What Years Are the Forks Interchangeable?

I'm building (or attempting to build) a race inspired 83'. I want to upgrade the front forks from a newer model Interceptor to not only get an upgraded suspension, but I would like the upgraded front brakes that the newer forks would give me.

I don't want to change the original specs of the bike, meaning I want to keep the same sized forks, unless newer forks have a better geometry than the originals.

So, my question is, does anyone know which forks are interchangeable with the 83'? I'd like them to bolt right on.

Thanks

 

NONE. They are 39mm and unique to that (Honda) bike.

Get some 1984 VF1000F triples (which are visually identical to VF750F) and then you can choose some 41mm forks and clip-ons.

 

So, the triple trees that are on the 750 are 39mm, and the 1984 VF1000F? The trees will bolt on to my frame but allow for 41mm tubes?

Is 41mm standard with forks?

 

Also, can you recommend higher performance forks? Maybe the bike and year to get these from?

 

That's a bit of an open-ended question but I will take a punt and give you my 5 cents worth.
1. Forks get stiffer in proportion to the square of the diameter. Bigger is better and 41 and 43mm are common current dimensions.
2. The two basic fork damper mechanisms are cartridge-style (which is more modern and tunable) and damper-rod (which is the older method)
3. Are you after external damping adjusters and preload adjusters? These are nice to have but not essential.
4. The forks carry the brakes and attach the wheel. If you change the forks you will probably also have to change the wheel, axle, callipers, disc and fender.
5. The fork length is critical if you want to maintain the steering geometry of the bike.

So it all depends on what you are hoping to achieve. Front-end swaps are a bit of a rabbit hole to dive down, and unless you are hell-bent on making a substantial change, just upgrading the stock forks and brakes would be my suggestion. Replace the bushings and seals in the forks, get some weight-specific springs and maybe add a set of Cartridge Emulators and you should end up with noticeably better performance in terms of compliance, support and bump-absorption. Same goes for the brakes where a replacement of seals and pads and possibly some braided lines will perk them right up.

 

Wow, thank you for that. What I was looking for was a way to upgrade the forks and brakes. I think (to your point) that I may be opening a can of worms unnecessarily.

I think making what I have better may be the way to go.

Thank you!

 

Terry is very knowledgeable and has helped me on some things with solid, real world suggestions and advice.

Your goals don't have to open up a huge can-o-worms. The VF1000F triples I mentioned will bolt right on and give you the ability to mount 41mm forks.

There will be some worms to deal with, but if you want anything like your opening paragraph describes, that's part of it. Custom = work.

 

This isn't going to be my regular bike; it's a fun project and it's going to be "race inspired". The idea was to improve the brakes and make it look more "racey" with more modern forks. It's not critical that I do this, especially if it will take some of the performance away. Did the 84' 1000F have improved brakes? If so, I would consider just swapping out th3 84's to get that performance.

 

You don't have to use the whole front end. I recommended the 1000F triples to get you to 41mm, where there are more modern options.

The stock 1000F front end is similar to the 750. Still damping rod forks, with rebound adjust on one fork. But 41mm looks racier for sure and is obviously stiffer. The brakes are very similar in design, but the TRAC system is updated and less archaic looking and the calipers have the cross-hair rough casting like the early Honda race bikes had.

1000R forks (41mm) look even racier, with their quick release axle clamps and modular fork brace. Add some 1000R Comstar wheels, you are looking very period correct racy. Those items are starting to get expensive.