Caliper to Wheel Face Clearance

[galaxy]

Didn't know if this would work best in the brake section or the wheel section, but here goes. (And sssshhhhhh...this question is about my S197 car, so keep that on the DL).

...How much clearance do you really, truly need between the caliper and the face of the wheel? I've got plenty of barrel clearance inside the wheel, but the face of the caliper is uber close to the inside face of the wheel. It's not touching, but it's certainly no more than 1 mm clearance on a good day, at the upmost tightest point. But, it is NOT touching anywhere. Have driven several miles, brakes up to temp, etc. I'm of the logic if it's not touching, it's not touching. I've seen some other cars with super tight clearances also. But, thought I'd ask.

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[CORNYOTE]

It'll self clearance lol. Good question though. not sure. I ran into a similar issue and run a 3mm spacer to be safe.

 

[galaxy]

hahahhaha...right?!?!

So the homework I did for the project (PP1 wheels w/Brembo calipers) all revealed a 5mm spacer would give you good clearance. I have a 6mm spacer and juuuuussstttt did barely make it, as stated. 6mm is at the threshold of my spacer comfort (for stock stud/lug nut engagement). Next size up I can find is an 8mm from OPM.

 

[Norm Peterson]

...How much clearance do you really, truly need between the caliper and the face of the wheel? I've got plenty of barrel clearance inside the wheel, but the face of the caliper is uber close to the inside face of the wheel. It's not touching, but it's certainly no more than 1 mm clearance on a good day, at the upmost tightest point.

As long as the wheel bearings are in good condition (and the wheel is straight, undamaged, and fairly rigid), you should be fine at 1 mm. Don't even think about using aftermarket "camber bolts".

I didn't have much more clearance than 1 mm out at the inboard flange, and even that didn't rub.

Norm

 

[Falk03]

I think 1mm is not enough. The wheel bearing have some play (maybe not much now, but it will eventually become bigger) and your wheels also do flex. Not when you are going straight, but when cornering they do.
I am not sure what a safe clearance is, but I would guess 5mm are fine.

 

[Norm Peterson]

I think 1mm is not enough. The wheel bearing have some play (maybe not much now, but it will eventually become bigger) and your wheels also do flex. Not when you are going straight, but when cornering they do.
I am not sure what a safe clearance is, but I would guess 5mm are fine.

I will tell you that the clearance in the above picture is only around 1.2 mm, and there was no wheel to strut contact even at an Aim Solo-measured 1.3+ lateral g. Forgestar F14 wheels in 18x11, if that matters.

Wheel flex at the top isn't going to be the same as it is down at the bottom.

5 mm is safe, but is definitely more conservative than necessary. Though it does buy you some confidence that if you ever had to change out the hubs that you'd still be OK on clearances.


Norm

 

[Falk03]

I agree, 5mm is conservative. Maybe 3mm are enough

 

[NightmareMoon]

OP is talking about clearance between the wheel face and the brake caliper, not the usual strut to rim clearance.

 

[Norm Peterson]

OP is talking about clearance between the wheel face and the brake caliper, not the usual strut to rim clearance.

I realize that.

What I'm saying is that if 1.2 mm lateral clearance is enough at the wheel flange, 1 mm at the caliper is also going to be enough. I've even seen 1/32" (0.8 mm) outer tierod end to wheel flange clearance work with 15" wheels on another car I used to have. That'd be close to caliper radius on OP's car.

Most people seem to get uneasy when inboard clearances are reduced much below OE.


Norm

 

[XeninWorX]

Go look at a Dodge Caravan. Their rim to brake clearance is ridiculous. Probably like 3-5 mm and people drive those things for hundreds of thousands of miles.

When I had my 06 Civic Si I swapped the front brakes to 04 TSX as it was a straight bolt on. For the winter I ran 04-05 Civic Si rims as they were 16”. I had 2-4 mm clearance on the spokes and the barrel. Even less clearance with the stick on wheel weights. Never had issues.

What are you running on the S197? I’ve got a 2014 V6 and have 4 piston Brembos that I’ll be installing next year. Just ordered 18” rims for the winter that, from various websites and even the manufacturer of the rim, say they’ll fit over the Brembos. There aren’t many pictures of the rims I ordered however the few pics that I did see were on cars with 4 piston big calipers.

 

[Norm Peterson]

Right now, the car has Forgestar F14 wheels on it, and there's plenty of room for the SVT/Brembo kit that I got through Vorshlag. Almost a finger's worth of room caliper to barrel, looks like more than that between the caliper and the spokes.


Norm

 

[Cobrakit]

As always it depends. I had 3mm clearance caliper to spoke and fine on road. Went to road coarse and it hit. Added 3mm spacer and next track session no problem.

 

[Norm Peterson]

As always it depends. I had 3mm clearance caliper to spoke and fine on road. Went to road coarse and it hit. Added 3mm spacer and next track session no problem.

Wheels shouldn't be flexing that much and bearings shouldn't have that much play.

Are you certain that it wasn't a pebble or other bit of "foreign object" getting caught in the 3mm gap?


Norm

 

[Cobrakit]

No debris and clearance hard to measure between caliper and spoke, so it could have been less than 3mm clearance statically. Bearings appeared to be ok. And 3mm spacer was smallest available when i went back to track. Sold that car so this is all from memory.

 

[Radiation Joe]

When I installed the TSW wheels I run in the summer, I was hit with a hair less than 1mm clearance to the caliper. I added a 3mm spacer for my own peace of mind.

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