180 fork on a 160 frame??

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180 fork on a 160 frame??
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Posted: Dec 10, 2017 at 21:37 Quote
I have a Commencal Meta HT Am Crmo, that is my do-it-all hardtail.
It has a 160mm pike that brings the headangle to 65° which is already pretty steep.
I want to upgrade to a 180mm fork because I ride some really chunky trails, and I huck some pretty damn big things...
If I put a 180mm fork on the bike, would it snap in half like everyone seems to think??

Posted: Dec 11, 2017 at 2:27 Quote
According to Commencal, the frame should be able to handle up to 170mm on the 2018 frame. 160-170mm is the recommended travel from what I found, though if you need 180mm, contact Commencal for the most accurate info. Also, keep in mind that putting a larger fork will raise the front of the bike.

Posted: Dec 11, 2017 at 7:15 Quote
If Commencal recommends 160-170mm travel fork for your frame, I would be very surprised if the extra 10mm of putting on a 180mm fork would cause it to break.

But over time the extra leverage of the longer fork combined with you possibly being a very aggressive rider doing a lot of big drops could cause the frame to crack and if Commercial were to find out that you were running a longer travel fork than recommended they might not give you any warranty.

Posted: Dec 11, 2017 at 7:53 Quote
Strictly speaking, you're adding ~7mm of effective ride height (180mm @30% sag = 126mm, 170mm @30% sag = 119
mm). That's about a 5.9% increase. As I understand mechanical leverage, your force calculation essentially linear (dependent on the length of your lever and the force applied at the end). So, increasing the length of your lever by 5.9% yeilds the same amount of force as increasing the force applied to that lever by the same percentage. Think of it this way: If you're a 175lb rider, would you be worried about your frame's integrity if you all of a sudden weighed 185 lbs? That's essentially the force difference if you add a longer fork.

But also I'm not an engineer so this could potentially be completely wrong.

I've over-forked 3 bikes (carbon and alu) and ridden them mercilessly with no problems. I'd go for it without hesitation. You will however, be screwing with the geo so make sure that the longer/slacker/higher thing is what you want or you're gonna be disappointed.

Posted: Dec 11, 2017 at 12:45 Quote
What he said above.
I'm no Einstein, but I am an Engineer, and I've done the angle calcs on frames to satisfy my own curiosity.The loading change due to the increase in fork height and angle is f*ck all.
If your fork is set up badly and you are bottoming out, then the shock load will eventually fatigue the head tube join and break the frame on any bike. Bridging a peaked landing would also not be good...

The fork length limit is more about geometry and handling (within reason) rather than frame integrity. Of coarse, no bike company will openly say that because they want you to spend money buying the 'right' bike.
+20mm will be no issue at all as long as you are happy with the way it rides.

Posted: Dec 12, 2017 at 11:10 Quote
I had a 180mm on my Mondraker Dune. Also normal 160mm. No problem. Also from the company it was no problem.
Only thing you have is that when you drive slow, yo can get the feeling like it's falling to the site when you make a turn. Don't know how to discribe it. But cycling slow, it give the feeling of a dead point you have to past and then like it was droppin in.

On high speed AWESOME!!!!

Posted: May 18, 2019 at 14:04 Quote
Hey dude did you go 180mm on the commy I'm looking at doing just that now torn between 170 or 180, currently running a yari at 160mm on my 2016 meta am ht 27.5, wondering how it went did it make it impossible to pedal uphill, I've rocked 200mm on a old Scott ht before and totems 888 on 150mm rear bikes and had no problems pedalling them uphil, just lots people say 180 is too much for a meta, tempted to just do it any advice would be appreciated tia



ridgerider199 wrote:
I have a Commencal Meta HT Am Crmo, that is my do-it-all hardtail.
It has a 160mm pike that brings the headangle to 65° which is already pretty steep.
I want to upgrade to a 180mm fork because I ride some really chunky trails, and I huck some pretty damn big things...
If I put a 180mm fork on the bike, would it snap in half like everyone seems to think??

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