Jump to content

Rota RB/RB-R, 4x114.3, 17", Z-Offset Wheels


What would you prefer?  

191 members have voted

  1. 1. What would you prefer?

    • 17x9.5" -19 On all four corners (as the group buy has been)
    • 17x9" -13 Front and 17x9.5" -19 Rear even if it costs an extra $200 ($950 shipped)
    • 17x9" -13 Front and 17x9.5" -19 Rear at the same price ($750 shipped)

Recommended Posts

I have been in contact with the Rota representative who is located about 30 minutes from my home. I inquired about having the Rota RB (it looks like a rewind/watanabe) made in a 17" by around 9-10 specification to our desired offset. A total of 25 people (100 wheels) would be required to run this deal. I think this one might be a long shot, but they are very attractive wheels and a 17X9.5 or so in a low negative offset might be just the ticket for our Z cars.


EDIT: Update - Pricing is $750 for a set of four shipped any where in the continental US. If you pickup in Hayward, it is only $700. These wheels will be setup to clear a stock suspension, but will most likely (almost 100%) require flares or fender rolling. I am working on determining the size that fits at the moment and will be making cardboard wheels in a 245/40, 255/40, and 275/40 size. The rears should fit 275/40 no problem. The fronts may need to step down to 255. We shall see. This will help me to determine an offset that works.


If you are interested and willing to jump on this, please express it. Suggestions on sizing are welcome as well. Images are in the link above.



1. Rudypoochris - Chris Moris - chrismoris@gmail.com

2. DSommer - David Sommer - dsommer479@yahoo.com

3. Sparkynacho - xxxxxx - sotoa01@yahoo.com

4. Rev240z - xxxxxx - bcproperties1@comcast.net

5. Panachedk - Adam O'Lena - amolena@uwm.edu

6. Streeteg - xxxxxx - Eguidice@hotmail.com

7. Dreco - xxxxxx - dreco@sbcglobal.net

8. Cowboy510- xxxxxx - coyboy510@hotmail.com

9. Cowboy510- xxxxxx - coyboy510@hotmail.com

10. DemonZ - xxxxxx - louho@hotmail.com

11. Shoryuuu - xxxxxx - shoryuuu@yahoo.com

12. Bjhines - xxxxxx - jwhines3@nc.rr.com

13. White_rice - xxxxxx - old_skool_rice@yahoo.com

14. Memc - xxxxxx - mfraserjr@gmail.com

Link to comment
Share on other sites

If I end up getting these wheels I will definately run flares on my car. If I stick with the 16X8 Rotas I have now, maybe, maybe not.


I used to think the same about 17"s on S30's. I think it looks fine now after seeing the cars with CCWs and other peoples builds. My main issue with 15" and 16" sizes is that there isn't really anything larger than 245 maybe 255, unless you go into Hoosiers and race tires. 17" you can go up to 285mm no problem with a wide selection.

Link to comment
Share on other sites

It is $750 free shipping in the USA for 4 in 17X9.5 -20 offset. What do you all think? We would need 25 people... thats alot.


EDIT: It doesn't have to be that size either, I just figure that is going to work out back. Does anyone know if that would be okay on the fronts with ZG's or is that really pushing it. I know the Wats are -13 16X9's, so these would stick out an extra half inch or so I would think.


These would be really serious wheels though. Ever see the lip on a 16x9.5 -19 watanabe... its fat. These would be a similar lip depth.



Link to comment
Share on other sites

Mustangs do have a 5 x 4.5 = (5X114.3) bolt pattern.


Also, Kim said the maximum size for a 17" wheel from them is 9.0-9.5. I think if we get enough people interested in a 17X9.5" wheel, we can get them to make them. To run these with ZG's I would think you'd have to be running coilovers for the added clearance to the strut. We should shoot for a backspacing around 5.0" backspacing. That equals a offset of about -6mm to -12mm should be about right..



Link to comment
Share on other sites

Just thought I would suggest the following.....I have been following this thread with some interest and I have noticed that there some predicting going on in regards to the wheel size and offset, I just thought I would suggest the following which should spark more interest in people actually purchasing. You could divide this into four categories which would make everyones order much less confusing to them and to the company making the wheels.


1. People running their Z with coilovers and with ZG flares - (specify the optimal wheel size, backspacing and offset for both front and back here)


2. People running their Z without coilovers and with ZG flares- (specify the optimal wheel size, backspacing and offset for both front and back here)


3. People running their Z with coilovers only and no flares - (specify the optimal wheel size, backspacing and offset for both front and back here)


4. People running a stock setup, some people like the look of the wide wheels but do not want to run flares. (specify the optimal wheel size, backspacing and offset for both front and back here)


Just thought I would add, that it is up to us as a group to figure out what is the best Wheel size, backspacing and offset for the wheels in each category, this is difficult for many people to calculate on their own.

Link to comment
Share on other sites

Okay. I agree on the offset comments above. I doubt these will fit without flares though so attention to all those planning on running stock. The wheels are probably just too large.


I have emailed Kim asking her to confirm that all we need is 25 sets of the same width and diameter. I also asked if I should compiled a list of people who are interested and their emails. Lastly I asked her to confirm a time estimate based off the knowledge that rota sometimes takes a while to deliver. She is the head of all north america for rota if I understand correctly and she has an office/warehouse 30 minutes from me. I might go meet her in person.


I figure we are going to need a list of people who are commiting anyways so please if you would like to get on this, just type your email and name and I will compile a master list edited into the very first post of this thread. DO NOT TYPE if you are un willing to commit. The price is $750 a set shipped to anywhere in the continental USA or $700 picked up in Hayward, CA.


Also, I did contact the 240sx forums and put a group buy post up, we shall see...

Link to comment
Share on other sites

The backspacing is going to be the same regardless of the width wheel you want to run. Opinions differ, but the general consensus seems to be that 5" backspacing works for those running coilovers. It would be less for those without coilovers, but personally I don't think it makes sense to run the width rims being discussed here without using coilovers.


Given the 5" backspacing you can calculate the offset needed based on the width wheel you want. Now there could be variances between manufacturers, and someone else posted problems installing their Rota's that seemed to be the correct offset.

Link to comment
Share on other sites

5" BS on a 9.5 inch wheel would be... 9.5+ 1" Lip = 10.5/2 = 5.25


Need -.25" = -6 offset


But is that too close for the front. Not talking strut to tire clearance. I mean tire to frame rail. My +10 16X8 grids touch with a 245 tire to the frame. Not badly, but enough to make it not clear. That would be the same back space. Could always use a bit of spacer, but it would be nice to make these fit right. Maybe rear and front offsets should be different while maintaining the same width? Watanabe 16X9 fronts use a 4.5" backspace same goes for the Wat rear. Maybe we should aim for that to be conservative? Something like -15 in the rear and -8 to -10 in the front using a spacer if needed.

Link to comment
Share on other sites

OK, I was asked to comment...


You are not going to get stock OEM type fitment from a wheel that's 3" larger OD and 4.5" wider then what the 240Z was designed for. You will have rubbing on the frame rails and TC rod in front at full lock. You will most likely have to trim the front edge of the parking light valance to clear at least the passenger side front wheel when turning left. Steering will be heavier.


Tire OD should be kept at 25" or less on the 240Z unless you plan on running bumpsteer spacers and/or relocate the front LCA inner mounting point. Even then, keeping tire OD below 25" is a good thing for these cars. Some sample tire sizes:




That's it in 17"...


For that size tire a 8.5" rim is fine and here's a picture of a 245/40-17 on a 8.5" rim:




A 5" backspace is typical for a coil over equipped 240Z. Spacers are sometimes used on the front for additional clearance and to get the front track wider then the rear for better handling.

Link to comment
Share on other sites

Offset doesn't matter, offset doesn't matter, offset doesn't matter.


What you need is 5" of backspace. Whatever offset that comes out to be, fine. If the wheel manufacturer needs an offset number to make the wheel, then either the manufacturer or you guys as part of the group by can do the math.


Offset is a by product of wheel rim width, wheel center thickness, mounting pad depth, and backspace. Since we as wheel buyers can really only specify wheel rim wdith and backspace, we get an offset number and have to work with it.


Wheel position can be adjusted using spacers. In the 4 sets of racing rims I've ordered for my own personal 240Zs I specify a 5.5" backspace and adjust clearance and fitment using wheel spacers.


You guys should also be concerned about caliper clearance and center hole ID.

Link to comment
Share on other sites

I'd would be much easier if evryone gave measurements the same way. Some wheels specify the offset and some the backspace.


From my experience the auto manufacturers are the ones that emphasize offset and the wheel manufacturers tend to focus on backspace. So when you read the wheel specs in a FSM or owners manual it talks about offset while the custom wheel spec sheets ask for backspace information.


And yes, the thickness of the wheel mounting flange and the wheel center does have an effect on offset, which the backspace number makes clear.

Link to comment
Share on other sites

Here's a link to a thread that discusses backspace and offset in detail including posts by people representing themselves as wheel designers.



There are many diagrams on the net depicting offset and backspacing, but the one included in the thread looks like a good one as it includes flange width. I guess in some cases the inner and outer flange widths can actually be different.


I just want to purchase rims that have the recommended 5" of backspace, when the only information I'm given is the offset. The Rota RB 17 x 8.5 wheels I ordered has an advertised offset of 4mm. Of course this information would also help determine the proper offset used to place an order for the 17 x 9.5 rims as well.

Link to comment
Share on other sites

I think I am just an unlucky group buy starter. :)


These wheels should really be flying out of here, but guess not. :P


Give it some time. A 73mm bore sounds more like it. I am talking to Kim I believe she told Justin any size and offset, but I want her/him to confirm that.


EDIT: Kim replied that any offset or bolt pattern is a go as long as there are 5 people (20 wheels) for that given offset or bolt pattern.

Link to comment
Share on other sites

Yes, but unfortunately the first group needs to be 25 people. LOL


I currently am making a 17" "wheel" out of cardboard with an adjustable measured offset. I will make 2 or 3 cardboard tires. Probably 3. A 245, 255, and 275mm tire set each with a "40" aspect to slip onto said mock wheel. This weekend I will fit them to my S30 with coilovers to find the optimal size. That way i can atleast get an idea. I will probably ship them to someone with ZG's currently installed for final measurements and backup gaurentee of fitment.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...