The Physics of Towed-Vehicle Braking

[10Boomer]

Originally Posted by micki49

We just had the Air Force One installed this week.

Any tip or tricks you look for with the install?


Sent from my iPhone using iRV2 - 2008 Monaco Camelot 40 PDQ

[Retired-Jake]

Just had my Stay-in-Play Duo installed today at SMI in Evansville, IN. On the drive back to TN, I could definitely feel the difference in braking. Sure wish I had this while we were running around the mountains a couple weeks ago.

Quality product, quality work on the installation. In at 0800, out by 1200. Highly recommend these guys.

Jake

[10Boomer]

Originally Posted by 10Boomer

Installing my Air Force One on Monday.


Sent from my iPhone using iRV2 - 2008 Monaco Camelot 40 PDQ

All done, went fine. Tows good. Had to adjust breakaway cable. SMI builds a great kits ( air brake system.)


Sent from my iPhone using iRV2 - 2008 Monaco Camelot 40 PDQ

[hoosierrun]

I have the SMI Stay-In-Play Duo system that appeared to be doing fine until yesterday. I lost the Toad brake indicator about 20 miles from home and wasn't sure what was going on. There was no place to pull over on these highways with Sunday traffic and a narrow shoulder so I had to drive home. As it ended up, I did loose the supplemental braking system because the Toad battery discharged on the trip. Apparently when that happens your Toad brake system won't work.

At home, I charged the battery for about 15 minutes and all is fine again. Perhaps I should look for a new battery, even though the one in there is only 2 1/2 years old.

So, how long will the Sta-In-Play Duo system work on the Toad vehicle before running down the battery? Yesterday's drive did require a lot of braking due to heavy traffic and vehicles always cutting into my safe distance area. My trip time was 2 hours from when the Toad was last driven.

[user293]

Most vehicles on the road aren't designed to tow. Your Motorhome and pickup trucks aren't really designed from scratch for towing. They have been modified, installed with towing equipment, add-ons, possibly supplemental steering and braking systems, etc. but essentially the designers did not premise the fundamental purpose of most of the vehicles on the road today with towing in mind. This includes most passenger & hauling trucks and motorhomes.

Mostly only semi trucks are designed from scratch for towing extremely heavy loads. Semi truck manufactures are constantly trying to improve semi truck design and safety. Semi's which I have driven duals cross country, what makes them safe is the driver. Semis most often get into trouble because of driver error and not because of the semi-truck or traffic, unless e.g. equipment failure such as the brakes. Even your common 10 ton truck is primarily designed to haul but not to tow. Is probably one of the reasons why you never see 10 ton box trucks towing anything.

When towing and not towing with a motorhome I normally follow my own rules of the road. 1. stay farther away from other vehicles than what the law states. (this can be sometime from twice to over a quarter mile depending on traffic speed and other traffic conditions. 2 drive slower and more cautious than the law demands.

The majority of accidents can be avoided by driving slower, giving other vehicles more space and taking precautions.

If e.g. the driver in the accident described was 2 to 6 times farther behind the vehicle and traffic there's a great possibility that the accident could have been avoided. Ample space should be given for traffic that's following when possible, to avoid being crashed into from behind.

I think it comes down to, most motorhomes aren't really well designed for towing. Same with most passenger trucks on the road, some tow better than others, most have a fundamental design for hauling but not towing. I think you must keep that in mind while towing, no matter how much and the different types of towing equipment you have installed to facilitate towing.

I have flat towed a ~3000 lb Jeep with a 23' motorhome. I also have an Even Brake. The mh has a blind spot of the toad, where you can't see the toad unless turning. I've thought about installing extra long tow mirrors (which may stick out too far) or a rear view camera, but I haven't needed to tow the toad or trailer with this MH.

Some older motorhomes installed a fresno lens on motorhomes with a rear window that can be viewed from the drivers seat. The lens didn't really do alot, it's purpose is to improve your rear view behind the motorhome.

The motor-home's fuel economy is terrible when towing. Some free-ways the fuel economy is slightly improved. About all the mh manufacture did for towing was install a tow hitch and tow light wiring.

[billdreamlv]

Originally Posted by user293

Most vehicles on the road aren't designed to tow. Your Motorhome and pickup trucks aren't really designed from scratch for towing. They have been modified, installed with towing equipment, add-ons, possibly supplemental steering and braking systems, etc. but essentially the designers did not premise the fundamental purpose of most of the vehicles on the road today with towing in mind. This includes most passenger & hauling trucks and motorhomes.

Mostly only semi trucks are designed from scratch for towing extremely heavy loads. Semi truck manufactures are constantly trying to improve semi truck design and safety. Semi's which I have driven duals cross country, what makes them safe is the driver. Semis most often get into trouble because of driver error and not because of the semi-truck or traffic, unless e.g. equipment failure such as the brakes. Even your common 10 ton truck is primarily designed to haul but not to tow. Is probably one of the reasons why you never see 10 ton box trucks towing anything.

When towing and not towing with a motorhome I normally follow my own rules of the road. 1. stay farther away from other vehicles than what the law states. (this can be sometime from twice to over a quarter mile depending on traffic speed and other traffic conditions. 2 drive slower and more cautious than the law demands.

The majority of accidents can be avoided by driving slower, giving other vehicles more space and taking precautions.

If e.g. the driver in the accident described was 2 to 6 times farther behind the vehicle and traffic there's a great possibility that the accident could have been avoided. Ample space should be given for traffic that's following when possible, to avoid being crashed into from behind.

I think it comes down to, most motorhomes aren't really well designed for towing. Same with most passenger trucks on the road, some tow better than others, most have a fundamental design for hauling but not towing. I think you must keep that in mind while towing, no matter how much and the different types of towing equipment you have installed to facilitate towing.

I have flat towed a ~3000 lb Jeep with a 23' motorhome. I also have an Even Brake. The mh has a blind spot of the toad, where you can't see the toad unless turning. I've thought about installing extra long tow mirrors (which may stick out too far) or a rear view camera, but I haven't needed to tow the toad or trailer with this MH.

Some older motorhomes installed a fresno lens on motorhomes with a rear window that can be viewed from the drivers seat. The lens didn't really do alot, it's purpose is to improve your rear view behind the motorhome.

The motor-home's fuel economy is terrible when towing. Some free-ways the fuel economy is slightly improved. About all the mh manufacture did for towing was install a tow hitch and tow light wiring.

I think I have your answer for the blind spot on your toad. See my post titled, "Toad monitoring with audio and wireless camera."

[user293]

Originally Posted by billdreamlv

I think I have your answer for the blind spot on your toad. See my post titled, "Toad monitoring with audio and wireless camera."

Looks to be a good solution if the camera is durable for the outdoors and waterproof. I would want to have an option to mount the camera outdoors, for towing trailers, cargo trailers, boats and other equipment.

I have several non-wireless Pulnix and Sony cctv cameras plus several types adjustable lenses including wide angle. I haven't installed a rear view camera because I wasn't able to find a suitable outdoor camera case that can be easily mounted on the rear of an RV.

[StevL]

This is a wonderful video demonstrating weight distribution of a trailer. Feel free to post the link elsewhere.

Video

Steve

[user293]

I have a Roadmaster Even Brake. It has worked very well and has never exhibited any sort problems.

However after reading the thread from the link below, makes me a little concerned of the possibility some toad brake manufactures may have not included enough safeguards in their toad brake design.

(see link to thread below)

For this toad brake owner I don't believe their toad brake problem should have ever happened. I can't really find any way to justify a toad brake causing this type of problem. I would think it would be relatively simple to install safeguards in the toad brake design to prevent this type of problem from occurring.

http://www.irv2.com/forums/f85/warni...ue-312871.html

[August West]

Originally Posted by hoosierrun

I have the SMI Stay-In-Play Duo system that appeared to be doing fine until yesterday. I lost the Toad brake indicator about 20 miles from home and wasn't sure what was going on. There was no place to pull over on these highways with Sunday traffic and a narrow shoulder so I had to drive home. As it ended up, I did loose the supplemental braking system because the Toad battery discharged on the trip. Apparently when that happens your Toad brake system won't work.

At home, I charged the battery for about 15 minutes and all is fine again. Perhaps I should look for a new battery, even though the one in there is only 2 1/2 years old.

So, how long will the Sta-In-Play Duo system work on the Toad vehicle before running down the battery? Yesterday's drive did require a lot of braking due to heavy traffic and vehicles always cutting into my safe distance area. My trip time was 2 hours from when the Toad was last driven.

The Duo uses about 15 amps while it is operating. That low amp draw is not enough to discharge a GOOD battery for days and days without starting/charging. I would highly recommend a charge wire and probably a new battery as towing is extremely hard on a lead acid battery. IMO, get an AGM battery (you can get OE sizes in AGM from Advance Auto, AutoZone, Sears, etc.) and they will not lose longevity due to a total discharge. AGM batteries can be discharged and recharged everyday without shortening their lifespan.
Once you have a charge wire and AGM battery, those troubles will cease.

[tim myers]

I have the Stay-In-Play Duo as well and a CRV with the tiny battery. Since the CRV requires the transmission fluid be re-circulated at least every 8 hours I am always starting the CRV at that time interval or less. When I do that I always let the car run for at least 15 minutes to help recharge the battery. If arriving at a campground for an overnight stop when the toad will not be unhooked I might let it run for an hour or so. I also carry a battery charger with Boost in case the toad will not start. So far I have not had to use it.

Do the SMI folks still monitor this thread, if so i have a question on proper setting of the brake system?

[hoosierrun]

Originally Posted by August West

The Duo uses about 15 amps while it is operating. That low amp draw is not enough to discharge a GOOD battery for days and days without starting/charging. I would highly recommend a charge wire and probably a new battery as towing is extremely hard on a lead acid battery. IMO, get an AGM battery (you can get OE sizes in AGM from Advance Auto, AutoZone, Sears, etc.) and they will not lose longevity due to a total discharge. AGM batteries can be discharged and recharged everyday without shortening their lifespan.
Once you have a charge wire and AGM battery, those troubles will cease.

Thank you very much. I did exactly as you said. I replaced the lead acid battery with one of the new Exide AGM batteries. This one: Exide Edge Fp-Agm24f Flat Plate Agm Sealed Automotive Battery | Autoplicity

I also added the towed vehicle battery maintainer (part #39332) and tied it on the 12 volt feed to the lube pump which comes from the coach motor charge wire.

I finished these modifications the day before we left for a 2000+ mile trip; our first extended towing trip, and everything related to the battery and braking system worked perfect.

[walt2137]

Originally Posted by hoosierrun

Thank you very much. I did exactly as you said. I replaced the lead acid battery with one of the new Exide AGM batteries. This one: Exide Edge Fp-Agm24f Flat Plate Agm Sealed Automotive Battery | Autoplicity

I also added the towed vehicle battery maintainer (part #39332) and tied it on the 12 volt feed to the lube pump which comes from the coach motor charge wire.

I finished these modifications the day before we left for a 2000+ mile trip; our first extended towing trip, and everything related to the battery and braking system worked perfect.

You might think about running a charge line from the coach chassis battery to the toad battery especially using a transmission pump you don't want to tow very far without trans being liberated.

[hoosierrun]

Originally Posted by walt2137

You might think about running a charge line from the coach chassis battery to the toad battery especially using a transmission pump you don't want to tow very far without trans being liberated.

Just to clarify... I tee'd into the the lube pump 12 volt line to power the battery maintainer. Everything is fused, and if by chance, the lube pump line shorted out, I would get an immediate alarm in the coach.

Since the lube pump is powered off the coach charge line, and the wire is sized with sufficient capacity to power both the lube pump and the battery maintainer, I should be fine with this set up.