'79 xs650 Modern Cafe Build

[catskillmtncustoms]

I got the swingarm all welded up today, and checked the fitment of the shock with the swingarm closer to the correct unsprung position. Everything seems to be good. Next step is making the tabs to mount the shock.

 

[ZAIN DIAZ]

very nice man

 

[izatso]

Just a question:

How are you figuring your un-sprung weight for the shock mount?

Wonderful build....going to use a lot of what you have done with an R-6 swing arm....thanks for the inspiration

Iz

 

[Airwolfie]

Looking ace!!!

 

[catskillmtncustoms]

very nice man

Looking ace!!!

Thanks guys!

 

[catskillmtncustoms]

Just a question:



How are you figuring your un-sprung weight for the shock mount?



Wonderful build....going to use a lot of what you have done with an R-6 swing arm....thanks for the inspiration



Iz

Thanks.

It's hard for me to explain right now, but basically I have a target swingarm angle of 10-12 degrees. So I'll mount the shock with the swingarm right around there. I plan on mounting the shock in a way that I can increase the swingarm angle. Then when the bike is complete I'll adjust the sag and swingarm angle to my target geometry.

I'll post up as I go so you can see the route I take. In the meantime check out Race Tech's Suspension Bible, it's a great book with a ton of valuable info.

 

[klrx7]

It appears you don't have enough leverage on your shock (mounted too far from swingarm pivot). But I am sure you have figured in the weight of the bike it came from and what kind of moment was on it. My brother in law had issues doing this same set up on his cb550-4. Took a while to get the right spring weight. Hope it works right! looks great. Enjoy the build!

 

[catskillmtncustoms]

It appears you don't have enough leverage on your shock (mounted too far from swingarm pivot). But I am sure you have figured in the weight of the bike it came from and what kind of moment was on it. My brother in law had issues doing this same set up on his cb550-4. Took a while to get the right spring weight. Hope it works right! looks great. Enjoy the build!

Thanks.

As far as the shock leverage I'm not exactly sure where your coming from? I understand the effects of mounting the shock closer to the pivot, as to create more of a lever arm acting upon the shock. But, I have selected my shock/spring rate (the best I could) to work with the bikes weight and this configuration. I can also change the spring rate and/or preload accordingly when tuning the suspension. Are you just eyeing it up in the pic and guesstimating, or basing it on something else?

I ask because maybe you know something I don't...

 

[catskillmtncustoms]

Sorry, a little slow on updates lately.

The frame is welded up and lower shock mounts in place.

 

[izatso]

Nice welds...
Sweet bike...
and...
thanks for the updates!

The book isn't here yet, but I am hopeful...very hopeful that it wont be long...
I have LOTS of metal to weld and sure don't want to screw it all up.

Thanks for the tips. Now hurry so you can ride it!

 

[ClarkSN95]

Subscribing, this looks AWESOME so far!!

I've got to get some pictures of mine thrown up in my own build thread, although I don't have anywhere NEAR your level of fabrication skills... lol

Keep up the good work, can't wait to see the finished product!!!

 

[catskillmtncustoms]

Subscribing, this looks AWESOME so far!!

I've got to get some pictures of mine thrown up in my own build thread, although I don't have anywhere NEAR your level of fabrication skills... lol

Keep up the good work, can't wait to see the finished product!!!

Thanks man! Fab skills come from practice, so keep working and get those pics up!

 

[catskillmtncustoms]

I've made some good progress this week. I got on the lathe and cut some spacers for the swingarm pivot, and spacers for the bolts holding the swingarm to backbone/engine mount. I also made the upper shock mount. No pics, sorry.
Then, after confirming that everything is still square I made the tabs connecting the swingarm pivot to the frame.

Now I need to get my wheels laced up and it's a roller!

 

[Brassneck]

Nice progress...been looking forward to this next stage for a long time, as I know you have!

 

[catskillmtncustoms]

I'm getting a lot of questions/pm's about my swingarm mount, so here is a pic with the swingarm removed.

The center support is cut from 1/4" steel plate and connected with 1" .120 wall tube. It bolts to the backbone at the two visible points and both top and bottom rear engine mounts. The pivot axle passes thru 3/16 steel tabs on the frame tubes on each side. This connects the swingarm pivot to the backbone, engine and frame tubes. This is very similar to the design used on some Nortons.

Thanks again for following, hope this clears things up!

 

[catskillmtncustoms]

Made some rear wheel spacers on the lathe and the final frame piece fitted. I put everything together for a test fit and it's looking good. The difficult fabrication is pretty much done!

 

[Airwolfie]

Wow, that is looking goooooooooooooooooood!!!

 

[izatso]

Nice.....VERY NCE!

 

[catskillmtncustoms]

Wow, that is looking goooooooooooooooooood!!!

Nice.....VERY NCE!

Thanks guys.

 

[wannabridin]

What are the plans for the gas tank and seat? Looks like the upper shock mount is in the way of the rear tank mount.

Regardless, I'm sure that will be nothing for you. It's looking REALLY good!!