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Sidecar Weight Distribution???
Quote from CCjon on June 5, 2022, 10:57 amDoes anyone know what is the ideal or recommended weight distribution for sidecars?
What percent should the sidecar wheel weight be in relation to the front and rear wheels?
Sidecar Wheel ? ___________%
The Rear Wheel ? _______________%
The Front Wheel? ______________%
Is it a wide range or a narrow range?
Does anyone know what is the ideal or recommended weight distribution for sidecars?
What percent should the sidecar wheel weight be in relation to the front and rear wheels?
Sidecar Wheel ? ___________%
The Rear Wheel ? _______________%
The Front Wheel? ______________%
Is it a wide range or a narrow range?
Quote from Al Olme2 on June 5, 2022, 11:33 amHaving done some research and actual weighing of rigs, there is no "correct" distribution. Before you start you have to determine a "normal" load and we all know that changes a lot. After that you need to know the skill of the driver and his/her tolerance for sidecar lifting. With just these three parameters you can see that the range has to be ridiculously wide. We weighed a rig once, driven by a young lady, with moderate experience, where the side wheel carried just 14% of the load. I would consider that dangerous but she was perfectly comfortable with it. She just made very slow right hand turns. One other thing to consider, but it is rarely adjustable, is sidecar wheel lead because it radically influences lean in turns. The only issue is that you seldom have a choice past the design phase.
For most folks the starting point is the classic "stand on the left peg with your right foot and try to pull the sidecar off the ground" test. If it doesn't come up or it comes up a little and settles back down, you're probably fine. This quick test, well known in the sidecar community, has the great advantage of being able to be performed, in seconds, every time you change the load in the rig.
There are established weight distribution bad ideas. The classic is to have Mom & Dad on the bike and a small child or animal in the hack. There are exceptions for very heavy sidecars but in general this weight distribution is suboptimal. If you've been around for a long time you might remember that this was the late Bob Zinda's pet peeve. Another bad idea is to have a heavily loaded sidecar that doesn't have a brake. Physics never sleeps.
There are so many compromises in every sidecar rig that trying to set rules for configuration is a lost cause. I always tell newbies that if someone tells you that you need exactly X amount of toe-in, you should thank them and run. There are few (or possibly no) absolutes in rig set up. There are many "good places to start" and rules of thumb but setting up a rig is an iterative process. Make a setting, RECORD THE SETTING, test and modify to suit until the mod makes things worse. At that point return to the previous best setting. Remember, changing toe in will also change lean and the corollary is also true.
Two seemingly identical rigs might well have identical set ups that work for one rig and not the other. Your set up is as individual as your rig.
Of course, that's just my opinion, you'll hear others.
Having done some research and actual weighing of rigs, there is no "correct" distribution. Before you start you have to determine a "normal" load and we all know that changes a lot. After that you need to know the skill of the driver and his/her tolerance for sidecar lifting. With just these three parameters you can see that the range has to be ridiculously wide. We weighed a rig once, driven by a young lady, with moderate experience, where the side wheel carried just 14% of the load. I would consider that dangerous but she was perfectly comfortable with it. She just made very slow right hand turns. One other thing to consider, but it is rarely adjustable, is sidecar wheel lead because it radically influences lean in turns. The only issue is that you seldom have a choice past the design phase.
For most folks the starting point is the classic "stand on the left peg with your right foot and try to pull the sidecar off the ground" test. If it doesn't come up or it comes up a little and settles back down, you're probably fine. This quick test, well known in the sidecar community, has the great advantage of being able to be performed, in seconds, every time you change the load in the rig.
There are established weight distribution bad ideas. The classic is to have Mom & Dad on the bike and a small child or animal in the hack. There are exceptions for very heavy sidecars but in general this weight distribution is suboptimal. If you've been around for a long time you might remember that this was the late Bob Zinda's pet peeve. Another bad idea is to have a heavily loaded sidecar that doesn't have a brake. Physics never sleeps.
There are so many compromises in every sidecar rig that trying to set rules for configuration is a lost cause. I always tell newbies that if someone tells you that you need exactly X amount of toe-in, you should thank them and run. There are few (or possibly no) absolutes in rig set up. There are many "good places to start" and rules of thumb but setting up a rig is an iterative process. Make a setting, RECORD THE SETTING, test and modify to suit until the mod makes things worse. At that point return to the previous best setting. Remember, changing toe in will also change lean and the corollary is also true.
Two seemingly identical rigs might well have identical set ups that work for one rig and not the other. Your set up is as individual as your rig.
Of course, that's just my opinion, you'll hear others.
Quote from john robinson on June 5, 2022, 1:16 pmHowdy, 1981 BMW R100RT, with a homemade sidecar, total 964.6lbs, with rider, 170 lbs, front wheel 373.8 lbs, rear wheel 416.5 lbs, empty sidecar 175.3lbs. These numbers are an average of three weighs. Cross checked the total at a commercial truck scale, read 940 lbs there..Sidecar is light, but outfit is stable without drift at 75mph.
Howdy, 1981 BMW R100RT, with a homemade sidecar, total 964.6lbs, with rider, 170 lbs, front wheel 373.8 lbs, rear wheel 416.5 lbs, empty sidecar 175.3lbs. These numbers are an average of three weighs. Cross checked the total at a commercial truck scale, read 940 lbs there..Sidecar is light, but outfit is stable without drift at 75mph.
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Quote from smitty901 on June 5, 2022, 6:31 pmMy experience says wide range. However that does not mean exceeding what the sidecars limits are.
Most of us know it gets harder to handle as it gets heavy..
When wife rides on the bike we move bags to the sidecar to balance things out.
My experience says wide range. However that does not mean exceeding what the sidecars limits are.
Most of us know it gets harder to handle as it gets heavy..
When wife rides on the bike we move bags to the sidecar to balance things out.
Quote from dholaday on June 6, 2022, 10:42 amCCJON
What Al said. You ought to post a link to the advrider threads on this subject.
Duncan
CCJON
What Al said. You ought to post a link to the advrider threads on this subject.
Duncan
Quote from CCjon on June 8, 2022, 12:29 pmThere is a practical application in balancing the load on a rig, but are there ideal balance percentages? Have seen R50%-F30%-S20%? Did those numbers come from a study or from experience? Are they even correct or just random numbers that looked good?
We are taught that 10-12% sidecar wheel lead is recommended based on studies and experience; now the accepted standard for a street rig. But for the balance percentages...
If there is no recommended weight distribution for rigs based on studies and experience, why do we bother weighing them?
There is a practical application in balancing the load on a rig, but are there ideal balance percentages? Have seen R50%-F30%-S20%? Did those numbers come from a study or from experience? Are they even correct or just random numbers that looked good?
We are taught that 10-12% sidecar wheel lead is recommended based on studies and experience; now the accepted standard for a street rig. But for the balance percentages...
If there is no recommended weight distribution for rigs based on studies and experience, why do we bother weighing them?
Quote from john robinson on June 8, 2022, 1:06 pmhowdy, I recently built my SC, and just for kicks and grins, wanted to know what the weight distribution is with the idea to somehow figure out the COG, there is no reason for me to know the COG, other than the question intrigued me, and I'm still working on figuring how to do that! yeah there is that German COG program, but I have a hard enough time with my native english.....
howdy, I recently built my SC, and just for kicks and grins, wanted to know what the weight distribution is with the idea to somehow figure out the COG, there is no reason for me to know the COG, other than the question intrigued me, and I'm still working on figuring how to do that! yeah there is that German COG program, but I have a hard enough time with my native english.....
Quote from john robinson on June 8, 2022, 1:18 pmEngine turning
First off, I built and finished this sidecar body in 2005. I used 6061 0.063 aluminum on a homemade buck for shape, first using poprivets with angled backing plates to hold the structure together, then heliarc welding the seams. I did not use any coating to protect the engine turning. It was on the road for about 3 years/14k miles, then stored in the ceiling of my workshop/garage until spring 2022, when I built this new SC frame. The original 1952 Steib S350 frame I had used for the first SC was badly rusted both internally and externally, and no longer structurally safe to use, IMHO. Besides I wanted an actual suspension, rather than the very minimal suspension the Steib had.
To make the engine turning pattern, I used a wired variable speed 3/8 drill, as the older wired drills will turn slower than battery style, and are easier to control. I used a fine wire 1 inch diameter steel brush. This fine wire splays out when pushed onto the metal. I used a pencil line to mark my lines. I strongly suggest to practice on a chunk of the same material you are going to display your handiwork on. Notice the difference in the pattern in this photo. I got tired, and when I came back it took a bit of time to recover the muscle memory to keep the pattern even. Overall it took me a bunch of time and practice. Several weeks or more off and on. It is not by any stretch, a Show job, just decorative, yet having said that, people who see the SC for the first time, almost always mention the turning.... so I guess I should be prouder of it...
Engine turning
First off, I built and finished this sidecar body in 2005. I used 6061 0.063 aluminum on a homemade buck for shape, first using poprivets with angled backing plates to hold the structure together, then heliarc welding the seams. I did not use any coating to protect the engine turning. It was on the road for about 3 years/14k miles, then stored in the ceiling of my workshop/garage until spring 2022, when I built this new SC frame. The original 1952 Steib S350 frame I had used for the first SC was badly rusted both internally and externally, and no longer structurally safe to use, IMHO. Besides I wanted an actual suspension, rather than the very minimal suspension the Steib had.
To make the engine turning pattern, I used a wired variable speed 3/8 drill, as the older wired drills will turn slower than battery style, and are easier to control. I used a fine wire 1 inch diameter steel brush. This fine wire splays out when pushed onto the metal. I used a pencil line to mark my lines. I strongly suggest to practice on a chunk of the same material you are going to display your handiwork on. Notice the difference in the pattern in this photo. I got tired, and when I came back it took a bit of time to recover the muscle memory to keep the pattern even. Overall it took me a bunch of time and practice. Several weeks or more off and on. It is not by any stretch, a Show job, just decorative, yet having said that, people who see the SC for the first time, almost always mention the turning.... so I guess I should be prouder of it...
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Quote from smitty901 on June 8, 2022, 2:22 pmHow your rig reacts to load and where it is placed is effected by so much. Wheel base of both the tug and the sidecar. Distance sidecar wheel is in front of rear tire center. Distance sidecar is mounted from the tug. Over all size of your rig.
In our case The bike is just over 900lbs side car around 325lbe empty. Running down the road weight in seat and trunk can be around 250LBS. Bike would likely have 225 lbs on bike Rider,Tour pack load and two saddle bags. Sidecar may at time have 10-20 pounds in the nose. It handles well in this general load plan.
When wife decides to ride on the bike. Items in saddle bags and tour pack are move to center of the sidecar. I know for a fact Tire pressure plays into it.
If I roll out with tires at what I know to be the right pressures for my Rig it is a little sluggish at first. Once tires warm up it response well. If I leave home and temps are in the 30 degrees and next state south temps are in the 80's I have to adjust for the difference.
Cold
195/65R16 rear bike 40 lbs max load 1985 LBS
130/70B18 bike front 36 lbs max load 600.
155/80R12 Sidecar 38Lbs 980 lbs max load
How your rig reacts to load and where it is placed is effected by so much. Wheel base of both the tug and the sidecar. Distance sidecar wheel is in front of rear tire center. Distance sidecar is mounted from the tug. Over all size of your rig.
In our case The bike is just over 900lbs side car around 325lbe empty. Running down the road weight in seat and trunk can be around 250LBS. Bike would likely have 225 lbs on bike Rider,Tour pack load and two saddle bags. Sidecar may at time have 10-20 pounds in the nose. It handles well in this general load plan.
When wife decides to ride on the bike. Items in saddle bags and tour pack are move to center of the sidecar. I know for a fact Tire pressure plays into it.
If I roll out with tires at what I know to be the right pressures for my Rig it is a little sluggish at first. Once tires warm up it response well. If I leave home and temps are in the 30 degrees and next state south temps are in the 80's I have to adjust for the difference.
Cold
195/65R16 rear bike 40 lbs max load 1985 LBS
130/70B18 bike front 36 lbs max load 600.
155/80R12 Sidecar 38Lbs 980 lbs max load
Quote from Al Olme2 on June 9, 2022, 9:40 amJan wrote; "We are taught that 10-12% sidecar wheel lead is recommended based on studies and experience; now the accepted standard for a street rig. But for the balance percentages... ". 10-12% of what? Wheel base?
I'd like to read that. Where did you find it?
THX
A
Jan wrote; "We are taught that 10-12% sidecar wheel lead is recommended based on studies and experience; now the accepted standard for a street rig. But for the balance percentages... ". 10-12% of what? Wheel base?
I'd like to read that. Where did you find it?
THX
A
Quote from CCjon on June 9, 2022, 10:59 amMeasure axle to axle distance (wheel base) to calculate, 10-12% of that to arrive at the suggested 8-12 inch lead for modern swing arm bikes.
Page 42, Hal Kendal's book in Sidecar Tech on here. The largest bike he mentions is a 750cc.
Percentages work better in today's marketplace as we have more rigs of all sizes and lengths available, from 50cc small scooters to 2300cc Rockets. Eight inches of lead on a Grom might be too much and twelve inches on a Rocket too little.
Didn't find a recommendation in Hal's book on weight distribution.
Is there a recommended sidecar weight distribution for our rigs?
Measure axle to axle distance (wheel base) to calculate, 10-12% of that to arrive at the suggested 8-12 inch lead for modern swing arm bikes.
Page 42, Hal Kendal's book in Sidecar Tech on here. The largest bike he mentions is a 750cc.
Percentages work better in today's marketplace as we have more rigs of all sizes and lengths available, from 50cc small scooters to 2300cc Rockets. Eight inches of lead on a Grom might be too much and twelve inches on a Rocket too little.
Didn't find a recommendation in Hal's book on weight distribution.
Is there a recommended sidecar weight distribution for our rigs?
Quote from Al Olme2 on June 9, 2022, 2:04 pmThere's a lot of good stuff in Hal's books but it's not all perfectly true. Be careful and test before adopting his recommendations. It turns out that while it looks like he wrote all those books, at least one was written by someone else.
Insofar as I know, there is no recommended weight distribution. I stand by my earlier answer, there just isn't one thing, or range, that works for everyone.
There's a lot of good stuff in Hal's books but it's not all perfectly true. Be careful and test before adopting his recommendations. It turns out that while it looks like he wrote all those books, at least one was written by someone else.
Insofar as I know, there is no recommended weight distribution. I stand by my earlier answer, there just isn't one thing, or range, that works for everyone.
Quote from john robinson on June 13, 2022, 4:48 pmHowdy,
I found a set of books, by Rod Young, "The Sidecar Technical Guide", and "The Sidecar Guide" they are a "Three Wheels Better" publication, copyright 2019...nothing in them about weights, just inch measurements for track, lead, toein, lean...had a good 'build it better yourself' set of plans in it, even a "how to" set of homemade leading link forks....and a how to fit Dnepr LL forks to a 1986 BMW R80 mono, nice to see different SC wheel suspensions,. I got nothing in this to push sales of these books here, just something I found that interested me... and thought they might interest somebody else..
Howdy,
I found a set of books, by Rod Young, "The Sidecar Technical Guide", and "The Sidecar Guide" they are a "Three Wheels Better" publication, copyright 2019...nothing in them about weights, just inch measurements for track, lead, toein, lean...had a good 'build it better yourself' set of plans in it, even a "how to" set of homemade leading link forks....and a how to fit Dnepr LL forks to a 1986 BMW R80 mono, nice to see different SC wheel suspensions,. I got nothing in this to push sales of these books here, just something I found that interested me... and thought they might interest somebody else..
Quote from DRONE on June 13, 2022, 9:53 pmRod Young is a member here (3WheelsBetter) and a pretty knowledgeable guy. Former owner of Motopodd Sidecars in the UK. He and I have traded PM's since 2011. Mostly about tires (tyres). LOL
He has his own website called, naturally, Three Wheels Better -- http://www.threewheelsbetter.uk/index.html
I've got his books. Excellent. He has a vendor thread here in the forum--
Also available on Amazon--
https://www.amazon.com/Sidecar-Technical-Guide-technical-modifying/dp/1088885276
https://www.amazon.com/Sidecar-Guide-existing-motorcycle-sidecar/dp/1088425372/
Rod Young is a member here (3WheelsBetter) and a pretty knowledgeable guy. Former owner of Motopodd Sidecars in the UK. He and I have traded PM's since 2011. Mostly about tires (tyres). LOL
He has his own website called, naturally, Three Wheels Better -- http://www.threewheelsbetter.uk/index.html
I've got his books. Excellent. He has a vendor thread here in the forum--
Also available on Amazon--