TRX 4 Sport Geared for Slow Crawling ?

[BL4Z3]

I was thinking of picking up a sport , I have an scx10 , but have not had a portal truck before , I have seen " box stock" videos that appear to show it doing slow crawls , & others that looked quite jerky , Can this thing do slow controlled crawls out of the box ? or no ? On my scx10 I just dropped down a few pinion sizes & it has real nice slow speed control ,..How would I achieve the same thing on a sport ? Im not sure how much the portal gearing figures in to it

 

[CTYankee]

The Sport does not have the two speed drive so it is geared to go a bit faster. The others with the two speed are geared lower/higher so they can go slower and faster than the sport in each mode. What you may be seeing is a two speed in low vs a sport. Or maybe a sport with modified gearing. Or a good drive and a bad driver. Or different conditions. You get the idea. Any of those could mean more jerky low speed.

Gear rations of the two systems out of the box are:
Sport: gear ratio of 36.25
2 speed TRX-4 High: gear ratio of 25.85
2 speed TRX-4 Low: gear ratio of 64.64

You can change the spur/pinion to get similar gearing and low speed performance, but lose top end of course.

 

[OSRC]

Same as your SCX10. Drop a few teeth on the pinion and it should be down about where you want want it. It's geared a little bit high out of the box in my opinion.

I like my crawlers to be slow and steady, so I picked up the 45 tooth spur gear as well. Currently running 9/45 and I'm very happy with it

 

[dungeonracer]

I believe the Sport's ESC has a training mode. If so, that would slow it down...

 

[Inspector86]

I believe the Sport's ESC has a training mode. If so, that would slow it down...

No that won't slow it down. The training mode just limits throttle to 50% max which you can also do manually with a little throttle control. Changing the Sport spur gear and pinion to 9/45 gears used with the 2 speed is the best method of slowing the truck while also allowing the motor to run cooler. Next I would ditch the stock XL5 ESC and install an HW1080 which actually works well with the stock Titan 550 21T motor. Finally, if you want to spend the money, I would install a HH Crawlmaster Pro 550 12T 5 pole motor. If you want low speed crawling but still want some speed then you can buy a 2 speed transmission off ebay for around $35.

 

[sgtlt]

A 9t pinion and a 45t spur both traxxas parts and my truck is the perfect speed. both 32 pitch

 

[BL4Z3]

So the 9 /45 gear combo would give good slow speed crawl control & how fast would the top end be ? I just want it about walking speed max ,.and really good low speed control , Im trying to make a parts list & slowly sneak in all the parts , before I get another truck , that way once I get the truck , I will already have all I need to make it the way I want before my wife can freeze the account , Its my first portal truck , but not my first truck

 

[Still Bill]

Other ways to get the TRX4 Sport set for slow crawling...
- Higher turn brushed motor. Go from the stock 21 turn to 27 turn or higher.
- Five pole brushed motor. Holmes Hobbies has some interesting motor options. And there is the new Reedy Radon 16T Crawler motor.
- Using a Hobbywing 1080 ESC can give you more adjustability via its fifteen adjustable settings.

Having both the Sport RTR and Sport Kit, I highly recommend going the Kit route and installing your own electronics. Was a fun build too.

 

[mass-hole]

Other ways to get the TRX4 Sport set for slow crawling...
- Higher turn brushed motor. Go from the stock 21 turn to 27 turn or higher.
- Five pole brushed motor. Holmes Hobbies has some interesting motor options. And there is the new Reedy Radon 16T Crawler motor.
- Using a Hobbywing 1080 ESC can give you more adjustability via its fifteen adjustable settings.

Having both the Sport RTR and Sport Kit, I highly recommend going the Kit route and installing your own electronics. Was a fun build too.

The kit was great and the HW1080 and Holmes Trailmaster sport combo only set me back ~$60.

 

[Stormin2u]

I agree , Traxxas 9/45 spur and pinion gears delivers a great crawling speed and torque.

 

[islandcrawler]

I agree with the above. Running the HW 1080 and HH Trailmaster 27t geared 9 45. It is not brushless fast but faster than I can keep up with at a brisk walking pace. The low-speed control and torque of that setup are great. I got around 45mins of runtime and still had 50% capacity left on a 3s 2200mah pack.

 

[Exalted85]

Did you have any problems with getting the esc wire to rx box? I couldn't seem to make it work..I had to reverse that box and double side tape it.