4 piston calipers: 2nd gen dimensions vs. 3rd gen??
 

I have read that the 3rd gen brake caliper dimensions are basically the same as the 2nd gen 4 piston calipers. I have seen pictures and they have some visual differences. I am curious as to if there are any significant dimensional differences such as possibly being slimmer. I ask because I have these for a special fitment and there are some wheel clearance issues. Any information is much appreciated.

Still curious for this information.

AFAIK there are the same except for cosmetic differences. I have seen many FDs with Tll front calipers.

^Yep. Just a cosmetic difference, that's it.

Dale

The earlier S4/5 caliper was less needful of massage to fit under a 15" wheel I found , the later caliper is fatter (and probably more rigid) and required a bit of file action to fit the same rotor.

My first FD came with a single front TII caliper installed. Can't say I noticed any issues driving but once I realized what had been done I purchased a proper FD one for cosmetic purposes then rebuilt them both.

It is my belief that this happens when purchasing rebuilt calipers and the wrong style is sent back for cores.

Excellent, informative response. Thank you. Where did you have to massage it? The face of the wheel or the barrel?

Left the wheel alone, nervously filed the caliper. It's going on 20 years ago now, I think it was the outer top edge and lettering - but don't hold me to it now - and you' have to expect wheels will make a big difference.

For some reason, remember the even earlier installation of the S5 calipers clearly, they only needed the transfer port "hump" taken down. Not sure if a stone got caught between the caliper and the wheel, or the wheel flexed enough in use to hit, but it was quite tight and there was a distinct witness mark all the way round on those old mesh wheels.

Subsequently, we got a bit smarter and had dogbones and hats made to make a better installation.