Carrying Kids on Folding Bikes

A lot of young people have folding bikes for commuting or travel. Then along comes their first baby and they don't see how their flimsy folder can possibly get them around together. But don't throw the bike out with the bathwater! You can get a kid seat onto most folding bikes safely and easily. Possibly expensively, too, but we'll get to that.


Most of this information applies to regular nonfolding bikes as well.


We usually carry our brood and kilos of assorted garbage I mean cargo around in a big, heavy cargo bike. It's terrific for what it's designed for. But if you want to tootle off for the weekend for a bike ride through beautiful Oskaloosa with your happy threesome, unless you have a truck of some kind you're not bringing the cargo bike with you. 


We didn't think you could get a kid on a folding bike the time many years ago when we went to Holland for my friend's wedding and a week or two on bikes in Friesland, the northeastern part of Holland. We went with a Birdy and a Bike Friday New World Tourist, each in a suitcase (the Birdy packs smaller), and a Burley D'Lite two kid trailer. You can hook a trailer to most folding bikes pretty easily. (We quickly found out how unpopular a trailer makes you in a country with bike paths, however, since you block the lane nearly completely and all the commuters stuck behind you call you names.) We also wanted to try out the odd bikes they have there and rented every cargo bike and tandem we could find, which were pretty popular with the kids. 

The Onderwater Tandem we rented was a big hit.

But we took our folders and the trailer for our longer ride. Well, after a few days sitting squashed next to each other in the trailer with clothes and food, the kids didn't want to get along with each other anymore and no number of windmills or piece of yummy cheese or stroopwafel was going to calm them down. 

You can't hear the kids in the trailer in this picture, so it looks peaceful. 
This is a bike route in Friesland, not a picture from Chicago.

In desperation, we dropped by a little hole in the wall bike shop in a smallish city in Friesland and waited for a few minutes while two blue-gray overalled mechanics dug through decades of Sturmey-Archer parts and came up with a Bobike Maxi SC rear seat. A few more minutes and they found the ATB Adapter for it, then proceeded to bolt it on to the Bike Friday. Here's how it goes on:

The adapter is the curved arm that clamps to the seat tube, and the seat attaches to it with the little locking pin, then the supporting posts from the seat itself slide onto clamps on the seat stays. There's a lock wrapped around the seat tube in this picture but it's not related to the bike seat. You just need a hex wrench to attach the seat. It does make it impossible to fold the bike without removing the seat, but that is quick and simple, and you can't actually fold a Bike Friday quickly anyway. They're more disassemble-able than foldable.

The Bobike Maxi seat is a really good solution, but not completely perfect. Unless you cut the bolts shorter on the seat stay clamps or adjust your spacing just right, the bolt on the drive side can hit the chain in some gears. Which ones depends on the gearing system on your bike -- ours has a SRAM/Sachs 3x7 and it's the lowest (biggest) gear on the cluster that is tricky. 



If you mount it carefully, you can minimize this problem, but then the clamps are close enough to your heels to be in the way. Your kid's feet might also get in the way here, so the seat works better with small kids whose feet in those little black buckets stay high up on the seat supports. We took the toe clips off the bike to address this. All in all, though, simply mounting the clamps carefully was easy enough and it works really well. 


I think cutting the bolt might solve all the problems above, but we haven't done it since we use the seat on several bikes. Now we have the same seat on the back of our tandem, though it moves from bike to bike a bit. 

Here it is mounted a couple of inches above the pannier rack, which just barely lets
us put two fully loaded panniers AND a child on the back of the tandem.

The Bobike seats will fit on most Dahons (except probably the ones with curved or sculpted rear stays like the Curve) and Bromptons, and any other bike with a seat tube and two rear stays (or one stay that's thin enough to hook the clamps on). The seat tube can be a bit thick without causing too much problem. Again, you can't fold the bike easily once the seat is on. I think many neighborhood bike stores have begun to carry Bobike in Chicago but I know that JC Lind has had them in stock when we looked in. Kool Stop now wholesales them, so nearly any bike shop can order you one.

There's also a seat that will fit a 5 to 10 year old from Bobike, and it uses the same mounting system as the one we showed above. 

EDIT 7/11/11: we have one of these now, called a Junior, and it works OK but has a tendency to twist to the side, sliding the clamps down the tapered seat stay on our bike. The kids love it but you should try one first if possible. A seat stay that tapers, narrowing toward the back wheel hub, makes this problem worse. The Junior supposedly holds panniers but really doesn't do a good job - they swing into the wheel and they're poorly supported at the top. But, again, it gets our 10 year old on a seat in a pinch, so it has its advantages too. He's pushing now for the other kids-on-folding-bikes solution: he wants his own! He'll fit on a Brompton but the nice inexpensive Dahons have too long a reach. Still looking for a good cheap option. (End of Edit)

Here's why you can't get a seat like this on the Birdy (or Curve, etc):

The rear stays are rectangular extruded aluminum and no standard clamps will fit on it. 

For this bike, since a rack can be fitted, either a cantilevered seat that fits thick tubing might work, or you probably need to get either a GMG 910 or 911 that sits on the rack (for larger kids; the 911 folds and then holds panniers, available in Chicago at JC Lind, maybe others) or a standard American child seat like the one in the next picture (a Blackburn, Rhode Gear, Co-Pilot or Topeak, available everywhere including garage sales, Rapid Transit and Roscoe Village Bikes). The basically standard Blackburn rack that comes with most of this style of bike seat will fit on many folding bikes and let you carry a kid, but it's a pain to remove to fold the bike and it's so high above the small back wheel that it changes the handling a lot. It only holds panniers when the child seat is removed and they tend to dangle into the spokes since there's no long seatstay to hold them back on a folder. 

You should mount it to the rear triangle so the bike will still fold. We have tried this seat on a folder but it isn't my favorite. It gave our kids very little room in front and it made the bike handle oddly, and it was hard to carry anything. A backpack would squash the kid more and there's no place for a pannier to hook on. If you could find a Blackburn type rack designed for a 20 inch wheel, that would solve most of the problem. Another issue is that the giant plastic seat won't pack smaller. This is an advantage of the folding GMG seat.

You can fit a standard rack like this one on the back of a Birdy if you do a little fiddling with the front attachment strips and mount them to the elastomer suspension bolt. The vinyl covered stainless steel loops we used on this old Schwinn Twinn tandem are available in neighborhood bike stores and might be a good solution for attaching the rack securely to your folding bike.

Make sure the rack attachment is very strong, or Junior won't be protected.

If you have a Brompton and you need a seat that really folds, there is one specially made for that bike in Catalonia formerly called the ItChair and now the Pere that fits a 4-6 year old (who can hold on) and sold for about $350 from Clever Cycles in Portland Oregon. This is too expensive for me, or I'd have a picture to show you of it, but it is really the perfect solution for a Brompton and a pre-kindergartener, and it doesn't affect your ability to carry luggage with the front pannier bag or the rear rack. The same manufacturer, Milan, makes a bracket that allows a Bobike Mini front handlebar mounted seat to work on the Brompton too. If I had to put someone on a Brompton folding bike right now, I'd probably try the regular old Bobike first, even though it messes up the folding feature, since it's cheaper.

So, OK, the Bobike seats have their own mounting brackets that hook to the seat tube and the seat stays. Others like the Co-Pilot and Topeak use a standard type rack that's too high for folding bikes' small wheels and changes the bike balance and handling, but will work if you can attach them to the rear triangle securely, and they fit a Birdy. Another group of seats just hang cantilevered off the seat tube.

These seats look like they might work well, but I haven't personally tried them. I think the important thing with all of them, though, is to hook them to the actual seat tube that is part of the main frame, and not to the seat post. The seat post on a folder is built to be strong, but I wouldn't trust it with the twisting load of a kid seat, and if it breaks you are both going to fall off. These seats include GMG Yepp, though don't buy one used without looking it up since a bunch were recalled years ago for safety issues. Others include Hamax and  Kettler. Kettler and Yepp seem to be available in several neighborhood bike stores in Chicago though I haven't seen a Hamax dealer here.

Let me know using the comments if you know of other brands or information. 

Another less than ideal option is a handlebar mounted seat. Some of these mount on a bracket clamped to the stem like this black Bobike Mini one, others fit on a different clamp: (we have used one for ages, but never on a folding bike - see the itchair link above for Brompton attachment for it)

The green one is an IBert. I think this whole class of seats, although they are terrific on a sturdy bike (some let the child sleep on a padded support in front), are a really bad idea on a folder unless they're tested and approved by TÜV or someone.  If the stem is long, unsupported, and dismantles or folds, it just doesn't guarantee the strength or reliability to carry a kid safely. Add to that the short seat to stem distance on most folders and you have an unsafe bike that's hard to control. Generally I think you should stay away from this tempting solution. 

If you do this a lot, another good option with older kids is a folding tandem like the ones from Bike Friday. They make triples and longer if you ask them about it. Rapid Transit is their Chicago dealer and the folding bike and recumbent specialist in the city. Again, most BF bikes are not quick to fold and unfold but very versatile. Or if your kids are big enough, you might also like those kidback trailer things that turn a regular bike into a tandem (available everywhere, sometimes called child carrier trailers). Some will fit on the back of a folding bike, though not all of them. We always find them available at Working Bikes.


Remember if you use a kickstand that you can't rely on it to hold your bike up when your child is in the new seat!


When we headed out again on our quick tour around Friesland, we were surprised at how simple it was to put the child seat on the folding bikes, and we were really happy to get the kids separated and out of the trailer that they had grown to dislike so much. Both of them really enjoyed having their own space, and they swapped places often. Since then, if we can't take the cargo bike,the Bobike seat follows us most places we go, attached to one bike or another. It fits on pretty much any bike, but it's hard to beat the combination with the Bike Friday, since it is low and stable and makes a good rack for groceries even if a kid isn't using it, and since you're not giving up much daily convenience by limiting the folding capabilities of the bike.


last update 9/12/12

ADD ON 2023:

Many of the products listed here are outdated brands or models but most kid seats are still the same. Overall the information is still pretty up to date. We eventually got a Pere at Cap Problema in Barcelona when we were on vacation there (https://www.capproblema.com/milianparts/productos/pere/) and it was completely awesome. A kid can sit on it a lot longer than it looks- I think ours was (a smallish) 10 years old before hating it. They also have other seat supports on their site- have a look. We got another great thing at Cap Problema that is just as useful for carrying kids - it's a package rack. I don't see it on their site now but it is a roughly 4x8 inch piece of sturdy plywood with skateboard sandpaper on top and a groove cut in it that fits the bend in the Brompton top tube. It clamps on with 2 U shaped vinyl covered steel bolts. It works well for distances of a few miles; the kid has to squat, but functional. It's a lot cheaper.