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-   -   Question about slight damage to carbon fork in '97 LeMond Zurich (https://www.bikeforums.net/bicycle-mechanics/1200354-question-about-slight-damage-carbon-fork-97-lemond-zurich.html)

TimbyMaTombo 05-04-20 11:21 PM

Question about slight damage to carbon fork on '97 LeMond Zurich *now with pictures*
 
Just picked up a '97 LeMond Zurich with full Shimano 105 a couple days ago that needs a good cleaning and tune up. Overall the frame is in pretty good condition with some nicks and small spots of rust. I'm planning on tearing the bike down to the frame to clean up all the parts but an concerned about the front fork. It's got a pretty good sized nick in the... shoulder (?) of the carbon fork. It's hard to tell if the carbon itself is damaged or just the paint but I am probably going to start looking for a replacement fork regardless just in case.

Looking online, I would have no qualms switching to an alloy fork but I'm not sure how to make sure it is compatible. As far as I know it is a 1" threadless fork with a 47mm rake. I'm trying to attach some pictures of the fork but I assume I will need it professionally inspected to know for certain if it's safe.

How would I go about finding a compatible fork? Could I expect to find an alloy one or would finding another stock for be the only viable option
Thanks

tFUnK 05-04-20 11:27 PM

Curious to see pics of the damage. Most likely it's still safe to ride. But as for a replacement fork, you already mentioned the important part: 1" threadless steerer (make sure it's as long or longer than the original fork steerer) with 47mm rake (give or take a few mm; 1" threadless forks are hard enough to find without this rake constraint). Also make sure it is drilled to take caliper brakes.

cpach 05-05-20 02:02 AM

I wouldn't stress over the rake too much, as 47mm is slightly uncommon, 45 is reasonably common, and 43 is the most common. You probably can't tell much between 2-3mm at all, less rake will be more stable at speed and less responsive. There are a couple of carbon options still kicking around new, and certainly NOS or used, or your bike would look plenty classy with a matching steel (not alloy, which in bikelandia means aluminum, which is a pretty awful fork material) fork as well.

If you want to go all in: https://www.woundupcomposites.com/product/road-x-1/, for sure.

I'd probably do https://us.ritcheylogic.com/us_en/bi...rbon-road-fork and not worry so much about rake.

TimbyMaTombo 05-05-20 07:19 AM

I'll need to go add some comments elsewhere to get my post count up to 10 so I can link images but when I do, I'll post the pictures of the damage. I picked the bike up for pretty cheap so I'm not wanting spend more than I paid overall on a new fork.

You're correct that I meant steel rather than alloy. There is a steel 1" threaded LeMond fork on eBay right now for pretty cheap that I'd be tempted to swap over; assuming I can get a threaded headset and quill for less overall than a new carbon fork. I just don't like the idea of my fork catastrophically failing while I'm riding.

Will return with pictures when I can. If I were to take the fork to get professionally inspected, is that something I would take to an LBS?

Crankycrank 05-05-20 08:58 AM


Originally Posted by TimbyMaTombo (Post 21456377)
Will return with pictures when I can. If I were to take the fork to get professionally inspected, is that something I would take to an LBS?

My experience with LBS Carbon diagnosis expertise is that it varies wildly. Take it to at least 3 or more shops. Understandably most shops are going to be very conservative to avoid any lawsuits by someone who experienced a broken fork after having been given the OK.

TimbyMaTombo 05-05-20 09:13 AM


Originally Posted by Crankycrank (Post 21456600)
My experience with LBS Carbon diagnosis expertise is that it varies wildly. Take it to at least 3 or more shops. Understandably most shops are going to be very conservative to avoid any lawsuits by someone who experienced a broken fork after having been given the OK.

I had a feeling that it would be a questionable what with liability and the opportunity to upsell.

2old 05-05-20 09:22 AM

If the individual is smart, he won't give an opinion unless it's very obvious one way or the other; if he's not, you wouldn't want to ask. I had a "scratch" in a carbon bar and my very intelligent (IMO) LBS owner, a friend, said it didn't appear to penetrate the clear coat so was OK. Seven years of hard off road abuse later I replaced the fork for one with more rise.

TimbyMaTombo 05-05-20 11:38 PM


Originally Posted by tFUnK (Post 21456061)
Curious to see pics of the damage. Most likely it's still safe to ride. But as for a replacement fork, you already mentioned the important part: 1" threadless steerer (make sure it's as long or longer than the original fork steerer) with 47mm rake (give or take a few mm; 1" threadless forks are hard enough to find without this rake constraint). Also make sure it is drilled to take caliper brakes.

Here are the pictures of the damage.
https://cimg7.ibsrv.net/gimg/bikefor...6489a75aa6.jpg
https://cimg4.ibsrv.net/gimg/bikefor...70fec5fd8c.jpg
https://cimg8.ibsrv.net/gimg/bikefor...68dc6be195.jpg
https://cimg2.ibsrv.net/gimg/bikefor...1677ebbbdf.jpg
https://cimg6.ibsrv.net/gimg/bikefor...d6fe992d1d.jpg

tFUnK 05-06-20 12:11 AM

Thanks for indulging. If it were me I'd ride that original fork without concern but I lean towards being risk tolerant.

Nice bike!

TimbyMaTombo 05-06-20 12:47 AM

Thanks for the input, I'll be wrenching on it for a little while so I've got time to decide. It needs a bit of love but it definitely seems worth the effort.

easyupbug 05-07-20 07:09 AM

If you were my brother-in-law puttering around the neighborhood I would say ride on, if you were my nephews who think they will live forever and find ways to damage rims & tires and break things, no way. You are probably between those groups somewhere so I would be looking very closely and trying to get opinions to see if the damage is beyond the clear coat. That said the question of how it happened may be material in that the pics look like a scratches, however, if it was actually impacts the underlying fibers and matrix could be damaged.

TimbyMaTombo 05-07-20 09:28 AM


Originally Posted by easyupbug (Post 21460620)
That said the question of how it happened may be material in that the pics look like a scratches, however, if it was actually impacts the underlying fibers and matrix could be damaged.

Unfortunately I don't know the circumstances of the damage, the lad I bought the bike from had it given to him by a relative that was going to throw it out.


If you were my brother-in-law puttering around the neighborhood I would say ride on, if you were my nephews who think they will live forever and find ways to damage rims & tires and break things, no way. You are probably between those groups somewhere so I would be looking very closely and trying to get opinions to see if the damage is beyond the clear coat.
I generally stick to MUPs for cycling and they are fairly well maintained here so I would like to think I'm gentle on my equipment. When I do get it rideable I could leave it to trainer duty until I can get a replacement fork; as much as I'd rather not buy a new fork, my desire to not eat asphalt is stronger.

Final question: there's a steel LeMond fork on eBay right now for a good price but it is threaded so I would need a new headset and stem. I like the idea of getting a somewhat matching fork but am concerned the steerer isn't long enough. I've measured my headtube and it is ~4 9/16" and the steerer is ~5 1/4". It seems like a Tange Passage headset has the shortest stack height at 30mm and by my rough calculation that would leave it about 10mm short. I've heard you can have the headtube faced but I'm not sure 10mm would be possible. I've attached a photo of the head tube for reference; there is room to remove material but not sure it's enough.

https://cimg0.ibsrv.net/gimg/bikefor...0430876eec.jpg

wsteve464 05-07-20 03:40 PM

I don't know the specific of Lemond bikes but before buying a new fork check the diameter of the current fork. Most threadless forks are 1 1/8 at the stem.

I'd sand it smooth paint it and forget about it.

squirtdad 05-07-20 05:43 PM

I am super conservative about these things..... it sure looks to me like the damage is through paint,primer and gel coat and into the carbon fiber (fibre for op) layer. the first pic shows what looks like a small crack. Personally i would not ride it, but again i am conservative

Mad Honk 05-07-20 06:04 PM

As carbon fibre goes this one is damaged. It will fail at that point, but it is just a matter of when. Without X-Ray testing to see how deep the cut is, it is questionable.
The depth of the carbon fibre is another issue. If it is very thick it may be just a surface cut. But a cut that thick in some thin tubes it is a definite failure about to happen. If it occurred in my shop it would come out of service. I don't want to test my liability insurance which is already high enough. JMHO, MH

blamester 05-07-20 07:08 PM

Grab the fork legs without the wheel and pull and twist them. Do you see any movement there. Do both legs move the same.
If it is compromised you will know straight away and the decision is made.
If it appears to be ok but your still not sure just replace the fork. And ride with confidence.
Going down a hill wondering if I have to brake hard will the fork also break won't be much fun.
You can't ride a bike if you think it is dangerous.

TimbyMaTombo 05-07-20 07:48 PM


Originally Posted by blamester (Post 21461967)
Grab the fork legs without the wheel and pull and twist them. Do you see any movement there. Do both legs move the same.
If it is compromised you will know straight away and the decision is made.
If it appears to be ok but your still not sure just replace the fork. And ride with confidence.
Going down a hill wondering if I have to brake hard will the fork also break won't be much fun.
You can't ride a bike if you think it is dangerous.


I'll try that out when I disassemble it for maintenance, thanks; would rather it break in testing at home than while riding. I was also going to tap around the fork to see if it sounded different in that area. I'll be on the lookout for a new fork in the meantime just so i can have confidence in it.

veganbikes 05-07-20 09:04 PM

I wouldn't bother riding it, too much of a risk.

I would replace with probably a Ritchey Fork because they do carbon 1" treadless that will work just fine here. I would not switch to threaded the only time I would stick with threaded is if the bike came with the fork and the fork wasn't damaged.

I wouldn't worry too much about putting money into the bike, it is a decent bike and worth a little love. Shimano 600 Tricolor is in my top three favorite groupsets and I just built a bike around it (though I did switch to a different front derailleur and crank but I could do a full 600 gruppo if I wanted as I have the parts but the Ultegra hollowtech II crank was a better option in my spare parts bin and since the frame wasn't braze on the Dura Ace front derailleur which is clamped was again better option.

If you like the bike make it work well for you, if it just another one in the pile or a transitional bike than get it functional and move on.


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