I have a 78 cb750K and I have an opportunity to purchase a 79 cb750F front end including all brake parts. I also can get the rear brake set up. I am wondering if the front end will swap easily and if there is anything else I may need along the way? And I understand the rear disk brake set up might not work without the right rear hub. Is there anyway to keep my wheel (drum brake) but add the disk brake (switch hubs?)? I am new to motorcycle mechanics but not new to auto mechanics. Any info would be appreciated. I need to let the guy know soon if I want the parts.
78 cb750k front end swap with 79 supersport
- Thread starter PharmD750
- Start date
rockcitycafe
I make things.
it should swap easily, but I think the 77-78F are a better front end for that bike if I remember right. the rear brake swap is not really worthwhile, disc vs. drum on a wheel that doesn't do much for stopping is kinda work for the sake of work
my-79-750-k
Therapy is expensive. Riding is cheap. You decide.
Don't bother with the rear disc brake, the amount of extra stopping power it would give you is negated by the fact that only 10-20% of your stopping power comes from the rear. The front end my swap over, although I'm hoping you are getting the triple trees as well, as I believe the 78K is 35mm forks and the F models had 37mm forks, which means you need new triples to fit the forks, as well as a bearing conversion kit for the different size steering stem. allballs.com has a conversion chart for the bearing sizes, invest in new steering bearings! They are cheap, and you need them anyway. Also, you need the front wheel from the F model, it's a different size and has the discs for the front end. Bleed your brake fluid/reservoir/lines/calipers. Get new pads, get the discs skim cut at a machine shop, new pistons and caliper seals. It's worth the hundred bucks or so to replace all the parts, we are talking about the parts that keep you from eating the rear end of a tractor-trailer. Ask if you have other questions, I swapped an 82 front end onto a 79, it's almost identical.
Ok. So is the 79F front end somehow worse than the 77-78k? I haven't been able to find one from the 77-78 around me. I was thinking that they were probably very similar. Would I be able to use my 78 front wheel with the 79 front? Also, what would a front end from a 79F be worth? Guy says it was functioning perfect when it was removed and the paint on the fender looks perfect so it makes me believe he was using it before he removed it. Thanks for the info!
Hey sorry I was typing my last post and didn't see the second reply. Thanks for the info. Yeah I am getting the triple trees and will be going through everything as I install it. In your opinion is it worth "upgrading" to the 79 dual disk setup? Only thing is the damn ugly rims I will then have to replace somehow.
my-79-750-k
Therapy is expensive. Riding is cheap. You decide.
The only way your wheel would work is if it had the bolt holes on both sides for bolting both the discs onto it, which I doubt it does. Key note: 79-82 Nighthawks have drum rears and mag wheels. They will swap right over since they are the same size and would match a mag front from an F. Better stopping power up front is ALWAYS worth upgrading to. Especially seeing a how your bike weighs 500+ lbs.
Mag wheels are great, static balance them once and they're good to go, spokes require tuning and you need to continuously check them because they will loosen and tighten ever-so-slightly over time. Also, mags look great painted and are a lot easier to clean, and weigh almost the same.
Mag wheels are great, static balance them once and they're good to go, spokes require tuning and you need to continuously check them because they will loosen and tighten ever-so-slightly over time. Also, mags look great painted and are a lot easier to clean, and weigh almost the same.
