Break over angles

[Espeefan]

Is it bad to get hung up over break over angles? Pun not necessarily intended! Thing is break over angles sure can make or break a crawler, but at what point is the belly clearance to high to be practical? Droop suspensions have great break over angles, and my droop suspension super class, Clod based crawler could probably climb some stairs, if I had some high clearance links on it. My brand new XR10, however, now has some high clearance links on it, but I was wondering what else I could do to increase the break over angle. Short of reducing the wheelbase, running bigger tires (I don't think there are any taller then Chisels?) and positioning the shocks to also increase the ride height and belly clearance, I don't know that there is anything better I can do. If you approach a step or ledge at an angle, most crawlers will probably pull themselves up and over, but head on, it's not going to have much of a chance.

For your consideration - my new XR10. I am only getting about 3" belly clearance at the moment. I have some adjustment left in the shock mounts, but I don't think it's going to net me any huge gains. I've yet to run this crawler, but I think it has some great potential. It's so light, narrow, and seems like it's got the good stuff to be a capable machine. That's a 8.25" step, in the picture - just about average human stair height.





What are your thoughts on break over angles? What kind of belly clearance do you guys have on your 2.2 crawlers? What kind of break over angle?

[jcboof]

I run between 3.25 to 3.5" of ground clearance on my berg. Breakovers are a tough on to try to set your truck up for. To high of GC is not a good thing just as too low is not good. The rear links do have a bit to do with breakovers but its really more in weight bias. I run my fronts about 6 to7oz heavier to help with breakover.

In a situation like your box, id just get my front tires up and then in a controlled fashion, bip the throttle. It will pop the rears up and over. I have a step at my house that is 10" tall and I can clear it with my truck. I cannot slow crawl it, but I have to almost jump it.

A lot of it is just technique.

[Espeefan]

Thanks JC. Interesting that you run only 6 or 7 ounces more in the front. I've been leaning more torward a near perfect 50/50 weight split with this truck. I've had some pretty front heavy crawlers and they seemed to have problems climbing slick veritcal surfaces. Just can't seem to push the front end up with the rear, even with motor on axle crawlers, running dual speed controllers, biasing most of the speed to the rear motor. 6 or 7 ounces is not very much. I would have thought a lot of guys run more then that, but I do think there is merit to a near perfectly balanced crawler. I think with this XR10, I'm going to make it as light as I can and near perfect 50/50 split. That seems almost the opposite of what a lot of guys do, but I'm still pretty new to setting up a crawler for comps. I've just been running around the rock piles in the back 40. Just for fun. If I can make this thing perform better, I'm all for it. I appreciate the advice.

[jcboof]

That 6 to7oz more that I run is PER WHEEL. In a perfect world, a perfectly balanced crawler would be nice. 50/50 would work fine on flat ground, but to have vertical climbing and breakover abilities, more weight is needed up front.

A lot of people like to have their rigs balance on the front of the skid. Front bias is VERY important in crawling. There is a limit though to how much weight you should run. There is such a thing as too much. If we were crawling on a lot of flat ground rocks with very few breakovers and very little verticals, I would set up a heavier truck, still keeping a good front bias though. On courses with more breakovers and climbs, id set up a lighter truck with a heavy front bias.

[Espeefan]

Got it. That makes sense. So just under a pound heavier to the front. I guess I'll have to experiment and see what works best for me. Should be interesting to see how this new rig crawls, once the rest of my parts arrive and I can finish putting it together. Thanks again.

[losikid]

make the rear end light and the front end a brick, thats how i get my low belly losi up everything, most the time i can just front dig but sometime i got to bliping the throttle to get past the center of mass (got to get the belly push on the fulcrum (edge of rock) then it will kinda float down to front wheels and front dig up the rest the ledge. I tend to break front drivetrain alot though running so heavy

[junior ax10]

I run blue and white rovers on my xr-10 and it has some good break over angles. i use the bent 101 30 degrees like your rig but also as any comp driver should know how to "lock" a front tire and release the dig and watch the magic before your eyes?? lol

But im sittin right at 3.25 to 3.5 inches of belly clearance!! i go up stairs at work like they are nothing not wide open either??? idk man unless you are willing to run like a 40% front and 60% rear??

Also idk what your wheel width is it will make the tires taller with a skinnier wheel. Also on my rig i dont run vented wheels so there again its the preference of what you basically wanna run!!! I run the rovers and my friend has chisels on same rims and his are just a hair shorter by about 1/4 inch. hope it helps ya out bud!!

[Espeefan]

Interesting information fellas. I was thinking maybe a guy could stuff some more foam into the wheels to get them taller too? How tall are the Rovers? Are those made by Hot Bodies? I'd love to adjust the shock positions to gain some more belly clearance, but the biggest problem I have with that is that the shocks start to interfere with the lower 4 links. It would have been nice if Axial would have made the adjustable shock mounts a little longer, to avoid the shocks laying back at such an angle.

[junior ax10]

Originally Posted by Espeefan

Interesting information fellas. I was thinking maybe a guy could stuff some more foam into the wheels to get them taller too? How tall are the Rovers? Are those made by Hot Bodies? I'd love to adjust the shock positions to gain some more belly clearance, but the biggest problem I have with that is that the shocks start to interfere with the lower 4 links. It would have been nice if Axial would have made the adjustable shock mounts a little longer, to avoid the shocks laying back at such an angle.

I see you are having a problem with the shocks hitting i have kinda rigged mine up to my low standards but have u clocked the axle any??? Another thing make sure u do have the right link ends on those lower links if not when i had mine stock they did interfer also!!

I just went and took a look at mine and on the stock xr-10 wheels the rovers are at 5 1/4 inches??? I have the dual stage pro-line foams in these and like above i don't run vents so they don't sit down like vented wheels??

The last set of wheels i had i think they was just a hair shy of 1 inch wide and the rovers was right at 5 1/2 to 5 5/8 inches tall!!!

Hope this helps??

[Espeefan]

Originally Posted by junior ax10

I see you are having a problem with the shocks hitting i have kinda rigged mine up to my low standards but have u clocked the axle any??? Another thing make sure u do have the right link ends on those lower links if not when i had mine stock they did interfer also!!

I just went and took a look at mine and on the stock xr-10 wheels the rovers are at 5 1/4 inches??? I have the dual stage pro-line foams in these and like above i don't run vents so they don't sit down like vented wheels??

The last set of wheels i had i think they was just a hair shy of 1 inch wide and the rovers was right at 5 1/2 to 5 5/8 inches tall!!!

Hope this helps??

I don't have any problems with the shocks hitting the links right now, but if I try to angle the mounts down, to increase the ride height, then the shock spring retainers and shock ends do start to hit the rod ends of the 4 links. I am running the correct rod ends all the way across the board, except for following Bender's recommendations to run an angled or off-set Axial rod end on the front lower links, because I now have the high clearance links on there. Rather then buy Axial hi-clear links, I made my own out of stainless rod, but I made them almost identical to Axial's tube links. I may have a little more then a 30 degree bend in them though. I think it may be possible to machine up a little better upper shock mount, or just throw some spacers behind the shocks and push them out further. I have not tried a whole lot yet. Just looking at ideas.

Not sure how tall the Pro-Line Chisels are, but they seem pretty comparable to Rovers, in over all height. The foams are soft though, so the tires do squat.

[junior ax10]

Originally Posted by Espeefan

I don't have any problems with the shocks hitting the links right now, but if I try to angle the mounts down, to increase the ride height, then the shock spring retainers and shock ends do start to hit the rod ends of the 4 links. I am running the correct rod ends all the way across the board, except for following Bender's recommendations to run an angled or off-set Axial rod end on the front lower links, because I now have the high clearance links on there. Rather then buy Axial hi-clear links, I made my own out of stainless rod, but I made them almost identical to Axial's tube links. I may have a little more then a 30 degree bend in them though. I think it may be possible to machine up a little better upper shock mount, or just throw some spacers behind the shocks and push them out further. I have not tried a whole lot yet. Just looking at ideas.

Not sure how tall the Pro-Line Chisels are, but they seem pretty comparable to Rovers, in over all height. The foams are soft though, so the tires do squat.

Yes i took the stock axial 101 30 degree bents and bent mine to bout 40 or 45 degrees?? Yes the chisels are close i just never could make them work for my driving i like the rovers?? my opinion again!! Also if i did vent my wheels they would sag more so keep that in mind!!

You could possibly just get longer 3mm screws and some spacers for the shock if u get what im saying??? This would move them out to be in more of a straight line running with the chassis??

If you take a look at my build thread i moved the entire upper shock mount to the outside of the chassis and then put spacers between that!! They are close to the bottom but if u look close enough u will see what i am talking bout sorry for the crappy pics phone pics!!

Just ordered my xr-10

[Krakker]

Sipe the chisels, it's really help the tire perform. I've got a sipe thread in the wheels N tires forum.
Add some weight to them front wheels.
Even if it contacts a little, I'd try and get some more GC by adjusting the shocks.
Part of the issue is the chassis's design. I can grab a 12.5" vertical ledge with my Bully, and "crawl" up the entire obstacle. (even with the Chisels I've siped.)

[Espeefan]

Originally Posted by junior ax10

Yes i took the stock axial 101 30 degree bents and bent mine to bout 40 or 45 degrees?? Yes the chisels are close i just never could make them work for my driving i like the rovers?? my opinion again!! Also if i did vent my wheels they would sag more so keep that in mind!!

You could possibly just get longer 3mm screws and some spacers for the shock if u get what im saying??? This would move them out to be in more of a straight line running with the chassis??

If you take a look at my build thread i moved the entire upper shock mount to the outside of the chassis and then put spacers between that!! They are close to the bottom but if u look close enough u will see what i am talking bout sorry for the crappy pics phone pics!!

Just ordered my xr-10

I have been considering spacing out the shocks too. For as good as these crawlers climb, stock, I know it should already perform better with the high clearance links. Now it's just a matter of tweaking what I can and playing with different shock mounting ideas.

[Espeefan]

Originally Posted by Krakker

Sipe the chisels, it's really help the tire perform. I've got a sipe thread in the wheels N tires forum.
Add some weight to them front wheels.
Even if it contacts a little, I'd try and get some more GC by adjusting the shocks.
Part of the issue is the chassis's design. I can grab a 12.5" vertical ledge with my Bully, and "crawl" up the entire obstacle. (even with the Chisels I've siped.)

Cool. I'll give that thread a look, if I can find it. I agree, Axial could have done things a little different with the chassis. Or even just changed the way the shocks and lower links mount to the axle. It's really tight. I've got some idea though. See what happens.

[Harvo]

If you can't crawl a ledge, there are two other ways to get up. You can smack the ledge with the skid at a higher speed and if the front is heavy enough or if the skid is angled like a moonbuggy, the skid will slide up until your rear tires hit and grab.

The other way is to get the front up, throttle hard so you do a little wheelie and let your rear tires hit the face of the ledge first. They will bounce up, throwing the front down on top, giving you plenty of mo to move on.

There have been some pretty cool slow motion videos of these methods on the site before.

My XR links are set up similarly to yours. It really doesn't like the "smack" method too much.

Here is one of the vids. Wathc the whole 2:40. The best one is at the end.

[stoneface]

I'm thinking the Flat Irons are one of the tallest tires, and they have a really good width(narrower) to traction. One thing I did for my links on my scorpion is, take the front steering link ends that have a lower off set eye hole (look like a side ways P). That gave me about a 1/8- 1/4 more clearance without raising the cg. it'll put the links higher up into the chassis. I had to space out the shocks to clear the links which gave me a wider platform. Oh, by the way those off set ends can be found in the upgrade kit for the AX10/scorpionFlat Iron tire. A 5" all-terrain tire specifically for 2.2" size wheels.

[Krakker]

Originally Posted by stoneface

I'm thinking the Flat Irons are one of the tallest tires, and they have a really good width(narrower) to traction.

You're not serious are you? FlatIrons tall ?? I don't think so. Their lug pattern and compound is terrible for ANY type of competetive crawling. They are strictly a scale use tire.

[Espeefan]

Harvo, thanks for posting that video link. I enjoyed it! Very cool to see the action in slow motion.

[stoneface]

I'm sorry, I must have been thinking of a scale build. I did use them on my mini crawler, and I liked the performance that they gave me. I could get traction where the rock claws that came on it. and it did raise the mini up about a 1/8 to 1/4". I know that there are comp tires out there., but they seem to be one type of surface tire. I believe, it might just be a matter of what we want our rigs to do. But, hey, if the flat irons aren't the tallest what would be ? cheers

[Krakker]

Didn't mean to sound off like a pie hole I actually thought you were yanking chain on them being tall.
Sedona's, Rovers, Boss Claws, Chisels, Panther leopards and X-locks are going to be the "Tall" tires to chose from.