Big manhole cover - sit down, stand up

[RBEmerson]

I was on a BMW F650GS loaner, zipping around a corner, and encountered a deep, big manhole cover. My general reaction to anything that's going to bang me around - train tracks, unavoidable potholes, etc. - is to stand up or at least get off the seat. In a turn and leaned over... oops, deep big manhole cover, and up I went. Good idea? Bad idea?

In general, the idea of standing up is to move the center of gravity lower - more stability. What about leaned over in a turn?

[Sport-Touring]

[rajflyboy]

Its my motto :

"When in doubt smoothly get on the throttle"

[RBEmerson]

Well, yeah, that will lift the front a bit.

The more I thought about the issue, more I'm inclined to think standing up wasn't a bad idea. Standing up drops the CG, so even if I'm leaning already, I shouldn't have a big problem with getting the bike over far enough for things to get exciting.

BTW, the thing was a near-crater. One of the all-time worst I've seen.

[birdrunner]

Well, yeah, that will lift the front a bit.

The more I thought about the issue, more I'm inclined to think standing up wasn't a bad idea. Standing up drops the CG, so even if I'm leaning already, I shouldn't have a big problem with getting the bike over far enough for things to get exciting.

BTW, the thing was a near-crater. One of the all-time worst I've seen.

Shouldn't standing UP  ----- RAISE  the centre of gravity.?

[jay547]

Be sure to report it to the city/county/responsible authority before someone is injured. Report it as a safety hazard and it will more likely get taken care of.

Jay = person whom works for a city street department.

[RBEmerson]

Be sure to report it to the city/county/responsible authority before someone is injured. Report it as a safety hazard and it will more likely get taken care of.

Jay = person whom works for a city street department.

Optimist. Boyertown borough has quite enough drains on their budget.

[jay547]

Optimist. Boyertown borough has quite enough drains on their budget.

That's generally the case everywhere. I mostly handle sidewalk and wheelchair ramp complaints and requests. With the budget that I'm allotted, I'm only able to do about 10% of them.

[RBEmerson]

Shouldn't standing UP  ----- RAISE  the centre of gravity.?

I know it's counter-intuitive, but CG drops because your weight is no longer on the saddle but on the pegs, which are lower than the saddle. Where you contact the bike is where your weight is applied. (Weight on the grips is a push because that weight probably doesn't change significantly from sitting to standing.)

[RBEmerson]

That's generally the case everywhere. I mostly handle sidewalk and wheelchair ramp complaints and requests. With the budget that I'm allotted, I'm only able to do about 10% of them.

Keep doin' what you're doin', sounds like worthy work to me.  

[R Doug]

From the BMW Motorrad GS Off-Road Training l attended, standing on the pegs does not lower the CG.  


But, it does offer the following benefits (with #2 and #3 being the key reasons you at least lift your butt off the seat for bumps).

First:  The most important reason for standing up is increase your vision ahead on rough terrain. That allows you to avoid obstacles such as potholes, rocks or mud, or to pick a better path so you don’t end up in the deepest rut, or to see whether there are oncoming vehicles over the crest of a hill.

Second:  Your legs become “part of the suspension,” so a sudden and large bump doesn’t jolt you off the bike as your legs absorb some of the impact. Don't lock your knees!  



Third:  Standing eliminates the jostling of the bike from your body weight. If you hit a rock or momentarily lose traction and the bike kicks sideways, standing helps minimize that the bike moves, not you because you have better leverage to counter.  A rider sitting on a bike tends to overreact to every sideways movement of the bike. Standing up divorces you from all these minor movements so you aren’t worried by every buck and weave. It also allows the bike to do its own thing without the distributing influences of unnecessary and reactionary handlebar corrections.



Fourth: Standing can give you extra control over the bike with your feet.  Try standing up on your bike and concentrating on not putting any steering or counter-steering pressure on the handlebars.  Then move your right knee slightly forward. This puts pressure on the left footpeg. Notice what happens. The bike will swerve to the left.

Sitting down and putting pressure on the footpegs doesn’t have near as much effect as when you stand and put your whole body weight into a footpeg.  You can use this pressure on the footpegs for steering the bike, but also for adding traction when the tail is sliding out.  Place you weight on the footpeg on the side the rear wheel is sliding toward.

Steering with your feet also means less handlebar input is needed and less reliance on front wheel traction.

[Windblown]

I was on a BMW F650GS loaner, zipping around a corner, and encountered a deep, big manhole cover. My general reaction to anything that's going to bang me around - train tracks, unavoidable potholes, etc. - is to stand up or at least get off the seat. In a turn and leaned over... oops, deep big manhole cover, and up I went. Good idea? Bad idea?

In general, the idea of standing up is to move the center of gravity lower - more stability. What about leaned over in a turn?

I'd say your instinctive reaction was good.  There were a couple of turns at a local track that were quite bumpy at the apex and I found I could get over them a lot better/faster with my butt hovering just off the seat. The results had more to do with adding legs to the suspension equation rather than shifting CG IMHO, but regardless, it worked.

[RBEmerson]

You hit on exactly why I went up. Even on my K1200RS I'll either give my quads and glutes a good workout, hovering just off the seat, or stand up as much I can. Beats the heck out of having my eyeballs rattled.  

[rajflyboy]

Throttle baby.   It's all about staying in the throttle. Not upsetting the balance on each wheel  

[Acadian Rider]

From the BMW Motorrad GS Off-Road Training l attended, standing on the pegs does not lower the CG.  


But, it does offer the following benefits (with #2 and #3 being the key reasons you at least lift your butt off the seat for bumps).

First:  The most important reason for standing up is increase your vision ahead on rough terrain. That allows you to avoid obstacles such as potholes, rocks or mud, or to pick a better path so you don’t end up in the deepest rut, or to see whether there are oncoming vehicles over the crest of a hill.

Second:  Your legs become “part of the suspension,” so a sudden and large bump doesn’t jolt you off the bike as your legs absorb some of the impact. Don't lock your knees!  



Third:  Standing eliminates the jostling of the bike from your body weight. If you hit a rock or momentarily lose traction and the bike kicks sideways, standing helps minimize that the bike moves, not you because you have better leverage to counter.  A rider sitting on a bike tends to overreact to every sideways movement of the bike. Standing up divorces you from all these minor movements so you aren’t worried by every buck and weave. It also allows the bike to do its own thing without the distributing influences of unnecessary and reactionary handlebar corrections.



Fourth: Standing can give you extra control over the bike with your feet.  Try standing up on your bike and concentrating on not putting any steering or counter-steering pressure on the handlebars.  Then move your right knee slightly forward. This puts pressure on the left footpeg. Notice what happens. The bike will swerve to the left.

Sitting down and putting pressure on the footpegs doesn’t have near as much effect as when you stand and put your whole body weight into a footpeg.  You can use this pressure on the footpegs for steering the bike, but also for adding traction when the tail is sliding out.  Place you weight on the footpeg on the side the rear wheel is sliding toward.

Steering with your feet also means less handlebar input is needed and less reliance on front wheel traction.

Good stuff Doug.  

[RBEmerson]

Throttle baby.   It's all about staying in the throttle. Not upsetting the balance on each wheel  

No doubt about that.

Watching guys shut down the throttle entering a turn, for example, is cringe-worthy.

[RBEmerson]

Re: steering by weight shift, please see Bernt Spiegel's The Upper Half of the Motorcycle, pp. 43-44, and the Ecomobile shown on p.44.

[Bounce]

Also change tack and try to cross such things as upright and at as much of a right angle to the path of the thing as possible (easier to do on rr tracks than on a round manhole cover).

You do not want to give up what little traction you have on metal surfaces to maintain a lean angle.

[RBEmerson]

Agreed on both points. For some reason, this crater surprised me although I go through the area fairly often. It was the part about being over, coping with a curve, and being partly on metal, that had me thinking. Further on, following the same road, there's a RR crossing. It's extremely rare for me to not be up when crossing this fun washboard.  

[rajflyboy]

Agreed on both points. For some reason, this crater surprised me although I go through the area fairly often. It was the part about being over, coping with a curve, and being partly on metal, that had me thinking. Further on, following the same road, there's a RR crossing. It's extremely rare for me to not be up when crossing this fun washboard.  

Well hey

I see you survived it!   You must have done something right.  

[RBEmerson]

Or got away with it.

I think "got away with it" happens more often than we like. That is, the bike (as a system) wasn't pushed past its comfort point, even if someone's comfort point limit was getting close.

Back to the Upper Half (which can be fascinating in places and like attending a psych. lecture in other), there's a little bit about a rider who put a counter (the click-click kind) on his bike, and clicked it for every mistake he made. The point being that, of course, initially the count is astronomical, but the goal was to lower the count. Nice tool if one is honest about what happens. Otherwise... fooling yourself again.