Second time was the charm. I watched a few videos on how to fit a motorcycle tire, as the process is slightly different than bicycles. The bead of motorcycle tires is much harder, and the tire itself is stiffer. What worked for me, after fitting one side of the tire:

• Insert the valve first, with a deflated tube, and lock it in place so it doesn't slide back in
• Insert the tube, jeep it deflated and pinch in half to help get it inside the tire
• Slightly inflate the tube to ensure no pinches
• Now fot the other tire bead, laying the wheel flat and pushing down carefully on opposite ends, while pressing the tire to make it bend a little

I inflated the tire to 25psi, and it feels stiff enough. I don't think these tires and tubes should go beyond 35psi.

I didn't notice much difference in speed or handling with these tires, but my RW4 is loaded with kid + caboose, front rack, large basket, and abus bordo lock, so it's already quite heavy, 2-3kg extra don't make much of a difference.

TL;DR: CST 3.00-18 and Micheline Airstop 18MC (2.50x18) worked for me for a total cost of ?40

I finally received the tire and was able to weight it and measure it against the stock.

The stock tire weights 1.5kg vs the 3.5kg of the CST. I feel that 3.5-4kg i standard for a motorbike tire of these specs. This is not a small increment in weight when both tires are installed and tougher tubes used (0.4kg vs 0.26kg).

The tire is incredibly stiff and I had a very hard time fitting it. Pro tip: start with the tube valve, then fot the tire or fishing the valve becomes impossible later.

In the end my inner tube exploded at ~25psi after fitting, first displacing the tire and then bulging up and exploding. These were the Michelin 18ME.

I am so tired of trying things  I had this bike running for 3 days out of almost 2 months.

I found a close match to the spec at a very reasonable price (25?): CST C-916 3.00-18 TT 47P

TT stands for TubeType, as opposed to TubeLess, so it's designed to work with a inner tube.

The speed rating and weight rating are both higher (175kg - 150kmph/93mph), so I expect the tire to be heavier than the stock, but also more durable.

One additional point of info regarding the tire dimensions: looking at the image below the markings on the sidewall report it to be 76/100-457 M/C 43B MOPED.

76/100 means that the tire is 76mm wide and 76mm tall, consistent with my measurements.

457 is the rim size in mm, which amounts to 17.992" or simply 18".

M/C stands for MotorCycle (same as MOPED), to distinguish from other types of tire usage.

43B indicates the max weight and max speed, with "43" being 155kg, and B being 50 kmph / 31mph.

With the information above it's clear these are 3.00-18 motorcycle tires.

Similarly to this post on reddit I've measured the tire width and shoulder height, and though I also don't have a caliper for very precise measurements, I get 75mm x 75mm, which roughly equates to a 70/100-18 or 80/90-18 or 80/100-18 or 3.00-18 or 2.75-18.

As a reminder, bicycle tires are measured differently than motorcycle ones, so RW4 tires are reported as 22"x3.0" but the bike wheel is actually a 18" one (as written on it as ETRTO 457mm-45mm or 18"-1.77").

The stock inner tube width measures 65mm or 2.55in when flat, so it looks like a 2.50-18 motorcycle inner tube would fit well, something like Michelin Airstop 18MC - 2.50x18. I purchased a Michelin Airstop 18ME and it fits well, but it's also relatively large at 90mm or 3.54in.

As many others, my front tire inner tube exploded while parked under the sun for less than 30 mins.

Rad does not have stock on tires and inner tubes, so I am left without bike for the foreseeable future, which sucks.

I followed the advice of other posters here and on r/radpowerbikes and purchased motorbike inner tubes (Michelin Airstop Butyl 18ME for 9?).

They are significantly heavier (530g vs 290g of the stock ones) and are a good third larger, but they seem to fit, though I'd not inflate them past 20-25PSI.

I am also looking at the Kenda 2.75/3.00-18 TR4 inner tubes, and the Michelin 18 MC 2.50-18 in case they are lighter / narrower.

Unfortunately the explosion damaged the tire or was caused by a tore defect, so I'll be looking at a replacement for that, too.

Michelin City Pro / City Extra tires look extremely heavy (>6kg) based on somewhat unreliable data found online. Duro HF918 or similar also look heavy at 2.5kg.

ceoloide

Howdy everyone,

what shifter cable brand / type does RadPower Bikes use on their bikes? More specifically, what does a RadCity ST 3 need?

I recently brought my RadCity 3 ST to a reputable bike shop in NYC, only to receive it with many things unresolved and more problems than I had before. Right now, the derailleur is not shifting up from any lower gear, and it's clear the shifter cable doesn't slide freely in the housing inside the downtube, while it moves freely in the derailleur section and inside the shifter.

I suspect the local bike shop replaced the wire or did something to the cable management, but I am not sure. I noticed today the shifter cable is marked "Jagwire Lex" so I am wondering if that's the original one or not.

Thanks everyone,

ceoloide