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R/C Tech Forums Thread Wiki: Official Xray XB2 2WD Buggy Thread
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Last edit by: dgrobe2112
Instruction manuals: (C/O BentKa)

Xray XB2 Carpet Edition Instruction Manual
http://www.teamxray.com/xb2/2016/dow...ual_v2_low.pdf

Xray XB2 Dirt Edition Instruction Manual
http://www.teamxray.com/xb2/2016/dow...w.pdf?update=2

BentKa: Carpet Edition 4 gear to 3 gear laydown conversion parts:
  • Gearbox #323014
  • Motorplate #324012
  • 36T idler gear #324236
  • Brace for waterfall #324031


Socket: Bodies Available:

Xray has two OEM bodies, the .75mm and the .50mm light weight:
light weight: https://www.amainhobbies.com/xray-xb...329701/p492942

OEM .75mm: https://www.amainhobbies.com/xray-0....329700/p477762

Also, I've fitted the yz2 body, both the light and regular fit fine, just make your own cut lines:
https://www.amainhobbies.com/yokomo-...z2-101/p417674


[i] J Concepts S2 Body [i]


Penguin Racing makes a high grip body that fits the DE and CE:
http://www.ebay.com/itm/X-Ray-Xb2-Hi...oAAOSw1S9WewHV



Socket: Wheel fitment:

According to some, you'll require different offset rear hexes to use B5M wheels. According to my Hudy setup board, B5M wheels are the same offset. I measured the overall width of the car with XB2 wheels, and then again with B5M wheels, same measurement.

On the front, B5M wheels were 1.5mm wider. Xray offers hexes to reduce width -.75 on each side, or you could spend 3-5 minutes and sand your OEM hexes down .75mm.

edit by dgrobe2112
here are the hubs for losi and AE

for AE Front 365354 -0.75
for Losi rear 365358 +3.00 (4 stripe)
for AE rear 365359 +3.75 (5 stripe)



Socket: Flex and the XB2:

Flex screws are as follows:

Plastic bulkhead between motor and waterfall. Can remove screw in chassis, or remove bulkhead altogether.

Waterfall has 4 screws, can remove the inner two or outer two. IIRC, removing the inner two provides more flex, and thus more bite.

Removing the battery brace. This gives a tremendous amount of flex on the middle of the car, and can sometimes be inconsistent. I do this for outdoor racing on low bite. I like the feel over the 4 gear in 17.5 racing, since the 4 gear will take some snap away off the corner.

Rear C block - has inner and outer screws. I haven't played with this, as it's a crucial pivot point of the car.

Medium arms and towers -> I don't believe the carpet car has the rear medium tower available, however the DE DOES have an optional hard part. I think the hard parts are more consistent, especially when it gets hot (90+ degrees F). However, the medium parts do NOT break unless you're severely talented. They also don't wear out.



Socket: Avid/Schelle Slipper mod:

Credit to WillS, Matt Trimmings, and myself for figuring this out months ago.

Parts you'll need:

B5M V2 3gear compatible top shaft.
TKO Special 5x13x5 bear OR 5x13x6 bearing Either can work. This replaces the spur side bearing on the top shaft.
5mm shims, same shims used in 1/8th scale clutch bells. Look for protek .1mm and .2mm kit.
Avid or Schelle b5m top shaft kit, with spur gears of your choosing. (DE can't handle a 69, the CE can)

Shimming: You'll need to install the bearing in the front portion of the removable piece for the shaft. Make sure the bearing is pushed all the way in. With the TKO bearing, you'll need to shim approximately 1.4mm on the front side of the top shaft. Roughly .3-.5mm with the other bearing. This is a "feel" and tolerance setting. I urge you to watch videos about setting clutch bell play in 1/8th scale to get an idea of what yield you want for end play. Too tight, it'll eat bearings.

Outside of trans case: Use Avid/Schelle top shaft spacer plus .2mm shim to offset slipper from motor plate perfectly. Install slipper as instructed, and use Avid/Schelle spring and XB2 slipper nut.

- NEW - Schelle now sells Xb2 Topshafts. They include a spacer, so no need for shims in gearbox, and comes with the smaller bearing. Both methods work.

Socket: Yokomo Differential or MIP pucks:

Credit to: WillS for figuring out pucks, and as well fitting the Losi 22 diff with the same mods.

Parts needed: Yokomo Bmax2 or YZ2 complete diff OR Mip PUCKS outdrives
Xb2 diff gear
Bmax2 V3 Worlds rear dog bones, or Bmax 2 pucks dog bones
You'll use XB2 axles, and will require no other mods for the axles or dog bones.
You'll need .2mm outdrive/diff shims. Shim approximately .5mm on each side of the diff, behind the bearings. The top portion of the transmission is what "sets" the diff in place, not the bottom half. A little play back and forth is fine, the stock diff has some play from the factory.

dgrobe2112: CE to DE conversion:
along with the parts needed.. you MUST have these following hardware, or it wont work

https://www.teamxray.com/xb2/2016/do...conversion.pdf

(3) XRAY 902340 M3x40 button head screws. these are the screws that mount the motor mount to the tranny
(4) XRAY 903322 M3x22 counter sunk screws. these are for the rear diff case, to mount to the chassis. i think i used some M3x18 and they worked ok.

Socket: Best method for setting up the XB2 ball diff:

The XB2 diff is stellar when setup correctly. The spring is too short and soft, allowing the diff to slip. You'll need to glue the rings to the outdrives with just a drop of CA, then add a 1mm shim between the spring and the outdrive. This preloads the spring and stops the diff from slipping so easily.

OR, you can run the AE diff spring, which is both slightly longer, and stiffer. The overwhelming issue is the stock spring allows the nut to bottom out on the outdrive before the diff is tight enough.

This shim:
https://www.amainhobbies.com/xray-al...a303122/p12070

This diff spring (don't need a shim, then.)

https://www.teamassociated.com/parts...thrust_spring/

Functional Aftermarket parts: (Not just bling!)

Servo Horn: (The B5M sized horns are too short to get full throw)
https://www.amainhobbies.com/protek-...800-bk/p273496


Socket: Exotek has a full suite of parts, some bling, some not. Here's a list (all fit DE and CE, unless otherwise noted):

Titanium front axles: http://www.exotekracing.com/xb2-titanium-front-axles-2/

Rear Hanger, HD (Adds 4 grams): http://www.exotekracing.com/xb2-rear...75-heavy-duty/

Brass C block, 18 grams added: http://www.exotekracing.com/xb2-rear...-brass-weight/

Alloy front camber mount: http://www.exotekracing.com/xb2-fron...er-mount-7075/

Carbon Fiber Chassis: http://www.exotekracing.com/xb2-carb...m-plate-2-5mm/

Alloy rear hubs:http://www.exotekracing.com/xb2-allo...ub-set-2-7075/

Alloy servo mounts, allow for use of LP servo:http://www.exotekracing.com/xb2-xb4-...-alloy-1-pair/

Titanium shock mounts: http://www.exotekracing.com/xb2-xb4-...shock-posts-2/

Slipper Eliminator: http://www.exotekracing.com/xb2-direct-spur-mount/
Xray eliminator is #324100

dgrobe2112: 2016-2017 new 3 gear laydown
Gearbox #323014
Motor plate #324012
36T idler gear #324236
Brace for waterfall #324031

dgrobe2112: Xray Spring Rate Conversion:
front C WHT
368174 2 str 0.65-0.85 3.71-4.85

358184 2 dot 0.65 3.71
368185 3 dot 0.72 4.11
368186 4 dot 0.80 4.57


Rear
368273 2 str 0.35-0.45 2.00-2.57

368284 1 Dot 0.35 2.00
368285 2 Dot 0.40 2.28
368286 3 Dot 0.45 2.57
368287 4 Dot 0.50 2.86

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Old 02-05-2016, 01:26 AM   #1306
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I have always found the Xray handling characteristic descriptions to be a little ambiguous.

Moving the shocks to the rear definitely helps in lower traction conditions. Be sure to adjust the droop to compensate for the wishbone angle though. This is a worthwhile tuning aid, but it is not a one size fits all fix for all low grip situations.
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Old 02-05-2016, 06:28 AM   #1307
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Old 02-05-2016, 07:03 AM   #1308
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Quote:
Originally Posted by AntH3000 View Post
Just.....wow.
He is right... Theoretically.

But sometimes theory doesn't play out in the real world.

I can't really explain this to someone without drawing a picture.

Regardless, it would seem that most are finding more grip with the shocks in back. It's just counter intuitive to everything we know about weight transfer. Maybe a long wheel base would help this car too, in low grip, as it seems slowing rotation is a greater benefit than adding weight transfer to rear.
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Old 02-05-2016, 07:20 AM   #1309
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Quote:
Originally Posted by BentKa View Post


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YYYYEEEEESSSS!!!!
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Old 02-05-2016, 07:38 AM   #1310
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Quote:
Originally Posted by BillyT. View Post
He is right... Theoretically.

But sometimes theory doesn't play out in the real world.

I can't really explain this to someone without drawing a picture.

Regardless, it would seem that most are finding more grip with the shocks in back. It's just counter intuitive to everything we know about weight transfer. Maybe a long wheel base would help this car too, in low grip, as it seems slowing rotation is a greater benefit than adding weight transfer to rear.
My understanding is that shocks to the rear puts its their weight behind where the wheel touches the ground. That means the weight is all born at the rear of the car, and if you consider the wheel a fulcrum (picture a see-saw), lightens the weight from the front. As such it would actually promote more weight transfer to the rear then front mounted shocks. Front mounted shocks would share some of the shock weight/load with the front of the vehicle, since it would be between the front and rear wheel fulcrum points.
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Old 02-05-2016, 07:40 AM   #1311
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Quote:
Originally Posted by avaldes View Post
Ok, I'm at work and don't have the car in front of me...why is moving the shocks to the back making the suspension stiffer? I thought I remember the holes being in the same place?

The rear shocks are the fulcrum point for the lever that is the whole car. The further forward they are, the easier it is for the rear of the car to squat. Move them back, and it takes more effort for the car to squat.

The further forward they are, assuming the same spring rate, the more weight they are supporting, and they effectively get softer, letting more weight transfer rearward under power. Move them back, they support less weight, and become effectively stiffer, and the car won't squat as much under power.

Maybe getting rid of that weight transfer is helping to drive the wheels into the ground more, instead of letting the energy pass into then over the rear, it just keeps driving down.

Looks like the shocks are on the back of the dirt car... so... guess I'll be moving mine next time out
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Old 02-05-2016, 07:50 AM   #1312
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Bent you tease!
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Old 02-05-2016, 08:41 AM   #1313
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Moving the shocks from the front to the back changes the static weight distribution to further rearward as you are moving mass rearwards, this gives more traction. It really is as simple as that (assuming you use equivalent droop). However, some of the explanations are quite funny, so carry on!
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Old 02-05-2016, 09:06 AM   #1314
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Quote:
Originally Posted by xray lover View Post
Bent, What should I do for traction in the mid to exit of the corner? I have my shocks in the back.
I took anti squat out of the rear and it really helped with grip mid-out. FR is kit, RR is 1 up.
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Old 02-05-2016, 11:17 AM   #1315
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Quote:
Originally Posted by BillyT. View Post
The rear shocks are the fulcrum point for the lever that is the whole car. The further forward they are, the easier it is for the rear of the car to squat. Move them back, and it takes more effort for the car to squat.

The further forward they are, assuming the same spring rate, the more weight they are supporting, and they effectively get softer, letting more weight transfer rearward under power. Move them back, they support less weight, and become effectively stiffer, and the car won't squat as much under power.

Maybe getting rid of that weight transfer is helping to drive the wheels into the ground more, instead of letting the energy pass into then over the rear, it just keeps driving down.

Looks like the shocks are on the back of the dirt car... so... guess I'll be moving mine next time out
Interesting.

You're describing the impact the weight of the car itself has on the performance of the rear shocks, based on the location of the shocks. IE: You're saying the further forward the shock is, the more weight it bears, thus the softer it is overall it feels given the same springs and such. The only thing I'd suggest is that the shocks are always tied to the same suspension arms and same shock tower. I believe the deltas you're describing would exist only if there were significant flex on the arm or shock tower, or both.

On the other hand, I'm saying that the location of the shock has an impact on how the overall car's weight is distributed front to rear. That weight bias would also have impact on shock performance as you describe, but I think it's due to different dynamics.

Like anything else, you still have to go by what you experience on the track.
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Old 02-05-2016, 11:22 AM   #1316
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Quote:
Originally Posted by AntH3000 View Post
Moving the shocks from the front to the back changes the static weight distribution to further rearward as you are moving mass rearwards, this gives more traction. It really is as simple as that (assuming you use equivalent droop). However, some of the explanations are quite funny, so carry on!
I recall a conversation I was having about shocks one time.. the fella kept saying that the weight of the tires and weight of the shock piston had an impact on how the car landed. Something about installing a brass piston would help with (deaden) his landings. I kept trying to describe that when you land, the tires (nor piston) don't actually move up ... the car itself settles down on the shock, and that the extra piston weight really doesn't have anything do with what he was trying to accomplish. He's basically carrying around unsprung weight.

Maybe I was wrong, but I still am having a hard time picturing the piston moving up when a car landed. However, I still enjoy these random conversations.
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Old 02-05-2016, 01:09 PM   #1317
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Quote:
Originally Posted by BillyT. View Post
The rear shocks are the fulcrum point for the lever that is the whole car. The further forward they are, the easier it is for the rear of the car to squat. Move them back, and it takes more effort for the car to squat.
Confused... I'd think the fulcrum is the contact patch. unless the Arm twists a lot, I don't get it... The weight thing I see being the order-1 effect. backpack effect, 911 vs. Cayman

(plus the order-2 effect of droop because of anti squat that was discussed a few pages back)

edit: Goehm had answered already.
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Old 02-05-2016, 01:42 PM   #1318
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Quote:
Originally Posted by goehm View Post
Interesting.

You're describing the impact the weight of the car itself has on the performance of the rear shocks, based on the location of the shocks. IE: You're saying the further forward the shock is, the more weight it bears, thus the softer it is overall it feels given the same springs and such. The only thing I'd suggest is that the shocks are always tied to the same suspension arms and same shock tower. I believe the deltas you're describing would exist only if there were significant flex on the arm or shock tower, or both.
It actually moves back quite a bit... If you think of the whole car as one arm, with the front wheels being the hinge pin... what happens when you move the shock out(back)? What happens when you move it in(forward)?

I see what you are saying though... it really isn't as simple as I am making it out to be... for one, the front of the car doesn't pivot on a fixed point.

I'm not arguing for one way or the other. I am a firm believer in throwing theories and numbers out the window.... I just want to understand what is happening.

I also agree that moving the weight(of the shocks) back certainly doesn't hurt... But I still think it's a little more complex than just that. Maybe not...
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Old 02-05-2016, 02:07 PM   #1319
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Quote:
Originally Posted by Lonestar View Post
Confused... I'd think the fulcrum is the contact patch. unless the Arm twists a lot, I don't get it...
I'm coming around to this... Still not 100%. But I get why it's not so cut and dry.

I really want to hear X-Rays logic to this, because they are saying the opposite of what everyone is finding.

Dirt car has them on the rear though, so that says a lot...
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Old 02-05-2016, 02:23 PM   #1320
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Question regarding the ball differential: is this using 1/8 diff balls? I tried to look at some replacement parts, and only see full diff sets and the diff gear so I couldn't tell. I counted the openings in the diff gear and see 12, so it leads me to believe they're 1/8 balls - which I think is a great thing. I love how the diffs build and last on my SRX2 which also uses 1/8 balls.
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