I'm going to put RIM WIDTH to the test!

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3/29/2019 4:03 PM

For those of you that already like running larger tires, you understand the benifets. Easier on the wrists, ability to run lower pressures more effectively, better surface area, etc. Not to mention, I personally love the looks of large tires on a BMX.

As for the rims, they are a bit less understood from what I gather. I typically recommend to buy the largest rim possible but unless you are running somewhat large tires, they can sometimes actually hinder your performance. There is a sweet spot for traction, tire stability and rim protection.

Too big of a rim with too small of a tire:
-Put your rim at higher risk of damage
-Lose traction since the tire will slip, rather than flex to the surface
-Expose more of your sidewall to a grinding surfaces

Too big of a tire on too small of a rim:
-Experience excessive tire rolling over the side of a rim when carving or turning
-Higher chance of snake biting your tube with lower tire pressures and a big drop or case

There are probably other possible problems I forgot to mention.

For this particular real-world test, I didn't go as big as possible, I purchased a Steamroller from Animal. The rim is 40mm width inside, lip to lip and is double walled and welded. The rim I will be comparing it against, is an industry standard, 34mm width, G-sport Rollcage.

I could have went for the Stranger XXL but it was more expensive and significantly heavier for the extra 2mm. I even looked at the stranger XXLT, which is the model with relief holes drilled for weight savings but the XXLT is still notably heavier than the Animal Steamroller. I do have brand loyalty but I am not opposed to buying a part from a company just because their image or reputation is not entirely favorable.

The other reason I bought the Steamroller is, I didn't want to spend another 30+ dollars on a new set of spokes and nipples since this new Steamroller is the same ERD (effective rim diameter) as my current Rollcage rim.

I plan on keeping my Rollcage as my next rear rim since it has brake-height sidewalls, minimal damage and I run a much smaller 2.25" tire in the rear for grinding and geo-altering purposes.

I know It's somewhat taboo to reuse spokes and nipples but I am confident in my wheelbuilding ability and the spokes in question. I have used hub guards day one with these spokes and although I grind very often, my front spokes are in pretty decent shape. I also plan on keeping the spokes in the same bedded-in positions by using the tape the cross sections method.

I will be testing with a used 2.4 BSD Donnastreet kevlar bead tire since it still has quite a bit of life in it and is what I am most used to with my current street bike.

I have really been appreciating lower tire pressures, as of recent and have been experiencing a fair amount of tire rolling over the rim. Lower pressures combined with my new goal of mastering some form of a 360 has made things even more noticable since I am experimenting with carving much harder and faster than I had previously. I am aware that a simple part change will not make me a 360 master over-night but I have a strong feeling it will help my progression enough to warrant the purchase.

I will post my results here and maybe even make a video describing what differences I feel.

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3/29/2019 4:30 PM

THIS is why forums exist. Looking forward to your experimentations, Professor

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3/29/2019 4:33 PM
Edited Date/Time: 3/29/2019 4:33 PM

But what will you be testing? Unless you're regularly destroying rims I don't see how you could adequately test this. Also, testing a rim that cross-laces against a rim that regular-laces(to the edge of the rim, no less) isn't a great test as the cross-laced rim will be quite a bit stiffer(the spokes act far more in both axes on a cross-laced wheel than regular-laced wheels, and even more so, considering the regular-laced wheel will have the spokes sitting at ~34mm apart, only really acting radially).

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3/29/2019 4:49 PM

p1p1092 wrote:

But what will you be testing? Unless you're regularly destroying rims I don't see how you could adequately test this. Also, testing a rim that cross-laces against a rim that regular-laces(to the edge of the rim, no less) isn't a great test as the cross-laced rim will be quite a bit stiffer(the spokes act far more in both axes on a cross-laced wheel than regular-laced wheels, and even more so, considering the regular-laced wheel will have the spokes sitting at ~34mm apart, only really acting radially).

My biggest reason for trying a wider rim is to see if I can mitigate the tire rolling over the rim issue I am feeling more and more with lower tire pressures.

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4/1/2019 4:53 AM

Bulletpup wrote:

My biggest reason for trying a wider rim is to see if I can mitigate the tire rolling over the rim issue I am feeling more and more with lower tire pressures.

That is a challenge-I've had and seen that done WAY too often. Too wide of a tire on a narrow rim makes that easy to do.

I look forward to your reviews sir.

Might I recommend a Youtube series of these kind of reviews? With the forum supporting you, it could take off pretty well.

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"Hey anybody ever make that mistake like right when you wake up in the morning and you believe in yourself?" -Kyle Kinane

"BIKES!" -Tom Segura

4/1/2019 5:14 AM

What you are calling low pressure here?

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4/1/2019 6:55 AM

streethack wrote:

What you are calling low pressure here?

40-50psi

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4/1/2019 7:21 AM

p1p1092 wrote:

But what will you be testing? Unless you're regularly destroying rims I don't see how you could adequately test this. Also, testing a rim that cross-laces against a rim that regular-laces(to the edge of the rim, no less) isn't a great test as the cross-laced rim will be quite a bit stiffer(the spokes act far more in both axes on a cross-laced wheel than regular-laced wheels, and even more so, considering the regular-laced wheel will have the spokes sitting at ~34mm apart, only really acting radially).

Bulletpup wrote:

My biggest reason for trying a wider rim is to see if I can mitigate the tire rolling over the rim issue I am feeling more and more with lower tire pressures.

dave lawrence wrote:

That is a challenge-I've had and seen that done WAY too often. Too wide of a tire on a narrow rim makes that easy to do.

I look forward to your reviews sir.

Might I recommend a Youtube series of these kind of reviews? With the forum supporting you, it could take off pretty well.

I have a few series similar to this. The main one I use for bmx exclusively is called "BMXperiments".

Ive done: inside out tires, plastic peg comparisons, 12" peg sleeves, riding with no pedal bodies, griding abuse videos, riding rhd wheel on the left, making plastic sleeves, riding fat bmx tires in snow.

Some of the stuff is goofy but still experimental. I would be all for forum support though! My bmx videos are very unpopular compared to my firearm related videos...

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4/1/2019 12:21 PM

streethack wrote:

What you are calling low pressure here?

Bulletpup wrote:

40-50psi

Unless you're built like a pretzel, why run them low?

It won't matter what rim you use if the pressure is too low, tire will still behave much the same. A few mm wider rim won't create some miracle.

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4/1/2019 12:39 PM

I looked at the federal wheels with the xl rim. They look cool but weigh too much lol

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45 refs and counting check profile.

4/1/2019 1:11 PM

streethack wrote:

What you are calling low pressure here?

Bulletpup wrote:

40-50psi

streethack wrote:

Unless you're built like a pretzel, why run them low?

It won't matter what rim you use if the pressure is too low, tire will still behave much the same. A few mm wider rim won't create some miracle.

You're correct, I also stated in my original post, I dont expect to just be able to do a bunch of things out of nowhere. If it helps me though, even incrementally, there is no reason for me no to run it. A wider rim will help the larger tire rolling over the rim.

I will share my thoughts and experiences, you can do nothing but benefit from my money and time spent.

Sincerely
-Wet J. Pretzel

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4/1/2019 2:12 PM
Edited Date/Time: 4/1/2019 2:13 PM

Here is a chart I found that may not apply 100% to bmx but I think its a nice chart that may lead to better handling.

Also found a picture that helps visualize the problem I am describing. I'm sure many of you experience something similar to my situation even if you are not aware of it.


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4/1/2019 3:01 PM

Still not sure what the mad scientist theory on running flat tires is about, that will cause more issues than anything else in the equation.

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4/1/2019 3:38 PM

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4/1/2019 3:42 PM

streethack wrote:

Still not sure what the mad scientist theory on running flat tires is about, that will cause more issues than anything else in the equation.

I ride lower pressures for comfort, mostly. I have wrist issues, joint pain and since I'm 30, I don't recover as quickly as I used to. I started off running 80 psi and started experimenting with different tire pressures in attempt to relieve wrist, ankle and knee pain.

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4/1/2019 3:56 PM

Yeah I run 60 with no real issues. But pressures are relative to the type of tire and body weight I think.

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4/2/2019 2:22 AM

streethack wrote:

Yeah I run 60 with no real issues. But pressures are relative to the type of tire and body weight I think.

Yep. Different rubber acts differently, as well as depth of tread/amount of rubber. And the weight of the rider is what should determine the ideal pressure. Personal preference is key, no matter how much science goes into it. There’s no ideal geometry of a frame for a rider of x height, y ability, that rides z terrain. It’s just personal preference.

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4/2/2019 5:06 AM

streethack wrote:

Yeah I run 60 with no real issues. But pressures are relative to the type of tire and body weight I think.

.pegless. wrote:

Yep. Different rubber acts differently, as well as depth of tread/amount of rubber. And the weight of the rider is what should determine the ideal pressure. Personal preference is key, no matter how much science goes into it. There’s no ideal geometry of a frame for a rider of x height, y ability, that rides z terrain. It’s just personal preference.

This is 100% correct.

In BMX there is a LOT of personal preference, which is why we have not followed road/cx/mtb into the intense science aspects-because it isn't specifically necessary. There IS validity to a guy who is 6 feet tall likely being more comfortable on a 21" vs 20" frame, BUT preference overtakes it every time.

I've seen dudes who are 6'6" riding 20.5 tt frames and 7.75" bars. I've also seen dudes who are like 5'2" riding 21" in frames and 9.5" bars.

Preference is key.

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"Hey anybody ever make that mistake like right when you wake up in the morning and you believe in yourself?" -Kyle Kinane

"BIKES!" -Tom Segura

4/2/2019 5:38 AM

.pegless. wrote:

Yep. Different rubber acts differently, as well as depth of tread/amount of rubber. And the weight of the rider is what should determine the ideal pressure. Personal preference is key, no matter how much science goes into it. There’s no ideal geometry of a frame for a rider of x height, y ability, that rides z terrain. It’s just personal preference.

Woah, woah, woah hold the fuck up. Steve? Is that you?

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I don't crash, I do random gravity checks...

4/2/2019 5:45 AM

50PSI with balloon tires? You probably have to pedal down hill to keep any momentum.

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4/2/2019 8:00 AM

bobPA wrote:

50PSI with balloon tires? You probably have to pedal down hill to keep any momentum.

The larger the tire, the less psi you need to roll.

You dont put 100 psi in your car tires do you?

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4/3/2019 2:42 AM

Bulletpup wrote:

The larger the tire, the less psi you need to roll.

You dont put 100 psi in your car tires do you?

No necessarily true, kinda like the above response; tire compound and tread etc gonna have different effects.

My 2.4 tires are basically like a slick when rolling straight and quite a wide contact patch, and they are sluggish as fuck compared to riding the bikes I had in my younger days with below 2.1 wide treaded stuff. Rolling resistance, like comparing a standard car tire to a drag radial or slick.. big difference man!

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4/3/2019 3:01 AM

bobPA wrote:

50PSI with balloon tires? You probably have to pedal down hill to keep any momentum.

Bulletpup wrote:

The larger the tire, the less psi you need to roll.

You dont put 100 psi in your car tires do you?

streethack wrote:

No necessarily true, kinda like the above response; tire compound and tread etc gonna have different effects.

My 2.4 tires are basically like a slick when rolling straight and quite a wide contact patch, and they are sluggish as fuck compared to riding the bikes I had in my younger days with below 2.1 wide treaded stuff. Rolling resistance, like comparing a standard car tire to a drag radial or slick.. big difference man!

Two same company tires, same compound, same tread, different sizes...the larger of the two will require less pressure but more air while the smaller will require less air but more pressure.

My example of a car tire compared to a bike tire was crude but that's all it needed to be.

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4/3/2019 3:20 AM

Of course on the tire pressure thing, but a bigger contact patch increases rolling resistance.

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4/3/2019 3:52 AM

streethack wrote:

Of course on the tire pressure thing, but a bigger contact patch increases rolling resistance.

From my research, a wider tire makes for a rounder wheel at the same psi as a lesser width bike tire.

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4/3/2019 3:57 AM

Here is the first video results of the test! I think it went extremely well! This test is not an end to all standard vs wide rims but if you are in a similar situation as I was, a wider rim will aid in stability for harder carving!



I also used the video to test my new camera equipment for my channel.
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4/3/2019 4:05 AM

Bulletpup wrote:

Here is the first video results of the test! I think it went extremely well! This test is not an end to all standard vs wide rims but if you are in a similar situation as I was, a wider rim will aid in stability for harder carving!



I also used the video to test my new camera equipment for my channel.

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4/3/2019 4:40 AM

streethack wrote:

Yeah I run 60 with no real issues. But pressures are relative to the type of tire and body weight I think.

.pegless. wrote:

Yep. Different rubber acts differently, as well as depth of tread/amount of rubber. And the weight of the rider is what should determine the ideal pressure. Personal preference is key, no matter how much science goes into it. There’s no ideal geometry of a frame for a rider of x height, y ability, that rides z terrain. It’s just personal preference.

HondaCRFRacer wrote:

Woah, woah, woah hold the fuck up. Steve? Is that you?

Steve has found his zen.

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4/3/2019 6:09 AM
Edited Date/Time: 4/3/2019 6:10 AM

Bulletpup wrote:

Here is the first video results of the test! I think it went extremely well! This test is not an end to all standard vs wide rims but if you are in a similar situation as I was, a wider rim will aid in stability for harder carving!



I also used the video to test my new camera equipment for my channel.

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I don't crash, I do random gravity checks...

4/3/2019 9:27 AM

Fixed the link.

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