Raider and Rocky Gearbox Mod - How to Run Taller Gearing (bigger than a 15T Pinion)

[Snaab9-2]

Ever since I was a kid, I was underwhelmed with the top end speed of my Turbo Raider. I saved my money and ditched the LeMans 05 stock engine after a while in favor of a Revtech 15x4 turn motor and it was better but still not great. The car accelerated well but quickly tapered off as it is so under geared (10.8:1).

Recently, I have been running the Raider and while on LIPO it is a bit quicker, it still behaves the same way. I spent about 4 hours over the past 2 nights trying to fit a bigger pinion in there. Over the past few months off and on, I had searched everywhere on the internet and could not find anyone that had fitted a bigger than 15 tooth pinion. I couldn't figure out why there was a limit of a 15 tooth (the manual states 14 is stock and 15 is the only option) and why couldn't I go even bigger to a 17 tooth or beyond (I had bought the 17 tooth pinion in the 80s that I never could figure out how to get into my Raider). In the manual for my Turbo Raider, there is a slot for one of the motor mounts that allows for some adjustment (slot F).... but not much. I guess in theory you can get a 15 tooth pinion in there with the stock 36/21 idler gear but it looked TIGHT. I tried to get the 17 tooth pinion in there but it just was not happening not matter what combination of holes I used (and the motor plate gets in your way on the backside, by design, limiting the range you can move the motor). Man they did not make this a user friendly setup!!! I gave up as I needed to get to sleep.

The next day I remembered I had an idler gear in my box of old parts that might have been for my Raider (it looked really small but I knew it had to be for my Raider or Big Brute). It was s (32/22 tooth) and while by itself it would make the gearing taller, I figured that might just also give me the space to get the 17 tooth pinion in there (as with the stock 14 tooth pinion and the 32 tooth idler the gearing was still shorter that I wanted at 9.6:1). Funny, thinking back on it now when I was building the Raider with my dad I remembered the 32 tooth idler gear but it wasn't mentioned in the manual and we were not sure what to make of it so we used the 36. I don't know why they didn't include the info from the Rocky's manual (the last picture in this post is the Turbo Rocky manual and the one above that is from the Raider....



Even with the 15 tooth (which the only one I have is in my Big Brute and I do not want to mess with that gearbox after I finally managed to get it together without binding issues) it would have been 9.0:1. I wanted to go even taller. So, using the Turbo Rocky manual, I noted there were extra motor mount combinations listed and maybe there was still hope. I tried using hole C (well I really tried all of the combinations) but I still couldn't get the play I needed to fit the 17 tooth. So.... I connected the slot and the hole at the top (I used a knife and cut it so F and A are continuous) and used hole C but I still couldn't get the play I needed because of the stupid motor plate with the weird shape. Ready for bed and wanting to be done.... I took some snips, cut the plate so it was a circle and filed it down use the concrete floor of my garage . It actually worked really well as the metal was so soft. Once I did that, it fit! I think I could use an even bigger pinion but I think this might be a good setup for me with a ratio of 7.9:1 based on my calculations (I used it on pavement).

One note, if you use a larger than 15T pinion you cannot put the motor in the car with the pinion attached (you have to install the motor and then install the pinion from the top of the gearbox) as the hole in the motor plate is too small.

I couldn't find anyone that has done this before on the internet so hopefully this is helpful to some folks and they can cut my 4 hours of time invested (and many hours researching things) into an hour or less! It seems like Kyosho really went out of their way to limit your gearing options in the Raider/Rocky. Hoping I don't end up cooking my Futaba 112B speed controller.

Here is a video of the install:

https://www.youtube.com/watch?v=5iCRBhjmmfI

And two other videos from the night before where I was trying to figure this all out:

https://www.youtube.com/watch?v=U-Z8y_6pPx4&t=74s

https://www.youtube.com/watch?v=eRlFkpHTs6I

[TheDiamondOne]

Pretty righteous mod u have done there. Always dug the rocky, turbo rocky. The raider not so much tho.

[Delorean]

Interesting reading, thanks for sharing

I don't own a Raider, but im always interested in gearing cars correctly etc, What i dont quite understand is, I'm assuming that when they say 32 idler or 36 idler, thats effectively like a spur gear (as in the 36t or 32t gear matches up to the pinion) and if thats the case, i'd have figured if you drop from the 36 to the 32t, then that should create enough space to add 4 teeth to the pinion, so an 18t pinion should work with the motor mounted in the A & D holes with the 32 idler if 14t pinion works with 36 idler ie. same tooth count (50 total)

[coxbros1]

Sounds about right....throw a 480Gold in it with a lipo and u got one Hot runner!

[1300GT]

If you can find it, get yourself Kyosho's RD-22 parts bag for the Raider. It has the optional 32 tooth gear in it.
Many years ago I bought a brand new raider and it was an absolute slug with the stock motor and gearing. I changed it to the 32 tooth spur and 18 tooth pinion which made a massive difference to the top speed.

[Snaab9-2]

If you can find it, get yourself Kyosho's RD-22 parts bag for the Raider. It has the optional 32 tooth gear in it.
Many years ago I bought a brand new raider and it was an absolute slug with the stock motor and gearing. I changed it to the 32 tooth spur and 18 tooth pinion which made a massive difference to the top speed.

Yeah, this post was about the 32 tooth gear in combination with adding a bigger pinion. What did you have to do to get the 18 tooth pinion in there? Were you able to do it without modifying anything (looks like Delorean might be onto something)? Maybe 17 is between holes but the 18 is possible with the 32 idler gear? If I run it and it still isn't quick enough I might go bigger.... but I think this will be good enough (specially as I am running taller tires than stock which is probably like going up another 1 or 2 teeth by itself )

If someone wants to sent me a 480 Gold motor I will happily run it!! I will pay shipping! I wish I knew someone that could put my RevTech on a lathe and freshen it up. She has some hours on her.

I wonder about the old school Kyosho Pinions. The one I took out looked like it was made out of brass or something. IDK if the silver ones are all aluminum but I am hopeful it doesn't wear quickly and eat my gears up. I guess I need a .8 mod pinion if I want to try something else? I can't find any info on any of the old school Kyosho pinions indicating if they are 32 pitch or .8 mod.

[juicedcoupe]

I've mixed mod .8 spurs and quality 32p pinions without any issues on Tamiya cars. I had read to avoid Traxxas pinions when doing this, as they tend to be noisy.

I recently had a mod .8 Tamiya pinion mixed with a 32p Associated spur. They appeared to mesh well but you could see aluminum dust everywhere in no time. But I believe that is just the aluminum Tamiya pinion, as they are known to be made from garbage metal.

[Coelacanth]

The Kyosho pinions for the original Optima and Javelin were soft silver aluminum. Kyosho Option House made a range of pinion gears in a darker grey hardened aluminum...the 8T to 12T (if I recall correctly) pinions were recommended for the Turbo Optima and Salute.

[Snaab9-2]

I've mixed mod .8 spurs and quality 32p pinions without any issues on Tamiya cars. I had read to avoid Traxxas pinions when doing this, as they tend to be noisy.

I recently had a mod .8 Tamiya pinion mixed with a 32p Associated spur. They appeared to mesh well but you could see aluminum dust everywhere in no time. But I believe that is just the aluminum Tamiya pinion, as they are known to be made from garbage metal.

So you think I may not want to run it like that too much? I was going to give it a test run but maybe I need to find something better if I like the ratio for long term use.

[juicedcoupe]

Like I said, that was a Tamiya aluminum pinion. They are well known for being garbage. The gear mesh looked and felt perfectly fine.

The only reason that I happened to have one in that particular size is that I never used it originally, opting for a steel pinion. I was using it to run in a freshly rebuilt transmission and you could see the aluminum dust on the motor plate within moments.

I've used Kyosho brass pinions without any noticeable wear before. I also have a vintage Kyosho aluminum pinion and it looks to be quality metal.

I have used aftermarket aluminum pinions without any problems as well.

[Snaab9-2]

Like I said, that was a Tamiya aluminum pinion. They are well known for being garbage. The gear mesh looked and felt perfectly fine.

The only reason that I happened to have one in that particular size is that I never used it originally, opting for a steel pinion. I was using it to run in a freshly rebuilt transmission and you could see the aluminum dust on the motor plate within moments.

I've used Kyosho brass pinions without any noticeable wear before. I also have a vintage Kyosho aluminum pinion and it looks to be quality metal.

I have used aftermarket aluminum pinions without any problems as well.

I see, thanks.

I think mine is probably Kyosho brand.

[Snaab9-2]

Here is a video of it running with the new gearing. https://www.youtube.com/watch?v=l-uYe3XMFtI I am still working on getting a decent camera angle.... I only had like 10 min today before I need to pick up my daughter from daycare so the video was rushed. It looks like (sounds like) the gearing is a little too tall as it doesn't have much torque up top and takes a while to get to top speed. The tires are pretty tall and balloon up when they spin fast making the gearing even taller at speed.

I may go back to the 14 tooth pinion and leave the 32-21 idle gear in it and see how it does (or first just put some normal sized tires on it). Top speed is 28 mph (I wish I recorded the speed with the stock gearing). The cooling fins on the speed controller were too hot to touch for more than 4 seconds (maybe 160 degrees) at the motor about 5-6 seconds (maybe 140 degrees) with it about 65 degrees outside.

I need that LeMans 480 Gold in there for some torque!!!

Here it is with the stock gearing and the same setup otherwise. https://www.youtube.com/watch?v=ut2cB7c39_w

[coxbros1]

480 gold with a tall gear is a nice combo!
also....no one ever usually see's what anyone looks like on this site so u get an image in your mind after reading peoples posts what they might look like....i gotta say when i saw in that 2nd video that you looked like an MMA fighter it wasn't what i was expecting!

[Snaab9-2]

480 gold with a tall gear is a nice combo!
also....no one ever usually see's what anyone looks like on this site so u get an image in your mind after reading peoples posts what they might look like....i gotta say when i saw in that 2nd video that you looked like an MMA fighter it wasn't what i was expecting!

I am just waiting for the day someone to make fun of my and my dorky Futaba transmitter with the long antenna so I can drop them like a sack of potatoes and choke them out. j/k

Must be my layers/coat making me look bigger than my 6 foot 175 pound dainty frame (and if I lay off the junk food and a beer several times a week while training for a race my small frame is only like 165 pounds). I guess closer to the size of Nate Diaz on a good day!

Not sure what you look like but if you look anywhere near as good as that car in your avatar you are a STUD!

[coxbros1]

480 gold with a tall gear is a nice combo!
also....no one ever usually see's what anyone looks like on this site so u get an image in your mind after reading peoples posts what they might look like....i gotta say when i saw in that 2nd video that you looked like an MMA fighter it wasn't what i was expecting!

Not sure what you look like but if you look anywhere near as good as that car in your avatar you are a STUD!

I look just like "The Diamond One"....no joke!