Increasing camper trailer ATM?

Submitted: Tuesday, Jan 05, 2021 at 08:20
ThreadID: 140940 Views:1077 Replies:3 FollowUps:6
Has anybody increased the ATM of a camper trailer? Trailer has 2 tonne bearings, 60mm stub axles and an ATM of 2000kg. I have read that if 2 tonne bearings are used on a 65mm axle, can be rated at 2.5 tonnes. Also understand breakaway brake controller needed above 2000kg ATM. (In Victoria). Any thoughts or comments.
Back Reply Expand Un-Read 0 Moderator

Reply By: Frank P (NSW) - Tuesday, Jan 05, 2021 at 09:39

Tuesday, Jan 05, 2021 at 09:39
I've done it, John, on my Kimberley Karavan in NSW. Many members of our Karavan owners club have done it also, in different states. Though the rules are national, each state applies them differently. Additionally, within states those rules appear to be inconsistently applied depending on the engineer you use to certify the upgrade.

NSW, as always, has the most stringent requirements and the most expensive process.

Bearing ratings and axle size are only parts of the deal. The engineer will probably (should?) consider chassis construction and suspension mounts, spring ratings and tyre and rim ratings and coupling.

You will need to ensure your GTM is upgraded as part of the certification process - that is arguably more important than ATM as all the trailer rules are based on GTM, including the breakaway brake requirement. GTM is the maximum weight the wheels are allowed to carry and is the one most easily checked at a roadside check point.

Trailer regulations are national, specified in VSB 1.
The requirement for breakaway brakes is a national regulation, not state-based and applies to trailers with a GTM (not ATM) above 2000kg.

You may find this PDF document of interest. After much research, I prepared it for our club.



Cheers
FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

AnswerID: 634640

Follow Up By: Member - John - Tuesday, Jan 05, 2021 at 09:56

Tuesday, Jan 05, 2021 at 09:56
Thank you Frank, very informative. Cheers.
0
FollowupID: 911970

Reply By: HKB Electronics - Wednesday, Jan 06, 2021 at 10:55

Wednesday, Jan 06, 2021 at 10:55
Try the manufacturer, my camper manufacturer did mine.

Lifetime Member
My Profile  Send Message

AnswerID: 634664

Follow Up By: Frank P (NSW) - Wednesday, Jan 06, 2021 at 11:31

Wednesday, Jan 06, 2021 at 11:31
Interesting, Leigh.

What were the original ATM and GTM and what did you end up with.

My Karavan was ATM 2200, GTM 1999. Ended up with 2500/2380
FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

0
FollowupID: 911994

Follow Up By: HKB Electronics - Wednesday, Jan 06, 2021 at 12:44

Wednesday, Jan 06, 2021 at 12:44
VISTA XL was 1650GVM, was increased by VISTA to 1900Kg. Those Karavan's are heavy units.

Lifetime Member
My Profile  Send Message

0
FollowupID: 911995

Follow Up By: Member - John - Wednesday, Jan 06, 2021 at 14:29

Wednesday, Jan 06, 2021 at 14:29
HKB, Aussie Swag went out of business in 2018, pity.
0
FollowupID: 911996

Follow Up By: Frank P (NSW) - Wednesday, Jan 06, 2021 at 22:04

Wednesday, Jan 06, 2021 at 22:04
"Those Karavan's are heavy units."

Yes, Leigh, they are. And that brings some limitations about where the tug can take it, but it really only affects the more extreme situations.

Everything is a compromise. We have chosen a degree of comfort and convenience that works for us over other options that might have let us do more extreme things.

As it is, we have given it a good workout and it keeps us both on the road. I'd post a map but it's stuck on the retractable table in the van, now in storage and not easily accessible :-(

But a short and very incomplete list:
Gibb River Rd, Mitchell Falls from Drysdale, abandoned section of the Old Gunbarrel Hwy, numerous fire trails in VHC and NSW Snowies and Blue Mts, Great Central Rd, Tanami Rd, Old Eyre Hwy, station tracks and destinations in lower Cape York Peninsular around Mayfield and Laura (prospecting), Adels Grv to Kingfisher via back roads, Gary Junction Hwy, Rudall River NP, etc.

Yes, it's heavy, but drive to conditions, know the limits and it's great.

If I don't want the limits I swag it solo. About to do that tomorrow.

Cheers
FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

0
FollowupID: 912004

Reply By: Nomadic Navara - Wednesday, Jan 06, 2021 at 12:59

Wednesday, Jan 06, 2021 at 12:59
A couple of things:

1.. the rating of an axle is limited to the rating of its weakest link. If you only have 2-tonne bearings the axle is limited to 2 tonnes no matter how big the cross-section of the metal.

2.. The requirements for a breakaway controller is based on GTM, not ATM
PeterD
Retired radio and electronics technician

Lifetime Member
My Profile  Send Message

AnswerID: 634665

Follow Up By: Member - John - Wednesday, Jan 06, 2021 at 14:33

Wednesday, Jan 06, 2021 at 14:33
Peter D, The rating of the bearings has been confirmed by ALKO head office, 50mm square, 2 tonne; 65mm Round 2.5 tonne, sounds bizarre I know, but they are the facts. The terminology is confusing, agreed it should be GTM.
0
FollowupID: 911997

Sponsored Links

Popular Products (12)