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When climbing longer 40-50% gradient sections my front wheel starts lifting even at cadences around 70. Leaning forward doesn't help much, I am already balancing myself on the rear wheel. Today the bike suddenly got out of control, I flipped and fell on my bum.

Longer stem? Saddle forward? Can you shorten the front suspension? What can I do to shift weight forward?

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    40%-50% gradients! Most people can't walk up 50%.
    – mattnz
    Commented Nov 3, 2016 at 19:20
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    People with crutches maybe. 40% gradient @ 5kmh requires roughly 7 W/kg. Cadence of 60 for the typical mtb gearing. Definitely sustainable for a few minutes if you're in shape.
    – AzulShiva
    Commented Nov 3, 2016 at 19:36
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    The 40% is an entire crock.... Using the Strava link provided by @Craggie, Patrick accelerated from around 14km/h to over 19km/h on the steep section. Using the teh quoted 7W/kg for 5km/h climb, at 20km/h, and 80kg rider on a 10kg bike needs 2500W to maintain his speed, let alone accelerate. bicycles.stackexchange.com/questions/21294/… gives some use figures to compare these against.
    – mattnz
    Commented Nov 4, 2016 at 0:56
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    @mattnz A 50% gradient is only a 27-degree slope. I'm pretty sure most people can walk up that.
    – David Richerby
    Commented Nov 4, 2016 at 11:03
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    @DavidRicherby I was going to argue, but you're totally right. upload.wikimedia.org/wikipedia/commons/thumb/e/eb/… shows it visually.
    – Criggie ♦
    Commented Nov 5, 2016 at 22:17

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Here's the actual climb in question, according to OP.

enter image description here

So if you are out of the saddle, clipped into pedals, and have your hips to the stem and are bending forward at the waist, then there's little more you can do to balance the bike.

Consider not wearing a backpack.

You might be able to vary your track on the path by zigzagging, or taking a slightly less head-on approach.

Try the climb again, while recording on strava. Then use the Compare function, or a link like this https://www.strava.com/segments/4354748/compare/MzU0NzM3Nzc4NSwxNTgzODc4OTU0NA== to compare your best segment effort to someone else's. The top time was only doing 1.4 km/h on the really steep bit at 0.7 km into the segment.

Generally the answer is momentum, and lots of it. And if you stop, you're stuck.

If you're there, try and watch other people ride the same track. See how they approach the same sections and where they push hard.

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Don't just lean forward... move forward such that you are sitting on the pointy nose of your seat... that's right position it so it feels like you are about to have your rear impaled. It requires leaning forward but it also lowers and shifts forward your center of mass.

Here is where I get all nerdy. Imagine an ellipse whose ends are defined by the front and rear tires contact points with the ground... the sides (or width) of the ellipse would be a function of speed, terrain surface, and a riders comfort leaning into turns... so we have this ellipse... when climbing if a line projected from your center of mass (gravity) to the ground along the earth's gravity vector falls outside your ellipse you are in an unstable position...

So get low, get forward, and keep two wheels on the ground.

Have fun out there.

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I think its the steep turn that is stuffing you up more than the grade alone.

enter image description here

Consider this instead, go around and out along the ridge. Then turn around on the slight crest, and nail it in a straight line back up the ridge-line. If you get out of the saddle I bet you won't have a problem.

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    That line is a little exaggerated and even going dowhnill by 20m but good point. Most of the time however there really is no space to do that.
    – AzulShiva
    Commented Nov 5, 2016 at 15:43
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I don't have a section that steep but I have a front wheel lifting problem on the last part of my commute since I have a lot of weight in the back pannier. No amount of leaning forwards stopped it when I'm fully loaded. So I drape a toolbelt over the handle bars which makes a big difference. The toolbelt weighs around 7 kg.

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As well as the suggestions already mentioned there is one tip that may help - when you are on a steep climb you will almost certainly be pulling on the bars - if you are pulling up on the bars then it will obviously encourage the front wheel to lift. Instead, think about trying to pull backwards on your bars - so imagine that you're trying to pull them towards your knees.

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  • I'm not pulling up on the bars. If I stand on the pedals I immediately lose traction. I try and keep every movement as smooth as possible
    – AzulShiva
    Commented Nov 5, 2016 at 15:40
  • @AzulShiva what size wheels does your bike have ? What pressures do you run in the tyres? I have had similar issues riding a 20" folder up a gravel path at about 12%, but same track no problem on a 26" wheel
    – Criggie ♦
    Commented Nov 5, 2016 at 22:16
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    You have pretty much no chance of maintaining traction if you stand up on the pedals - stay seated, keep weight forward, keep the pedalling really smooth - I imagine you'd want to be in your lowest gear.
    – John M
    Commented Nov 6, 2016 at 20:02
  • 27.5". Around 30psi. Might wanna lower it...
    – AzulShiva
    Commented Nov 7, 2016 at 20:33

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