You can change gearing in the gearbox, or in the portals, to achieve overdrive/underdrive. In the video you described overdrive as changing the gearing so, the front wheels spin faster than the rears and underdrive as the fronts going slower (than the rear wheels, I assume?). Not sure if you misspoke, but underdrive is changing the gearing in the rear so, that the rear wheels spin slower than the fronts. In both cases, it results in the front wheels spinning faster than the rears. I think in most cases, people will use overdrive in straight axles and underdrive in portals but depends on the driver and gearing options based on the rig.
You can overdrive or underdrive either axle, and you can over-gear or under-gear either axle too, so I guess we just need to be clear what we are referring to.
Rock on! Happy that someone caught that easter egg. I saw them 3 weeks ago in AZ. I hope to eventually do The Boomslang Gig Report channel and do concert reviews and commentary. Right now it's empty.
Very interesting! However, it seems that the video was about weight distribution rather than over underdrive on slopes. I thought you were going to point out things like the advantage of rear over drive when cresting, and the advantage of front overdrive when starting to climb with the front.
Good points. The wheel with the most weight has all the traction, so that I why I took the weight bias angle, but for sure there are more aspect to explore.
On my vanquish, when out crawling for the first time having on the fly overdrive % selection, it was so cool to do the same lines and crawls with both ratios and seeing the difference. It was incredible the difference low OD % and high % had and oddly they were both better and worse in specific situations. Thanks for the video I wish I had it 20yrs ago.
Your videos continue to get better and I'm really enjoying them! 👍 Giving us the science and theory behind what you're saying makes it more clear. I do think you dive a little too deeply into the subject at times but just my opinion. Like any theory though, you need to back it up with real world testing. So, I would love to see some videos with you out on the rocks and doing some driving to see if things go the way you predict. Designing mountain bike suspensions, you know things don't always go to plan. Keep up the great work! 👍
Here is a nice demo from by friend Danny "The Hammer" Smith where he illustrates my conclusions very well - a high amount of overdrive works great when it hooks up, and other times when the front weight bias is low it doesn't make as much of a difference. ruclips.net/video/VFweRpUKO3M/видео.html
Great video, thanks for the info! Do you think over drive in the front or under drive in the rear is better? What would be the pros/cons of each option?
Think of it this way - your rig will travel forward slightly slower than the front wheel speed. This is because the rear wheels are putting on the brakes, just a little, so it prevents the car from driving at the full speed of the faster turning front wheels. So do you want your rig to have faster or slower forward speed? If you want slower, underdrive the rear. If you want faster, overdrive the front. Personally, I gear down everywhere possible - I run 4S and want it to creep as slowly as possible. Better slow speed control, longer battery life, higher torque. Mechanically, it doesn't really matter if you change the front or rear. Pick the one that moves your overall speed in the direction you want.
That’s good to know. I heard rumblings that someone was doing it when I published this, but it seemed pretty uncommon and info was sparse. Let me know if you have any links or names.
Great vid! Thanks! So I guess moving your weight forward is all good going up. But coming down, the common agreement is that it's not good. Hence, the golden 60/40 "rule". So do you subscribe to this or have you found that going over 60% front bias is fine and it's other factors that contribute to the claimed downhill problems going above that golden 60%? Have you got any mechanical tricks one can do to the rear of a crawler to lessen the negative effects of going over that 60% (If that is the Goldilocks percentage of front weight. ) Thanks!!!
60/40 is a great rule of thumb. However, it's a little too perfect of a number. I know a lot of great drivers that are closer to 64% in the front. Not saying I am great, but I like 63-64. Yes, it can be a problem going down, so you have to balance how and where you like to drive. Also, you can manage the downhill by keeping the front wheels rolling faster than the rear. You need to keep accelerating on the way down, and don't hit the brakes or let up on the throttle. Small stalls will flip you over more easily. I have a great video I shot last week of a long rock ramp, where I could not get the front going fast enough and the rear end eventually overtook it and flipped over. I am going to go back with faster gearing and see if I can stick it.
@@BoomslangSuss Thanks for the reply! Always stuff to monkey around with, just like MTB'ing. :D Have a good weekend! Sub'd and looking forward to more analysis and testing.
Your anti squat video may have enraged some people, but physics don’t care kids! And as I’ve said in my crawler group, gravity doesn’t work sideways…you’ll eventually unload, front overdrive helps a lot though as does low centre of gravity.
Thank you Professor! I'm going to go look for your other instructionals next....
Much appreciated. Let me know if there is a topic you want to see exploited. 😅
You should have more views! Great videos.
I agree, and thank you kindly. I'm confident more people will watch once I get additional content added.
Keep them coming bro you're doing a great job
Thanks so much!
I love these kinds of videos. Keep them coming!
Thank you. I have a long list to make, so stay tuned.
This is how I naturally thought it worked but you are adding so much more to my basic understanding.
Love these videos. Thank you!!
Great to hear!
You can change gearing in the gearbox, or in the portals, to achieve overdrive/underdrive. In the video you described overdrive as changing the gearing so, the front wheels spin faster than the rears and underdrive as the fronts going slower (than the rear wheels, I assume?). Not sure if you misspoke, but underdrive is changing the gearing in the rear so, that the rear wheels spin slower than the fronts. In both cases, it results in the front wheels spinning faster than the rears. I think in most cases, people will use overdrive in straight axles and underdrive in portals but depends on the driver and gearing options based on the rig.
You can overdrive or underdrive either axle, and you can over-gear or under-gear either axle too, so I guess we just need to be clear what we are referring to.
That was great...using VORTEX from JINJER to show what you meant. JINJER, my favorite band. Great tutorial on Over and Under drive. Thanx...
Rock on! Happy that someone caught that easter egg. I saw them 3 weeks ago in AZ. I hope to eventually do The Boomslang Gig Report channel and do concert reviews and commentary. Right now it's empty.
youtube.com/@boomslanggigs?si=Sd9h4FepyXOJ-mk2
Thanks for another great video!
Very interesting! However, it seems that the video was about weight distribution rather than over underdrive on slopes. I thought you were going to point out things like the advantage of rear over drive when cresting, and the advantage of front overdrive when starting to climb with the front.
Good points. The wheel with the most weight has all the traction, so that I why I took the weight bias angle, but for sure there are more aspect to explore.
On my vanquish, when out crawling for the first time having on the fly overdrive % selection, it was so cool to do the same lines and crawls with both ratios and seeing the difference. It was incredible the difference low OD % and high % had and oddly they were both better and worse in specific situations. Thanks for the video I wish I had it 20yrs ago.
Which Vanquish? I can see that being true - better and worse in different situations.
@@BoomslangSuss in my case I had the Phoenix out. But a few now have the transmission that’ll do that and has dig.
Your videos continue to get better and I'm really enjoying them! 👍 Giving us the science and theory behind what you're saying makes it more clear. I do think you dive a little too deeply into the subject at times but just my opinion. Like any theory though, you need to back it up with real world testing. So, I would love to see some videos with you out on the rocks and doing some driving to see if things go the way you predict. Designing mountain bike suspensions, you know things don't always go to plan. Keep up the great work! 👍
Great video, thanks!
Glad you liked it!
Here is a nice demo from by friend Danny "The Hammer" Smith where he illustrates my conclusions very well - a high amount of overdrive works great when it hooks up, and other times when the front weight bias is low it doesn't make as much of a difference.
ruclips.net/video/VFweRpUKO3M/видео.html
Great video, thanks for the info! Do you think over drive in the front or under drive in the rear is better? What would be the pros/cons of each option?
Think of it this way - your rig will travel forward slightly slower than the front wheel speed. This is because the rear wheels are putting on the brakes, just a little, so it prevents the car from driving at the full speed of the faster turning front wheels.
So do you want your rig to have faster or slower forward speed? If you want slower, underdrive the rear. If you want faster, overdrive the front.
Personally, I gear down everywhere possible - I run 4S and want it to creep as slowly as possible. Better slow speed control, longer battery life, higher torque.
Mechanically, it doesn't really matter if you change the front or rear. Pick the one that moves your overall speed in the direction you want.
FYI, 1:1 buggies are doing under/over drive now days.
That’s good to know. I heard rumblings that someone was doing it when I published this, but it seemed pretty uncommon and info was sparse. Let me know if you have any links or names.
Great vid! Thanks! So I guess moving your weight forward is all good going up. But coming down, the common agreement is that it's not good. Hence, the golden 60/40 "rule". So do you subscribe to this or have you found that going over 60% front bias is fine and it's other factors that contribute to the claimed downhill problems going above that golden 60%?
Have you got any mechanical tricks one can do to the rear of a crawler to lessen the negative effects of going over that 60% (If that is the Goldilocks percentage of front weight. )
Thanks!!!
60/40 is a great rule of thumb. However, it's a little too perfect of a number. I know a lot of great drivers that are closer to 64% in the front. Not saying I am great, but I like 63-64. Yes, it can be a problem going down, so you have to balance how and where you like to drive. Also, you can manage the downhill by keeping the front wheels rolling faster than the rear. You need to keep accelerating on the way down, and don't hit the brakes or let up on the throttle. Small stalls will flip you over more easily.
I have a great video I shot last week of a long rock ramp, where I could not get the front going fast enough and the rear end eventually overtook it and flipped over. I am going to go back with faster gearing and see if I can stick it.
@@BoomslangSuss Thanks for the reply! Always stuff to monkey around with, just like MTB'ing. :D
Have a good weekend! Sub'd and looking forward to more analysis and testing.
Your anti squat video may have enraged some people, but physics don’t care kids! And as I’ve said in my crawler group, gravity doesn’t work sideways…you’ll eventually unload, front overdrive helps a lot though as does low centre of gravity.
Facts.
Did I hear a little clip from jinjer?
You did! Impressive.
Rock on! Big fan! Digging the channel too!