Q about sport transmission

[Halfshaft]

I got a TRX-4 Defender with light kits recently as a 2nd RC car (the first is a worn-out TMaxx converted to electric). For more than one reason, that TMaxx is ready to be retired, but my daughter and I are enjoying driving two trucks at the same time.

So I'm thinking about getting another TRX-4, but maybe a cheaper version.

The sport model comes with spools not diffs, and a single-speed transmission, but I can't find out what the gearing is for the tranny. Is it the same as the high gear on the TRX4 crawler trucks? Or is it its own ratio?

 

[Voodoobrew]

I don't remember off hand but the gear calc in my signature has the answer you're looking for I believe. I put it there so I wouldent have to remember.

__________________________
Handy gearing spreadsheet

 

[Voodoobrew]

Looks like the sport is high gear but you can buy the larger spur and smaller pinion for $20 or a 2speed tranny off ebay for $40. If you get the tranny you can just use some hot glue to lock it in 1st gear. Easy to remove if you ever want to upgrade.

Of course now your back up in price again.

They are durable trucks, used is an option too. Best rc deals I have seen are here and Facebook for used. But they dissappear fast.

__________________________
Handy gearing spreadsheet

 

[svt923]

The sport trans is the same as low gear in the 2 speed internally but has a smaller spur and bigger pinion than what comes on the 2 speed equipped trucks.

 

[Halfshaft]

Looks like the sport is high gear but you can buy the larger spur and smaller pinion for $20 or a 2speed tranny off ebay for $40. If you get the tranny you can just use some hot glue to lock it in 1st gear. Easy to remove if you ever want to upgrade.

Of course now your back up in price again.

They are durable trucks, used is an option too. Best rc deals I have seen are here and Facebook for used. But they dissappear fast.

__________________________
Handy gearing spreadsheet

True, buying on the cheap rarely ends up that way!

That spreadsheet was really helpful to understand what Traxxas did with the sport.

The sport trans is the same as low gear in the 2 speed internally but has a smaller spur and bigger pinion than what comes on the 2 speed equipped trucks.

I see, the same gear ratio in the tranny, but a lower input ratio.

I was also looking at the sport kit. With my inventory of parts, the only item I'm missing is a brushed motor for that build, so that's an option to consider.

Thanks for your help guys.

 

[Voodoobrew]

oh right my bad, I was looking at it on my phone and.....
I just read it wrong...
You are correct, same as 1st gear.
Sorry for the confusion.

 

[Halfshaft]

Well, after going through a couple ideas, the best deal was to just get a Sport.

LHS (Hobby Town) showed TRX4 Sports at $20 less than other places, and the one we wanted ended up being their display unit and they gave another $20 off. So I got a blue TRX4 for $314 plus tax today with curbside pickup.

After a quick snip and soldering of an XT60 connector into the truck, my daughter was in business and is thrilled.

The Sport's top speed is a little below the TRX4's speed, so that's where the gearing ends up. I like the Sport's overall setup for what it's designed to do.

 

[mass-hole]

Well, after going through a couple ideas, the best deal was to just get a Sport.

LHS (Hobby Town) showed TRX4 Sports at $20 less than other places, and the one we wanted ended up being their display unit and they gave another $20 off. So I got a blue TRX4 for $314 plus tax today with curbside pickup.

After a quick snip and soldering of an XT60 connector into the truck, my daughter was in business and is thrilled.

The Sport's top speed is a little below the TRX4's speed, so that's where the gearing ends up. I like the Sport's overall setup for what it's designed to do.

Ugh, i just did XT60’s for the first time the other day. Took a couple of tries to figure it out bit once i did they are nice. I like them a lot.

I just bought a 2 speed trans for $36 on ebay per the recommendation above. Not sure what i wanna do about the shift servo yet. I really wanted to keep this truck spartan.

 

[Halfshaft]

Nice score on the tranny!

Ugh, i just did XT60’s for the first time the other day. Took a couple of tries to figure it out bit once i did they are nice. I like them a lot.

Yeah, I like XT60s a lot, they were such an improvement over the Dean's-style connectors that were popular several years ago. And I see those are still offered on some batteries.

When soldering XT60s, I usually put the connector into a vise with the terminals facing up. But in the case of short wires like to the truck's installed ESC, I use some tape to hold the connector to something heavy, like a piece of scrap metal or something. That's usually enough to hold the 1/4" stripped wire end in place for soldering.

 

[vinnieb729]

With the XT60's, you can grab the little solder posts with a needle nose pliers and spin them 90 degrees so the little cups you're soldering into are facing the same direction on both posts. Makes it even easier "thumbsup"

 

[Halfshaft]

That's a great tip!