Jump to content
junkmunki

Rough Rider differential

Recommended Posts

I just picked up a couple of early Rough riders to use as spares, and one of them has a differential fitted. This is the first one i have had in one of the SRB gearboxes.

Any ideas who make these, and if anybody else uses one, would it make a big difference to the handling of my Sand Scorcher?

J

Share this post


Link to post
Share on other sites
1 hour ago, junkmunki said:

would it make a big difference to the handling of my Sand Scorcher?

Not used one myself , but the re-re SRB's and the influx of the new MIP diffs suggest it might

Share this post


Link to post
Share on other sites

The diff certainly makes the SRBs less tipsy on harder surfaces. I run one in my Fighting Buggy/Super Champ and it turns a bit sharper thanks to the ball diff. Mine is the Tamiya version they brought out years back. Along with Thorp and MIP, there was a gear diff made by Nodis.

  • Like 1

Share this post


Link to post
Share on other sites

The one i have fitted is a plastic outer gear with screwed in planet gears.

32 minutes ago, Saito2 said:

The diff certainly makes the SRBs less tipsy on harder surfaces. I run one in my Fighting Buggy/Super Champ and it turns a bit sharper thanks to the ball diff. Mine is the Tamiya version they brought out years back. Along with Thorp and MIP, there was a gear diff made by Nodis.

Can you identify it from the pictures? 

 

1 hour ago, KEV THE REV said:

Not used one myself , but the re-re SRB's and the influx of the new MIP diffs suggest it might

Do the re re Scorchers use a differential? If they do, it may be this is where its from.

J

DSC_5571.JPG

DSC_5572.JPG

  • Like 1
  • Thanks 1

Share this post


Link to post
Share on other sites

I have not seen many geared SRB diffs!  That is interesting.  I wonder if that is Nordis diff @Saito2 mentioned?  

With a differential, it is much more stable on road.  There was a member who said how easy it is to flip it, once it comes onto a parking lot.  Below is why. (most members would say, "who doesn't know this?" But I'm sure there will be new members who'd be reading this later).  

wGR2OIF.jpg

Here is a diagram of a car turning left (seen from the sky).  Orange lines are the tire marks on the ground. The right side is longer than the left: the right tire must turn more.  Differentials allow that.  However, Rough Riders and Sand Rovers don't usually come with differentials. 

That means one side must lose traction.  When the car is turning left, the outside (right) gets more traction because centrifugal force is making the car lean toward the right side. More weight is on the right.  I suspect that the inside tire (left side if you are turning left) skips.  The car is already tilting right as it turns left. Right suspension is lower.  Left tire jumps slightly to make up for the difference.  That's a good recipe for for rolling toward the right side. (below diagram is seen from the rear)

9rix5lj.jpg

If it does not roll over to one side, it resists turning.  Which is why cars with differentials have better steering responses.  

However, No-diff is not all bad.  No differentials = locked diffs.  Locked diffs are better in sand, mud, anywhere there is less traction. With locked diff, there is no "diff unloading."  While differentials are good on paved road, it can make the car utterly useless in sand.  Diffs allow both wheels to lose power when one wheel loses power.  If you had see people pushing cars in mud, or snow, that's because of the "diff unloading" even in real cars.  

Thorpe and MIP sold ball-diffs.  They are better than regular geared diffs.  Ball differentials are a form of limited-slip-differentials (LSD).  They are best of both worlds.  They allow tires to "differentiate" on road.  Also when one tire loses traction in sand, the other does not lose all power.  

You are lucky if your spare car came with a diff.  If you want, you can clean off the grease and use Anti-Wear grease to make the diff work with some resistance.  The stickier the grease, more LSD effect you'll have.  On open diffs like that, I use "bad horsie diff lock" or "3Racing ultra high viscosity diff oil" sparingly, so they wouldn't ooze out.    

 

  • Like 1

Share this post


Link to post
Share on other sites

I probably wouldn't use it, but i have to get myself some 'Bad Horsie' diff lock grease... what a fantastic name...:lol:

  • Haha 2

Share this post


Link to post
Share on other sites

The one pictured isn't a Nodis diff. The Nodis unit was more of a planetary style rather than the bevel gear diff pictured. I've never seen a bevel gear SRB. Pretty neat. Here's the Nodis unit:

art_05012006093028_1.jpg

As Kev stated, the re-re doesn't come stock with a diff. No SRB (and I'm including the Super Champ) ever came with a diff, original or re-release. When Tamiya introduced the re-release versions, they designed a new brass ball diff unit as an optional upgrade, item no. 84113.

  • Like 4

Share this post


Link to post
Share on other sites

I was racking my brain trying to remember this one . I looked it up years ago to see if they were still at this address as I used to live round the corner to them , but they are not there anymore unfortunately . how many of these would you buy now at £20 a pop !! - expensive back then

  • Like 1

Share this post


Link to post
Share on other sites
2 hours ago, Juggular said:

I have not seen many geared SRB diffs

I wonder if this one has also been made by a small engineering works from stock components available

  • Like 1

Share this post


Link to post
Share on other sites

Without a doubt the diff makes a big difference! It simply means that lovely painted body that you've just mounted on the chassis stays lovely not ending up shiny side down skipping along whatever hard surface your driving on! 

  • Like 1

Share this post


Link to post
Share on other sites
3 hours ago, Saito2 said:

The one pictured isn't a Nodis diff. The Nodis unit was more of a planetary style rather than the bevel gear diff pictured. I've never seen a bevel gear SRB. Pretty neat. Here's the Nodis unit:

art_05012006093028_1.jpg

As Kev stated, the re-re doesn't come stock with a diff. No SRB (and I'm including the Super Champ) ever came with a diff, original or re-release. When Tamiya introduced the re-release versions, they designed a new brass ball diff unit as an optional upgrade, item no. 84113.

Wow, that is also very interesting. 

I would have bought that just to see if it has balance issues!!

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...