Inmotion V8 got a 16x2.5" tire

[mrelwood]

I have preferred wider tires since day one, and when my friend asked just after a few months of riding wether his V8 could fit a wider tire, I was intrigued. Watching teardowns and measuring the tire well it seemed likely that a 16x2.5" tire could fit with relative ease. Turned out there was a bit more work involved than I expected, but not at all too bad. And some of it was from this being the first Inmotion for me to open up.

Since the 2.5" tire is quite a bit taller than the original 1.95", the shell had to be lifted to sit higher. But since the shell reaches the front and back of the tire as well, some room had to be made there as well. Luckily only the inner shell has to be modified, and the plastics covering the front and back of the wheel can be left untouched, resulting in a mod that doesn't show at all once finished.

I have a few tires left over from trying out various ones on my 16S, so we decided to try to fit a rebranded CST C-1488 (Nikola, MSP, MS3, latest 18XL), since it is slightly on the smaller side of it's rated size.

 

1. Cutting the shell

I have a PVC cutting disc for my Dremel, which is great for exactly this kinds of work. The shell must be cut at both ends of both halves of the shell, so four places in total.

Lifting the shell as much as possible still comes slightly short at the structural ribs at the top of the wheel. Slight reshape was in order.

 

2. Closing up the shell

After cutting the shell the headlight and the speaker are exposed, so the shell needs to be closed up. I reshaped the bits of plastic that I cut off and hot glued them to make the walls. I forgot to take photos on the final insulation, but I just used a thin neoprene strip hot glued on the wall edge. It will then meet with the similiar inner wall on the other half of the shell.

 

3. Lifting the shell

The shell is attached to the pedal brackets with 4 bolts per side. Drilling new holes for the bolts as low as possible can reach a maximum of 15mm lift. Together with the reshaped ribs this makes for a just enough vertical clearance. The width is not an issue at all. Note that the other side of the drilled holes must be shaped with a router bit on the Dremel to make room for the bolt heads. I used washers only for the topmost bolts, since there is no room at the lower ones.

 

4. Finalizing

The front and back covers hide the modifications, but the attachment points for the last screw is now gone. I drilled and reamed a new screw hole at about 15mm upwards from the original hole to keep the end of the cover in place. The last screw now only screws into the thin inner shell, but I expect it to be strong enough.

 

5. V8 16x2.5" behaviour

I had only ridden the V8 shortly a few times, so I don't have a precise recollection of it's original behaviour. Other than it felt obviously small and unstable to me, since I'm used to the MSX, and a 16x2.5" 16S before that. After the mod however the wheel feels quite natural and familiar to me. It definitely tends to stay upright much more than the original, but due to the low top speed of the V8 it's not an issue as much as it can be on faster wheels. It also follows banked roads more, as was to be expected.

As a very big plus, the wheel can now easily turn in a small space just by tilting, which makes balancing at walking speeds much more stable. I'd also say much easier, but tilt-steering it's a different technique to twist-steering and since I'm much more familiar with larger wheels and wider tires, I'm a tilter. Twisters would probably find the behaviour more laborous at first, but unless they are ready to learn proper tilting, a 2.5" tire might not be advantageous to them.

 

The owner of the wheel has only ever ridden a 16x1.95" for about 6 months, so the first trip was of course strange for him. But I'm sure I'll be hearing positive comments in about a week, on the stability and even slight increase in top speed. Since the diameter of the 2.5" tire is quite a bit larger, the top speed of the wheel will increase roughly by 2 km/h. Enough to be felt for sure.

Edited March 17, 2020 by mrelwood

[EUC Custom Power-Pads]

Very nice. 

Did you intentionally choose the direction of the tyre? I was not sure when I changed to the c1488 on 16X, because there is nothing written on the tire. So I did it the same way Gotway did with the Nikola and now the MSP, hoping Gotway would know the direction. 

[mrelwood]

I was about to put it the other way around, but there was an arrow-like formation next to the logo, and we thought it could (badly, but still) represent the intended rotational direction.

I don’t think the direction matters much for an EUC, at least for the V8 speeds, so we decided to go with that.

[Patrick Mckowen]

Great mod -- I think a 2.5 is in my future once I have worn the 1st one out. Where did you source the tire?

Cheers

[mrelwood]

The tire was originally purchased from Aliexpress in 2017. I saw someone having recently located the CST C-1488, but don’t remember which thread it was. Perhaps it was the ”How wide tire can you fit in the Tesla?”

[Sentient]

Excellent post. Thanks for this @mrelwood! The V8 is my first (and only) wheel. I am learning to appreciate it more every time I ride it. The smallish tire would be a great upgrade I believe.

I may try it if waiting for the V11 gets to be too much:)

[Cychotic]

This makes me want to see if it's possible to put a 16x3" tire on my V10.  Nice mod!

[tst]

Is it needed to put in a bigger inner tube as well?

[mrelwood]

1 hour ago, tst said:

Is it needed to put in a bigger inner tube as well?

It has been said that one step in either direction is ok, so you should be ache to use a 2.125” tube in a 2.5” tire. But most V8 units come with a 1.95” tire and tube, and that tube is tiny. It would surely be way too risky to use in a 2.5” tire.

 Personally though, I would get a tube that fits the tire exactly. I don’t see a point in possibly increasing the risk of a sudden flat. If you’re riding at that time, there’s no way for you to stop or steer without falling.

[alcatraz]

It's a fantastic upgrade because it's the lightest 16x2.5in wheel out there. A city commuters dream, I'd think. 

[alcatraz]

I'm trying to work up the courage, to do a similar mod to fit a 16x3 in tire on a Tesla.

[tst]

I'm replacing my V8f tire to a 16x2.4 knobby type.

I doubt wheter your and my tires are really 2.5 and 2.4.

Yours should be 63mm wide. But it looks less. My 2.4 tire is just a few mm winder than the stock 2.125. So what's printed on my tire is not correct at all. It does take more space but that is from the knobs and because it's just a few mm higher.

 

The supposed 2.4 knobby tire next to the old 2.215 tire. Almost the same

Edited December 3, 2022 by tst

[Funky]

On 12/3/2022 at 11:23 PM, tst said:

I'm replacing my V8f tire to a 16x2.4 knobby type.

I doubt wheter your and my tires are really 2.5 and 2.4.

Yours should be 63mm wide. But it looks less. My 2.4 tire is just a few mm winder than the stock 2.125. So what's printed on my tire is not correct at all. It does take more space but that is from the knobs and because it's just a few mm higher.

 

The supposed 2.4 knobby tire next to the old 2.215 tire. Almost the same

Don't forget old one has been sitting on rim.. So it has gotten wider, after being full of air and on rim. (Changed form..)

Same as buying new 5102 tire, it looks so thin/small. But putting it on rim and filling full of air - it gets bigger/wider.

 

Also mounting M/C tire on EUC rim which is 40mm wide. Makes tire width smaller. Because rim "pinches" the tire.

After mounting it - measure it's width, if it's ~60mm wide, then it's 2.4". Mine 18x2.5" was ~64mm wide. (Also each tire model/manufacturer are different size.) Like K66 tire is 80/80 size. It should be 80mm wide. But in reality it's 76mm wide. Next tire, but from different manufacturer or model - that is also 80/80 can be 82mm wide in reality.

 

Edited December 5, 2022 by Funky

[alcatraz]

Brand new tires (on bikes at least) stretch a little but not much.

Over the time of riding they actually shrink because the tread wears away.

You could drop the pressure and ride carefully if the tire rubs a tiny bit when new. Then after the tread wears a bit you can pump it up to your desired pressure.

[tst]

Big thanks to mrelwood for this mod. I mounted the housing +-7mm higher. Only on the front and back side of the wheel I had to dremel away the protruding plastic out of the wheel well.

The tire I got is a Naiputun 16x2.4 bought from https://happy-motorparts.de/HMParts-16x24-Kinderwagen-Elektro-Scooter-Reifen

update; the tire got damaged after +- 300 km forest trails. Probably it got damaged by rocks. I bought a new one.

It suspect it's the same as the ones under other brands like Innova.

It seems there are different versions of the same knobby tire out there. They look the same. I ordered 2 times. But the last tire I got was wider (61 mm vs 57 mm) and heavier/stronger (+- 760 gram instead of 560 gram). The stronger tire is less nimble, but more stable.

 

This here is after I installed the first narrow knobby tire:

Just did the first ride with the knobby tire. The grip is good. Very reassuring. Leaves, sand etc it's no problem. It doesn't lose traction. With inclines I used to lose grip. Now it doesn't lose grip but it gets as far as the motor can handle. I did an incline that was impossible before. Though the grond is frozen now which makes it easier.

I'll give it some time so the tire can really settle and hopefully become a bit more flexible. I'll also experiment with different tire pressure. Right now it's just unstable on the road. Hard to keep in a straight line. After a while I'll also deflate and re-inflate it to hopefully get the optimal fit on the rim. An option would be to make a little 3d jig / template and cut away part of the side knobs so the whole tire profile becomes more round.

Update: I lowered the pressure a lot. After 20 km off road it's considerably less unstable. This tire really needs to break in. The grip is very good in dry cold weather. Can't wait for rain and mud to test that. It's still a lot less stable on the road than the stock tire. I used a lot of baby powder to give the tube freedom to move.

Update 2: It's getting better with the stability. Wet leaves are no problem. Slight mud is very manageable. Wet sand and grass is no problem at all. In wet mud the wheel can slip sidewards but most times the side knobs get a grip and it recovers. I'm happily surprised that as of yet no sand or mud got stuck between the knobs. The wheel is just clean all the time. I thought it would clog up but it doesn't so that's awesome.

About the impact on the battery range. I doubt wheter the tire is the big difference. It probably is due to rider behaviour. See, going uphil, muddy areas etc is easier now. So you take your wheel in situaties where you would normally go around. That takes a lot of work from the motor and thus more energy. You can also go faster through bad terrain. That also eats up more battery.

More knobby then this would be overkill. Maybe in summer this is even too much knobby. I'll add powerpads to compensate for the small loss of stability.

Euc's are illegal here so I only drive the forest.

Seems like this knobby is the same as people used on the V10f

 

Edited April 1, 2023 by tst

[v8nice]

On 12/17/2022 at 6:18 PM, tst said:

Big thanks to mrelwood for this mod. I mounted the housing +-7mm higher. Only on the front and back side of the wheel I had to dremel away the protruding plastic out of the wheel well.

The tire I got is a Naiputun 16x2.4 bought from https://happy-motorparts.de/HMParts-16x24-Kinderwagen-Elektro-Scooter-Reifen
It suspect it's the same as the ones under other brands like Innova.

The knobby:
-has a bit bigger outer diameter than the standard tire.
-It's 57mm wide, not 64...
-It weighs only 636 gram while the standard Chao Yang is 740 gram and that doesn't even have heavy knobs. Maybe the side walls are less strong.
-It's very thin in the places where there's no knobs. I hope it won't get punctured.
-The rubber feels a bit harder then the standard. Though Chao Yang seems to be among the softest tires out there.

Just did the first ride with the knobby tire. The grip is good. Very reassuring. Leaves, sand etc it's no problem. It doesn't lose traction. With inclines I used to lose grip. Now it doesn't lose grip but it gets as far as the motor can handle. I did an incline that was impossible before. Though the grond is frozen now which makes it easier.

I'll give it some time so the tire can really settle and hopefully become a bit more flexible. I'll also experiment with different tire pressure. Right now it's just unstable on the road. Hard to keep in a straight line. After a while I'll also deflate and re-inflate it to hopefully get the optimal fit on the rim. An option would be to make a little 3d jig / template and cut away part of the side knobs so the whole tire profile becomes more round.

Update: I lowered the pressure a lot. After 20 km off road it's considerably less unstable. This tire really needs to break in. The grip is very good in dry cold weather. Can't wait for rain and mud to test that. It's still a lot less stable on the road than the stock tire. I used a lot of baby powder to give the tube freedom to move.

Update 2: It's getting better with the stability. Wet leaves are no problem. Slight mud is very manageable. Wet sand and grass is no problem at all. In wet mud the wheel can slip sidewards but most times the side knobs get a grip and it recovers. I'm happily surprised that as of yet no sand or mud got stuck between the knobs. The wheel is just clean all the time. I thought it would clog up but it doesn't so that's awesome.

About the impact on the battery range. I doubt wheter the tire is the big difference. It probably is due to rider behaviour. See, going uphil, muddy areas etc is easier now. So you take your wheel in situaties where you would normally go around. That takes a lot of work from the motor and thus more energy. You can also go faster through bad terrain. That also eats up more battery.

More knobby then this would be overkill. Maybe in summer this is even too much knobby. I'll add powerpads to compensate for the small loss of stability.

Euc's are illegal here so I only drive the forest.

Seems like this knobby is the same as people used on the V10f

 

Hi ,you have pictures of your mods?beceause is not the same frame in v8 and v8f.Is not exactly the same frame and not same pedal fixation.

[tst]

On 1/18/2023 at 8:04 AM, v8nice said:

Hi ,you have pictures of your mods?beceause is not the same frame in v8 and v8f.Is not exactly the same frame and not same pedal fixation.

Unfortunately not, but it's very straightforward. I have the v8f and the tire that I posted. The knobby is only bigger. You only have to take away some plastic at the front and the back of the wheel well. The insides at the top can stay like it is. I used a dremel. But a jigsaw might also work. Or a mini japanese hand saw. Or a reciprocating saw, put in a metal blad that will not ruin the plastic like a wood blade might do. Or melt it away with a soldering gun.

It is however necessary to lift the whole shell by at least +- 5 - 8 mm. So that's not much. I made 2 little spacers from wood to fill the void. The spacers I taped with double sided tape on top of the big metal part that is fixed to the motor axle. That way, when you later sit or push on the shell it will not rest on the bolts but the force will to on the spacers. You have to drill new holes in the plastic so you can mount the shell a bit higher. 4 at each side.

The 2 little covers that are under the pedals, the ones on a little hinge that give acces to the air valve, well I just removed those completely.

I'm very happy with the tire. The road stability is a bit less. It's not like your driving on rails like with the standard tire. But the better grip is well worth it as I only ride in the forest.

 

Edited March 4, 2023 by tst

[MCV]

I've finished my upgrade but i did much different from your method. I actually lifted the  housing about 3/4 inch higher. Made some new mounting holes and cut some plastics on the front and back fenders.

[MCV]

Upgrade i made to my EUC

https://www.deviantart.com/story2tease/art/995317642