new darkside tire?

[Spillman]

I'm new here and dont even own the R3 Roadster yet but wanted to ask about the rear tire choice.

I have read where most riders prefer the 225/50 ct. I am vertically challanged at 5'6'.

If I were to use a 225/50 tire that makes the wheel overall height of 26".

If is used a 205/40 that would make a tire height of 22.4", a lowering of 3.6".

That would make the difference in having to tippy toe and being able to make a stop with the balls of my feet.

The question I have is why wouldn't this work, is there a reason the 255 is better?

The tire width difference is less than an inch but the reach for me is over 3 inches. Seems like a good trade off.

I wouldn't have to go to shorter shocks which only drop you just over an inch at the cost of $400 bucks whereas the tire is a savings of $150 plus bucks and gain 3.5 inches in drop.

Is my logic all wrong?

Is there another reason why the 225 is the most popular size tire?

Here is my choice for a tire.

tires-easy.com - Details: Toyo PROXES 4 205/40 ZR16 83W BSW

 

[nolton]

I'm new here and dont even own the R3 Roadster yet but wanted to ask about the rear tire choice.

I have read where most riders prefer the 225/50 ct. I am vertically challanged at 5'6'.

If I were to use a 225/50 tire that makes the wheel overall height of 26".

If is used a 205/40 that would make a tire height of 22.4", a lowering of 3.6".

That would make the difference in having to tippy toe and being able to make a stop with the balls of my feet.

The question I have is why wouldn't this work, is there a reason the 255 is better?

The tire width difference is less than an inch but the reach for me is over 3 inches. Seems like a good trade off.

I wouldn't have to go to shorter shocks which only drop you just over an inch at the cost of $400 bucks whereas the tire is a savings of $150 plus bucks and gain 3.5 inches in drop.

Is my logic all wrong?

Is there another reason why the 225 is the most popular size tire?

Here is my choice for a tire.

tires-easy.com - Details: Toyo PROXES 4 205/40 ZR16 83W BSW

Read about the experiences with Toyo Proxes from other riders before you go there.
225? From what I've read its a speedo issue.

 

[tdragger]

The 225/55 seems to be the most popular size darkside for the Std/Classic/Roadster line.

The 225/50 has been used successfully by several owners with the trade off of increased revs at speed, loss of fuel mileage, and an increase speedo error.

I don't know for sure regarding the smaller tire size. My instinct says to not go there. The trade-offs may be unsatisfactory.

Some Captains have lowered the front along with lower cost rear shocks. The high-end progressives, while great, are not the only solution. On the www.newr3.com site, they sell the Icon shorties for a lot less.

You also have seat options to consider to shorten the reach to the ground.

 

[CanberraR3]

Couple of things. Firstly your maths is out. Reducing the height (ie diametre) of the tire by 3.6 inches will only lower your bike by 1.8 inches - remember the axel is in the middle of the wheel, not the top).

Nevertheless, reducing the diametre of your rear wheel/tire by 3.6 inches reduces the overall rolling circumference by around 11 1/3 inches (or almost 14%) and changes your final gearing accordingly. In other words each revolution of the wheel will have you traveling almost a foot less distance - roughly 6' instead of 7' with each turn.

Putting aside the speedo error this will cause, at the same RPM you will have a significant drop in speed; or conversly, at the same actual speed your engine will be reving higher and you'll be using more fuel. The only plus I can see is that you'll probably accelerate quicker if you can control wheel spin, but you will have a lower top speed.

With whatever tire you choose you need to remember that any departure from the original diametre (height) will change your final drive gearing. Not necessarily a bad thing but it does complicate things.

This seems to me to be a very inefficient and impractical way to lower your bike if that's all you're trying to achieve, and I'd suggest looking at other options - shocks and seat seem the obvious ones to me.

Just out of curiosity, did you use a car tire on the M109?

 

[TriumPhil]

Yeah, what he said (excellent write-up CR3!), plus the 225/55 is dimensionally the closest car tire size to the OEM Metzeler, thus helping to keep the geometry as close as possible to stock with the alternate tire.

BTW, Spillman, to my knowledge the most popular Toyo car tire for your rear rim is the Proxes T1R. I know that when I bought mine in mid-Spring last year, there were very few 225/55s on hand anywhere in the US. It was almost as if Toyo was phasing out their inventory, at least in that size (which only fits on Honda and Acura autos). Here's a write-up on that tire: tires-easy.com - Details: Toyo PROXES T1-R 235/45 ZR17 97Y with rim protectionleiste, BSW

Note that the T1R has a slightly softer (stickier) compound than the Toyo you were looking at. Also the speed rating is considerably higher on the T1R. One more note... again, to my knowledge the 205 size that you specified will fit on the '08 and later R3T's rim, but not on your roadster, an older Standard or on the R3 Standard Tourer. The T1R, lacking the center rib of the tire you sourced, would be the winning pick between the two Toyos for both handling and better, more even wear, I'd think.

 

[Spillman]

Couple of things. Firstly your maths is out. Reducing the height (ie diametre) of the tire by 3.6 inches will only lower your bike by 1.8 inches - remember the axel is in the middle of the wheel, not the top).

Nevertheless, reducing the diametre of your rear wheel/tire by 3.6 inches reduces the overall rolling circumference by around 11 1/3 inches (or almost 14%) and changes your final gearing accordingly. In other words each revolution of the wheel will have you traveling almost a foot less distance - roughly 6' instead of 7' with each turn.

Putting aside the speedo error this will cause, at the same RPM you will have a significant drop in speed; or conversly, at the same actual speed your engine will be reving higher and you'll be using more fuel. The only plus I can see is that you'll probably accelerate quicker if you can control wheel spin, but you will have a lower top speed.

With whatever tire you choose you need to remember that any departure from the original diametre (height) will change your final drive gearing. Not necessarily a bad thing but it does complicate things.

This seems to me to be a very inefficient and impractical way to lower your bike if that's all you're trying to achieve, and I'd suggest looking at other options - shocks and seat seem the obvious ones to me.

Just out of curiosity, did you use a car tire on the M109?

Quick answer,

No ct on the 9.

I have a 260/40r18 and a 160/60r18 for the front. The originals are 240 and a 130. Using a ct makes sense to me. Getting used to the lip on the ct as far as I can tell wont be a big deal. Should get used to it fairly quickly.

I'll look at my math again to see what I did wrong.

And yes, the reason for choosing this tire was to get me lower to the ground. I may have to look harder at the shocks and seat and be happy with that.

I would still get the bike stock with out mods to the height. Thats not going to stop me. I really like the seat position (height) I have with the 9 though, I am flat footed and some. I also have 2" bones on it. That helped.

This will be my second bike in a year. 35k on the 9. hadnt had a bike in 25 years since just out of the service. I trybing to make up time. I'm really enjoying my bike and I will love riding the Rocket.

How about relocating the location where the shock connects on top to lower the rear end. Is there room for that.

I am not a bike builder or anything like that so If I say something stupid thats why, I wont hold it against me.

 

[TriumPhil]

Take a look at my post above, S-man.

I am in total agreement with CanberraR3, i.e., if this is a quest to make the bike more suitable to your build, customizing the seat and/or suspension is the way to go about it.

Most of us would recommend that, if possible, you beg, borrow or steal a ride on the Darkside prior to deciding whether or not to change the type of rear tire you are going to use. There are pluses and minuses for either point of view regarding which tire is the "best" and those attributes and drawbacks will vary, as well, based upon the type of rider you are and what kind of riding you ordinarily engage in.

 

[nolton]

Couple of things. Firstly your maths is out. Reducing the height (ie diametre) of the tire by 3.6 inches will only lower your bike by 1.8 inches - remember the axel is in the middle of the wheel, not the top).

Nevertheless, reducing the diametre of your rear wheel/tire by 3.6 inches reduces the overall rolling circumference by around 11 1/3 inches (or almost 14%) and changes your final gearing accordingly. In other words each revolution of the wheel will have you traveling almost a foot less distance - roughly 6' instead of 7' with each turn.

Putting aside the speedo error this will cause, at the same RPM you will have a significant drop in speed; or conversly, at the same actual speed your engine will be reving higher and you'll be using more fuel. The only plus I can see is that you'll probably accelerate quicker if you can control wheel spin, but you will have a lower top speed.

With whatever tire you choose you need to remember that any departure from the original diametre (height) will change your final drive gearing. Not necessarily a bad thing but it does complicate things.

This seems to me to be a very inefficient and impractical way to lower your bike if that's all you're trying to achieve, and I'd suggest looking at other options - shocks and seat seem the obvious ones to me.

Just out of curiosity, did you use a car tire on the M109?

A Mathematician!!!!!!
I will have to keep that in mind.

 

[CanberraR3]

I have read where most riders prefer the 225/50 ct.

Where did you read that? Surely most riders prefer MTs (which doesn't mean we necessarily think they're perfect or even particularly good) and even some darksiders would "prefer" to use an MT. The problem seems to be lack of choice, cost, poor mileage (and if you do some performance mods, it's even worse - without trying), therefore even more cost, and the desire for more traction.

I don't know for sure, and darksiders will correct me, but I doubt there would be too many riders who'd use a car tire under any circs IF there was an MT available that met their needs.

Why would you consider a CT for an R3 if you wouldn't put one on the 9?

I have a 260/40r16 and a 160/60r16 for the front

Did you really put a 16" wheel on the back of that - I recall the C109 runs a 240/55x16 but the M runs an 18.

 

[Spillman]

Couple of things. Firstly your maths is out. Reducing the height (ie diametre) of the tire by 3.6 inches will only lower your bike by 1.8 inches - remember the axel is in the middle of the wheel, not the top).

Canberra,

I had to think about it for a while.

Your right.

I forgot that the effective lowering height is only half that of the total diamater "IF THERE IS AN AXEL" involved.

Well that takes me back to shocks and seat.

Another question, does the odometer mark the speed corectly or is it like other metrics. Mine sayes its doing 75 when in reality its only 70mph.