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Discussion Starter · #1 ·
This has happened to me twice while climbing out of the saddle on rooty singletrack.
I went out of the saddle and pushed my weight forward over the handlebar. Suddenly the bike just disappeared behind me and I faceplanted hard. It happened so fast I still held the handlebars when I went down face first. Luckily there was not a rock there. The force into the ground was so hard I started nose bleeding.

The importer had changed some parts (seatpost, saddle, a bit shorter stem) from the stock setup.

Could there have been some other changes to the geometry (that I'm not aware of) that could make the bike riskier to ride? If so, what kind of geometry changes would increase the risk of going OTB while climbing out of the saddle.

Anybody else experienced this?
 

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You're climbing, out of the saddle with your weight forward....are you going OTB due to hitting a root or square edge bump? Were you going pretty fast at the time? I expect it's "operator error" and that whatever has changed, you'll adapt.

I'm on a newer geometry bike, steep STA, etc. and I have found that torquing up very steep climbs I no longer have to get as far forward. I noticed that, with my weight as far forward as I was used to, it unweighted the rear enough to cause a loss of traction. Reducing the forward weight bias a little has solved that problem.
 

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Discussion Starter · #3 ·
Msu Alum: Thanks, yeah I was going really slow, I don't recall hitting a root or a rock. It just happened so fast - the bike slipped back under me in a millisecond (or so it seemed). I may have put my weight too far forward over the bars to get traction but I thought it was impossible to go OTB when climbing.

Bike is a 29er from 2013. 110/100 mm travel. 69.5 HTA. 74 degrees seat tube angle.
 

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You're climbing and you leaned forward. Basic physics says that going OTB is what you should expect. You found the limit at which that happens.
Don't put so much weight over the front wheel in the future.

That's definitely happened to me more than once. Putting a big effort into a climb where precision is essential and hit something unexpected and BAM.

The solution is going to involve a lot of variables, but 99% of it is going to boil down to riding technique.

What specific model, year, and size is the bike? What non-stick parts are on it? How tall are you?
 

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Elitest thrill junkie
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Fork setup, also fore-aft stiffness. If the fork binds instead of absorbs bumps, it'll pitch you over easy. Sometimes a stiff low-speed compression setup will help to do this too, but blowing through the travel and significantly steepening the HTA can also contribute.
 

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Discussion Starter · #6 ·
Mack turtle: Thanks, yeah could be technique but I have not found many similar stories about riders going OTB uphill.

I'm 186 cm (6'1") and bike is a Ghost AMR Lector 2990 2013. Size 52.
I haven't been able to find reach and stack numbers.

Non-stick parts... I put GX Eagle on. And the shock is a Monarch XX but shouldn't matter in this case.
 

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Discussion Starter · #8 ·
Jayem - good point about the suspension. This is a short travel XC machine. Compressing most of the fork when leaning forward on the climb could steepen the HTA to a critical point where the front wheel just disappears under you.

Cheers!
 

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Don't go so far forward. Check suspension settings. Pretty much covers it.

Happened to me once on flat ground, but what put me so far forward in the first place was the fact that my chain broke while I was laying down power.
 

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I've done that too, twice i think. Once like harold with a chain break. You're pulling on the bars to lay down power... then you're feet can't support you and now you're pulling yourself over the front wheel. The fix isn't geometry or fork deflection or whatever... it's to have a calm upper body. Pull on the bars, but don't just strain at them like you're playing tug-o-war. Keep your weight centered.
 

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Interesting conversation.
I can't visualize this happening, however it seems to have been a relatively common occurrence.

How I visualize a slow spped, steep climb with obstacles (roots/rocks) while having a terribly weight front-bias, I would expect the rear tire to slip out due to lack of weight over the rear, resulting in a tip over. Last thing I can understand how there is enough forward momentum to toss the rider over the bars an an uphill and no forward speed.

I'm sure it looks impressive, so well done on helping riding buddies see a 'funny'.
 

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Discussion Starter · #14 ·
scottzg - I appreciate your thoughts and thanks for joining Uphill OTB'ers Anonymous. :)
Seems like a good idea to keep weight centered and also consider the terrain before sprinting (in case of chain break). Better to fall on gravel than rocks.
 

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Discussion Starter · #15 ·
Forest Rider: Yeah it's kind of funny. I was taken by surprise because it happened so fast. When my face hit the ground, I didn't even have time to let go of the handlebar. Full body weight on the face.

I started nose bleeding but luckily nose didn't break. Luckily there was soil there instead of a rock.

Remember to make your helmet cover your forehead folks!
 

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I’ve introduced 2 strong road/ tri riders to mountain biking. Both have crashed OTB uphill on technical sections their first time out. My guess is that they have so much power but haven’t learned technique yet. How to lift the front even while standing. I never had the problem my I came into mtb without enough power to make it up all the hills so it all progressed together. For what it’s worth both guys crush me on the road but I have to wait for them on the trail. No doubt they’ll be faster than me in a year or 2. Good luck I think it’s pretty common.


Sent from my iPad using Tapatalk
 

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Discussion Starter · #17 ·
Autosmith - thanks for entering 2 more riders to Team Uphill OTB'ers! I also do Road - FTP is just over 300 watts, so that could be part of the equation. I'll think more about lifting the front more - even when standing.

I appreciate your suggestion :)

Cheers!
 

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I haven't otb'ed climbing but I've come close on my 26 hardtail race bike (but not racing) with steep head tube angle when I've hit a root or rock when carrying some momentum.
 

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Interesting conversation.
I can't visualize this happening, however it seems to have been a relatively common occurrence.

How I visualize a slow spped, steep climb with obstacles (roots/rocks) while having a terribly weight front-bias, I would expect the rear tire to slip out due to lack of weight over the rear, resulting in a tip over. Last thing I can understand how there is enough forward momentum to toss the rider over the bars an an uphill and no forward speed.

I'm sure it looks impressive, so well done on helping riding buddies see a 'funny'.
There are I'm sure other factors involved. In my case, part of it was a sudden jerk to the front (after the chain snapped and some combination of my arms pulling my body forward, my body suddenly falling downward, etc). I'm sure part of it involved suspension compression, too, which will steepen the head tube angle and further promote you being thrown OTB. I had an OTB last fall where I was beginning a descent and not paying enough attention to myself (I was sweeper after a group of kids, and watching them instead). I hit a small bump in the trail, which combined to compress my fork a little and the deceleration pitched me forward (I was already a bit too far forward, admittedly). the combo threw me OTB.

Forest Rider: Yeah it's kind of funny. I was taken by surprise because it happened so fast. When my face hit the ground, I didn't even have time to let go of the handlebar. Full body weight on the face.

I started nose bleeding but luckily nose didn't break. Luckily there was soil there instead of a rock.

Remember to make your helmet cover your forehead folks!
Also be sure to maintain your stuff. I was working in a shop that hosted big road rides several years ago. One of my coworkers was ON the ride (while I covered the shop that evening). He was in a fast group that night, and one rider who was notoriously aggressive accelerated into a sprint on a straight, flat stretch of road. His chain snapped when he stood up and pitched him OTB at over 30mph. He face planted into the road and took out my coworker and a bunch of other riders. He smashed his face and was gurgling blood. There were doctors and nurses in the group who attended to him and called for an ambulance. He ended up dying in the hospital that night. This guy was also known for not maintaining his bike very well, and others believe that his chain broke this time as a result of that.

VERY luckily you didn't face plant on a rock. The consequences of something like that are definitely not funny. The only sort of helmet that'll do much for this is a full face, though.
 
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