I came up with this contraption for days when my kid needs a pick-up from school. He rides the bus to school, but on days when he has sport practice he misses the bus home.
I was inspired by this blog post which describes the idea of strapping the front wheel of one bike to the back of another. But my version uses a board with strap mount points that attaches to three MIK Side studs on the side of my rack using 3D-printed sockets.
The secret (that I learned from that blog post) is to make a tight strap connection from the head tube of the towed bike to the rack of the tow-er so that the towed bike doesn't fall over sideways.
It seems pretty secure. But my bike wobbles continuously while towing. Not too badly, but enough to discourage me from making hand signals. I think maybe because the rear wheel of the towed bike is not in line with the wheels of the towing bike. Or maybe because the steerer tube of the towed bike is leaning a little to the right.
I'm thinking of trying another idea I read that would line up all the wheels: attach a spare hub to my rack, remove the front wheel of the towed bike, and use the axle to connect to the attached hub.
20 Comments
reader@lemmy.zip · 22 pts · 3d
looks like bike sex
hallettj@leminal.space · 14 pts · 3d
Well I'm not gonna unsee this comment
lntl@lemmy.ml · 1 pts · 2d
!bikesfuck@lemmynsfw.com
LemminNewbie@lemmy.today · 8 pts · 3d
Is it possible to attach the towed bike backwards so the front wheel is on the ground? I'm no engineer I'm just curious how it would ride with the steering wheel on the ground
hallettj@leminal.space · 10 pts · 3d
Good question! I did try that, and the setup was much less stable than with the rear wheel on the ground.
I think the issue comes down to a bike geometry concept called "trail". Bikes are designed so that the contact patch of the front tire is behind the steering axis. If you look at a bike's head tube, and draw an imaginary line straight out from that tube the line intersects the ground somewhere in front of the contact patch. That causes the bike to want to keep its front wheel pointed straight - the contact point tends to trail behind the steering axis like a shopping cart wheel that always flips around so that the wheel is always behind the axle that connects the wheel to the cart.
"Trail" is specifically the distance between the point where the steering axis intersects with the ground, and the contact patch. Some bikes have a large trail, and those are the most stable. Some have short trail, and have "responsive" or "twitchy" steering.
When I put the bike on backward the contact patch was in front of the steering axis so the bike wanted to flip its front wheel around backward, causing it to swing around wildly.
So how about if I proactively turned the front wheel backward? I don't know - I don't remember if I thought of that when I did the experiment!
Edit: How did "axis" become "access"? Wth autocorrect?
LemminNewbie@lemmy.today · 4 pts · 3d
Interesting, thank you for the insightful reply. I guess when my car gets towed from the rear because it's rear wheel drive it's different because there are two wheels.
_haha_oh_wow_@sh.itjust.works · 7 pts · 2d
I was just about to suggest the alternate idea you're considering: This seems to be the go-to for hauling another bike hitched up in this way.
nilloc@discuss.tchncs.de · 7 pts · 2d
I think the front hub idea could work, but I’d want to keep the towed bike as low as possible to help with balance. It’s got a much higher center of gravity with this setup.
Alignment should help though.
I towed my son around on one of these
when he was younger and it could be wobbly even though it was perfectly aligned. At least when he wasn’t paying attention to his balance too!
hallettj@leminal.space · 1 pts · 2d
Yeah, a low center of gravity sounds like a good idea. It would be nice if I could attach to something coming off of the back of the bike instead of the rack. But I don't want to go for a trailer at this point.
The passenger trailer concept looks like fun for younger kids! I used to have a long-tail cargo bike to get the kids around. But after they both finished elementary school I wasn't using it enough to keep it around.
TerraRoot@sh.itjust.works · 6 pts · 2d
I think if the towed bikes headtube and axle were in line with your towing bike the wobble would disappear, the offset of the whole towed bike will also affect things if you don't allow it to rotate about it's front wheel axle.
Have you consider whipping the front wheel off your kids bike, then attaching it via the axle drop outs to the towing bike? You can still use your board mount to carry the wheel.
I just hold on the head/bars of my kids bike, but it's a really short trip..
hallettj@leminal.space · 3 pts · 2d
Yes, I'm thinking about attaching a spare hub to my rack so I can take off the wheel, and attach the fork to that hub.
I don't think holding the bike will work for me. It's 2.6 miles with lots of traffic and hills.
higgsboson@piefed.social · 6 pts · 2d
I have already spent too much time trying to figure out a cheap and semi sustainable way to tow both of my kids' bikes to and from the bus stop.
This post is going to cause me to spin my wheels again...
hallettj@leminal.space · 3 pts · 2d
Well I hope you get some value out of all the time spent!
litchralee@sh.itjust.works · 5 pts · 3d
I am taking notes. This is awesome!
DarrinBrunner@lemmy.world · 4 pts · 3d
Why doesn't he just ride his bike to school?
hallettj@leminal.space · 5 pts · 3d
We might do that at some point. My older kid biked to the same school for a year. But there are serious hills on both ends of the trip, and it's not the friendliest bike route so both kids prefer the bus.
The year my oldest biked he used to call me from the bottom of the hill on the way home. I have a special bike tow rope that I used to tow him up. It is kinda fun! But obnoxious for him to have to wait for me.
hanrahan@slrpnk.net · 3 pts · 2d
ebikes are a solution there, for the hill assist
hallettj@leminal.space · 2 pts · 2d
My 14-year-old is now using a class 1 ebike which he rides to high school. My 12-year-old isn't ready. So it's helpful to get in this practice!
artyom@piefed.social · 3 pts · 3d
What's the tow bike? Looks neat...
hallettj@leminal.space · 4 pts · 3d
The one is front is an Orbea Diem, which is pretty great. The one in back is a Fuji Crosstown that I find to be an enjoyable ride, but it is sized for my kid, not for me.