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Anyone know how to tell the difference between a high tensile and chromo fork

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Anyone know how to tell the difference between a high tensile and chromo fork

Old 06-01-18, 09:25 PM
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Anyone know how to tell the difference between a high tensile and chromo fork

So, I bought a bike with a replacement chrome fork, basically for the fork... but, I have no idea whether it's a high tensile material or the coveted... chromoly. How does one tell, if one buys it used? Thanks, in advance, for your comments...
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Old 06-01-18, 09:43 PM
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Weight might give a clue.
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Old 06-01-18, 10:02 PM
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How about a picture, or several showing details? A fork that is just chrome-plated might not be as nicely finished as a CroMo fork that has been plated. The better fork might have forged tips and a nicer crown and the steerer tube might have some stamping on it to indicate what you have.

Last edited by thumpism; 06-01-18 at 10:21 PM.
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Old 06-02-18, 12:35 AM
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Stamped fork crown and stamped drop outs = yuck!

Investment cast crown and forged drop outs = yum!
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Old 06-02-18, 05:22 AM
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Some high ten carbon steel forks also have a seam visible along the legnth of their fork legs. Peugeot Carbolite 103 bike forks had the said seam (a small, shallow groove) running along the back of their fork legs. Nothing wrong with them at all, as the seam was always done very well.and very cleanly.
Most CrMo forks had seamless fork leg tubes.
Fork crown construction (Cast or pressed steel) does not always tell you too exactly what the fork is all about. Some mid and higher model bikes could still have pressed steel fork crowns instead of cast. IIRC, Some Treks had pressed steel fork crowns and they weren't cheap bikes....
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Old 06-02-18, 07:18 AM
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Unless the fork is marked in some way, AFAIK there's no definitive non-destructive means of identifying the alloy. Spark testing can help, but you need to be able to grind some of the metal:


(A) High-carbon steel
(B) Manganese steel
(C) Tungsten steel
(D) Molybdenum steel

https://en.wikipedia.org/wiki/Spark_testing
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Old 06-02-18, 09:14 AM
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There's some nice Hi-Ten forks out there. I'm thinking specifically of Schwinns- the Passage / LeTour Luxe- the 84 and later World Tours and Travelers... well made bikes with Hi-Ten, maybe actually NOT for cost saving but for the properties of a Hi-Ten fork. Maybe...
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Old 06-02-18, 09:24 AM
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Originally Posted by The Golden Boy View Post
There's some nice Hi-Ten forks out there. I'm thinking specifically of Schwinns- the Passage / LeTour Luxe- the 84 and later World Tours and Travelers... well made bikes with Hi-Ten, maybe actually NOT for cost saving but for the properties of a Hi-Ten fork. Maybe...
i have an 81 miyata 912 with a high tensile fork. the bike rides like a dream and is actually pretty light.
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Old 06-02-18, 11:19 AM
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Originally Posted by Bad Lag View Post
Stamped fork crown and stamped drop outs = yuck!

Investment cast crown and forged drop outs = yum!
That is what I use. I go by the quality of the build. Nice forged dropouts are usually put on better quality forks.

Fake chrome crowns were put on the lowest quality forks.

I don't know if there is a general rule with fork rake, but again, the higher quality racing bikes got less fork rake, while the lower quality commuters got more fork rake.

It doesn't definitively give a material, but it does give some idea of the quality.
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Old 06-02-18, 11:22 AM
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Hopefully, I get to pulling it off this Sunday. It looks to be Hi-Ten, because it has stamped drop outs. Either way, I'm going to end up using it, and, Hi-Ten doesn't really bother me. Pictures, weights... all coming, assuming I can overcome the technical difficulties associated with both.
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Old 06-02-18, 12:27 PM
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Originally Posted by CliffordK View Post
That is what I use. I go by the quality of the build. Nice forged dropouts are usually put on better quality forks.

Fake chrome crowns were put on the lowest quality forks.

I don't know if there is a general rule with fork rake, but again, the higher quality racing bikes got less fork rake, while the lower quality commuters got more fork rake.

It doesn't definitively give a material, but it does give some idea of the quality.
Isn't fork rake a matter of geometry? A bike with "slack" head tube angle will likely have too much trail if fitted with a low offset fork, if I understand how this works. A racing bike with a steep head tube angle would have a fork with less offset in order to get sufficient trail for a stable riding machine. I understand that inexpensive bikes made for leisure cyclists probably have low head tube angle and, therefore, more fork offset, but there are plenty of "relaxed" geometry frames of good quality.
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Old 06-02-18, 12:43 PM
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Originally Posted by JohnDThompson View Post
Unless the fork is marked in some way, AFAIK there's no definitive non-destructive means of identifying the alloy. Spark testing can help, but you need to be able to grind some of the metal:

https://en.wikipedia.org/wiki/Spark_testing
That's pretty cool... I wonder if I would be able to definitively tell? Being new to the sparks and all? Almost wizard's work, reallly... ever try to determine something this way yourself John?
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Old 06-04-18, 07:02 PM
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I haven't gotten the fork off the frame yet, because I'm not ready for it yet, and this seems like the best way to keep all the parts in one spot...
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