Caliper Attachment to Uprights

[yessamgerg]

So i've spent some time searching and wasn't able to find the answer to this so I figured I would ask...

The common attachment for the brake calipers seams to be a stud installed into the upright, as the uprights have to be an aluminum alloy and the studs appear to be titanium or steel, how are the stud actually fixed inside of the upright? Presumably as the brake calipers are safety critical they would be positively retained into the upright but there doesn't seem to be any external locking feature. Below is a picture that illustrates my question, they (force india) also seem to use something similar for the UCA attachment point.

http://www.racecar-engineering.com/wp-c ... eejay3.jpg

[Lycoming]

I presume (I don't know for sure, I've never seen one up close) that they put an insert into the upright whose female threads contain some sort of locking mechanism, for example a locking helicoil.

[Luke]

I presume (I don't know for sure, I've never seen one up close) that they put an insert into the upright whose female threads contain some sort of locking mechanism, for example a locking helicoil.

I would presume high temp loctite. The thread on the hub side may or may not be a bigger than the thread for the nut on the caliper to stop the stud unwinding when removing the external nut.

[riff_raff]

I believe the calipers are attached to the upright with a pair of radial shear studs. The studs are installed into the upright with an interference form of thread locking. And the calipers are secured with all metal locknuts.

[Facts Only]

In terms of the Force India, there is a steel insert in the upright such (you can see the large top face in the picture), the stud will be bottom fit and probably thread locked with loctite (or similar). The two larger diameters on the stud (you can see them in the middle of the stud) will be dowl sized (g6 with H7 hole in the caliper and insert) to align the stud into the hole and the caliper onto the stud. A Kayloc nut will be used to secure the caliper onto the stud (you can see this type of nuts on the top wishbone attachment), in terms of size I would guess M6 into the upright and caliper.

[PhillipM]

Looking at that picture they may actually be different sized front to rear, looks like around a 10mm rear and 8mm front, unless it's the perspective screwing with me.

[flyboy2160]

I presume (I don't know for sure, I've never seen one up close) that they put an insert into the upright whose female threads contain some sort of locking mechanism, for example a locking helicoil.

I know this is being anal nitpicky, but Helicoils suck unless you're doing a repair and don't have room for a full thread insert. Those cast/3D'd posts/blobs into which the studs thread look easily large enough to allow a full thread insert. These can be securely locked into the piece, whereas the Helicoils are a PIA to reliably secure. If you have careful, skilled mechanics, I'd rather thread directly into the Aluminum than mess with Helicoils. And you Helicoil fanboys can go right ahead and flame me - I don't care: I hate Helicoils. (Where else but F1T could we have a Helicoil flame war!?! )

[riff_raff]

From that picture it almost looks like those studs are a Rosan (ring locked) type of fastener. For sure those studs use some form of thread lock on the end installed in the upright, otherwise they would likely back out when the locknut holding the caliper in place was removed.

It is common when installing a steel or titanium stud into aluminum to use a larger diameter coarse pitch thread on the end of the stud installed into the aluminum, so that the pull-out strength of the stud end in the aluminum is balanced with the tensile strength of the nut end of the stud.