Absolute minimum Caliper clearance...is 1mm too close?

[dlaunde]

I just swapped my 18x8.5 Neuspeed RSe10 wheels for 18x8.5 RSe12 wheels. Running Brembo BBK's on the front and the Neuspeed 350mm rotor + caliper carrier kit on the rears.

With the RSE10's no issue of clearance. But with the RSe12's, the Brembos only have 1.5mm of clearance to the inner wheel wall (not the spokes, those are fine). And the rear calipers are closer, with two points only having 1mm of clearance to the inner wheel wall (barely more than a credit card thickness).

I have asked around and some say 1.5mm is minimum but others, especially those who race, say they run calipers that a playing card barely clears and never had issues. This is for a mainly DD with spirited driving/light tracking.

Thoughts?

 

[jimlloyd40]

Too close for comfort for me. I would use spacers. Plus you'll need to keep the balancing weights towards the inner wheel so they don't hit the caliper.

 

[dlaunde]

Too close for comfort for me. I would use spacers. Plus you'll need to keep the balancing weights towards the inner wheel so they don't hit the caliper.

The weights actually have plenty of clearance where Neuspeed mounted them.
Spacers wouldn't help though, since it is the inner wall of the wheel where the clearance is tight.

 

[jay745]

It'll be fine unless you hit something and bend your wheel slightly.

 

[victorofhavoc]

Is it really 1.5mm or is that an approximation? I'd be worried about the wheel weights getting hot from the lack of clearance, dislodging, and getting stuck betwixt the caliper and wheel. I've had that happen a couple of times. Aluminum tape holds them down well. Rocks bouncing in are another concern.

Racing is a different world from street driving. On a track you don't have nearly the debris and potholes that you do in the rear world. Wheels do flex on heavy impacts and flow formed wheels flex a decent amount...

 

[Faceman]

https://www.vwvortex.com/threads/do-rims-flex-bend-under-heavy-cornering.4173249/

Yes, wheels do flex. How much depends on many variables. 1mm may be okay if you don't mind the possibility of your wheel weights being trimmed by the caliper.

 

[dlaunde]

The wheel weights actually have plenty of clearance in relation to the calipers (3mm at a minimum). It is just the inner barrel of the wheel itself in some spots where the clearance is the 1-1.5mm

 

[victorofhavoc]

you can always run it and find out. My PP calipers with 17" wheels have about 4mm of clearance and on track I have lost as many as 5 wheel weights at one time. most of the time they just disappear to the track, but sometimes they get lodged in funny places. Once they go loose, not even Newton is predicting where they'll go.

This is why I don't do roadforce stick on weight balancing anymore. I just request a static balance and have them do the crimp on weights on the inside of the wheel. For grippy tires or slicks, it's sometimes not even worth it because of how much they spin on the rim during braking.

You could always just accept the risk. Nothing wrong with that either. If you lodge a rock and take some paint off the caliper or wheel, who cares? Calipers can be painted or powder coated easily. Neuspeed wheels are abundant and cheap (relatively).

 

[jay745]

you can always run it and find out. My PP calipers with 17" wheels have about 4mm of clearance and on track I have lost as many as 5 wheel weights at one time. most of the time they just disappear to the track, but sometimes they get lodged in funny places. Once they go loose, not even Newton is predicting where they'll go.

This is why I don't do roadforce stick on weight balancing anymore. I just request a static balance and have them do the crimp on weights on the inside of the wheel. For grippy tires or slicks, it's sometimes not even worth it because of how much they spin on the rim during braking.

You could always just accept the risk. Nothing wrong with that either. If you lodge a rock and take some paint off the caliper or wheel, who cares? Calipers can be painted or powder coated easily. Neuspeed wheels are abundant and cheap (relatively).

Put flashing tape over the weights if you are tracking, been doing it for years and it solved the problem

 

[Bernb6]

Wheel weights can be lost because of heat. I've actually been in the paddock and it heard my weights dropping off. A hint for those who lose weights on track, pick up some aluminum plumbers tape at the hardware store and tape over the weights. The tape will reflect heat away from the weights and help keep them on.
Bern

 

[dlaunde]

Well already had a pebble or rock salt get stuck in the rear caliper and scratch the wheel.
I guess it's a good thing these are my winter wheels.

 

[victorofhavoc]

Better to have loved and lost than to have never loved at all.

At least it's on the barrel and not curb rash...?