Baja 5B Electric roller for $345 should I do it?

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So I bent the center U channel chassis, looks like I'm upgrading to the polymer one whether I like it or not. Everything else is fine just the center chassis was bent.

Also the parts for the drivetrain upgrade have all arrived except for the machined steel diff gears. So it will have:

Heavy duty dogbones and drive cups
Aluminum three section transmission case (easier to remove diff)
CNC machined diff housing.
machined hard steel transmission gears
machined hard steel diff gears
 
Atomic Skull said:
So I bent the center U channel chassis, looks like I'm upgrading to the polymer one whether I like it or not. Everything else is fine just the center chassis was bent.

Also the parts for the drivetrain upgrade have all arrived except for the machined steel diff gears. So it will have:

Heavy duty dogbones and drive cups
Aluminum three section transmission case (easier to remove diff)
CNC machined diff housing.
machined hard steel transmission gears
machined hard steel diff gears
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Where are you getting those parts from if I may ask?
 
Neelis said:
Where are you getting those parts from if I may ask?
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Titracing, Fearless RC, Xmax Racing and some other places. sometimes in the US and sometimes off Aliexpress if it's something I can wait on. Dailymed on Ebay has a lot of Baja stuff too and I got the machined steel transmission gears and diff gears as well as the polymer front chassis from Daves Discount Motors.

I've also put a heavy duty 5mm thick rear chassis plate and a heavy duty front upper steering plate on it now as well.
 
Atomic Skull said:
Titracing, Fearless RC, Xmax Racing and some other places. sometimes in the US and sometimes off Aliexpress if it's something I can wait on. Dailymed on Ebay has a lot of Baja stuff too and I got the machined steel transmission gears and diff gears as well as the polymer front chassis from Daves Discount Motors.

I've also put a heavy duty 5mm thick rear chassis plate and a heavy duty front upper steering plate on it now as well.
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Thanks for the input.

With Arrma and Team Corally I think I know my way around parts and upgrade, but for the Baja it is still a bit of a mystery to me. I will start with building it and using it and see what breaks and what I would like to improve.
 
Neelis said:
Thanks for the input.

With Arrma and Team Corally I think I know my way around parts and upgrade, but for the Baja it is still a bit of a mystery to me. I will start with building it and using it and see what breaks and what I would like to improve.
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The only things I would consider "high priority"is:

The front axles, the stock ones use an E-clip which makes shimming them a pain, they have better ones that use a screw and washer to hold the axle in the bearings that you can get cheap off Aliexpress.

Zero degree aluminum rear hubs, I dislike the overly complex plastic stock ones. Conversely I would not upgrade the front steering knuckles due to the likelihood of damage, the plastic ones are like $15 a set and handle impacts better that metal would.

Three piece aluminum transmission case. This allows you to remove the differential without needing to disassemble the entire back of the car. You can instead pull the rear bulkhead and unscrew the back of the transmission case to remove the diff. If you need to remove the transmission to access the diff I'd recommend replacing it at that time.

Also Rovan V2 suspension arms are much beefier than the HPI style ones. You can get a full set for around $30.

If you want to make an electric Q-baja (aka shorty) it's possible. You'd need to move the batteries to the top of the transmission plate (possible by repurposing a pair of battery holders from another car and moving the ESC to the front chassis. You'd also need to replace the symmetrical steering system with a Turtle Racing servo saver steering assembly or a stock HPI style one and then use the Fast Eddy battery box eliminator. This would make room in the front chassis for the ESC.
 
Atomic Skull said:
The only things I would consider "high priority"is:

The front axles, the stock ones use an E-clip which makes shimming them a pain, they have better ones that use a screw and washer to hold the axle in the bearings that you can get cheap off Aliexpress.

Zero degree aluminum rear hubs, I dislike the overly complex plastic stock ones. Conversely I would not upgrade the front steering knuckles due to the likelihood of damage, the plastic ones are like $15 a set and handle impacts better that metal would.

Three piece aluminum transmission case. This allows you to remove the differential without needing to disassemble the entire back of the car. You can instead pull the rear bulkhead and unscrew the back of the transmission case to remove the diff. If you need to remove the transmission to access the diff I'd recommend replacing it at that time.

Also Rovan V2 suspension arms are much beefier than the HPI style ones. You can get a full set for around $30.

If you want to make an electric Q-baja (aka shorty) it's possible. You'd need to move the batteries to the top of the transmission plate (possible by repurposing a pair of battery holders from another car and moving the ESC to the front chassis. You'd also need to replace the symmetrical steering system with a Turtle Racing servo saver steering assembly or a stock HPI style one and then use the Fast Eddy battery box eliminator. This would make room in the front chassis for the ESC.
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Thanks, this is super useful.

With front axles, you mean the hinge pins right?
Screenshot_20260309_090808_Chrome.webp


I already considered to upgrade that, because that's an inheratage of the 20 year old design.

And thank you for all the other suggestion, will definitely look into it.
 
Neelis said:
Thanks, this is super useful.

With front axles, you mean the hinge pins right?
View attachment 12086

I already considered to upgrade that, because that's an inheratage of the 20 year old design.

And thank you for all the other suggestion, will definitely look into it.
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No I mean these:
https://www.aliexpress.us/item/2251832808007981.html
https://www.aliexpress.us/item/3256804752391873.html

The stock front wheel/axle uses an e-clip, the updated ones are easier to install and remove. The pin type is useful if you want to install and remove wheel extenders because then you can change the hex without removing the steering knuckle. I personally prefer the solid type with a retaining washer because the hex and axle are a solid unified unit.

I use these rear hubs, some might not like them if they prefer toe which these hubs do not allow.

https://www.ebay.com/itm/202855578218

A complete set of front steering knuckles minus bearings and ball studs is $11 plus shipping.

https://www.ebay.com/itm/257186080952
 
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Screenshot_20260310_090613_Chrome.webp

It seems the design is different on the Flux self build kit.

Thank you for the other 2 links, this helps.
 
Notice that it says "HD front hub" there, the old ones use an e-clip. The ones that come stock on Rovan cars use the old type.

Found this video on youtube comparing an HPI and a Rovan Baja. The biggest differences are in the suspension Rovan has built their version more like a basher than a race car.

 
I have decided to add HD shocks:

https://rovanrc.com/product/rv85336/
https://rovanrc.com/product/rv853351/

And a Kraken RC extended arm kit.

https://www.krakenrc.com/products/x2e-extended-suspension-arms-conversion-kit-for-hpi-baja-krc50005

This will also require new dogbones and (maybe) new steering links though the stainless steel rod ends I plan on replacing the plastic links with are longer than the originals so I may be able to reuse the turnbuckles with the new rod ends.

I found this image that shows the Kraken RC arms compared to the HPI original. They are much thicker than even the Rovan arms.

arm_comp.webp
 
Some people have been using the front shocks as upgrades for the front and rear shocks on the Outcast 8S.
 
Atomic Skull said:
So extended steering links are all stupidly overpriced, instead I will use a 120mm double ended m6 studs.

https://www.aliexpress.us/item/3256801193662118.html

I'll just take the distance between the two ends on the existing links and add 25mm to it. They are right hand thread at either end but that shouldn't be much of an issue.
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And this is the great thing about this hobby! Just use whatever works 👏🏼👏🏼
 
It seems the Rovan extended dogbones are only 12mm longer. Rovan's "extended" arms are only 1/2" longer per side compared to the usual 1" (2.5cm each side or 5cm wider wheelbase). So I will be returning them and ordering these instead:

https://www.ddmracing.com/fastlane-...ed-driveshafts-for-fastlane-extended-arm-kits

The FLM extended arms kit is the same width as the Kraken RC one. I can't just use the Kraken extended driveshafts without falling back to 22mm drive cups or I would just use those.
 
New arms and motor, they are all left/right universal except the rear upper, but you could replace that with a stock Rovan arm if it were ever damaged though this seems unlikely. The M6 bolt or the hinge pin would probably bend before the arm breaks. The plastic is a slightly rough textured hard composite. Supposedly it's some dupont materiel and the arms are made in the US.

kraken_RC_baja_arms.webp
 
New links, couple bucks from Aliexpress vs $40 for extended link set. Shown with original turnbuckle for comparison.

baja_0004.webp


These survived a good hit on a curb earlier today and all that happened was the link popped off the ball (no actual damage) so I'd say they are more than adequate for the task. The "ideal" distance between the two link shoulders is 97mm and I was able to get them to 96.8 and 96.6 which is acceptable tolerance for steering at this scale.
 
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Bashing after it rained the previous night always results in a mess.

Installed the new shocks. The springs interfere with the front Kraken RC arms when the suspension is fully extended but this can be solved by rotating the spring so that the arm is between two of the coils. This is a "non standard parts on top of non standard parts" problem. Also the rear shocks are about 2cm longer than the stock shocks at full extension and while this allows more downtravel it also makes the drive cups bind against the lower suspension arms so limiting straps are absolutely required. For the time being I used some heavy duty zip ties to limit suspension travel until I can work up a more elegant solution.

The wider wheelbase and new shocks vastly improve handling and resistance to traction roll. As with the rear shocks the front shocks also have slightly more extension but here that doesn't cause a problem and instead results in increased suspension travel range without issues as the front wheels are not driven. You can see a noticeable difference with the new shocks on rough terrain the car glides more over bumps than it did previously.

baja_0005.webp


baja_0006.webp


baja_0007.webp


Before anyone mentions it yes the drive axle boots are in fact trashed.
 
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The front and rear use the same spring (155mm long) and this causes the front to stand hard on it's suspension even with with the adjustment ring loosened all the way, so I had to shorten those springs by fully compressing them in a vice, nuking them with a heat gun and quenching them. This removed about 2cm from the uncompressed lenght. The rear shocks have the opposite problem the suspension is too soft imo (2.6mm springs) but the spring is exactly the same length and diameter as an X-maxx spring so I will be replacing them with these 2.8mm springs and if that isn't enough 3mm springs are available.

I am also going to experiment with converting these from emulsion shocks to bladder shocks using GMP silicone bladders for X-maxx shocks which have the same bore diameter. I figure because they have an emulsion style bleeder hole I'll need to place the bladder on top of the shock body first with no air under it open the hole in the cap and then screw the cap down over it.

EDIT: Also I forgot to mention that I put an extra large wing on it.

EDIT Also I just now noticed I'm missing an e-clip on one of the upper front hinge pins.
 
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