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Riding downhill wit...
 

[Closed] Riding downhill with a steep head angle

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[#4578168]

OK, I'm off the bike after yet another OTB and I'm bored of talking about semi-naked women, so let's try this one 🙂

Reading mags etc you'd think that in order to ride down anything steep and technical you need a bike with a slack head angle and lots of travel. Since I must have been over the bars half a dozen times in the past couple of months I'm liking this idea, but surely folk were riding down steep technical stuff back when all head angles where steep. And what about 29ers? They seem to all be 69 degrees or steeper. Surely they aren't banned from downhill courses.

So, what's the steepest stuff you've ridden on a bike with a head angle greater than 69 degrees?


 
Posted : 21/11/2012 11:19 am
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[i] I must have been over the bars half a dozen times in the past couple of months [/i]

Go on a skills course.


 
Posted : 21/11/2012 11:20 am
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So, what's the steepest stuff you've ridden on a bike with a head angle greater than 69 degrees?

A drop, probably. Maybe even an undercut drop.


 
Posted : 21/11/2012 11:23 am
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all a slack head angle, long forks and a short stem does is move your weight further back that is why the they go downhill better.


 
Posted : 21/11/2012 11:24 am
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I do 90% of my riding on my '09 Giant Anthem which has a 72 degree head angle & haven't been over the bars this year (yet)
Riding plenty of steep stuff in Derbyshire & Wales without problems.


 
Posted : 21/11/2012 11:25 am
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Don't compare HTAs on 29ers and 26ers.


 
Posted : 21/11/2012 11:31 am
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Head angle is a moot dimension for riding with suspension forks.

On a steep descent if your weigh is forward then your head angle will have steepened significantly due to your forks compressing...the longer the forks the greater the change.

I actually prefer ridgid forks for smooth steep stuff because of this.


 
Posted : 21/11/2012 11:31 am
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On a steep descent if your weigh is forward then [s]your head angle will have steepened significantly due to your forks compressing[/s] you're asking to go over the bars

FTFY 😉

The angle is fairly irrelevant I'd say - a steep roll in with a nice transition can be tackled more easily than something less steep with out a transition. Wwaswas's advice is sound!


 
Posted : 21/11/2012 11:33 am
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Also, HA is usually stated at rest, from some factory measurement, without reference to suspension sagged, fork length, tyre size, stem and bar length, headset cup depth etc etc.


 
Posted : 21/11/2012 11:35 am
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Reading mags is the problem... far better to be out riding.


 
Posted : 21/11/2012 11:35 am
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Slack head angle will make riding steep stuff more pleasant (especially if it's also rough too, ie not just a smooth slab), but still possible to ride it on bikes with steep HA.

Currently riding essentially a jump bike with a long seatpost for XC, so very steep headangle and very short wheel base, makes steep stuff interesting, but still perfectly possible.


 
Posted : 21/11/2012 11:38 am
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Reading mags is the problem... far better to be out riding.

I'm with you there. Just need my hand to stop hurting 😐

It sounds as though a new bike of out then. Although, a bigger wheel should be less likely to get stuck in wheel traps, which is attractive.

Skills course? Maybe. I mean I know it's the best way to improve quickly but it's not really my thing. Wouldn't rule it out, but it smacks a bit of working at your play.


 
Posted : 21/11/2012 11:41 am
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Vertical, with a 74.5 head angle is the steepest I've tackled.


 
Posted : 21/11/2012 11:44 am
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Steep stuff:

Follow Me - Guisbrough Woods (the entrance to the trail is actualy a drop from a cliff, not quite as bad as it sounds, but it is vertical for about 3ft)
Stripes - Guisbrough Woods (named after the brown stains it leaves in your pants)
Nomad - Guisbrough woods (no idea why it's called that, maybe because the whole trail looks steep enough to be about to de-camp and move down the hill)

They do like to build 'em steep in Teesside!

All ridden on my swift which has a 71.5HA IIRC and rigid forks.


 
Posted : 21/11/2012 11:44 am
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[i]71.5HA IIRC and rigid forks.[/i]

probably less steep than a slack bike with 150mm forks at full compression then 😉


 
Posted : 21/11/2012 11:45 am
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Depending on how and what you are riding you need to move your weight around. Weight of the front makes steering a Pita. Skills are you best first stop. Once you understand what's going wrong then make the changes to the bike


 
Posted : 21/11/2012 11:46 am
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I do 90% of my riding on my '09 Giant Anthem which has a 72 degree head angle & haven't been over the bars this year (yet)

Got a 2010 Anthem and though I've not been OTB often it does feel like it gets close to that point easily. Not very confidence inspiring and as a result my riding is getting tamer. And it wasn't exactly gung-ho to start with.

Probably just need a dose of MTFU 🙄


 
Posted : 21/11/2012 11:51 am
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Vertical, with a 74.5 head angle is the steepest I've tackled.

Like wise

OP - How have you got your forks set-up? Are you just making poor line choices? Are you putting your seat down.

The main advantage of a slack HA is stability at speed, holding a line in the rough. It does help a little with coming to an abrupt stop when pointing down, but isn't the decider if you're going otb.


 
Posted : 21/11/2012 11:54 am
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I have a 71 degree head angle and on really steep stuff I feel I have to drop the saddle and shift my weight back and down as far as I can, which is fine when I'm going slowly, but if I pick up speed at all I think there's not enough weight on the front wheel and I tend to lose control very quickly and fall off. I hope to get better with practice.


 
Posted : 21/11/2012 12:00 pm
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Bikes have got slacker over the years, but the trails have remained the same....

No idea what the HA is on my old Patriot (2000) is, but I don't have any difficulty riding the same trails as a new 2013 bike...


 
Posted : 21/11/2012 12:07 pm
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Got 2 bikes

HT with 71deg 100mm travel and Full sus with 67.5deg and 150mm travel.

Been over the bars several times in the HT but never on the really steep bits, usually as a result of a ditch or water bar. Only been OTB on the full sus once - again it was a stealth ditch.

Don't deny that confidence and control going downhill on HT is not in same league as the full sus though. They need to be ridden differently IMO.


 
Posted : 21/11/2012 12:17 pm
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I used to go over the bars a lot! It's pretty much my signature move. I do it a lot less now and i think it's down to a number of things.

- I went from a 2001 Stumpjumper fsr with a steep HA & some pretty poor Judy forks to a 2010 Stumpjumper FSR with much better forks and quite different geometry. Before changing the bike, I did swap the fork on the old one to a Reba which was a decent amount longer and definitely helped, as well as being better controlled so it didn't dive as badly.
- I think that riding trickier conditions helped me gain experience, choose better lines and have more confidence that the bike would roll over an obstacle.
- having faith & not panic grabbing the brakes was a big thing for me. I often used to chicken out at the very last minute, grab a brake which would stop the front wheel and any momentum I had which would allow me to roll over an obstacle would disappear leading to the inevitable.

For me, there are two types of over the bars moments. The first is when you are pitched forward due to the steepness of the trail & you can't get your weight far enough back. The second is when you are on steep, rocky trails where your front wheel stops dead & your momentum carries you over the bars.
In both cases I think technique, confidence and practice are the main issues, rather than bike geometry. But having said that...my new Stumpjumper feels a lot more stable & gives me more confidence but it's hard to quantify how much of that is the bike & how much off it is improvement in my technique & confidence


 
Posted : 21/11/2012 12:24 pm
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Just got back from my skills course, and there was a section of it specifically about steep descents - one over a rolling, gentle lip and the next over a sharp apex, or a 'blind' lip.

Was encouraged to ride both with pedals level, weight in the middle (over the BB) and even to ride the front brake on the first one - went very smoothly. Check out the vids towards the bottom of the page here:

[url= http://ukbikeskills.blogspot.co.uk/2012/11/tim-irving-dave-and-plumber-get.html ]link[/url]

I don't think head angle or forks have much to do with it - far more likely to be your body position and bike setup. Fror example, if your brake levers are too far rotated (closer to 180 degrees round your bars than 90 degrees) then you're be far more likely to OTB when you hit a bump or a drop. With apologies to Jedi for giving away skills, and paraphrasing them badly into the bargain.


 
Posted : 21/11/2012 12:31 pm
 br
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IME Its pretty much 90% body weight/position and 10% equipment.

I'm tall and have long legs, and with my seat up means I need to be more careful than my shorter legged riding buddies.

+1 Training.


 
Posted : 21/11/2012 12:53 pm
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What angle are your brake levers at? As daft as it may seem, this probably has more to do with going OTB than the head angle of your bike.


 
Posted : 21/11/2012 1:02 pm
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Thanks folks.

I'm pretty sure I know what caused all my recent OTBs. It just wasn't the same thing each time 🙂

Mind you, I've not considered brake lever angle. Mine point forward, I'd guess about 30 degrees below horizontal.

My half dozen OTBs included:

A bit of bad luck/laziness. Riding through loads of puddles (too many to be bothered to manual/wheelie them all) then hit one that is deeper than expected with a wheel trap at the bottom. Wheee.

Generally riding stuff that is beyond my ability/comfort (Balblair Black) leading to panic braking. Just need to take some time to build up some skills on easier stuff first.

Poor line choices i.e. "I reckon my suspension will cope with that hit. Oops, guess I was wrong".

Badly setup suspension i.e. air pressure too low so fork tended to dive through travel.

Letting my weight get too far forward.


 
Posted : 21/11/2012 1:20 pm
 br
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all skills mate, you'd benefit from a course


 
Posted : 21/11/2012 1:35 pm
 dday
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+ 10 @timnwild!


 
Posted : 21/11/2012 1:40 pm
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I don't know what my head angle is but I do know I rode up and down Mam Tor perfectly well with 5" forks accidentally shortened to 2"


 
Posted : 21/11/2012 1:44 pm
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Tilt you levers up - less the 20deg from horizontal. That way you drop your wrists and won't rotate round the bar in the OTB. (I'm sure Tony will forgive for giving away Jedi 101).


 
Posted : 21/11/2012 1:47 pm
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In a nut shell

wwaswas - Member
I must have been over the bars half a dozen times in the past couple of months

Go on a skills course


 
Posted : 21/11/2012 1:59 pm
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Slacker bikes make steep sections easier and less challenging, but can also make for a less eventful ride. I believe within reason you can alter your riding style to mitigate a steeper bike, but that does only go so far. Try hitthing a really steep section heading down into a catch berm at speed...you'll end up with all your weight pitched up over the front...this is much less likely to happen on a slacker bike as your weight is already naturally further back.

Trust me, ive done it...ridden a bike designed for slopestyle as a 'do it all' local DH trail type bike and reguarly had the front wheel tuck in under me/OTB. Mostly because it was steep and on the short side. On my other bikes, it just doesnt happen, not on the trails i had all the trouble with the other short/steep bike anyway.

I would also recommend some sort of training. I personally don't think the average Joe needs to go to a specialist facility but have a chat with the guys up your local woods, im sure one of the friendly DH riders will spend some time with you just boosting your techiniques a little.

I myself spent some time with a mate who lacked confidence and the ability to turn fluidly at speed, not to mention a total fear of leaving the ground. With half a day riding sections over and over he was off the ground and railing berms with some speed.

Its all about a bit of shared knowlege and practice nothing more.

I would say look at what bike you have and what you want to be doing on it. If slacker suits you better for what you want then you gotta get shopping.

Every bike could do the job (look at the Martyn Ashton roadbike/trials/trails video...sure he rode all that on a roadie but it would have been a lot easier on a parl/jump bike!)

Good luck with it


 
Posted : 21/11/2012 2:03 pm
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Get a dropper seatpost, or put your seat down when rding downhill. You'll be able to move your weight about then, which'll stop you going over the bars.


 
Posted : 21/11/2012 2:09 pm
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This forum has gone seriously backwards in terms of understanding how frame and fork geometry affects bike handling.


 
Posted : 21/11/2012 2:23 pm
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@roverpig - all of the examples you list would have lead to a crash on a slack angled bike

There is no doubt a more modern design bike with most probably slacker angles and 120mm forks would be better and if you have the budget go for it but what you really need is to find some people to go riding with


 
Posted : 21/11/2012 2:26 pm
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It's over-simple to just talk about steepness. Steep and straightforward can be done on pretty much any bike, but steep with a stack of rocks in it starts to ask a lot more of rider and bike. Halfpipes are steep.

As a wee frinstance, the steepest sustained part of the fort william wc track is the wall. But it's not difficult at all really, just a case of falling off it. Doing it on my Soul was no bother.

But, you go further up the mountain and you get a lot of less steep, more technical stuff where a slacker bike is more stable.

But slackness is just one part of a bigger picture tbh.


 
Posted : 21/11/2012 2:32 pm
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You have greater tolerance for error in weighting/position on the steeps when your bike is longer at the front. The down side is it steers slowly on flat corners until you get all over the front. It just depends what feel you like or are used to.

on really steep stuff I feel I have to drop the saddle and shift my weight back and down as far as I can, which is fine when I'm going slowly,

It's not exactly due to the steepness per-se. You are pushing the bike ahead of you to resist your braking forces. Is fine.

but if I pick up speed at all I think there's not enough weight on the front wheel and I tend to lose control very quickly and fall off.

So when you are rolling and not braking, regardless of what gradient you are on, adopt a more normal/central position.


 
Posted : 21/11/2012 2:57 pm
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I don't think the head angle really matters if it's steep but smooth - what matters more is keeping your centre of gravity behind the front wheel's contact patch and ideally centred over the bottom bracket.

The bigger issue I have is that my fear of heights kicks in when I look over the edge of something really steep and picture myself falling all the way to the bottom, a problem I'm trying to cure by riding as much steep stuff as I dare.


 
Posted : 21/11/2012 6:32 pm
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slacker head angle gives you more confidence on the steeps

saying that im sure the junior winner here has some sort of xc bike!
2:24/2:25 or are they prizes?


 
Posted : 21/11/2012 6:35 pm
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Don't have a problem with it. Ride lots of the DH tracks at inners on a scott scale/spark. 71 head angle.

Just weight positioning.


 
Posted : 21/11/2012 6:54 pm
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Weight positioning is obviously the biggest part but the bike can make a huge difference. Otherwise we'd be riding steep frames for DH.


 
Posted : 21/11/2012 8:17 pm
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I thought it had more to do with suspension Tavel length. The longer (and therefore softer) the front suspension the slacker the head angle to cope with the geometry change as the suspension compresses, though i'm sure that is a gross oversimplification. Weight distribution has to be the biggest part of it - as long as your body's centre of gravity stays behind the front hub then you'll be fine whatever the head angle.


 
Posted : 21/11/2012 9:06 pm
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My Blur has a 71deg head angle and riding down steep rocky stuff requires real concentration; I have to spoon the front up over stuff the whole time as the front wheel seems to slam into stuff.
I#ve just fitted a 1deg Work Components headset to slacken the bike and lengthen the wheelbase and the difference is massive; it rides over stuff instead of slamming into it (I can also wind my fork out to 140mm which helps even more). Slight downside is that the bike is more tippy at slow speed, but you get used to it.


 
Posted : 21/11/2012 9:35 pm
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Weight distribution has to be the biggest part of it - as long as your body's centre of gravity stays behind the front hub then you'll be fine whatever the head angle.

The centre of gravity for a bike is not the front hub, it's dictated by your own weight distribution in relation to your bike, usually somewhere between your saddle and bottom bracket. As long as you drop your heels and hips as the trail steepens, your weight should in theory stay behind this centre of gravity and you won't rotate forwards.... i.e. over the bars. The amount you move is dictated by the steepness of the gradient (you shouldn't just shift your weight right back as someone said above). You do the same thing moving forwards on the bike as you climb.

Bike geometry / head angle just gives you a bias towards climbing or descending, but riding down steeps should be achievable with the head angles we're talking about.

Rocks, roots, steps etc also need to be dealt with at the same time, but the principles remain the same.

NB: all the above is much easier said than done in my experience 😉


 
Posted : 21/11/2012 9:44 pm
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So when you are rolling and not braking, regardless of what gradient you are on, adopt a more normal/central position.

Easier said than done, but I will try...

Here's a question though: you're rolling down a very steep slope with your weight back, and halfway down there's a step. What are you supposed to do so you don't go over the bars when the front wheel drops over the step and the front suspension dives down? If you lift the wheel or shift your weight further back, won't you lose control of the front of the bike?


 
Posted : 21/11/2012 10:02 pm
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