Mojave Larger tires for mojave. Backflip 4s. Details inside.

[Summitp]

I have found the threads here, and the F@#$book threads around larger tires for a mojave to be frustrating, and lacking in detail around what actually works, and how to get it to work. So my goal here is to show in detail how to make the backflip 4s wheels and tires work with a mojave, mine is an exb.

This change will net significant improvements in handling. The truck exhibits fewer rollovers, and is more stable in fast rough conditions. It is also more adjustable in the air thanks the the larger rotating mass.

First off, the backflip 4s wheels and tires are significantly larger than stock. So you will need to regear. I am running a mamba monster 2 2200kv system. I regeared with a 13t pinion and motor temp after rompin a full 6s pack were 185f, but it's chilly out.

Second, you will need to trim the body significantly to get them to not rub under compression. You will also need to trim about 3/4" off either end of the front bumper so they don't rub when turning.

Third, the hex depth on the backflip wheels is approximately 1.5mm deeper than the stock wheels, and will rub against the hub carriers with the stock hub hexes. You can run some alternate hex, or, what I did, is use a small spacer. I found some copper crush washers commonly used in oil filters for bmws (and many other uses) and they were a perfect fit. This gave the clearance needed for the wheel to clear the hub carriers.

Fourth, I do recommend bumping up the thickness of the shock oil on all 4 corners. I am using 710cst losi oil. The suspension is still pretty soft, but better control over the larger wheels and tires is needed over stock, and the thicker oil gives you that.

So, here you, some pics, and a running video.

Youtube video... Thanks to my 8yo cameraman.

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[SentFlying]

Looks really good dude

 

[Summitp]

Well, that didn't take long. Front diff is fubar. Just about locked up. The drivetrain spins fine, but the front diff action is grinding and tough to operate. As the drivetrain rotates fine, the issue must be inside the diff housing (the actual diff itself, not the ring and pinion and support bearings). That being the case, I am going to order up stuff to build a new diff, probably not a limited slip one, but one that can be built tough and built to last. I can tune the thickness of the oil in the diff to get the action I want. And since the drivetrain spins fine, I will continue to beat on it until it dies or the new one is ready to install.

 

[SentFlying]

Maybe the front diff was already in need of a rebuild? Did you run it on grass?

 

[L3phturn]

Well, that didn't take long. Front diff is fubar. Just about locked up. The drivetrain spins fine, but the front diff action is grinding and tough to operate. As the drivetrain rotates fine, the issue must be inside the diff housing (the actual diff itself, not the ring and pinion and support bearings). That being the case, I am going to order up stuff to build a new diff, probably not a limited slip one, but one that can be built tough and built to last. I can tune the thickness of the oil in the diff to get the action I want. And since the drivetrain spins fine, I will continue to beat on it until it dies or the new one is ready to install.

You can still tune the diff with oil thickness as well as plate placement in the LSD diffs. I would head to JennysRC and pick up Mojave EXB front and a center as well. Added benefit is that diff fluid is difficult to find right now, especially the heavy stuff. You can use diff fluid 1/3 as thick in an LSD diff, maybe less. Plus the new 29mm diffs and input gears are stronger.

 

[Summitp]

I have run it on grass, and we beat on em pretty hard. I pulled the diff apart last night, found no broken or damaged pieces, so I cleaned, reassembled, and filled with 50k diff fluid that I had on the shelf. A test run showed it to be working fine, but I think this issue will come back. Shims are the solution I think. Or, it looks to me like rebuilding according to minimum lsd effect will also prevent the problem, as it will press the round lsd ring further into the side gear that drives the output.

See attached photo.

 

[L3phturn]

I have run it on grass, and we beat on em pretty hard. I pulled the diff apart last night, found no broken or damaged pieces, so I cleaned, reassembled, and filled with 50k diff fluid that I had on the shelf. A test run showed it to be working fine, but I think this issue will come back. Shims are the solution I think. Or, it looks to me like rebuilding according to minimum lsd effect will also prevent the problem, as it will press the round lsd ring further into the side gear that drives the output.

See attached photo.

View attachment 120900

I tried adding shims behind the pin to my original spec ESC but in the end the LSD minimum effect felt the best. I used exactly 1 059, 1 060, and the LSD plates as above for minimum effect. Running well so far but haven't bashed it super hard. Then again I'm running it on snow and ice, so I am working the diffs hard with tons of wheel spin. I also used the KEXB to pull one of my daughters down the icy street in a sled. LOL. I had to push the sled to get it started but it worked from there. Put a lot of strain on those diffs, but no damage.

 

[Edough13]

Just a thought, might be better to swap out the hubs and hex's to the K6s set. Should give you even more clearance from the body and also widen the stance a bit adding more stability. Should be able to pick up a set from Jenny's for pretty cheap.
For front diff if it's newer you may just need to add another shim to ring and pinion as the gears have worn into each other, again just another thought

 

[LuigiMain]

Looks great with the bigger tires

 

[Summitp]

The cleaned and reassembled front diff survived a raucous 6s session. Still feels fine.

Love the backflip tires.

 

[KevinC]

Discovering this thread now as I am looking for wheel options for the Mojave. I would like to try something bigger.
Thx for the info.

cheers,
kev

 

[Summitp]

I really liked the outcast 4s setup. I finally stripped a wheel out after 5 months running 6s and regular beatings. I went to buy another pair, and the store was out, so I am running 3.8 prolines now. Also very good. No washer required with the prolines.