Inner tube & tire alternatives for RW4

[ceoloide]

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

[ceoloide]

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.

[ceoloide]

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.

[ceoloide]

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.

[Ddaybc]

That picture of the tire looks like a perfect blend of smooth tread and the ability to be used on sand, gravel and even snow/slush. Good choice for the RW4.

[jules_snafus]

Hello, does anyone know if it is possible to fit a slimmer one (2.50-18)? I bought a Pirelli City Demon 2.75-18 on the fly because it was available in the next shop. Now I have it on the back. The Pirelli feels very safe, but you can already feel the profile and that everything is a bit slower. For the rear it is a good choice. For the front I would like something with less tread, something more agile. Can anyone help me? Thank you!

[squish321]

Hi All,

I just registered for this forum, for the very same reason as this post.

My front tire exploded while I was at grocery store yesterday. It was 6:30 pm, definitely past the heat of the day. 10 minutes earlier and I was rolling downhill at 35 mph. Big, heavy bikes really do get going!

This explosion, had it happened on my downhill, would have been catastrophic to my health either through a life crippling injury or a broken neck. Needless to say, I am seriously distressed as I continue to overthink this today.

Have other people reported this type of explosive failure? At this point I no longer trust the tires/tube sold with the bicycle and will not continue to use them. I looked at the Tannus option on their website, anyone else have thoughts there? 

[rjp]

UPDATE. I knew I read it somewhere, so I got out my Tannus installation guide and on page 3 under Tips For Installing Tannus Armour it states (It is common for the Amour to compress over time. It still is providing shock absorption and puncture resistance but will perform better when properly maintained. To minimize compression deflate the tires while not use. This allows the Armour compound to rebound to provide ideal performance.) So does that mean when your not riding your bike, your suppose to let the air out of the tires? I'm sorry but that's not happening. I don't know how everyone else feels, but if I would have known that earlier, I would not have purchased the Armours. 

[santacruzpaul]

UPDATE. I knew I read it somewhere, so I got out my Tannus installation guide and on page 3 under Tips For Installing Tannus Armour it states (It is common for the Amour to compress over time. It still is providing shock absorption and puncture resistance but will perform better when properly maintained. To minimize compression deflate the tires while not use. This allows the Armour compound to rebound to provide ideal performance.) So does that mean when your not riding your bike, your suppose to let the air out of the tires? I'm sorry but that's not happening. I don't know how everyone else feels, but if I would have known that earlier, I would not have purchased the Armours.

YES! agree again rjp

[ceoloide]

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.

[ceoloide]

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

[RadMig]

You might want to call Rad because you made be part of the safety notice recall where the tires are puncturing and exploding not only do the heat but due to the inside strip on the inside of the rim as it covers the spoke screws I would call them and see if you RW is part of this safety recall. Check your email to see if you got the safety notice do not ride. See my post in this RW forum titled safety notice. Good luck be well and travel safe. PS I think I bought my on August 5th and it arrived on the 14th. I only ride in my development in the mornings for now so I only have 15 miles on it but they told me to stop riding it for 2 weeks until they come up with the solution.

[RadMig]

Update on my post from last week to you sir. Judging by the pictures you posted your tires had the ribbed sidewall and subsequently are definitely part of the safety recall safety notice do not ride sent by the company on the 31st of August. I'll bet you got the security safety notice do not ride email also since I posted. The company is offering replacement parts and compensation for a license local bike mechanic to replace these tires but the safety notice response with the fix notes it might take two to three months for them to send the parts. Of course these are W-4 tires and tubes are out of stock on the company website and as you know impossible to find other than through this company. I certainly hope at this point you have called the company to make sure you're part of this safety notice recall and fix. However this blog post will now be invaluable to people like me who have the approved tire which is a smooth sidewall and not ribbed. As you can imagine I have every type of tire remedy except for the correct tires and tube! Fix a flat slime tannis ect  all the best and I'm grateful that you and your family are in good health and there was not a major catastrophe as a result of your dilemma. All the best thank you for your blog post here