Tag Axle vs Single Axle

[Gary RVRoamer]

Nobody mentioned "bridging", where the tag axle rides up on an incline while the drive axle is lower, thus lifting the drive axle off the road. This can happen crossing a dip (like a drainage channel) or a fairly sharp incline. A couple years ago I saw a tag coach stranded when crossing a high RR track bed. Had to get several planks under the drive tires to get him off it.

[KenZ71]

Sounds like a manual tag dump would solve the bridge issue.

[Gary RVRoamer]

A dump would certainly help, at least on smaller inclines or dips.

[Mr_D]

Better stability and added carrying capacity. My tag lifts about an inch or so off the ground when activated for tight turns or backing.

[Dutch Star Don]

I will admit tolls can be brutal in a tag axle coach. We don't have issues with them here, but on a trip back east, we were hit at one for $56.00 because they considered me a semi when towing a toad.

[New 2 Newmar]

Don't forget that they just look nicer too. Nothing like a full body paint rig with a tag axle.

[jcussen]

I have seen some dump and cement trucks that have complete lifting tags. I know that if they are loaded will need them to meet axle load regs, but if tags are in the air, would you be charged for that axle at a toll both?

[GEM1N1]

Pick a windy day. Go test drive a tag and non tag back to back.

Your decision will be made.

[Gary RVRoamer]

I've owned tags and non-tags and think the windy day thing is vastly overstated on these forums. When there is an observable difference, it is more like that the reporter has upgraded from a 25,000 lb coach to a 40,000+ lb rig, so of course it is much less susceptible to cross winds.


There is some benefit in ride quality for certain conditions, basically potholes where the tag wheels can keep the chassis from dipping as the drive wheel falls into the hole, then vice versa when the drive is back on the flat and the tag falls in. Doesn't help as much for wider bumps/dips, though.

[Milford 47]

I think the real key is if you are one that likes to load up your MH then you are going to have a weight problem and you can even with the heavier Coaches with tags.

The ability to carry more weight, increased breaking, and stability are the reasons I went with the tag and of course they are safer due to the foot print.

At the end of the day everyone should just get what works for them and not look back.

[dandandan]

Tag is a nice to have, but a DP with motion control units (MCU) will provide significantly enhanced stability in cross winds.



Many tags are delivered with their weights not in proportion and excessive weight on the front axle.


A lot of complexity with not as much need now that 24k axles are available.

[Milford 47]

Higher rated axle weights and larger tires sure don't negate the benefits of the extra axle and brakes.

There is only one reason to not have a tag when looking at 40 feet or larger and that is they simply cost more to purchase.

[dandandan]

Originally Posted by Milford 47

Higher rated axle weights and larger tires sure don't negate the benefits of the extra axle and brakes.

There is only one reason to not have a tag when looking at 40 feet or larger and that is they simply cost more to purchase.

Extra brakes does nothing for stopping distance if brakes are properly sized.


Max braking is the coefficient of friction of tires vs road (CF) times the normal force (essentially weight)


So if you replace a 24k axle with a 16k & 8k axle to keep it simple stopping force is the same


CF x 24k = CF x (16k + 8k)


If you increase the weight from 16k to 20k & 10k you have more stopping force but also a LOT more weight to stop so again no help (no hurt either if properly weight balanced)


The problem comes if the tag deviates from 2/3 weight on duals and 1/3 weight on tag. When improperly distributed the under weighted axle will lock up the under weighted axle first and skidding friction is lower or anti lock brakes prematurely activate. either way improper weight distribution on tag axle can significantly decrease braking while proper weight distribution is same as a single rear axle.


This can be a big issue as many tags are delivered with poor weight distribution and most owners never correct the issue.



Tag gives stability, but complexity and additional cost detract. I rarely see people with ideal 1/3, 2/3 weight balance on their tag.


40-42 ft single axle MHs with MCUs are the sweet spot for cost and simplicity IMO

[CampDaven]

Originally Posted by Milford 47

There is only one reason to not have a tag when looking at 40 feet or larger and that is they simply cost more to purchase.

When I bought my 09 Monaco w/tag in 2014, in the mix of the available rigs the 36-38 ft were more expensive. The 43/tag rigs were cheaper and undesirable due to the market. Everyone wanted the State Park size!

Originally Posted by dandandan

Extra brakes does nothing for stopping distance if brakes are properly sized.

...improper weight distribution on tag axle can significantly decrease braking while proper weight distribution is same as a single rear axle.

This can be a big issue as many tags are delivered with poor weight distribution and most owners never correct the issue.

Tag gives stability, but complexity and additional cost detract. I rarely see people with ideal 1/3, 2/3 weight balance on their tag.

40-42 ft single axle MHs with MCUs are the sweet spot for cost and simplicity IMO

I have “extra brakes” because I’m way under loaded. I bought it partially because of the tag! I love a great ride.

Mine has had proper weight distribution since it was built. The tag pressure adjustment was right on with Monaco manual. There was nothing to “correct”.

So much for the braking, pricing, and tag cost/complexity.


Now, please, what is the MCU that I don’t have nor need?

Happy Trails