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-   -   Is rear motor dead? (https://www.rctech.net/forum/electric-off-road/888530-rear-motor-dead.html)

Jhafler 08-13-2015 03:01 PM

Is rear motor dead?
 
Is it dead? I hope not.

hairymuffin 08-13-2015 04:06 PM


Originally Posted by Jhafler (Post 14139126)
Is it dead? I hope not.

I don't think so, especially in stock..don't think you have to run mm to be fast..I think it matters more in mod,easier the go faster in mod

Cpt.America 08-13-2015 04:22 PM


Originally Posted by Jhafler (Post 14139126)
Is it dead? I hope not.

In low traction conditions, RM will still likely be the way to go.

vr6cj 08-13-2015 05:12 PM


Originally Posted by Cpt.America (Post 14139231)
In low traction conditions, RM will still likely be the way to go.

Our local track is low traction and we have all switched and stayed MM. I recently tried converting my b5m to b5r and switched back after doing worse. I mean it was fine and I had a faster hero lap but no where near as consistent as b5m.

Might be Im also so used to MM now and have setups that work well too.

I)arkness 08-13-2015 06:23 PM

at my local track low to medium grip everyone has gone to mm due to the hype i guess, i still set some good times and able to win in stock with my rm. really think its more just setup and driver skill

speaking with one top driver he summed up as rear mount you add brass to front of chassis, mid mount your adding brass to rear of chassis to eventually you get almost the same results

Coopz 08-13-2015 06:48 PM

My driving skills are not good enough to really notice any real difference switching to mid motor. I have 2 Hobao H2's and one is set for mid and the other is rear, the only difference I notice is the rear motor car is better over the jumps, more neutral balance.

bdyche 08-13-2015 07:09 PM

Rear motor may have the advantage in the worst of conditions, but my mid motor cars have been absolutely fantastic on some pretty rough tracks. With modern tires being as good as they are, the extra forward bite of 4 gear MM transmissions and the U.S. pros running mid motor, there will be more baseline setups that will work on outdoor tracks than there has been in the past (virtually nothing until 2014, really). Really it will be just a matter of choosing the right tires for the conditions as MM is much more tire sensitive than RM.

goehm 08-13-2015 07:43 PM

It's not dead. Consider it an option. I bought a RM version of my buggy and tried it when our track was low traction. The car felt so comfortable and felt fast and I felt like I could push it ... but when I compared laptimes my MM was faster.

QDRHRSE 08-13-2015 08:03 PM

We tested B5Ms vs B5s all winter long and soley based on lap times I think RM is pretty much done. Once all the old rc purists retire or die nobody is going to use a RM car.

DG Designs 08-13-2015 08:41 PM

It may be on life support but i really hope it sticks around. I don't think anyone will disagree it is less edgier than MM. RM is still a great entry level car. I almost think i would be better off with RM since i am lucky if i get to the track more than once a month. I also think the mindset of of MM for Mod and RM for stock is completely backwards. Why would you take the car that inherently pushes and put it in the car that needs less rear bite. I have a RM half built right now that i am seriously considering setting up as a 13.5 car. build it to 1499, and it could probably hang with a lot of hotter motors, especially at the smaller indoor tracks.
I think just like it was thought MM couldn't work on low bite,(until they started developing set ups around it) RM can also work on high bite when someone wants to work on the setup. Its possible to run as low as 2 degrees of toe in and when have you ever seen a RM setup with the same weight old from and back. Combine those 2 things and i have a hard time thinking that car is going to push.:sneaky:

tsair 08-13-2015 09:12 PM


Originally Posted by DG Designs (Post 14139627)
RM can also work on high bite when someone wants to work on the setup. Its possible to run as low as 2 degrees of toe in and when have you ever seen a RM setup with the same weight old from and back. Combine those 2 things and i have a hard time thinking that car is going to push.:sneaky:

Holy cow, I didn't even think about reducing rear toe in, dropping knowledge like gold! Thanks, I drive a RM at a local indoor mid-high bite track.

DG Designs 08-13-2015 09:32 PM


Originally Posted by tsair (Post 14139657)
Holy cow, I didn't even think about reducing rear toe in, dropping knowledge like gold! Thanks, I drive a RM at a local indoor mid-high bite track.

Just put the MM inserts in the RM hubs, negative toe in.

Jhafler 08-13-2015 10:56 PM


Originally Posted by DG Designs (Post 14139627)
It may be on life support but i really hope it sticks around. I don't think anyone will disagree it is less edgier than MM. RM is still a great entry level car. I almost think i would be better off with RM since i am lucky if i get to the track more than once a month. I also think the mindset of of MM for Mod and RM for stock is completely backwards. Why would you take the car that inherently pushes and put it in the car that needs less rear bite. I have a RM half built right now that i am seriously considering setting up as a 13.5 car. build it to 1499, and it could probably hang with a lot of hotter motors, especially at the smaller indoor tracks.
I think just like it was thought MM couldn't work on low bite,(until they started developing set ups around it) RM can also work on high bite when someone wants to work on the setup. Its possible to run as low as 2 degrees of toe in and when have you ever seen a RM setup with the same weight old from and back. Combine those 2 things and i have a hard time thinking that car is going to push.:sneaky:

Yes very true!

ray_munday 08-14-2015 12:51 AM


Originally Posted by DG Designs (Post 14139627)
..... I also think the mindset of of MM for Mod and RM for stock is completely backwards. Why would you take the car that inherently pushes and put it in the car that needs less rear bite.....
I think just like it was thought MM couldn't work on low bite,(until they started developing set ups around it) RM can also work on high bite when someone wants to work on the setup.....

Hi DG, I wouldnt agree that is is a 'mindset', rather its based on the results people have had around the world from testing and the basic physics involved.

A mod car has much higher acceleration (and therefore weight transfer) than a stock car so the light front end of an RM car becomes much easier to unweight. This makes wheelstanding / on power push more of an issue in mod. Also, you are generally travelling into corners much faster in mod, where the rear motor 'pendulum' effect is much stronger, so MM cars are generally easier to drive fast. The downside to MM is that at initial throttle, there is less weight on the tyres so more care has to be taken when you first accelerate. If there is low traction, you dont have enough weight transfer to build up enough traction on the rear tyres, hence more weight is required at the rear in these conditions.

In stock, with less top speed and less acceleration, I think there is less difference from RM to MM. You get more initial bite with RM and there is less chance of wheelstanding, although as grip comes up MM will carry more corner speed. Locally in stock its pretty close [ I)arkness is very competitive with his RM car as he mentions below] but in mod its 99% MM.

Based on my testing on outdoor tracks with MM vs RM over the last 18mths, Im always as quick or quicker with MM. Sometimes you need to add weight to the back of the MM to get enough forward traction, but as the track grips up its easy to take weight off and get corner speed back. Also, even with a bit of weight at the rear the overall weight is more centralised with MM, giving more responsive handling. With RM you have to add a lot of weight to the front as the track grips up, so you end up with a car that has a lot of weight at the front (brass) and a lot of weight at the rear (motor), which adds up to a high yaw inertia.

If the grip is very low and/or you dont have fresh tyres, yes RM is much easier to get around the track and I agree for beginners that makes it easier until they have throttle control. Although my 9yo son is much quicker with MM as he can attack corners harder with less spinning out.

As for making RM work well in high grip - its very difficult in mod for the above reasons. We all tried! But once MM cars became available it was a night and day difference in high grip.

Re the future of RM: with tyres improving on all surfaces, I think MM is here to stay but we will see 2 variations -1) rear biased MM (like the B5M) where the motor sits a long way back and gives good performance on all dirt surfaces (with some added weight at the back for low traction) 2) Front biased (eg Yok YZ-2) for very high traction / artificial tracks.

Ray

Jhafler 08-14-2015 01:42 AM

How is it that rear motor is for beginners but mid motor is said to be easier to drive? I started out in rear motor (reason being I was a noob) and have yet to switch to mid because: A. Can't afford a new car (b5) and B. Can't get to the track enough to "relearn" how to drive/set up a mid motor car. I guess I started this thread to see if I really needed to get the rear to mid motor conversion for the b5. I'm an intermediate driver at best. Am I really going to notice a difference between the two?


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