Fixitandy,

My first question to you is - are the tires on the machine air tires (w/valve stem) or solid molded (no air valve stem)? I am assuming they are air tires based on your commends about introducting a liquid into the tires but never like to AssUme anything so I give you 3 persepectives and advise.

If the tires are air type then your options would be:

1. Install a solid molded tire meaning there is no air cavity beyond the tread. This would give some added weight to the rear of the machine plus no worry of flat tires. You may need to change the rims - check with your local dealer if necessary. This is a manufacturers approved option I am sure. There are two types of solid tires one with a soft center to improve road shock absorption (names like Super Soft, Super Elastic, etc) but will tend to be a bit more bouncy and probably weigh less. The other is a standard solid tire it provides a harder ride and is made with more dense material (more weight) but it is tougher on the machine if operating surfaces are uneven.

2. The other option for an air tire is to do what you said add the liquid you are referring to the rear tires. That liquid is called calcium chloride and as you say it is commonly added to farm tractors and to rough terrain forklifts (a.k.a. turned around farm tractors) for operation around job sites (uneven surfaces). However, the tires will still compress and "baby buggy) as the liquid will compress as air is used to give proper inflation pressures. I am familiar with this approach, grew up on a farm and sold rough terrain forklifts.

3. If the unit already has solid tires then the advice that Edward T suggested to add plates to the rear is a possibility. I have seen this done on Nissan and other makes but first get the approval of the manufacturer (or authorized representative of the manufacturer a.k.a. dealer). They may have limits to how much weight can be added, where it is to be placed and sometimes the steering tires and rims may need to be changed (increased in size) to handle the increased in load when the unit is running empty. About 60% of the machines total weight is supported by the steering tires/rims when it is does not have a load on the front end (forks).

Hope this helps.