or you could change to a wider tyre.

Here is my experience of using a child seat on the rear of 20" foldie, rear carrier mount kind. Polisport Models, or Decatlon models.

- The foldie will be very unstable once the child on it...the front tend to lift if ur weight is not on the saddle.

- Using those proper ones like Polisport / Decathlon models..ur heels will likely hit on the child's foot that protudes from the chair...too close to pedals.

- U can get away with the leg collision issue, if ur mount type on the rear is on the seatpost...but my strong opinion, ur putting ur child at risk. Im very concern of the single seatpost have to support ur weight, togther with side load from the seat mount.....not worth the risk to me. Not to mention, your bike will tilt over easily.

I tried the cheap ones like those below RM100 selling online..rear rack mounting...but the mounting tools/ strap seat quality/safety..i rather not for any further journey or child is heavy.

If ur child is still lightweight, can try those that mount on the front between u and the handlepost..at least the weight support is loaded on the seatpost and body frame..and ur there to secure the kid.

So, long story short...Big bikes like mtb or touring bikes..still the way to go for using rear mounted child seat for me.

53 seems abit low for a 16-incher, but it would be godsent if you climb alot

otherwise i see ppl banyak main 56-59

Bro Nas445, how bout the feel of the bike ? U shifted from 20inch to 16inch, right. Which one u more prefer ?

the biggest different in pikes gen1 and gen2 is their handlepost, reach and frame length.
1st gen smaller than the 2nd gen. and handlepost more close to rider, making taller rider like me suffer for a long ride.

the biggest different between pikes gen 2 and brompton is the rear triangle. pikes gen3 are more to cosmetic. i would said its facelift version. the only different is their fork, package bundle on to it.
the rear triangle length are different from brompton, based screw are different and even the tensioner position are different,. i had to mod my litepro tensioner to fit my pikes. besides that, u still can use brompton/after market elastomer, seatclamp, mudguard, racks and also the easy wheel.

and yeah, many pikes user mod their 2nd cog to bigger sized for more wide ratio gearing. as u can see, the internal hub pikes are not the same like brompton. its the same model, but brompton made a special tweak on the hub.

pikes and brompton gave 13t/15t combo of cog. but brompton had wider ratio in their internal hub. to make it possible feel like that and save ur pocket, many of pikes user change their 2nd cog to 19t or 21t is the max. i've tried to put 18t to my setup. but i more prefser closer ratio on all my bike. still adopting this 18t for a while since i had 2 wheelset.

the touring spec i used 18t. and this highprofile wheelset i change to 16t and feel very comfort about it. dont know about u, but i dont like wider ratio since pikes or brompton are limited to 6speed only.

the easiest way without changing the cog is to used double chainring crank either with fd+shifter or manually change it without loosing close ratio and got wider gear option. but still, it wont be nice to put double chainring on my eyes.hahaha...

u seem interested on pikes. are u owning one?

oh this model. quite ok lah.. its compact
hahaha... i just bought used. the rear hub originally from pikes gen 2. but the wheel are litepro brand and front hub is dahon 74mm qr type

u can get the internal hub online. shopee also had. if u dont bother extra gearing, try to use sram automatix. im using it with my dahon dabike. 2 speed auto, no need shifter and ur bike became neat and tidy

my friend had the same expirience like you with his gust. later he upgrade his rear brake to caliper brake and problem solved.