Bob & et al,

** So are you saying we may have a different wear pattern on the tires ?
** So you are saying the camber will need to be increased?
** Does extra width increase tire rub?
** Does the extra width reduce top speed because of wider tire patch?

Yup it is raining again here in the Northwest, so the questions float to the surface.
JBPDXOR

Wondering if any csr's are willing to discuss installation and car set up process with the new csr's. Same goes for the new toe link fittings. Who has them available?

Opps, I meant share the process of installing and setting car up with the new control arms, not new csr's.

When I installed the new arms the camber settings changed about 1/2 degree on 2 out of 4 locations. I figured this was due mainly to locating the upper ball joint corrrctly in a fore/aft direction...this was not the case with the old arms. I also had to adjust caster on one side as well. But I really think that this was due to how bad my old arms were.

This is an 3-year old thread, but the primary one I saw on this topic. I first noticed there was an old and new upper control arm in an SRF for sale ad.

From the posts, the upper arms fatigue over time. Is this correct? This thread talks about visual inspection; is dye penetrant inspection also used? Do the new upper control arms hold up better or worse than the originals?

The is a WTB older upper control arms in the advertising section. What is the reason someone would want the older style upper control arm?

If buying a used SRF/SRF3, is there a preferences for one UCA or another? Are there specific wear or fatigue criteria that should be inspected for?

The tubular rockers are lighter and stiffer. The new design came about because the source for the old design dried up, so they went with a clean sheet re-design. Nothing wrong with the old rockers, and a lot of us still use them because we're cheap bastards. When the gap between me and the top SRF drivers is due to the weight/age of my rockers, then I'll upgrade.

DavidNJ wrote:This is an 3-year old thread, but the primary one I saw on this topic. I first noticed there was an old and new upper control arm in an SRF for sale ad.

From the posts, the upper arms fatigue over time. Is this correct? This thread talks about visual inspection; is dye penetrant inspection also used? Do the new upper control arms hold up better or worse than the originals?

The is a WTB older upper control arms in the advertising section. What is the reason someone would want the older style upper control arm?

If buying a used SRF/SRF3, is there a preferences for one UCA or another? Are there specific wear or fatigue criteria that should be inspected for?

The old UCA's were susceptible to cracking under the mid-section of arm, often going unnoticed until a physical inspection. I've found this generally when cleaning the underside of the UCA and running my fingers across the area to feel for a crack. An annual or post-crash physical inspection is recommended. They should be replaced at that point, although it may be possible to weld the cracked area.

They can also "pucker" from abuse (crash/curb damage), causing them to bend or twist slightly, especially noticeable on the upper outer side of the control arm. This is generally OK if not too severe, but will affect alignment. There have been services available in the past straighten minor bends, but I can't personally attest to their effectiveness. There's enough suspension adjustment available to dial around any minor tweaks.

I expect most people wanting old arms are satisfied with their current setup and want a more cost-effective solution to replacing a damaged UCA than a full replacement with the new arms.

The new arms are, as noted earlier, much stiffer and seem to hold up better to minor wheel-to-wheel. They do have, as also noted, one flaw in that one of the two upper rods bracing the UCA can contact the frame under full suspension compression, especially at low ride heights. I've had two with minor dings from hitting the frame in non-crash situations (especially aggressive curbs or off-course bumps).

While they do hold up better, they also will tend to pass more energy in a crash or hard wheel-to-wheel contact to the frame and spindle, so it's good to inspect those parts more closely for twisting or cracking.

Other than the bottoming problem, I would recommend them if you want a lighter weight and stronger part, but I also don't see that it's a critical change to remain competitive.

breton wrote:... I've found this generally when cleaning the underside of the UCA and running my fingers across the area to feel for a crack. ...

Or if the camber changes every time you let the car down off the jack.

The parts list I saw, dated April 2016, shows 3 different UCA models. What is the difference?

I think the 'specials' were ones that were retrofitted as the original batch was missing a support bracing mechanism. I ran those on my old car and they were great... no difference from the non-retrofitted ones. CSR can verify but I suspect that's it.

Don't sweat the UCA's. You can win a Majors race on either set or even a mix of the two (old in the rear, new in the front for instance). It's happened already this year.