly good Voyageur and modify the fork. In the short term, it'll probably get parts from my Traveler. I'm thinking I'll play around straightening the Passages original fork in small steps. I've got a chance to try out everything from long trail to short trail now If the fork looks sketchy during/after straightening, I'll can decide between a replacement steel fork (would require brazing canti bosses on) or a carbon CX fork (would mean going threadless). Probably go steel then I can get the second rack bosses as well and keep things as they should be...
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Old 08-07-14, 07:23 PM   #25
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