Bomber vs Yeti vs Rock Rey

[DeathVirus]

Yeti vs Rock Rey
Comparing almost apples-apples I’ve locked the diffs on both Yeti and Rock Rey, run on 3s 5000mah packs and on 2.2 Proline Hyrax’s with single-stage foams. My default terrain is grass. I’ve lowered the hearing by 2 teeth on the pinion on each truck from stock bc I felt they felt overgeared for 3s out of the box.

Climbing- I had assumed the Yeti was the better climber bc the stock Servo is so slow on the Rock Rey and bc the Rock Rey cogs so badly but upon further inspection I realized the Yeti has a more forward weight bias which helps tremendously in crawling situations

Handling- the more balanced forward-to-rear weight bias of the Rock Rey helps it handle much better. Also, the metal chassis does add weight down low which keeps it more planted and it usually lands back on its feet if it does roll over. The motor and the batter are also in lower positions than in he Yeti which gives it a lower center of gravity.

Suspension- the Rock Rey out of the box has almost-spot on suspension settings. I did raise it up a little because it was sitting a little low but it handles rough terrain very well. I had to stiffen the front Yeti shocks to 60wt oil from the stock 30wt bc it just wasn’t enough. 60wt in the front of the Yeti is the sweet spot to me. The turning radius is much better in the Rock Rey as well even with the locked diffs. I didn’t upgrade any of the steering components in either truck. The Rock Rey’s wheels wobble when turning at full lock. I suspect it’s the stock flexible steering linkages. This does not happen with the Yeti. I’ve kept them both stock bc there’s no Servo saver and these trucks are for my 6yr old boys.

Electronics- the Yeti has a smoother power delivery, cogs much less, and is also quieter. The Castle system is nice and highly adjustable. The Rock Rey’s system is obnoxious even with the lowest start mode. It has ridiculous power and insane acceleration BUT if both had the same punch setting the Yeti will wheelie or flip over faster. It might be due to the Rock Rey having stiffer rear springs.
The stock servos are crap but I feel the Yeti has the better one although its analog and also weaker. It’s faster by a little on paper but seems much faster when you’re actually driving it. Analog 143oz/in @.21s for the Yeti vs Digital 161oz/in @.24s for the Rock Rey and yet the Yeti seems much faster

Transmitter- the Yeti has a much better RTR transmitter. The foam feels nice and firm on the wheel and the trigger gives you feedback. The Rock Rey has just a plastic wheel and has zero trigger-feel. You feel very disconnected when driving it.







Of course by design the Bomber was the best crawler. No rocks here but lots of roots. The Rock Rey had the best handling hands down and was also the fastest and quickest even with the lowest punch setting. The Yeti was in between- climbed better than the Rock Rey but faster and handled better than the Bomber. The Yeti and Rock Rey had almost-locked diffs with silly putty (17 billion CST) and used Proline single stage foams with 2.2 Hyrax tires. The Bomber has Proline dual-stage foams with vented 2.2 Hyrax tires. All wheels had vent holes open.


If all upgrades were equal, electronics (Tekin RX8+HH Puller Pro/Hitec Servo), shocks, steering components and suspension links, I believe the Yeti would be faster around a U4RC track. Around a short course track with diffs unlocked I believe the Baja Rey is faster than a Yeti Score though.


The Bomber is mine. The Yeti and Rock Rey are for my twin 6yr old boys. They’re pretty good considering they’re scale vehicles and started them off with monster trucks when they were 4.

[DeathVirus]

RR10 Bomber
13/64 gearing with stock 5.67 internal ratio
Axial HD UD gears 43/13 6.417 internal ratio
Castle Sidewinder 3 with Vanguard 3150 motor
XT60 connector
Passive cooling: (2) Bastens aluminum heatsink
Savox sw-1210sg (277.7oz/in, .15s)
Castle 10A BEC enclosed in TRX receiver case
Axial aluminum servo horn
Axial 2spd kit with regular 2:1/1.08 gearing
Traxxas 2075 shifting servo (125oz/in, .17s)
Stock suspension geometry
Front shocks outboarded on bottom links
Front: Powerstroke green/blue (2.1/3.5lb-in)
Rear: Pro-spec stock yellow 2.4lb/in
Front/Rear: 20wt/30wt shock oil
Anti-squat upper arm setting in rear
Axial "soft" Rear sway bar 4.027lb/in
Removed rear spare tire and housing
Slipper clutch 1/2 turn out
Proline 2.2 Hyrax G8 compound tires
Proline dual stage foams
Front: Gear Head 2.2 CAC Ez-Loc Aluminum BL ring (3.8oz) with Gear Head 6-lug Plus .500 Hubs
Rear: Proline 2.2 Faultline wheels
Rear: Integy +12mm offset
TSS Brass Knuckles 1.6oz each
1oz lead weight on top of steering servo
1oz wrapped around each end of front axle
1.25oz wrapped around each end of rear axle
Tactic TTX300 transmitter
Energizer Ultimate Lithium in transmitter
Steering dual rate: reduced by 2 notches
Sidewinder ESC Setting: 1.Forward/brake/Reverse, 2.Brakes 25%, 3.Reverse speed 75%, 4.Punch control level 1.High, 5.Drag brake 10%, 6.Dead Band Normal(.1ms), 7.Voltage cutoff Auto, 8.Motor timing High(10-20 degrees), 9.Motor type Brushless
Gens Ace 3s 5000mah 50c "short" pack XT60
Wheelbase: 14.75”
Front/Rear track width: 12.4"/12.25"
Front/Rear Ride Height: 1.73"/1.89" (measured at pumpkin to ground)
GPS'd Top speed: 11.7mph/20.3mph
Theoretical Top Speed: 10.36mph/19.18mph
Calculated Motor Power: 945 watts (1.3hp)
Calculated Axle Torque: 10.6/5.72ft-lbs
Rollout: .29:1/.53:1


Yeti
14/64 gearing with stock 5.67 internal ratio
CC Vanguard with Vanguard 3150 motor
Deans connector
Passive cooling: (2) Bastens aluminum heatsink
Tactic TSX45 (143oz/in, .21s)
Stock suspension geometry
Front: Stock green (4.33lb/in)
Rear: Stock yellow (1.14lb/in)
Front/Rear: 60wt/30wt shock oil
Front shocks mount: C/2
Rear shocks mount: Stock
Anti-squat upper arm setting in rear
Axial "soft" Rear sway bar 4.027lb/in
Proline 2.2 Hyrax G8 compound tires
Proline single stage foams
Front: Walker Evans 3-piece beadlock design
Rear: Walker Evans 3-piece beadlock design
Braini Silly Putty/slipper factory stock/locked
(80M CST slow compression, 17B CST rapid deformation)
Tactic TTX300 transmitter
Energizer Ultimate Lithium in transmitter
Steering dual rate: reduced by 1 notch
Vanguard ESC Setting: 1.Forward/brake/Reverse, 2.Brakes 30%, 3.Reverse speed 50%, 4.Punch control level Medium 40%, 5.Drag brake 10%, 6.Dead Band Normal(.1ms), 7.Voltage cutoff Auto, 8.Motor timing Medium(10 degrees), 9.Motor type Brushless, Medium Start Power
SMC 3s 4500 90C True Spec Premium
Wheelbase: 14.25”
Front/Rear track width: 12.8"/12.8"
Front/Rear Ride Height: 1.65/1.85" (measured at pumpkin to ground)
Front wheel travel: 2.25″
Rear wheel travel (straight vertical): 3″
GPS'd Top speed: 25.8 mph
Theoretical Top Speed: 25.24mph
Calculated Motor Power: 945 watts (1.3hp)
Calculated Axle Torque: 4.35ft-lbs
Rollout: .70

Rock Rey
10/25 Mod1 gearing with 2:1 internal ratio
Dynamite Fuze 130amp with 2800kv motor
EC3 connector
Passive cooling: (2) Integy heatsink
Associated XP DS1015 servo (201oz/in,.108s)
Losi aluminum servo horn
Stock suspension geometry
Front: Stock springs
Rear: Stock springs
Front/Rear: Stock 30wt/30wt shock oil
Front shocks mount: Stock
Rear shocks mount: Stock
Stock Rear Rock Rey sway bar
Proline 2.2 Hyrax G8 compound tires
Proline single stage foams
Front: Proline 2.2 Denali wheels
Rear: Proline 2.2 Faultline wheels
Rear: Pro-Line 6-Lug 12mm Standard Offset Hex Adapters
Braini Silly Putty/Braini silly putty/locked
(80M CST slow compression, 17B CST rapid deformation)
Spektrum DX2E: ~25% AVC setting
Energizer Ultimate Lithium in transmitter
Dynamite Fuze ESC Setting: 1.Forward/brake/Reverse, 2.(3)Drag Brake 10%, 3.(5)Low Voltage Cutoff 3.2V, 4.(1)Start mode level1(20%?), 5.(1)Max Brake Force 25%, 6.Max Reverse Force 25%, 7.Initial Brake Force=drag, 8.Neutral Range Normal, 9.Timing 0 degrees
Dynamite Reaction 3s 5000mah 50C
Wheelbase: 15”
Front/Rear track width: 12.75"/12.75"
Front/Rear Ride Height: 1.535/1.65" (measured at pumpkin to ground)
Front wheel travel: 2″
Rear wheel travel (straight vertical): 3.2″
GPS'd Top speed: 32.9mph
Theoretical Top Speed: 31.9mph
Calculated Motor Power: 1638watts (2.2hp)
Calculated Axle Torque: 5.72ft-lbs
Rollout: 1.04

[BattleShrink]

Nice! What are your thoughts on yeti vs. rock rey for a guy who already has a bomber?

[DeathVirus]

Originally Posted by BattleShrink

Nice! What are your thoughts on yeti vs. rock rey for a guy who already has a bomber?

As you’ve probably read or heard over and over, the Rock Rey is a pain in the arse to work on. Whatever you gotta do, do it all at once and be done with it. Don’t even bother with fluids bc you’ll just end up having to change them out when they wear down. Silly putty works great. Use less if you need a little slip. I change the diffs to putty, Servo horn to aluminum (even though the new ones are better than the first iteration, and changed the pinion to 10T from stock 12T. It runs hot on 3s with the 12T and cogs much more. The steering is much improved over the Yeti out of the box.

The Yeti is much easier to work on and is quieter. Has a smoother startup especially if you know what you’re doing on Castle Link. The battery I use is top notch on the Rock Rey while the Venoms I use in the Yeti is high resistance. 1-2ohms resistance tops on the Dynamite but normally 1ohm on all 3 cells. The Venom gets 9ohms one cell and normally 5-6ohms resistance on the other 2 and the Yeti still cogs much less.

Stock steering Servo is EXTREMELY slow in the Rock Rey. So slow you’d think it was an old analog Servo with loose Servo saver. Yeti has better Servo out of the box. I have better ones but on trucks like these I prefer them to be slow for my kids. Don’t want them to be too twitchy or they’d flip all over the place

I like the Rock Rey more overall for bashing. Looks cooler overall and very fast. If fully upgraded though I’d take the Yeti. It makes a better racer bc it has more consistent traction. The layout gives it good balance. For some odd reason it’s alot harder to go through trails with the Rock Rey. Weight distribution is better in the Yeti to me for trails

[Crawler Cads]

Great post DeathVirus, appreciate that detail.
I absolutely love the Rey and it's a bargain at Horizon right now. More and more parts being manufactured for it as well.
That all said though it's interesting to see the Nomad which is another great looking racer.
If money and time were no object I think a custom (rcnetwork) db48 would be in order, http://www.thercnetwork.com/rc-cars/...ed-u4rc-racer/
Thanks again for the write-up

Sent from my Pixel using Tapatalk

[DeathVirus]

Originally Posted by Crawler Cads

Great post DeathVirus, appreciate that detail.
I absolutely love the Rey and it's a bargain at Horizon right now. More and more parts being manufactured for it as well.
That all said though it's interesting to see the Nomad which is another great looking racer.
If money and time were no object I think a custom (rcnetwork) db48 would be in order, Tekno DB48 Desert Buggy - Customized U4RC Racer - The RCNetwork
Thanks again for the write-up

Sent from my Pixel using Tapatalk

I was seriously considering the Nomad because I love 1/8th scale durability and I’m so used to independent suspension and so are my kids.. but out on the trails the limited ride height and long wheel base would keep it high centered on just about anything!

Really depends on what you’re going for. If you already have a Bomber then the Nomad is a no brainer. The Losi Ten SCBE is also something to look into as well

The RCnetwork’s DB48 is pretty amazing but that’s a lot of custom work he did and I’ve never owned a Tekno

[DeathVirus]

Made an update to original post comparing the Yeti to the Rock Rey

[DeathVirus]

Have a Savöx SW1211SG (208.3oz/in, .10s) on order for the Rock Rey which should be in by tomorrow along with a Losi 25T aluminum horn. I didn’t realize my son was actually struggling with the slow servo until he slammed into a tree. We also had some difficulty maneuvering around some tight spots yesterday when we were crawling around a construction site.

The Yeti’s Servo, although weaker on paper, seems a lot better and seems to be working pretty well for my other son. I also feel kinda lazy replacing the Servo on the Yeti. It seems like more work than changing out the one in the Rock Rey

[mond]

Originally Posted by DeathVirus

I was seriously considering the Nomad because I love 1/8th scale durability and I’m so used to independent suspension and so are my kids.. but out on the trails the limited ride height and long wheel base would keep it high centered on just about anything!

Really depends on what you’re going for. If you already have a Bomber then the Nomad is a no brainer. The Losi Ten SCBE is also something to look into as well

The RCnetwork’s DB48 is pretty amazing but that’s a lot of custom work he did and I’ve never owned a Tekno

The SCBE is a lcg short course with a tube body. It's no where even remotely as capable as something that can mount proper 2.2s. The SCTE hubs on them reduce wheel choice, as does the chassis width. I've got an SCTE 2.0 with the SCBE body. Looks cool but it's not a rock racer. That Associated though, that looks capable.

I concur on the Rock Rey. PITA to work on but to get a Yeti as durable and possibly as capable requires $$$$$. The RR kit with a good servo and sensored setup and a SSD front diff is pretty bomb proof for a fraction of the cost of a Yeti with all the weak points fixed.

[DeathVirus]

Originally Posted by mond

The SCBE is a lcg short course with a tube body. It's no where even remotely as capable as something that can mount proper 2.2s. The SCTE hubs on them reduce wheel choice, as does the chassis width. I've got an SCTE 2.0 with the SCBE body. Looks cool but it's not a rock racer. That Associated though, that looks capable.

I concur on the Rock Rey. PITA to work on but to get a Yeti as durable and possibly as capable requires $$$$$. The RR kit with a good servo and sensored setup and a SSD front diff is pretty bomb proof for a fraction of the cost of a Yeti with all the weak points fixed.

The biggest difference to me is the steering radius. The steering radius on the Yeti even with an unlocked diff is much worse than the Rock Rey with all diffs locked. But that’s expected from Losi IMO. I’ve always liked Losi; My brother had a Brian Kinwald buggy and it had amazing steering and handling.

One thing that’s odd though is the Rock Rey has a much higher gear reduction at the diffs than the Yeti and yet it has much worse torque twist. Even at level 1 punch you can’t pin the throttle on the Rock Rey because it will go crazy and flip over. With the stock Servo and AVC set to 25%, if you pin the throttle it will fishtail atleast 3 times until it tracks straight. That’s why I ordered the Savox SW-1211SG instead of the SW-1210SG because it’s much faster. Using a faster Servo on something that has a gyro significantly improves its effects.

I will continue to improve both. The only thing that has broken so far is the Rock Rey pulled the eyelet off the shock shaft when my son hit a tree. Upon further inspection I found that he wasn’t tracking straight because he accidentally turned the steering trim (which is very easy to do) on the transmitter. He couldn’t correct it fast enough because of the super slow stock Servo. I fixed it by supergluing the eyelet back on the shock shaft and it’s stayed put ever since. The plastics seem stronger and flex much less on the Rock Rey than the Yeti too. I noticed the flex on my Bomber but I don’t see any reason to change anything out yet until it breaks a link or something

[CoolRunning]

I also own all three.

My stock Rock Rey outcrawls my Yeti. Yeti even has fancy tyres and lots of small mods to keep it reliable. Both have completely locked drivetrains (front, rear and centre). RR is clearly much faster. Better jumper too.

I’d love 2 speeds for both trucks.

Yeti is a bit easier to work on though I would have barely needed to pull the RR apart if I hadn’t locked the diffs where the Yeti needed some regular TLC along the way to keep it running.

Bomber is easily the best slow crawler with a 2 sp and brushed motor.

I like all three but need to spend a bit of money on the Yeti to sort out some handling issues atm.

Over a year later, the RR still needs nothing and goes like a champ.

Bomber has also been bulletproof. Amazing really.

[DeathVirus]

Originally Posted by CoolRunning

I also own all three.

My stock Rock Rey outcrawls my Yeti. Yeti even has fancy tyres and lots of small mods to keep it reliable. Both have completely locked drivetrains (front, rear and centre). RR is clearly much faster. Better jumper too.

I’d love 2 speeds for both trucks.

Yeti is a bit easier to work on though I would have barely needed to pull the RR apart if I hadn’t locked the diffs where the Yeti needed some regular TLC along the way to keep it running.

Bomber is easily the best slow crawler with a 2 sp and brushed motor.

I like all three but need to spend a bit of money on the Yeti to sort out some handling issues atm.

Over a year later, the RR still needs nothing and goes like a champ.

Bomber has also been bulletproof. Amazing really.

I’ve had a different experience. The Yeti has been the cheapest so far. Aside from changing the front shock fluids and locking the front diff all I’ve done is change the pinion and tires/foams. I was even able to reuse the stock wheels. I always put heatsinks on my motors and I already the Bastens ones on hand.

The Rock Rey has been almost the same except I didn’t have to mess with the suspension at all. It handles everything like a champ. But I did have to buy new wheels to go with the tires/foams and new battery since I didn’t have anything EC3. I don’t know how you were able to crawl with the Rock Rey. We had difficulty staying on line because of the crappy stock Servo

The Bomber has been the most expensive by a wide margin. The stock suspension just didn’t work out no matter how much I tuned it. Going relatively fast over the slightest bump or dip would unsettle it, destabilize it, or make it donkey kick like no other. It couldn’t even take a high-speed corner. When I finally did the Powerstroke/Pro-Spec upgrade it was night and day. It can handle all the rough terrain at speed, still be able to crawl, and corner relatively well (for a solid axle) even in grass or pavement. The 2 speed has been amazing. It’s like having a drag brake button! I’ve also had to upgrade to the 43/13 HD bevel gears though. THAT vastly reduced torque twist- it not only crawls up steep ledges MUCH better [without back flipping] but I can also pin the throttle in grass and it will take off straight. It was all worth it

I still have the Stampede 4x4 as our resident full-independent suspension setup but it’s a work in progress.. trying to make it more scale is tough when it wasn’t designed to be scale and I don’t want to copy Jang’s Chimera.

[mond]

The Rock Rey really benefits from better foams. The tyres are too large for standard CI or Proline closed cell foam though.

[DeathVirus]

Originally Posted by mond

The Rock Rey really benefits from better foams. The tyres are too large for standard CI or Proline closed cell foam though.

The Proline Hyrax 2.2’s fit in their single stage closed cell foams. It’s not snug like it is in the dual stage foams or the stock open cell foams but it does still fit. I like the extra stability from the closed cell foams

[Jboucher]

Originally Posted by DeathVirus

The Proline Hyrax 2.2’s fit in their single stage closed cell foams. It’s not snug like it is in the dual stage foams or the stock open cell foams but it does still fit. I like the extra stability from the closed cell foams

I had the same question on my yeti Jr, Im using lil'nova single stage in my MT/R 1.55 tires.
The foam dosent fill the tire like a dual stage. It needs and rely on that air space to get good traction according to CI.

Works awesome for speed bashing and light crawling.

Sent from my Nexus 6 using Tapatalk

[mond]

Originally Posted by DeathVirus

The Proline Hyrax 2.2’s fit in their single stage closed cell foams. It’s not snug like it is in the dual stage foams or the stock open cell foams but it does still fit. I like the extra stability from the closed cell foams

I have them on my Rock Rey and cut the center out of the crappy open cell foams that come with them, wrapped that around the closed cells to take up that extra space. Not true two stage but there's no real slack in the hyraxes now.

[durok]

A slightly humorous note - I'm going to be using Rock Rey Maxxis Creepy Crawler tires mounted on nice and wide GearHead RC beadlocks for basher tires on my Bomber...

They've been soaked for a week in "Bitches Brew" - a volatile, vaporous, and venomous mixture of Purple Power / Simple Green / Greased Lightning super-strength cleansers.

They are currently stacked on their sides, wrapped in plastic sheeting - and are very sticky.

Awaiting the build completion...

[DeathVirus]

Originally Posted by mond

I have them on my Rock Rey and cut the center out of the crappy open cell foams that come with them, wrapped that around the closed cells to take up that extra space. Not true two stage but there's no real slack in the hyraxes now.

That’s creative! I think they made the closed cell foams tight enough to fit the Flat Iron XL so that’s why there’s the extra slack when using the Hyraxes. The extra slack doesn’t bother me at all though. It’s like running your tires low at the drag strip.. it just creates more grip! It feels like it has more grip than the dual stage foams.. except my Bomber does have weight added to it unlike my kids’ Yeti and Rock Rey.

[DeathVirus]

Originally Posted by durok

A slightly humorous note - I'm going to be using Rock Rey Maxxis Creepy Crawler tires mounted on nice and wide GearHead RC beadlocks for basher tires on my Bomber...

They've been soaked for a week in "Bitches Brew" - a volatile, vaporous, and venomous mixture of Purple Power / Simple Green / Greased Lightning super-strength cleansers.

They are currently stacked on their sides, wrapped in plastic sheeting - and are very sticky.

Awaiting the build completion...

I wonder how soft they’re turn out. They were pretty soft out of the box

[DeathVirus]

An hour and 15 minutes later I finally finished installing the Servo! The Savox 1211SG’s wire was far too short but I had an Associated XP DS1015 that I was no longer using so I used that instead. It’s not as good- (water-resistant instead of waterproof), it’s weaker at 201oz/in and slower at .108 compared to 208.3oz/in at .10s but it’s close enough.

What took so long was the Servo was reversed and I didn’t know I had to rebind it to work with the AVC. Had to rebind 3 times because I accidentally reversed the throttle too lol. It works amazingly well now though. Even on concrete it hooks up straight right away