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Just looked at my numbers and yea I was thinking backwards the hubs in my possession are indeed 1mm in and not out.
I would agree on spacing the caliper rather than the hub, being cheaper/easier/better, except that the caliper bracket mounts to the outboard side of the upright mounting tabs and that would space the assembly out rather than in.
Assuming there is sufficient travel available in the caliper sliders and pad abutments(where the pads slide in the caliper bracket as they wear), I cant see this causing any issue.
The MR2 hubs without the hub spacer would push the caliper off the pins 1mm(caliper would move left in the pic away from the bracket), and bring the rotor 1mm closer to the bracket
Ah, I didn't realize the bracket was outboard of the knuckle, between the knuckle and the rotor. Depending on how hard we wanna chase this, you could simply shave 1mm off the bracket mounting faces and have correct alignment with no spacers at all. Seems to be plenty of material there.
Last edited by themonkeyman; 02-26-2018 at 07:02 PM.
The 45mm ID will be too big, the bearing shim only needs to contact the inner race, so it will need to be a close fit with the 40mm inner race ID.
This would be perfect;
There is a fat chamfer at the base where the bearing seats, chamfers everywhere.... that shim would not allow the bearing to seat. I just measured the chamfer radius and "OD" and its just over 44mm. You must use a 45mm ID shim. (1.75" would work great too)
Im not modding uprights or caliper brackets, and this is intended to be a bolt on affair for the end user.
There is a fat chamfer at the base where the bearing seats, chamfers everywhere.... that shim would not allow the bearing to seat. I just measured the chamfer radius and "OD" and its just over 44mm. You must use a 45mm ID shim. (1.75" would work great too)
Im not modding uprights or caliper brackets, and this is intended to be a bolt on affair for the end user.
you could simply shave 1mm off the bracket mounting faces and have correct alignment with no spacers at all.
My plan is to grind the bracket instead of shimming the hub, if it's even needed. I wouldn't grind on the mounting faces since it would be difficult to keep them square and coplanar, but there's at least 1mm that can be safely ground off on the side where the rotor would contact the bracket. And I'm not worried about over-stroking the slide pins 1mm.
Edit: Just measured it and there's 2.5mm clearance with a stock hub, so you could potentially run the Toyota hub with no grinding and no shim. And there's no chance of over-stroking the pins.
I partially retract my previous post. Long story short... if you want to play it safest, stick with GeneSplicer's design and use the 1mm shim between the bearing and hub.
I had a long drive today and for some reason got to thinking about backing plate thickness, and how much engagement the backing plate has with the sliding faces on the caliper bracket once the pad is fully worn down. Just got a chance to take measurements again. I had some M5 washers in the garage that are exactly 1mm so I used those to space the caliper bracket outward 1mm to simulate the toyota hub being inset 1mm. At best I measured 1.5mm of overlap between pad and bracket, and the worst spot was a little under 1mm. So stock would be 2-2.5mm of overlap. 1mm of overlap is cutting it too close for me. It will be fine if you never run the pads to the backing plates, but I'm sure some people reading this thread will be using these hubs on enduro cars where trying to finish a race on backing plates is a real possibility. In that case I'd be worried about the backing plate wedging itself between rotor and caliper bracket and locking the wheel up. I know a guy who had a big crash in a spec miata when a front left wheel randomly locked up in the carousel at mid-ohio, which jerked the car off track to the left and straight into the beginning of the pit wall barrier. After disassembling everything, the only cause they could find was a front left brake pad that had somehow been bent and got itself wedged between the rotor and bracket, locking the wheel. Scary...
I ordered those washer and will be including them in "kits" if they work out well. I may glue them to the hubs so end user doesnt have to worry about aligning them, etc. While the stepped ring is great, I cant make them for $0.86.
Last edited by hi_im_sean; 02-28-2018 at 08:18 AM.
That's the reason my buddy used a larger washer that stepped down to 1mm... it's really self aligning.
I did not take the diameter of axle nut into consideration, but if he measured it right, he did... otherwise I need to put it back into the lathe.
Still waiting on my Elim to come back. Mine will be going into Keisler drop spindles, so not an exact representation of true miata.
We gave thought about not using a spacer - but then got REALLY ---- about the spm s1 rule set, which is:
15. Front & rear hub assemblies may be modified or replaced provide they retain OEM wheel location.
- lol at Butthole Bot striking @nal
Last edited by GeneSplicer; 02-28-2018 at 08:48 AM.
That's the reason my buddy used a larger washer that stepped down to 1mm... it's really self aligning.
I did not take the diameter of axle nut into consideration, but if he measured it right, he did... otherwise I need to put it back into the lathe.
Still waiting on my Elim to come back. Mine will be going into Keisler drop spindles, so not an exact representation of true miata.
We gave thought about not using a spacer - but then got REALLY ---- about the spm s1 rule set, which is:
15. Front & rear hub assemblies may be modified or replaced provide they retain OEM wheel location.
- lol at Butthole Bot striking @nal
Looking at your pics, he definitely accounted for the nut diameter.
Ok - I'm realizing the washer spacer isn't going to work as it's larger in OD than the inner bearing race - meaning as it turns with the hub, it'll also be rubbing against the dust seal and outer bearing race. Not good. So what I need is a shim no larger than the OD of the inner race. Shouldn't be a problem to make though
Ok - I'm realizing the washer spacer isn't going to work as it's larger in OD than the inner bearing race - meaning as it turns with the hub, it'll also be rubbing against the dust seal and outer bearing race. Not good. So what I need is a shim no larger than the OD of the inner race. Shouldn't be a problem to make though
The shims i posted earlier exactly match the OD of the race face. I 3d printed a little tool to center them, while I adhere them to the back face of the hub. Works great, ill gladly send you the tool or the file to print one.
Here's one large difference between an OEM miata hub and the MR-S.... Miata "base" has what is maybe a machined indentation?
MR-S does not, much thicker too.
They look cool installed on the car too!
I thought there was an issue with IS300 studs vs 94-05 rear Miata studs..... turns out I actually yielded one of my spindles with my janky 12ton HF press *doh*. The install of these have been as easy as OEM. Sean glued the small spacer on the back-side because he knows I'd forget it, the spacer on the front/nut side is easier to remember since it's large. My first event for these will either be April 21/22 at Mid-Ohio in TTE or May 18/19 at ViR in TTE
Maybe I'm blind but I see where you corrected some one on the part number they posted but didn't see the actual part number.....sorry for pissing in your Cheerios.
Maybe I'm blind but I see where you corrected some one on the part number they posted but didn't see the actual part number.....sorry for pissing in your Cheerios.
Thanks for the link
Well post #60 wasa picture of the CAD with the part number in large bold letters at the bottom right. Not sure why that's now showing now. My bad.
02-26-2018, 06:51 PM
the hubs in my possession are indeed 1mm in and not out.
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