Anti-dive benefits

I just bought an 83 Seca 900 and I realized that the anti-dive device has been disabled by the previous owner (or the owner before him, because the previous owner didn't say a word about it), as can be seen on the picture before the last of this album:

http://tinyurl.com/ah6utym


It lead me to these two questions:

1-what are the actual benefits of this device?

2-what is the worst thing that could happen if I ride the bike without this device?

Thanks in advance

Francois

 

1. The bike won't have near the tendency to dive when you stab the front brakes

2. IF the dievice is disabled or not functioning, you will have a tendency to have more nose-dive when grabbing a handful of front brake. You can buffer that a little by additional air in the forks (don't go over the limit). The Schrader valve is located near the top of the left fork just in behind the fairing. If you can't find it, let me know and I"ll take a pic of the location for you.

Dave F

 

Thanks Dave!
So basically, the bike will act as any other bike I've owned before!

 

The Anti-Dive Mechanisms fitted on Yamaha XJ-Bikes didn't get very good reviews by the Motorcycle Press.

The remarks were that even when the Anti-Dives were working at their best, ... they really didn't do a great job keeping the nose from kneeling-down in controlled braking.

The moving parts in the No-dive units on the 900 needed to be kept clean or they would quit working all-together.

It was hard to keep contamination out of the lower section that housed the 3-level adjustment screw causing the adjuster to seize,, which led too many owners disabling the No-dive units rather than replace them.

 

>So basically, the bike will act as any other bike I've owned before!

Yup, and Rick explained why.

Dave

 

All right, thank you both! Now that I know this, to reconnect this device will not be my priority.

I put a link to a Photobucket album, but next time I'd like you to see the pictures in the post without opening a link, how would I achieve that?

 

Photobucket offers you a bunch of different "links" for each picture; you simply insert the "" link into your post.

Here's your pic:

[img]http://i102.photobucket.com/albums/m92/bidule3859/Seca900%201983/mon%20seca%20900%201983/DSC00753_zps73634ce3.jpg


I might suggest you remove the current "block off" method (the stack of crush washers or whatever that is on a full-length banjo bolt) and simply substitute a shorter, solid bolt of the correct size. With one crush washer.

I looked in your album.

From the look of things, your first priority needs to be TIRES.

 

Thank you bigfitz52, i'll give it a try for the next picture in the Test Zone.

As for the tires, the rear one has to be changed for sure but the front one is OK to my eye, unless the Spitfire 11 are not recommended for this bike???

 

Looking at the front tire it visually does not look too bad, the Sawdust/dirt on it makes it a bit challengeing to see the tread. Something to keep in mind though with motorcycle tires is how old they are. For your fronts, the date code is clearly visible at the top of the wheel in the picture that Bigfitz linked in at 4408. Which means the tire was manufacured in the 44th week of 2008. Not bad for a bike tire, but something to keep in mind that you have a 5 year old tire on there. Keep an eye on it or replace it. That's your call.

 

Keeping the nose up on a 900 can be facilitated by adding a short Pre-Load under the Tube cap.

I added a 25mm Pre-load to mine and it took out a good bit of kneel-down.

 

Hey Rick

I actually appreciate your suggestion, but I have to admit that I don't know what adding 25 mm of preload under the tube cap would mean...a picture or a detailed explanation would be useful. I'll add them to the notes concerning what I should do to the bike before the first ride.

 

It means adding something under the fork cap to compress the spring. Most common would be a short section of square cut tubing (wall thickness equal to spring thickness or more) or round rod, with the appropriate OD. You could also use washers or other shims. On my old kz650, a stack of quarters was perfect. Cost me $4 to add the preload I wanted though.

 

It's simply putting a spacer inside the fork. It goes on top of the springand fits between the spring and the top of the inside of the fork. What it does, is basically put more load on the spring to begin with. Then, when you hit the brakes, the springs already have some "Pre-loaded compression" and you're just adding to it. The psring's "pre-load"will be compression energy already induced and stored forwhenevery do hit the brakes., keeping you from having such 'nose-dive'.

Dave Fox

 

Now I understand but it will be more clear (clearer?) when I have the bike in front of me.

Thank you guys.