Crossing washes/ruts at speed.

Hit one today at ~55mph and the bike did not like it.  It sent a shock through the bike that was exceeding violent, but the bike stayed up and I stayed on it, thanks to the Scotts damper!

 

Other than slowing down, how are you supposed to get over them.  Obviously hitting them square on at 90 deg will help but that's not always an option.

 

At the last second I tried to get the front wheel up, but my 300 2t will not power wheelie at 55 mph.

 

Maybe my shock & forks need rebuilding?  It's an 06' with 130 hours on the meter - I bought it last year with 20 hours on it.

Edited by Colorado^

Tuesday morning bump...

 

What do you guys do if you come across a rain rut across the trail that you were not expecting?

 

I'm not talking about a huge wash out, just a small rut ~ 5-6" that crosses perpendicular to the trail.  The one I hit sent the bike into a big wobble / tank slapper.  I would probably be in the ER right now if I didn't have a steering damper.

 

I'm used to a mountain bike, that you can just bunny hop in an instant.

Edited by Colorado^

maybe try slowing down??? that would always help :jawdrop:  If you don't ride the trail very often take it slow and watch for ruts. I've had my fair share of wrecking cause I was moving to fast over a rut, I don't have a steering damper and I do fine if i take it slow. also going slow you can pull your bike up in a wheelie to make it more desirable to hit  :thumbsup:  I have a 03 YZ450 and I have no problem popping the front tire off the ground even in 4th gear, so maybe you need more power or just take the trail alittle slower than you do.  IT IS NOT MOUNTAIN BIKING, you are throwing a 250lb bike around instead of a 10lb mountain bike.

I think you should send your suspension away for a service.....

As for the ruts, try and look ahead and maybe just slow down a bit...

Thanks for the help guys!

 

More power would be good.  I'm at 10K ft so my 300 is down on power a lot.  I recently had the head shaved and the cylinder decked at Slavens Racing.  I also switched to the red PV spring. But even now it's still a bit tricky to get the front wheel up with (I don't have the skills to pop it up with the clutch).

 

So assuming that I had a more powerful bike that could wheelie in 4th, can you bunny hop a rut in 4th by chopping the throttle once the front wheel is up? Obviously you'd also have to preload and get the rider inputs right, like you do on an mountain bike.

 

I usually do look ahead and slow down.  I knew there was a rut there, but it was hidden behind a waterbar/jump.  Honestly I didn't think too much about hitting it, I thought the bike was going to float right over it.  Normally I hit the ruts at 25-30mph and it's all good.

 

I see youtube videos of guys just going for it, riding much faster than their line of sight (baja 500 etc).  I was following a guy on a new 500 and I could hang until we got over 50mph and then my suspension didn't feel very safe at those speeds if you happen to hit something.

Jeff can dial in your susp to work perfectly at those higher speeds but then you will give up a lot of plushness and traction at lower speeds in those CO rocks. If that 300 with his engine mods will not pull a wheelie you may be riding in too tall a gear.  All engines no matter how powerful have a "sweet" spot that is optimum for instant wheelies. Jeff can give you anything you want. But you have to realize that there is a huge difference in 25/30 and 55mph when hitting an obstacle. Physics does matter, whatever the technique.

I can rev the bike out, pinned with fast clutch-less shifts through 2-3-4 and it won't lift the front. Even when I get caught off guard with my weight in the wrong place the front wheel won't lift.  The only way I can get it to lift is if I compress the forks and hit the throttle on the rebound stroke while leaning back.  And even then I have to be in the sweet spot of the RPM.

 

Is there such a thing as suspension that does well in 10-20 mph rock gardens that can also can take the big hits a speed? I'd be willing to buy new suspenders if that's what it takes.

 

While I LOVE my 06' 300 xc-w 95% of the time, I wonder if I should have bought something else?  Seems to me that a bike needs to be able to lift the front wheel to pull off advanced techniques, like hopping bigger logs.  Of course a better rider could just use the clutch.

The front wheel doesn't have to be up in the air. If you lighten it up a bit (using throttle and body position) you should have no problem crossing a rut that runs 90 degrees from your direction of travel.

 

If the rut is <45 degrees from your direction of travel you will most likely need to slow down or use a bit more technique to get across.

First off, rut is a pretty general term. There are ruts the width of a bike tire and ruts the size of bike and rider. Sounds like the problem is that your hitting a square edge hard. Suspension only works if the force is applied in the direction the suspension cycles. Drop down into the rut and drive the front of your rear tire into a square edge (perpendicular to the direction of the suspension cycle) and most of the force gets transferred strait through the bike with minimum damping.

 

All techniques for crossing ruts, and a bunch of other techniques for going fast, require you to be able to pull your front end up. This doesn't mean a 12 o'clock wheelie, you just need to be able to get it high enough off that ground that you can carry it with power some distance (doesn't have to be close to the balance point). Even at altitude, in 5th gear, you should be able to bring your front end off the ground no problem. At high speeds power alone won't be enough to bring the front end up. It sounds like you need practice the body english and how to work the suspension to bringing your front end up at pace. The thing to practice would be learning how to bring it up with minimum throttle input. The less power you need to bring it up, the further from the 'sweet spot' you can be and still do it successfully. And you should be able to do it all with out the clutch.

 

As for the actual rut crossing, it depends on the size, but going based on what i've already said, the place to start is going to be  bringing your front end up as your going across it. On small ruts the goal is to bring your front wheel up, rotating the bike to try to line up the direction your suspension cycles with the direction the force is going to be applied through your rear tire. As you get more technical, you can do things like load the suspension as your approaching the lip so that it rebounds just as you are bringing the front end up. It introduces a little upward momentum to the bike as you cross that rut. That momentum along with pushing the front end back down will in essence be a bunny hop.  

 

edit: I just read your 2ed post. A 6 inch rut should be no problem to wheelie over. You just have to bring the front wheel up and stay on the gas. This whole explanation is way overboard.  

Edited by Die_trying

First off, rut is a pretty general term. There are ruts the width of a bike tire and ruts the size of bike and rider. Sounds like the problem is that your hitting a square edge hard. Suspension only works if the force is applied in the direction the suspension cycles. Drop down into the rut and drive the front of your rear tire into a square edge (perpendicular to the direction of the suspension cycle) and most of the force gets transferred strait through the bike with minimum damping.

 

All techniques for crossing ruts, and a bunch of other techniques for going fast, require you to be able to pull your front end up. This doesn't mean a 12 o'clock wheelie, you just need to be able to get it high enough off that ground that you can carry it with power some distance (doesn't have to be close to the balance point). Even at altitude, in 5th gear, you should be able to bring your front end off the ground no problem. At high speeds power alone won't be enough to bring the front end up. It sounds like you need practice the body english and how to work the suspension to bringing your front end up at pace. The thing to practice would be learning how to bring it up with minimum throttle input. The less power you need to bring it up, the further from the 'sweet spot' you can be and still do it successfully. And you should be able to do it all with out the clutch.

 

As for the actual rut crossing, it depends on the size, but going based on what i've already said, the place to start is going to be  bringing your front end up as your going across it. On small ruts the goal is to bring your front wheel up, rotating the bike to try to line up the direction your suspension cycles with the direction the force is going to be applied through your rear tire. As you get more technical, you can do things like load the suspension as your approaching the lip so that it rebounds just as you are bringing the front end up. It introduces a little upward momentum to the bike as you cross that rut. That momentum along with pushing the front end back down will in essence be a bunny hop.  

 

edit: I just read your 2ed post. A 6 inch rut should be no problem to wheelie over. You just have to bring the front wheel up and stay on the gas. This whole explanation is way overboard.  

 

Thanks for the explanation.  That's pretty much what I'm trying too do.  At 10,000ft my bike is down around 30% in power, so it's only got around 30hp.  There's just no way I can see to get the front wheel up in 5th.  I can keep it pinned in second and the front won't come up on flat ground.  It will come up if I'm pointed up hill, or if I wheelie over the back side of a jump, or if I pre-load the forks.  It'll also come up if I hit the gas as the forks rebound off a rock or the lip of a jump.

 

I think my technique is right, but the bike is just way underpowered at this altitude to be useful at power wheelies.

 

Does a ~30hp bike (250f?) power wheelie at sea level?

I can keep it pinned in second and the front won't come up on flat ground.  It will come up if I'm pointed up hill, or if I wheelie over the back side of a jump, or if I pre-load the forks.  It'll also come up if I hit the gas as the forks rebound off a rock or the lip of a jump.

 

I think my technique is right, but the bike is just way underpowered at this altitude to be useful at power wheelies.

 

Does a ~30hp bike (250f?) power wheelie at sea level?

 

If you can pop the front end up of a rock or when going up a hill, they you can do it on flat. Your just lacking technique. I can guarantee you, unless your bike is having mechanical issues, your bike can be pulled up into a wheelie in any gear from flat. It just takes a little bit more then a 'power' wheelie.

 

The thing it sounds like you are missing is loading the rear shock. When you gas it hard, your rear shock compresses. That is energy that could be used to pull the front end up being lost to the rear spring. So before you go to pull it up into a wheelie, you jump into your pegs, compressing the forks and shock. Once the shock is compressed you start pulling back on the bars and applying the throttle. It takes some practice to get the timing and motion down, but you should be able to bring your front up in every gear relatively quickly.

 

Highest altitude i've ridden a 250f at was 5000-6000 feet and I could still wheelie no problem.

Edited by Die_trying

If you can pop the front end up of a rock or when going up a hill, they you can do it on flat. Your just lacking technique. I can guarantee you, unless your bike is having mechanical issues, your bike can be pulled up into a wheelie in any gear from flat. It just takes a little bit more then a 'power' wheelie.

 

The thing it sounds like you are missing is loading the rear shock. When you gas it hard, your rear shock compresses. That is energy that could be used to pull the front end up being lost to the rear spring. So before you go to pull it up into a wheelie, you jump into your pegs, compressing the forks and shock. Once the shock is compressed you start pulling back on the bars and applying the throttle. It takes some practice to get the timing and motion down, but you should be able to bring your front up in every gear relatively quickly.

 

Highest altitude i've ridden a 250f at was 5000-6000 feet and I could still wheelie no problem.

 

So the idea is not to just compress the forks, but preload both ends (using your legs) and then pull up and twist the throttle on the rebound stroke, right?

 

I do that when I'm jumping the water bars, but never thought to do that for a wheelie. 

 

Thanks a million for the explanation/analysis.  I'll give it a try and report back in a few days  :thumbsup: 

Since power is an issue, why not get the right module and tuning for the bike, and get that power back.

 

I've had my 250 XC up to 9k, made a small adjustment on the trail and was good to go.

 

My friend just moved from CO, back to Cali. His 500 was horrible due to the altitude. Once he got the right tune done, no problems.

He regained full power, and now that he is back in Cali, he switched it back to somewhat stock.

Since power is an issue, why not get the right module and tuning for the bike, and get that power back.

 

I've had my 250 XC up to 9k, made a small adjustment on the trail and was good to go.

 

My friend just moved from CO, back to Cali. His 500 was horrible due to the altitude. Once he got the right tune done, no problems.

He regained full power, and now that he is back in Cali, he switched it back to somewhat stock.

 

By module are you talking about jetting?  The bike is jetted correctly for my altitude & temps.  Jetting for high altitude just gets the air/fuel mixture where it needs to be since there's less air up here.  But it can't make up for the lack of oxygen so while the bike will run properly, it will still loose ~3% for every 1,000ft in altitude.  No way around that except a turbo or two, which isn't an option anyway.

I'll give it a try and report back in a few days  :thumbsup:

 

Well a few days turned into a few weeks. 

 

Anyway I found loading both ends of the suspension helped, but it still seemed hit and miss for getting the front up.  I still had to be in the right RPM's otherwise it would just unload the forks a little, but not really pop the wheel up.

 

But sometimes these things take time to adapt to, so I'll keep trying and see how it goes.

 

Here's a video of what I want to be able to do.

 

I looks like you have the right idea...it didn't sound(in the vid) like you were hardly getting on the throttle. It was explained well in an earlier post...suspension preload, body position, throttle, etc. It's all one fluid motion( practice, practice, practice). Good luck.

I looks like you have the right idea...it didn't sound(in the vid) like you were hardly getting on the throttle. It was explained well in an earlier post...suspension preload, body position, throttle, etc. It's all one fluid motion( practice, practice, practice). Good luck.

 

Not me in the video, but yeah it didn't take the guy a lot of throttle.  I'm so used to 35lb mountain bike that I can float or bunny hop in an instant.  Obviously bunny hopping on a dirt bike it's going take some setting up and isn't instant, but it it would be nice skill to have so you don't have to slow down and/or risk a tank slapper.

if you spent as much time practicing as you do mathing out how much power your bike doesn't have you would have solved the problem already

if you spent as much time practicing as you do mathing out how much power your bike doesn't have you would have solved the problem already

 

I usually ride 3-4 times a week, but I only started riding last year and our riding season is short.

 

Sorry if basic physics bothers you, I'll try not to use multiplication in the future.

Edited by Colorado^

Yeah sometimes you need the physics of something to fully understand the right way to accomplish a task.  And I've never heard of anyone bunny hopping a dirt bike but that doesn't mean you can't do it. when you do take a video and post it, I want to see how you do it. I would use it if I was able to do it :thumbsup:

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