3" Tire on a 4" rim?

[Bigcam59]

I posted this in "how to" and got almost no responses so I thought I'd try here. Has anyone tried mounting a 3" tire on a 4" (aka Mongoose Dolemite) rim? I'd try it myself to find out but I'm not in a position to get to the basement workshop- literally! (recent knee surgery)

 

[Wildcat]

I had a Mongoose Beast and got tired of the weight and tried to put a set of 26 x 3.0 Kenda flames on them. They wouldn't reach to the edges of the rims so it didn't work for me. So, I stuck with the big heavy tires, and lowered the gear ratio.

 

[MattiThundrrr]

@Wildcat is that a Girvin Flex stem on there? Never seen that on a fat b!

 

[Wildcat]

I'm not sure, no name was on it when I picked up a box of old parts at the flea market. It had a small shock absorber on it and it actually worked. Here it is on an Emory.

 

[MattiThundrrr]

Yeah, not a Girvin, my mistake. Girvin used elastomers. More like a Softride. But not quite

 

[MattiThundrrr]

Or maybe a JD Suspension!

 

[Wildcat]

That's it!

 

[Dr. Tankenstein]

Back on topic......
Cam,I’m sure a lot of guys have stretched a 3” tire onto a 100mm.
I personally, have not tried it yet.
Maybe ping Warren Wong on FB?

And good luck and fast healing from the surgery.
Cheers buddy!


Sent from my iPhone using Tapatalk

 

[Wildcat]

I found something:

https://electricbike-blog.com/2016/...tell-all-the-ladies-that-its-4-inches-really/

 

[rrtbike]

There is another post on this somewhere on this site.
Anyway in response to the original question.... Use the 4 inch tube if you want to do it.

 

[ChopNstretch]

Here you go, I have yet to formally introduce myself but this is a great site.
I just mounted a 3” tire on a 4” rim as an experiment, I don’t like it but what a great place to run into someone with the same thought.

 

[Bigcam59]

Thanks! Due to a knee replacement it will be a while before I'm up and building again, but the pics give me a pretty good idea what to expect.

 

[MattiThundrrr]

Looks a little scary... Contact patch gets smaller as lean angle increases! Is there a head on view? Are there ridges at the "corners" where sidewall meets tread?

 

[clamdigger]

Seeing that picture got me to thinking about tire construction for flat protection. Generally if there is an added belt like Kevlar , it is under the tread only. Few purpose built tires have bead to bead protection. Sidewalls are much thinner, in general.