Go Back   Montana Owners Club - Keystone Montana 5th Wheel Forum > MONTANA OWNERS CLUB COMMUNITY > New Member Introductions
Click Here to Login

Reply
 
Thread Tools Display Modes
 
Old 01-24-2005, 07:20 AM   #1
Montana_2947
New Member
 
Join Date: Jan 2005
Location:
Posts: 3
M.O.C. #2947
Motorcycle Lift

Hi,
We are owners of 2003 Big Sky Montana and have recently bought a Harley Davidson Road King. We would like to install a motor-cycle lift to the back of the Big Sky if possible.

If anyone has done this type installation or knows of someone who may be able to proived us with additional informaiton - pros and/or cons, we would appreciate the input.
Thank you,
CUFANS
Montana_2947 is offline   Reply With Quote
Old 01-24-2005, 09:11 AM   #2
stiles watson
Montana Master
 
Join Date: Sep 2004
Location: Leona
Posts: 6,382
M.O.C. #2059
When these RV's are built, the manufacturer has to maintain a balance between strength and weight. The stronger the frame the heavier the weight. If I have my facts straight, beginning with the 2003 models the frame was beefed up a little. However, Keystone still does not recommend adding any kind of additional cantilevered weight beyond the back of the Montana. It is not just the weight. It is also a function of the distance from the supporting axle.

A cantilevered weight subjects the frame to the most severe stress at the point of the rear axle. The severity of this stress is magnified when weight protrudes from the rear. The frame of your unit was not designed to compensate for these kinds of physical forces. These are the laws of physics, not just scare tactics from some engineering cowards.

To get a mental image of what I speak, pick up a ten pound weight with one hand. Not too hard. Now tie the ten pound weight to a fifteen foot pole, then pick it up with the other end of the pole. The difference is significant.

All this to say, if you are going to add a cycle lift, you need to beef up the frame all the way back up past both axles to ensure you don't break off your tail someday on less than stellar road surface. That would be an aweful comsplateration.
stiles watson is offline   Reply With Quote
Old 01-24-2005, 12:28 PM   #3
azstar
Montana Master
 
Join Date: Dec 2003
Location: Chandler
Posts: 624
M.O.C. #740
CUFANS,

I'm going to assume you were able to use the search in this Forum, for Motorcycle. After reading the two pages there you have decided to go forward with your idea.

Stiles is right on the money with his comments. If your going forward, I would like to suggest doing a little more calculating. Lets look at a couple of things.

If the Bike weighs say 750 lbs. and we keep the weight down by using a ramp with a fixed carrier to save some weight, rather than a Hyd/Elect lift. We might be at about 900 to 1000 lbs. added to the rear of your Rig. This weight is unloading the weight on your pin. You can and should calculate this loss of pin weight. The lost pin weight and the added Bike with carrier weights all winds up on your 5ers axles. In this case it might add 1500 lbs. to your axles. Do you have 1500 lbs. of capacity to give up? Need to find axle ratings to see.

You could off-set the loss of pin weight by welding new spring shackles on and moving the axle rearward, but you now need new wheel wells and if for some reason you wanted to tow with out the Bike you've got way too much pin weight.

Stiles wrote about cantilevered weight. In this case the new over hung Mass is in motion. The inertia of this Mass can easily double the load of the Bike on to your 5ers frame. Now your axles might see an additional 3000 Lbs. or more than it has ever seen before.

Bottom line, can it be done? Yes. After years in Structural Eng.in the AeroSpace Bus. I could never give up on an idea. Sometimes to my detriment, but I do love a challenge.

Above all please do your homework. This is serious business. Lives could be lost.

Wish you well
azstar is offline   Reply With Quote
Old 01-24-2005, 02:29 PM   #4
azstar
Montana Master
 
Join Date: Dec 2003
Location: Chandler
Posts: 624
M.O.C. #740
CUFANS,

Thinking more on the subject, I would go with the Trailer behind the 5er and use a Tire pressure monitor set up in the TV to keep an eye on the Cycle Trailers pressure. That was my only big concern regarding trailers behind 5ers. I have no experience with these Pressure Sensors but I believe some of our members have reported good things about them. They use them in their 5er wheels, but why not put one in the M/C Trailers wheel?

In case you haven't seen this, http://cruiserlift.com/products.htm

Happy Camping
azstar is offline   Reply With Quote
Old 01-25-2005, 01:10 AM   #5
BillyRay
Montana Master
 
Join Date: Oct 2003
Location: Malta
Posts: 3,075
M.O.C. #607
wow too much thought into this one! thought I was back in math class.
BillyRay is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Motorcycle Lift for Montana John Bowers Tow Vehicles & Towing 49 08-28-2008 02:59 AM
Motorcycle bigbob7777 General Discussions about our Montanas 19 07-29-2007 06:34 PM
Montanas and hydraulic motorcycle lift Susan Clark Additions & Improvements 7 07-07-2007 08:04 PM
Motorcycle lift vs. trailer Montana_1970 Tow Vehicles & Towing 25 06-20-2005 04:43 PM
Motorcycle Lift for Montana Big Sky Montana_2947 Additions & Improvements 3 01-24-2005 08:18 AM

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Montana RV, Keystone RV Company or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 10:04 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2018, vBulletin Solutions, Inc.