Ok guys, am turning to the group for ideas, suggestions, warnings and insight. Bought a very low mileage (showing only 38 miles) 2024 Honda Trail 125 to haul on the tail of an RV to use as a campgrounds scoot. But... I want to add a lightweight (probably aluminum) cargo sidecar to it.
My thoughts are:
1. Reduce countersprocket teeth from 14 to 13 for more torque
2. Raise handlebars and seat for my height
3. Add USB outlet for iPhone
4. The bike weights 260, need to keep total weight with sidecar to less than 325-335
5. Use a narrow bicycle type wheel or similar for sidecar to give more ground clearance and easier rolling.
6. No brake on sidecar
7. Locate mounting spots on bike for subframe and upper struts
8. Will be keeping speed to 30-35 mph, tops. No Alaska backroads planned for it.
9. Plan to keep a narrow wheel track, +/- 26-28" c2c
If you have already build a creature like this or have been planning a sidecar build for the Trail 125, would love to hear your thoughts, suggestions, problems encountered, solutions, etc.
What are your ideas ??????
CCjon - Jan
Nice score! I like what you say you're going for, especially, raising the handlebars - Ape hangers aren't showing off for you! 
My only question is why add a phone charger? If you're planning on putting around campgrounds, will you be far enough from "home" to need a phone charge?
Query: how do you plan to add a bicycle tire to the car without it becoming comically high? Unless you're going to use an offset axle for the sidecar wheel which might be brilliant!
Illegitemi non carborundum est!
Jan do NOT reduce the number of teeth on that countershaft sprocket from 14 to 13.
Raise the number of teeth on the rear wheel sprocket by 3 teeth.
A 3 tooth increase on the rear sprocket = the same as a 1 tooth decrease on the front sprocket.
Rather than reduce the size of the circle that the chain has to go around on the front sprocket, which means turning that chain into a tighter circle, it is far easier to add a slightly larger sprocket to the rear wheel, and those rear wheel sprockets are readily available for the Honda Trail 125.
Get a 16" wheel and tire from Bushtec, that they use on their trailers...and use that as the wheel/tire for your sidecar rig.
Two Million Mile Rider
Exploring the World in Comfort
The Bushtec trailer weighs 140 lbs, not sure how much of that is one wheel. Only have 60-70 lbs to work with for the sidecar and subframe... less is better.
Was looking at bicycle trailers, found this one. Total weight is 40 lbs. Use just one 20" tall wheel, keep the other wheel as a Prince Harry.
Also have an aluminum sturdy cargo basket that could be cut down to a smaller, narrower size., mount an full width axle, but how ro create a lightweight shock or rubber bushing for the axle.
Still toying with ideas, exploring even the wildest options for the build.
On the question of mounting the wheel to the sidecar, are you thinking of a full axle or a spindle? Spindle would give you the option of virtually any size wheel.
Illegitemi non carborundum est!
Cool idea! 😎
Any thought to making it a "Leaner"?
Reason for the ask is much less stress on the sidecar and motorcycle, so everything can be kept on the light side. Carefully crafted you could just fold the sidecar up to the bike to load on the back of the RV.
Hold my keyboard and watch this! 🙃
Just for an idea on the sidecar side of things: https://www.farmtek.com/prod/109630.html?srsltid=AfmBOorRERN1VabaR1iEIciDjEBC6decXxoPFOJgK7ZWlKsqNyzk2UsiYak
Hold my keyboard and watch this! 🙃
Cool idea! 😎
Any thought to making it a "Leaner"?
Reason for the ask is much less stress on the sidecar and motorcycle, so everything can be kept on the light side. Carefully crafted you could just fold the sidecar up to the bike to load on the back of the RV.
Scott, we all know that you are just giddy that Jan's new Honda Trail 125 is YELLOW, and not one of those Red or Green models.
Two Million Mile Rider
Exploring the World in Comfort
Just for an idea on the sidecar side of things: https://www.farmtek.com/prod/109630.html?srsltid=AfmBOorRERN1VabaR1iEIciDjEBC6decXxoPFOJgK7ZWlKsqNyzk2UsiYak
Actually, I have to say that Scott has touched on a brilliant idea. (it hurt me to say that, but he does have brilliant ideas now and then)
Jan @jan-2, what about towing a very lightweight FOLDABLE aluminum trailer behind your YELLOW Honda Trail 125, rather than making it a sidecar rig ?
This all aluminum FOLDING trailer would be ideal to tow behind your Trail 125, and still give you the maneuverability of a 2 wheeled bike, but the carrying capacity of a sidecar tub, yet can be folded up and placed next to the bike on the hitch carrier.
It would take a LOT less fabrication to make a trailer hitch for the back of the Trail 125, than it would to attach a sidecar to the bike.
AND....if you think about placement of a trailer hitch onto the back of the bike....LOOK at the current height of the rear rack on the Trail 125.....then LOOK at the height of the front HANDLE of this aluminum folding trailer. I will bet you a dozen Stroopwaffles that they are very close to the same height, so....simply mount a Heim joint post onto the bottom of the rearmost rail of the rear rack of the Trail 125, and mount a Heim receiver onto the front center of that trailer handle, so that the Heim joints can connect the trailer handle to the rear rack of the Trail 125.
This allows for a more narrow track of the bike and trailer, rather than a wider track of the bike w/Sidecar. It allows more versatility of riding narrower trails, allows the bike to lean on rougher surfaces, such as trails, rather than a fixed position of straight up.
It also allows the Trail 125 to be ridden as a solo bike, with NO attachment to it at all, or it can have the trailer attached to the back of the bike, and has a 250 lb. carrying capacity in that aluminum trailer.
Two Million Mile Rider
Exploring the World in Comfort
Sheath, Flying Monkeys, I totally agree with you both, the idea of a folding trailer would satisfy the hauling requirements, is lightweight and compact when folded.
As my orthopedic doctor reminded me today, "Yes, you are more active than the vast majority of people in their eighties, but your body is still aging." The stability factor of a sidecar has a strong appeal as I plan to keep riding.
These little Trail 125's add back the fun factor of riding at a reasonable price. 🤡
As my orthopedic doctor reminded me today, "Yes, you are more active than the vast majority of people in their eighties, but your body is still aging."
I can't believe that you took the advice of your orthopedic doctor over the advice from your Sidecar Forums Doctor.
Oh, the Humanity !
And I thought we were friends 😫
Two Million Mile Rider
Exploring the World in Comfort
Y'all are still my bestest friends, Am told when I see someone wearing a white coat, my hearing improves... 🤠
Pondering the cost $30 ea., reduced weight, no tubes, limited speed / operating restrictions of the campgrounds Trail 125, these might be an option for the sidecar wheel... or not? What say y'all?
PARAMETERS
Tire Model: 20x2.0"
Tire diameter: 20"
Tire Width: 1.9"
Hub Type: Centered Hub
Hub Length: 2.45" (2-1/2")
Bearing Diameter: 3/4" or 5/8"
Dynamic Load Capacity: 250 LBS
PUNCTURE-PROOF & INFLATE-FREE
Would need upgraded bearings for sure.
*************
One goal is to have the total sidecar weight including subframe to be less than 60#
Jan, if those wheels/tires above will fit onto whatever axle diameter you will be using, then go for it, or them.
Those tires on those wheels are pretty hard rubber, not designed for cushioning impact at speeds of even 20 mph, but hey, at $ 30 each, they may be worth trying.
Question, giving the framework of the Trail 125, is it really necessary to have a subframe built for the bike ? Trying to keep the weight of this project down, could mean building a subframe out of moly, or aluminum, and that fabrication could be the most expensive part of the entire project.
Given the parameters you have set for the use of this Trail 125 sidecar rig, is it really going to be necessary to build a subframe, vs simply clamping on to the Trail 125 frame ???
Oh...I was wearing a white coat when I typed this 
Two Million Mile Rider
Exploring the World in Comfort
