I'm Back and need some advice please...New front end.

Hi Guys,

I had to stop work on the XJ550 for a while but getting stuck back in now. I've picked up a bargain to replace the front end since mine was pitted beyond rescue. I had the forks, callipers & yokes of 1991 XJ600 (Pre-Diversion) donated which went on like a dream until I tried to mount the callipers onto the forks, I figured that since I was using the original front wheel, I used 550 brake rotors, which are to big for the callipers, any suggestions on how to get them to fit.

I've looked at XJ600 rotors but they appear to be flat, with a different fitting on the wheel. Whereas the rotor on the 550 has a recess where it fits to the wheel.

Thanks guys
Ian

 

You're most likely going to need the rotors from 1991 XJ600...IF they'll even fit onto the XJ550 wheel which, I doubt, but they may. If the 1991 XJ600 rotors do NOT fit on your XJ550 wheel, you have two options; have a machinist turn down the over all diameter of the rotor from the 550 (not the best thing to do but if you're not able to fit a 1991 XJ600 rotor onto your XJ550 wheel...) or buy a 1991 XJ600 front wheel and rotor and live with the mis match front and rear...but come to think of it, you have a chain drive so really, you are in a better situation than us with the shaft drive. Research the diameters and try. Good luck.

 

Yeah, they were the two trains of thought I was following, not sure how the machining of the 550 rotors would affect the braking. Another thought I had was using XJ600 rotors and putting spacers behind it so it's out the required distance, but I'm worried about that causing a week spot under braking.

 

Measure...and NO spacers. Easy way to check, take your wheel with the rotors that are on it now off the front end. Attach the calipers to the forks with wheel off. Now slide the wheel back on (I know its not going to bolt up) and you'll be able to tell if its the proper width and go from there.

 

NO spacers on the rotor, for the axle it is totally fine.

 

Ah ok. I thought that was going to be the case, wanted to double check though

 

How different is the width? I swapped my front end on my 82' XJ750 maxim to an 82' XJ650 Turbo front end so I could have a center mount instead of front mount fork (at the axle) and also to match 18" wheels front and rear. No 16"/18" rear and 19" front.

 

The difference isn't that big, less than an inch maybe. I haven't measured it up. I'm also thinking that I could get a bracket made up that bolts onto the fork then bolt the calliper to that. If its made of a block of steel the same width as where calliper bolts onto the fork would that be strong enough? That maybe my easiest option I'm in college and could have one of the engineering tutors do it.