Knobby tire on KS18L / KS18XL - will it fit?

[reach]

Hi there,

I'm surprised that the search function didn't show any good results for this IMO obvious question. Maybe I was using it wrong, pls forgive me if so.
I'm considering to switch from my Inmotion V8 to the KS18XL. On the V8 it was great fun to ride on knobby tires, so I'd like to make sure the new wheel allows this as well.

My dealer wasn't sure, but told me that there's very little space between the original tire and the chassis.

Can you help me with this please? Of course any concrete recommendation of a certain type would be best. Thanks!

[UniVehje]

I have used a knobby tire on my 18XL. This one fits and works very well. It’s a bit strange at first but once you get used to it, it behaves nicely. I’m away from home and don’t remember the model number. Maybe @mrelwood can tell you what this model is as I bought it from him. 

[mrelwood]

@UniVehje’s tire is a “2.50-14 Minicross tire”. Googling with that phrase will find many purchasable items.

 That specific brand is Yuanxing (zoom in the photo ), but the brands for this tire type are dime a dozen, you can disregard that.

[Rywokast]

there is not very little space with the original tire lol, unless you compare it to a monster maybe... the original tire measures like 2.3" in diameter so theres actually quite a bit of space, i use the C-1488 currently and there is still a good amount of clearance, it measures about 2.55" width.... i would say as long as you dont go over something thats maybe 2.75" in width tops, there should be no issue at all with what tire you choose as there is ample clearance with the top of the inside of the shell

Edited July 20, 2020 by Rywokast

[UniVehje]

5 hours ago, Rywokast said:

i would say as long as you dont go over something thats maybe 2.75" in width tops, there should be no issue at all

I tested a tire that measured 2.75” and it fits but only barely. I used a bit of sand paper to stop it from rubbing. Pictured at the top here. You can see a clear difference to the standard tires at the bottom  

[Rywokast]

4 minutes ago, UniVehje said:

I tested a tire that measured 2.75” and it fits but only barely. I used a bit of sand paper to stop it from rubbing. Pictured at the top here. You can see a clear difference to the standard tires at the bottom  

very cool, that looks awesome... yea the 18XL stock looks so tiny compared to most new eucs xD

i have to ask, whats up with the white string tied around it?

Edited July 20, 2020 by Rywokast

[UniVehje]

1 hour ago, Rywokast said:

very cool, that looks awesome... yea the 18XL stock looks so tiny compared to most new eucs xD

i have to ask, whats up with the white string tied around it?

The string was just for testing some idea to build something around the wheel, nothing special. 

Now that I think about it more, the original MSX stock tire might also fit 18XL. There have been many people wishing for 18XL with 18x3” tire. The Vee Rubber 2.75” tire was faulty specimen (not centered) but otherwise it felt really good. The difference was big and it felt like a bigger wheel. 

[Rywokast]

55 minutes ago, UniVehje said:

The string was just for testing some idea to build something around the wheel, nothing special. 

Now that I think about it more, the original MSX stock tire might also fit 18XL. There have been many people wishing for 18XL with 18x3” tire. The Vee Rubber 2.75” tire was faulty specimen (not centered) but otherwise it felt really good. The difference was big and it felt like a bigger wheel. 

ah ok,, I seriously doubt it.. even the 2.5" C-1488 is over 2.5" almost 2.6 so I seriously doubt the 3" variant would be able to fit unless you shaved the sides but that's a whole lot of work to end up with a thinner tire anyways haha.. nice 

[mrelwood]

55 minutes ago, Rywokast said:

ah ok,, I seriously doubt it.. even the 2.5" C-1488 is over 2.5" almost 2.6 so I seriously doubt the 3" variant would be able to fit unless you shaved the sides but that's a whole lot of work to end up with a thinner tire anyways haha.. nice 

The MSX original (18x3.0 H-5102) measures just north of 2.7” in width, so it truly could fit the 18XL.

 Tire dimensions are a very strange ballgame. If the 2.5” C-1488 measures about 2.55”, 3.0” H-5102 measures 2.75”, 2.75x14 is referred to as a replacement for 80/90-14 tires (80mm = 3.15”) in all cross-compatibility charts, some 120mm MC tires are wider than some 140mm tires, and so on.

[Planemo]

1 hour ago, mrelwood said:

The MSX original (18x3.0 H-5102) measures just north of 2.7” in width, so it truly could fit the 18XL.

Very true, all I would add is that rim widths can bear significant differences to the width of a fitted tyre. Now if (and I mean if cos I dont know) the 18XL rim is wider than the MSX, the fitted width of the 5102 may be more than the 2.75" we see on the MSX.

[Rywokast]

5 hours ago, mrelwood said:

The MSX original (18x3.0 H-5102) measures just north of 2.7” in width, so it truly could fit the 18XL.

 Tire dimensions are a very strange ballgame. If the 2.5” C-1488 measures about 2.55”, 3.0” H-5102 measures 2.75”, 2.75x14 is referred to as a replacement for 80/90-14 tires (80mm = 3.15”) in all cross-compatibility charts, some 120mm MC tires are wider than some 140mm tires, and so on.

oh really, what the hell lol... thats so friggin weird, because the 5102 2.5" is way smaller than the 1488 2.5" but for the 3" variants this is reversed haha.. cant trust anything  guess you just have to have someone who owns it measure for you, thats good to know! so getting a larger 18XL tire is a lot easier than i thought

[null]

Would this mean the 18x3 C-1488 might fit the 18XL?
Cool the 18x3 H-5102 might, however it is a bit slippery I believe. (hence interest for C-1488)

Edited July 20, 2020 by null

[UniVehje]

4 minutes ago, null said:

Would this mean the 18x3 C-1488 might fit the 18XL?
Cool the 18x3 H-5102 might, however it is a bit slippery I believe. (hence interest for C-1488)

We are at an uncharted territory here. I don’t think anybody has tested this. We just need someone brave to try it out!

[Rywokast]

2 minutes ago, UniVehje said:

We are at an uncharted territory here. I don’t think anybody has tested this. We just need someone brave to try it out!

im just wondering as well what the implications of this would be for power.... we all know the MSX has more raw power, but what about sticking on a bigger tire onto an euc, in theory that would slightly increase your top speed which obviously KS has capped, but in terms of power output, would that make it then easier to overpower the euc? not that either of them are in any way easy to overpower

[null]

Indeed, I'll introspect a bit to see if I'm courageous enough, coming back with info if anything happens

[mrelwood]

 

2 hours ago, Rywokast said:

what about sticking on a bigger tire onto an euc, in theory that would slightly increase your top speed which obviously KS has capped, but in terms of power output, would that make it then easier to overpower the euc?

This is a more complicated calculation than one would think. While the wheel would be capable of providing less force at the riding surface, the wheel will also accelerate further as well as require a deeper lean to exhibit the same amount of force. Torque is calculated by Force * distance from the center. So in the end the effects probably cancel each other out.

I didn’t feel that the maximum torque limit would’ve been close with the 2.75-14 “Sherman” tire on my MSX. Then again, I extremely rarely reach the limit anyhow. What did change quite noticeably though was the amount of effort required to accelerate and brake. And stability of course.

[reach]

Thank you all guys for your quick and comprehensive responses!

[Jia Liu]

On 7/20/2020 at 8:39 AM, null said:

Would this mean the 18x3 C-1488 might fit the 18XL?
Cool the 18x3 H-5102 might, however it is a bit slippery I believe. (hence interest for C-1488)

I just tried C-1488 when swapping 18XL motor, unfortunately, it doesn't fit The tire is just a bit too wide at the top. I will install the knobby tire when it arrives.

[null]

That’s too bad, but thanks for sharing!

[Jia Liu]

Just installed the knobby tire along with the 2200w motor, it feels like a new wheel again  I have more difficulties to make tight turns on the new tire than the stock tire (gyro effect??), but on trails, it runs great, absorbs lots small bumps and gives me more confidence.

This is the tire I got if anyone wants to give it a try: https://www.amazon.com/gp/product/B01DCMQRX6/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1 . The brand is Yuanxing. 

Installing new tire on KS18XL is a lot easier than my Gotway wheels (MSP and Nikola) 

[Mufnman]

On 7/19/2020 at 5:10 PM, UniVehje said:

I have used a knobby tire on my 18XL. This one fits and works very well. It’s a bit strange at first but once you get used to it, it behaves nicely. I’m away from home and don’t remember the model number. Maybe @mrelwood can tell you what this model is as I bought it from him. 

UniVehje, Thank god. This is what I have been searching for with my 18xl. What is this exact tire description?? Yuanxing ....?

Also the other tire with the vVvV patern looks like it would be great in the snow. What are these exact dimentions.

I dont want to get stuck putting old one back on.

[UniVehje]

5 minutes ago, Mufnman said:

What is this exact tire description?? Yuanxing ....?

Yuanxing 2.50-14 is all there is on the tire. No model markings. 

[Mufnman]

I am finally going to purchase one of the 2.50x14 knobby tires. Do you have any problems going 30mph with such a small rim? Did you purchase a 14 ks rim or aftermarket rim?

[mrelwood]

15 hours ago, Mufnman said:

I am finally going to purchase one of the 2.50x14 knobby tires. Do you have any problems going 30mph with such a small rim? Did you purchase a 14 ks rim or aftermarket rim?

The rim is a fixed part of the motor, it can’t be replaced.

 To understand the size markings of tires, read here:

 

[mrelwood]

On 9/28/2020 at 5:52 PM, Mufnman said:

UniVehje, Thank god. This is what I have been searching for with my 18xl. What is this exact tire description?? Yuanxing ....?

The tire that @UniVehje had on his 18XL was an universal “Minicross 2.50-14” tire. Any tire that comes up with that search phrase should be essentially the same.