78 xs650 fork options (new owner)

[mo_man19]

Hey everyone, so I'm new to the forum, I just picked up a rigid 78 xs650 literally a few days ago and am eager to do some work on it, it's in pretty rough condition as far as electrical and cleanliness of the project. Previous owner seems like he Mickey moused a lot of stuff.

So the reason foe the title is what are my options for replacing the forks? Main reason I want to do this is I'm hoping I can get upgraded calipers along with this that will be compatible with the spoked wheel. If someone can let me know the different options along with the amount of work required I would appreciate your time. I don't have access to any machining or anything of that sort so please keep that in mind. Thank you

 

[halfmile]

A few pictures of what the bike is like now will help a lot.

 

[mo_man19]

Here's one, I'll take a few more soon GOD willing

 

[jpdevol]

Those appear to be original forks and front-end (other side may reveal more). That set-up, properly rebuilt/refurbished, should be fine, unless you want to change for styling reasons.

The existing fork upper tube should measure 35mm and the existing axle should be 17mm

You can adapt a whole range of other forks if you swap triple trees too:
https://www.allballsracing.com/forkconversion/

To retain the current wheel, you would need to stay with forks designed for a 17mm axle - may require different spacers and speedo drive

 

[5twins]

Yes, there's nothing wrong with the original forks or front brake if you renovate them and do a couple updates. You'll want to completely disassemble the forks and clean all the "grunge" out of the insides. Just changing the fork oil won't do this, won't get all the sludge build-up out of the bottoms. You need to physically swab it out. Then, I'd do the Minton Mods to the damper rods and refill with 6.5 to 7 ounces of 10 wt. fork oil. Or you can set the oil level by measuring (6" from the tops of the tubes, springs removed, forks fully compressed).

For the front brake, a total diassembly will also be required, of both the caliper and MC. With those all cleaned out, add a stainless line, some quality pads, and drill the disc .....

So, if you are really eager to do some work on the bike, you can start with this, lol. Your rear brake should also be serviced. See post #3 here .....

https://www.xs650.com/threads/how-difficult-is-it-to-replace-the-rear-drum-brakes.25632/

 

[mo_man19]

Thanks everyone for your replies, maybe I wasn't too clear, so the reason foe this question is because I was hoping to get stronger calipers, I live in los angeles where they allow lane splitting and I do that everytime I ride and, sometimes there are people that jump out in front of you and you need something better, I've ridden sport bikes and cruisers and I really prefer the stopping power of the sport bike calipers, so with that said are there any strong caliper option to mount as is? Without changing wheels or forks then?

 

[jetmechmarty]

Kits are available for Brembo calipers. I think Pandemonium has them for the 65 mm caliper.

 

[5twins]

I think you may be selling the stock set-up short. Properly renovated and updated, it works quite well. I'll bet yours doesn't work very well at the moment. I don't even see a brake line hooked up in your pic, lol.

Something to keep in mind is that hard braking with a single disc really puts some twisting force on the forks. You won't want to run with no fender like that. You want a fender of some sort to tie the fork legs together, or better yet, a fork brace.

 

[jpdevol]

Not often seen, but you can put a GSXR front-end (or similar) on a rigid frame - if so inclined

 

[mo_man19]

I think you may be selling the stock set-up short. Properly renovated and updated, it works quite well. I'll bet yours doesn't work very well at the moment. I don't even see a brake line hooked up in your pic, lol.

Something to keep in mind is that hard braking with a single disc really puts some twisting force on the forks. You won't want to run with no fender like that. You want a fender of some sort to tie the fork legs together, or better yet, a fork brace.

Okay so you're saying just to rebuild the brakes pretty much?

 

[5twins]

..... and the forks. In both cases, it's not so much a rebuild as it is just a disassembly and thorough cleaning of the parts. I've renovated quite a few of these forks and brakes without the need to replace much at all (just new fluid of course). Stainless brake lines are dirt cheap now off eBay and that's the main item that needs replacing on the brake. The original rubber brake lines have usually gone soft by now so no matter how much you bleed the brakes, you'll never get a good, hard lever feel. It's not air in the system, it's the lines gone bad. You can get by with the original pads if they're still good, but new better ones don't cost that much. The Ferodo Platinum pads in my pic are a wonderful pad if you can find them. I wasn't that impressed with them when I first installed them. They didn't seem much, if any, better than the old stock pads they replaced. But after a few hundred miles and getting them bedded in, they started working and grabbing much better.

Many of us also replace the stock MC with one that's slightly smaller. This gives better brake "feel" and modulation. The stock MC has a 14mm bore. The hot ticket is an 11mm one. Personally, I like to use originals from other Yamaha models. The benefits of this are the high quality along with the replacement accepting your brake lever, using your brake light switch, and having the reverse thread mirror mount.

Yes, these used MC's look that way, showing some wear, but that blends in well with the rest of the bike. It is, after all, a 40+ year old machine, lol.