82 honda cb750K front fork suspension question

[CB70]

My bike has the forks with the air hose connecting the forks. Can I just eliminate that and put on normal fork tube cap bolts? Are these forks 35mm and what's the length? What other model bike front forks can I use that is compatible with my 82 Honda CB750k without having to do any modifications? Shorter would be better but definitely do not want longer ones? Thanks

[shinyribs]

You can remove the air caps and replace them with stock non-air type caps. Or just ignore them, but I know they are not the prettiest things to have to look at.

Almost every one of the early CB's have 35mm tubes. All of the 69-78 SOHC are 35's and come in right at 30'' tall according to the ones I've owned. Most all of the 79-83 DOHC bikes also have 35mm tubes, but I know one member here had ( I believe it was an F model) that did indeed have 37mm tubes.

Early Sportster's are one bike I know that has 35's, but all Harley parts are pricey and they are pretty long forks anyway.

One of our head honcho's here, TOOLS1, has a how-to on how to shorten you stock forks,though. Can't be free! here's the link:  http://honda-cb750-s.456789.n3.nabble.com/How-to-shorten-forks-td4042465.html

Another ,even easier option, is to just slide your fork tubes up in the trees. Takes about 5 minutes and does no permanent alterations to anything on your bike. You might consider trying that first and then riding the bike to see how it does sitting lower. Just to make sure you don't have and clearance issues anywhere.

Hope this helps.

[CB70]

Thanks Shiny, your response was very helpful. I did lower the triple tree to lower the front end a bit and it works fine. That's why I was wanting to know if I can get get rid of the air hoses and just replace them with the screw end cap bolts. It'll look a lot better. I'm considering getting clip ons and putting them above the triple tree since it'll be too low putting them under. I've lowered the triple 1.5" which is the amount of space I'll need so I can mount the clip ons above the triple tree. I have decent clearing and i probably won't have problem with frame or exhaust bottoming out. But just to be on the safe side, you think I should get stiffer springs (front forks), especially if I get rid of the air suspension? Thanks again

[shinyribs]

That's a good question about possibly needing stiffer springs after eliminating the air. I guess the easiest thing to do would be to bleed all the air out of it now and see how it acts. That should be a pretty real-world test.

[TOOLS1]

They get pretty wimpy without air.
TOOLS

[shinyribs]

TOOLS1 wrote

They get pretty wimpy without air.
TOOLS

Well, that answers that question.

Just a thought, and I've never looked in to this at all, so don't laugh too hard. But what if you could relocate the air valves to a less noticeable location? Maybe the oil drain holes on the bottom of the legs? You could still drain the forks the same, but you'd have to be careful filling them with air. If you had to bleed any out you'd obviously lose oil. That is, unless you held them upside down whole doing it.

Like I said, just a thought. But it seems doable and cheap $$$ which is how my brain functions.

[sgtslag]

Get Progressive Fork Springs -- require that all air be removed, as it would make them too hard.  Progressive Springs are dual-rate springs.  I installed them in both my '79 750K, and my '93 Voyager touring bike; the Voyager had air-assist forks, but no longer -- and it works fantastic.

I would recommend you upgrade the rear suspension with Progressive Shocks (airless -- less to go wrong, work superbly), at the same time, as doing only half of the suspension, will show the shortcomings of the other half...  Did this on both bikes, as mentioned prior.  Both rode/handled amazingly well, like brand new, modern bikes, after the upgrade.  Will cost you a bit, but the upgrade is worth every penny.  Cheers!

http://www.progressivesuspension.com/metric/index.html

[CB70]

Thanks sgts for the suggestions, I've contemplated on going with the inexpensive shocks or just do it and get the good stuff (Progressive).  

[shinyribs]

The progressive fork springs are pretty affordable, but the rear shock are what's pricey. Fork springs run about $70 last time I looked (put some in my '76-loved them). Rear progressive shocks were around $250. I passed on those...

[Art Vandelay]

CB70 How did you make out with this? I am doing for seals on my 81 and I sure would like to eliminate that air line as well.

[sgtslag]

Shiny, I had to replace the Progressive 412's on my Voyager touring bike last week (one shock was leaking; I had gone with the Standard Duty Springs originally -- mistake on a heavy touring bike...).  I picked up a set of new 412's off of e-Bay for $170, Heavy Duty Springs included, and installed.  They retail for around $250, so I got them for quite a deal.  Cheers!