|
We already discussed this via a PM, but since it's now a thread I'll post my response here too.
We had the Holiday Rambler 32FKD converted to Mor/RYDE fully independent suspension & disc brakes by Mor/RYDE. The 32FKD had a similar GVWR to our current Arctic Fox of 11,500# but it weighed 10,100# empty vs. the 8370# of our Fox. Just 1400# of CCC not including water just isn't enough for us, so we towed the rig from WA to Indiana and had Mor/RYDE replace the 5,000# steel spring axles with 7,000# rubber spring axles. We also upgraded the tires from LT225's to LT245's.
Mor/RYDE used the same Kodiak disc brake hardware that's typical of most disc brake-equipped trailers, but offered us 3 different master cylinders. One was a price leader model for the budget minded with about 0.7-0.8 seconds required to develop pressure, one was the mid-range model needing about 0.4-0.5 seconds. The best was a new dual-cylinder model that had separate cylinders for each axle and developed pressure in about 0.2 seconds. We went for the gold.
The bill looked like this:
* Mor/RYDE 'IS' suspension on TT: $2007
* Disc brake conversion: $2995
* Mor/RYDE 'RL' suspension modification on F350: $750
Skipping the discussion of the Mor/RYDE suspension and moving on to the disc brakes . . .
The disc brakes were 99% fantastic. The difference in the smoothness of braking and increased stopping ability was readily noticed by DW sitting in the passenger seat. They stopped FAR better than the drum brakes and their braking power is linear just like the 4-wheel disc brakes on the truck. Drum brakes are inherently 'self-actuating' which means that once the shoes contact the drums, they amplify the application force. But, once that initial application leverage has been applied, further application force yields decreasing braking effort. As a result, the TT stops just like the TV does. The difference in fade is equally dramatic. After meandering around Canada for a month on the way home, we came down a mountain grade. Six miles of 6% grade. I decided to see what the brakes could do, so I accelerated to 60+ MPH and then braked to 40 MPH, accelerated to 60+ & braked to 40, again and again all the way for 6 miles. At the bottom of the grade I pulled over on a wide spot of the shoulder applying the brakes firmly to a dead stop. The rig simply stopped as if it was a first stop. Cool. This was the one part of the job at Mor/RYDE that DW thought was worth the money.
The 1% of the disc brakes that wasn't great was that 0.2 second delay means that the TT never brakes before the TV. That means the Hensley is put in compression which leads to an immediate change in the virtual pivot point, which leads to a definite change in the trajectory of the TV. In other words, the truck skews a bit to one side just as if one of the rear brakes wasn't working properly. A front brake problem causes the steering to pull and the vehicle to turn. OTOH, a rear brake problem doesn't change the steering, but the vehicle shifts to one side instead. Without making I steering correction, I'd say the truck shifted about 12-18" to the right. The good news is that it's easily corrected by making a small adjustment in the steering. I quickly learned to turn the wheel slightly left every time I applied the brakes. Once that initial steering correction was made, the vastly improved braking of the disc brakes more than made up for the skewing. One advantage of our PullRite is that it is immune to this issue.
Will we install disc brakes on the Arctic Fox? My hunch is that we will when it's time to replace the tires, if not before then.
__________________
Steve & C. J.
2009 Arctic Fox 29V PullRite 20K hitch
2005 Chevy Silverado 2500HD 4X4 Duramax/Allison
|