XS750 fork swap

[MacMcMacmac]

Is it just the 750 Specials that used the smaller discs and had the different caliper mounting points?

I was wondering if I could just swap in a 750 front end with a new stem and triples and be done with it. The stock forks are hopeless, even with Progressive springs and the preload cranked up all the way. I would like to retain the stock 650 double discs and calipers I have on my bike already. I have found a set of 78E forks in good condition. Well, not good condition exactly, they are new, never installed, still in the box, with the Yamaha part numbers sticker on the end along with the stem and bottom triple.

 

[fredintoon]

Hi Mac,
is the NOS 78E stuff from an XS650 or is that the XS750 stuff that you want to put on your '83 Heritage?
Your existing calipers will fit right onto XS750 (and XS850 and XS1100) STANDARD forks.
If you don't yet have the XS750 forks, think about XS1100 forks, their tubes are bigger yet, at 37mm vs the XS750/850's 36mm.
The XS750/850/11 SPECIAL forks have a forward-mount axle and Weird Harold calipers but they'll swap too, 'trees and all.
Or swap 'em with STANDARD trees to reduce steering trail for sidecar use.
The XS750/850 STANDARD fork lowers hold the calipers closer to the axle so the XS650/1100 disks will be too big.
However, the smaller XS750/850 disks are identical to the XS650's REAR disk.

 

[MacMcMacmac]

The NOS forks are XS750E Standard model. I thought they might use the same rotors and mudguard as my 650, but if not, then I won't bother.

 

[fredintoon]

Hi Mac,
it's up to you but if I had those forks I'd go for it.
The fender swaps OK and the rotors are XS650 rear rotors which you'd likely find in the list's classifieds.