Custom 18x9.5 wheel with 280mm tire on ChrisMooreMafia’s Rocket

[Einar]

My fear are these points:

1) you over inflate or the tire will overheat, it might expand enough to rub on that arm again. Rubbing will not cool it down.
2) since the wheel looks larger in diameter, it will influence how you sit on it, higher, making your handlebars lower, raising your butt. This, in turn, will make your grab on to handlebars with more strength leading to tired or even loss of feeling, buzzing hands, your horizon level might be affected to hold the head at a more awkward angle.
3) following the same thought, how it brakes, since one axle is higher than the other, perhaps, making the whole emergency braking experience way different, unlikely in a better way. ABS computer might do its braking through programming for a "stock" tire while applying incorrectly its pulses for this new size. The suspension will act differently, perhaps loading the front tire too quickly.
4) because the new wheel is heavier, you will suffer even worse MPG on low speed stop-n-go. Hope the weight will not affect the life of the final drive. Surely will affect the low end torque for worse.
5) because the new wheel is higher, you'll likely to often run out of suspension, hitting that cover above.

You can see in the video that this setup clears the hugger, which even the Exedra Max doesn't. So, any change in overall circumference is less than you'd get with that. Plenty of people have run those and never hit the underside of the tail. This setup increases overall diameter by 1.1%, whereas the Exedra Max increases it by about 4%.

As was pointed out, the lower profile of the tire (35 vs 50) mostly counteracts the increased diameter of the rim, so the overall diameter is only about 1.1% different. So, the axle only moves upward 9/64ths of an inch. That's miniscule from a steering geometry standpoint. Very slightly quicker turn-in and very slightly less stable, but not enough for a human to tell the difference. For context, that difference is about half the difference between a new non-OEM rear tire's tread and the same tire when it's time to change it (assuming 9/32 new and 2/32 at the wear bars).

Braking? The moment arm is only 1.1% longer, so you'd need to provide 1.1% more pedal force to get the same braking force at the contact patch. Nobody is that precise or could tell the difference. If anything, it makes you slightly less likely to cause the ABS to kick in.

Raising you up and putting weight on your wrists? Again, it's about half the difference between a new and worn tire. But let's do the math: Wheelbase is 1,677 mm, and this rim/tire combo raises the axle by ~3.4 mm. Applying the Pythagorean theorem with 1,677 as the resulting hypotenuse and 3.4 as the side opposite the angle we're calculating, that's a change in angle of 0.102°. There's no way you can tell the difference of 1/10th of a degree. You're not getting "loss of feeling, buzzing hands" or "head at a more awkward angle" to any noticeable extent with that.

As for ABS, the system cares about relative rotational speeds between the wheels, the rate of change to those speeds, and likely the braking force applied. 1.1% is well within the built-in margins for the system, since tire wear alone can change the radius by around 2% anyway. Again, people are running Exedra Max rears without issue and they have a larger difference in radius (about 4%).

 

[A1A Rider]

At 4:39 into the vid, you can clearly see that one tire appears to be bigger in diameter than another. Since nothing else was given, this was the only thing I had to go on. The seller now appears to be totally rude and appears incapable of a business relationship.

 

[dfresh]

I don’t know if it’s something I would spend for but I do appreciate it when people take the time to make quality aftermarket products and I give kudos to the seller for being on here and taking the time to answer questions.

 

[BlackMambaDc]

You can see in the video that this setup clears the hugger, which even the Exedra Max doesn't. So, any change in overall circumference is less than you'd get with that. Plenty of people have run those and never hit the underside of the tail. This setup increases overall diameter by 1.1%, whereas the Exedra Max increases it by about 4%.

As was pointed out, the lower profile of the tire (35 vs 50) mostly counteracts the increased diameter of the rim, so the overall diameter is only about 1.1% different. So, the axle only moves upward 9/64ths of an inch. That's miniscule from a steering geometry standpoint. Very slightly quicker turn-in and very slightly less stable, but not enough for a human to tell the difference. For context, that difference is about half the difference between a new non-OEM rear tire's tread and the same tire when it's time to change it (assuming 9/32 new and 2/32 at the wear bars).

Braking? The moment arm is only 1.1% longer, so you'd need to provide 1.1% more pedal force to get the same braking force at the contact patch. Nobody is that precise or could tell the difference. If anything, it makes you slightly less likely to cause the ABS to kick in.

Raising you up and putting weight on your wrists? Again, it's about half the difference between a new and worn tire. But let's do the math: Wheelbase is 1,677 mm, and this rim/tire combo raises the axle by ~3.4 mm. Applying the Pythagorean theorem with 1,677 as the resulting hypotenuse and 3.4 as the side opposite the angle we're calculating, that's a change in angle of 0.102°. There's no way you can tell the difference of 1/10th of a degree. You're not getting "loss of feeling, buzzing hands" or "head at a more awkward angle" to any noticeable extent with that.

As for ABS, the system cares about relative rotational speeds between the wheels, the rate of change to those speeds, and likely the braking force applied. 1.1% is well within the built-in margins for the system, since tire wear alone can change the radius by around 2% anyway. Again, people are running Exedra Max rears without issue and they have a larger difference in radius (about 4%).

Thank You.

 

[TURBO200R4]

I have been in business for 50 years and when a customer comes in and think he/she knows more than i do then I say I do not want to work on your vehicle.
Now it is very annoying when a customer keeps asking you questions and not answering the questions that need to be answered in order to answer his questions.
I know I am in trouble when customer starts up with
Back in 1978 had a chev with the same problem as the 2016 ford I have now so you have to listen to 20 minutes of what it was doing and how it took 4 mechanics to find the problem which has absolutely nothing to do with why he is in the shop today.
Some listen and some don't you try to teach but in the end you just do the best you can.

 

[BlackMambaDc]

Are there any anti-theft nuts for the rim?

I don’t offer any, but for my setup I did black titanium open end lug nuts.

 

[Einar]

At 4:39 into the vid, you can clearly see that one tire appears to be bigger in diameter than another. Since nothing else was given, this was the only thing I had to go on. The seller now appears to be totally rude and appears incapable of a business relationship.

You could have just asked politely for the dimensions rather than guessing from a video.

 

[1olbull]

Great back and forth!
Love the maths . . . And the Greek!
My experience has been the ABS is fault isu based more on the circumference and the relative rotation. The difference being (if I remember correctly) about eight percent before it faults and ABS. shuts off.
BRW - I speak of the 2300cc only.