Topic: Question for the Fabricators/Welders

[ewendkos]

My CB550 is a work in progress.  When I picked it up, it had been half-hardtailed as shown below:


I was originally going to go full-bobber with it, and I still might.

Here's the question:

I'm thinking that I might actually prefer some suspension in the back, and after doing a lot of research and browsing around the inspiration gallery, I'm really liking the brat bikes, and something like this:


At any rate, I'm looking for some advice. 

First, is it going to be easier to full-hardtail this, or easier to go with the brat style?  Keeping in mind that I'm not a welder, so I'll be finding someone else to do the work for me.

If I go with the brat style, should I work with what I have?  Should I try to find a new swingarm?  Should I try to find a new frame?

Thanks for your input!

[mystic_1]

Based on the mods already made to your frame, I think it would be easier to finish doing a "proper" hardtail on it then it would be to get the rear suspension working again.

To finish the hardtail, you'd add lower bracing from the rear axle plates to the bottom of the frame below the swingarm pivot, then cut away the swingarm from in front of the axle plates to the pivot.

To restore the rear suspension, you'd have to undo all the backbone mods and restore the upper seat rails and shock mounts.

mystic_1

[crazypj]

you can fabricate a rear sub frame or find one off another bike to weld on. (just remember to cut off more than you need at junkyard)
 If you were going to lower rear you would have to do some cutting and welding anyway.
 The main parts haven't been messed with so you should'nt have any handling problems (well no more than normal for a CB550  )

PJ

[Freaky1]

If the top half is straight then your off to a good start and like Mystic_1 said it would just be easier to finish off the hardtail work. I have seen some articles where this approach has been used to insure the frame stays straight, rather than fabing the whole thing from scratch.

[mystic_1]

For example....



Also, add gussets.

mystic_1

[petescb]

Well, first, somebody really mutilated that nice W650 Kawi.  As for your 550, I'd get a frame for it.  You're definitely going to want some rear suspension.  As with most things related to bobbers and choppers, everything looks a lot cooler than it actually is to ride.  If you ride it hardtail, it will get tiresome in about 3 miles.  And then it will be parked in your garage when you realize you don't want to get beat up just going for a ride.  And then you'll to try to sell it on eBay. 

[Cormac]

OR, you build something you like, and get some callouses on your butt. Of my six brothers, I'm the only one who doesn't have at least one hardtail. They all ride the hards just as much as their sprung bikes, in most cases the only reason they bother with suspension is for the wives (something to consider I'm afraid). Even my 64 year old dad rides a rigid, probably 'cause anything with a suspension would just bottom out anyway...

Best thing to do, go borrow somebodies (like the dealerships) and see what you like.

BTW, I'm hacking mine up shortly as my wasted hips just don't like straddling the waterbarrel called factory cb750 seats...

[mystic_1]

ewendkos, got some closeup pics of the welds?

BTW, been reading your blog, some thoughts:

1. Replace steering bearings with tapered replacement bearings.  $43 on ebay:
http://cgi.ebay.com/ebaymotors/HONDA-CB550-ALL-BALLS-STEERING-STEM-BEARINGS-CB-550_W0QQitemZ350286954645QQcmdZViewItemQQptZMotorcycles_Parts_Accessories?hash=item518ebac095

2. I see you've discovered Tal-Strip.  Use gloves

3. Special tools you may need to do the top end include a torque wrench, valve spring compressor, feeler gauges, calipers, some method of cleaning the gasket surfaces, manuals, and patience

mystic_1

[ewendkos]

Everybody - thanks for the input!

I should've known from reading through this forum that everybody has an opinion! 

I've now convinced myself that I want rear suspension.

Here's some closeups of the welds (the top sides are all painted over)...



This one's a bit blurry, but you can see some of the issues.



Wow the welds look worse in the photos than they do in person.  But that's a bad sign to me.  If me, as a non-welder/fabricator can see the problems here... probably worth my time to get either another frame or swingarm.



This one's of the underside where it's not painted that blue... and it looks pretty bad 




1.  Definintely planning on putting in the tapered bearing kit.
2.  I learned the hard way with that Tal-Strip!  Gloves only help.  My hands itch when it touches that stuff.  I invested in industrial sized gojo.
3.  I'm shopping for a torque wrench now.  I have feeler gauges and manuals (and patience!).  Will need the rest - any suggestions?

So....?  Time for a new frame? 

[crazypj]

The main welds are stock Honda, not quite as #$%*ty as the others.
 In the last/bottom pic the vertical weld is not Honda but the rest is (yep Honda MADE it look like that)
 You still have stock front section and swing arm.
 It really wouldn't be  a big deal to cut rear section off  a frame (pretty much any steel frame, even modern sport bike alloy sub-frame if you weld on mounting tabs) and have it properly welded into position.
 As long as the rear shock mounts are even none of the rest matters too much (except from aesthetic standpoint)
 The flat piece in U at end of top 'tube' was fuel tank mount and in all probability does very little or nothing to strengthen frame, I've cut them out and re-welded into position a few times when doing mono-shock conversions.
 Basically, if that frame is titled, you may as well fix it the way you want bike to be rather than start with a 'new' frame and cut it up

PJ

[mystic_1]

In the last/bottom pic the vertical weld is not Honda but the rest is (yep Honda MADE it look like that)

That vertical weld you mention looks fairly scary to me.  I wonder if the joints were sleeved.  If not, doubly scary

ewendkos, strip that paint off the welds and inspect them closely, it may not be as bad as it looks but it may be worse.  No way to tell without closer inspection.

If you find a titled stock frame for cheap, that'd be a way to go, but this frame is savable imho because as crazypj says the front section looks fairly unmolested.

I will say that the line from the backbone down to the rear axle is better than some of the other hardtails I've seen but those welds sure make me nervous.

mystic_1

mystic_1

[ewendkos]

I did a bit of work today, but I think at this point this belongs in the build thread that I started at http://forums.sohc4.net/index.php?topic=64582.0

Would you all mind following there?