Suspension Upgrades

[Syscrush]

OK, I just got my first paycheque for my new contract, and it's starting to get cold, so it's time to get serious about upgrading the suspension on this bike.

I've changed my mind about how radical I want to go in the time that I've had the bike and become more and more fond of the current looks. I was originally intending on a swap to some wide 17" wheels and possibly a swap to a SSSA, but I've decided now that I want to keep the stock geometry (or very close to it), stock ride height (or maybe a -0.5-1.0" higher), and my CB1100F golden boomerangs. No interest in any frame bracing/mods at this point.

I'm going to keep all info I discover about having this work done here in this thread.

Here are the options I'm considering currently:

FRONT:
Definitely swapping to handlebars and keeping stock gauges & controls. Don't care if I keep the stock fuse box and ignition key location or not. Good cartridge internals sprung and damped for me & the bike are mandatory - nothing with damping rods or emulators. Better calipers would be nice, don't mind new rotors but I don't want them much bigger than the stockers or they'll obscure my wheels.

1. Keep the stock forks, swap the internals with good cartridge stuff, custom over-top triple setup like Randak's to mount the bars, but styled more to my taste. Keep the 2-piston CB1100F calipers I already have.
2. 43mm RSU cartridge forks from a bike of similar size/weight (probably a Bandit 1200) with some upgraded/tuned cartridges. Will probably need custom triples, definitely need some spacers & bearings sorted out to work with the current front wheel & speedo drive, and custom brackets to mount the fender. Would use the rotors & 4-piston calipers from the donor bike.
3. 43mm USD cartridge forks from a bike of similar size/weight (probably 'Busa, or XZ-14), valved & sprung for me & the bike. Again, custom triples are almost definitely necessary. Again, would use rotors & 4-piston radial calipers from the donor bike (I really like the looks of USD+radial, so would not choose USD forks with an axial caliper mount).

Option #1 is the easiest & least expensive, and I don't really find flex of the stock forks or triples a problem for how I ride on the street (which is quite conservative). But my concern is that with all of the other upgrades done, that flex may become more noticeable and irritating. Also, I really don't like the looks of either the double-height top triple setup when going to bars, or the looks of having the fork tops protruding so far out of the triple. Of course, if I lift the bike front & rear, the problem of protruding fork caps goes away.

Another pro for #1 is that the forks are definitely long enough to let me add that height - might take some very tricky triple clamps to manage it with modern forks unless I can score oddballs from a road-focused adventure bike like a KTM 990 SMT, Buell XB12XT, or Tiger 1050.

Options #2 & 3 are probably similar level of difficulty & cost, and the same performance for a rider like me - the decision there is which look I prefer. RSU's would look OEM, USD's provide the bling... Either one would make talk of flex irrelevant and better braking than option #1.

REAR:
Definitely keeping the twin-shock setup, and definitely going with some good shocks that are adjustable for compression, rebound, and preload (but probably not remote/hydraulic preload) with straight-rate springs. I would like something better-looking than the stock swinger, and something that will take readily available bearings for ease of maintenance. Stiffer would be a nice bonus, but isn't a primary concern.

The shocks I'm considering that meet my requirements for quality and appear to be available for the CBX are:

1. YSS
2. Ohlins
3. WP
4. Bitubo

Any other suggestions for something in that same league would be much appreciated.

As for the swinger, I want to keep stock length. I would like to raise the bike overall a little bit (0.5-1.0") if it can be done without messing with the chainline too much. Options I'm considering include:

1. Mod the stocker to brace it and rework the pivot section to take new bearings that are more easily found.
2. Find a suitable donor alu swingarm and have it modded to fit & work with the twin-shocks. If I go this way, I want a box-section swinger, not the kind of bulky units on modern sportbikes.
3. Have something custom built from scratch.

I'm open to suggestions on this stuff. I'll update as I research prices & options, then as I buy parts & have the work done. I talked to a local builder today who says that he's interested in doing the work and that he can definitely take care of it over the winter if I source the parts I want to use. He builds drag chassis for cars & bikes, plus sells his own line of swinger front ends, so I think he's someone I can trust when it comes to getting the geometry right. I'm also going to ask my usual bike mechanic if this is something he wants to take on, but I don't think that he usually does that much custom work and he'd have to farm out the machining of spacers/adapters/brackets, etc.

Plenty to think about. I want to finalize all decisions in the next 2 weeks and have my parts in hand by the end of Oct. All I know for sure at this point is that I am VERY EXCITED about getting these upgrades done over the winter so I can ride the bike with more pleasure & comfort next year.



I think I'll keep a running list here of my current plans & what ends up actually on the bike:

1. Swingarm: Chromed aluminum from TRAC http://tracdynamics.com/pages/swingarms
2. Sprockets: 43 tooth black rear Stealth from Supersprox, and an 18 tooth front from CBX Performance. https://www.supersproxusa.com/Products/ ... ockets.php
   CBX Performance
   
   Note: My local retailer and/or Driven screwed up and I was sent the wrong sprockets and chain and told that they don't have a fitment for the CBX. Some of the folks at Driven supposedly have some CBX history - but it didn't seem like anyone involved in the screw-up wanted to work with me to get it sorted so I have no interest in ever giving them a dime.
3. Chain: Black 530 X-Ring chain from Supersprox
4. Shocks: YSS RG 362-360 TRCL-09 w/ optional compression adjuster http://www.yssusa.com/series-g.html - the valving on these looked pretty bad on the dyno, so they were revalved by Rick at Cogent Dynamics http://www.motocd.com/
   
   Note: After getting the YSS sorted out, I learned about the Ohlins HO 146. It has the same 4-way adjustability (preload, rebound, compression, and length) as the YSS, and the valving should be good to go out of the box. http://www.ohlins.com/Our-products-new/ ... rt/HO-146/ It's spec'd for a CB900, but Dan Kyle may be able to provide them ready to go on the CBX - although this may require some mods to the bike and/or shocks to get them to fit. http://www.kyleusa.com/ The cost for the 146 is about the same as the cost for the YSS + revalve.
5. Forks: Pro-Link forks rebuilt with AK-20 cartridge internals from Traxxion Dynamics http://www.traxxion.com/ and new tubes from TNK (available from Race Tech) http://racetech.com/page/title/FTNK%20Fork%20Tubes
6. Triples: Custom top & bottom
7. Front rotors: 310mm 2007 GSX-R1000 rotors, custom adapters
8. Front calipers: 65mm Brembo axial mount 4-piston, custom brackets
9. Front master cylinder: Bandit 1200, custom stainless lines
10. Footpegs: 1" drop pegs from Knight Design - they don't make a CBX peg, and these will need some tweaks to be able to fit. http://www.knightdesignllc.com/Products ... _Pegs.html
11. Bars: LSL Superbike Fatbar (I had to ditch the CR High Pro Taper Contour bars http://www.protaper.com/products/handlebars/contour because they didn't work with the CBX switchgear), with a KTM Duke 690 clamp assembly - chosen because I know that they work perfectly with the KTM GPS mount, which I like a lot. The bars may need some modification to fit the KTM clamps. http://www.spieglerusa.com/controls/fat ... ebars.html
12. Gauges: Speedhut - they offer an incredible array of customization, each gauge set is made to order. I hated to do it, but I had to ditch the stock speedo because the rotor adapter precluded the stock speedo drive unit. I ordered a matching speedo, tach, and clock (which will replace the voltmeter) from these guys. http://www.speedhut.com
13. Oil cooler: Earl's 13 row cooler plus a Thermostasis 190°F thermostat, plumbed with AN-6 braided lines and black fittings. http://thermostasis.com/
14. Stands: sidestand and centerstand were both lengthened a bit to account for the increase in ride height. The sidestand was cut & welded, the chromed centerstand had some stainless feet added to the bottom to get the rear wheel 1/4" off a flat, level surface.

[EMS]

Wow! Quite a plan! Nobody can accuse you of not having enough approaches..
A couple of thoughts:

Options 2 and 3 may not comply with your desire to maintain or increase stock ride height. the boomerang wheels are a little smaller and it is really hard to find an USD fork that is the same length as the stock CBX front end.
Some older (early 90) Suzuki GSX units work, I don't know exactly which.
If memory serves me well, there is a "F" top triple with the same 35mm clamping diameter as the CBX and Superbar mounts. (CB750F, maybe) that would address some of your concerns with Option 1.
I was able to obtain a complete Ducati Multistrada front end which is an almost perfect length match for a CBX. You may want to explore that.
As far as the swingarm, I will use a Suzuki GS1100 aluminum swingarm that has been cut shorter and rewelded. It is a dual shock design, so you do not need to add the shock mounts. 1980-1983 GS1100, I believe.
You could always use a Prolink swinger and have shock mounts added. Length is about 1-1½ more.

If you go with Öhlins rear shocks, they will tear a whole in your wallet. Don't know how much the others are, but a set of the Swedes will set you back around at least $850.- unless you find a set of good used ones that someone is willing to part with for agood price.

[Syscrush]

Thanks a lot for the pointers. I was looking at both the GS and prolink swingers. It seems to me that the GS one cleans up a bit better - I like the box section look better than the I-beam. With my 6-into-1 exhaust, the left side will be very visible.

I just found your swingarm thread and that Calfab unit is amazing. When I mentioned having something custom fabbed, that's the style that I was thinking of. I'm going to send a photo of it to my builder and see what he says about it.

As far as budget is concerned - I really believe that you get what you pay for when it comes to suspension. The other 3 options I'm looking at are all in the same territory price-wise as the Ohlins. I know YSS is a bit cheaper, but I'm more concerned with getting the right look/function than a few hundred bucks here and there. I'm not looking to spend money for its own sake with this project, but I'm also not going to sacrifice the end result by cutting corners. I've done that in the past and always regretted it.

[Syscrush]

I was able to obtain a complete Ducati Multistrada front end which is an almost perfect length match for a CBX. You may want to explore that.

Thanks! That fits with what I was thinking of when I mentioned adventure bikes as potential donors. The Multi has much more suspension travel than the CBX - did you rework the internals to stiffen the springs and hit the stops sooner?

[EMS]

Thanks! That fits with what I was thinking of when I mentioned adventure bikes as potential donors. The Multi has much more suspension travel than the CBX - did you rework the internals to stiffen the springs and hit the stops sooner?

I am not there quite yet. So far, it is just physical fitment. I haven't even changed the stem on the Ducati tree to fit into the CBX neck. As far as suspesnion travle is concerned, they may need a spacer, but we will cross that bridge when we come to it. This whole project is really on the back burner.
I had a spare 79 frame and two engines and needed a purpose for it. That's why I started planning this. But there are other things that have priority.

Another minor thing you have to address with any fork replacement is the instrument pod and headlight mount. If you desire to keep the original, you have to fabricate some kind of bracket for both. I have a couple of large Suzuki headlights, one with its original mountings, which I can think I can modify to go on the forks.
I also like to keep the original instrument pod and this should be fairly easy to make a holder for. You mentioned the speedo drive and I have not given that a thought yet.
What i have to do there, depends on whether I will use the Ducati wheel or not.

Keep us posted with your plans. Sounds interesting.

[Syscrush]

What has to happen to a GS1100 swinger to fit the CBX? I quite like the looks of the swingarms from Trac. I've asked them what it would take to get something for the CBX that matches the stock length & geometry, but they already have a GS1100 unit for a price that wouldn't be matched by any fabricator that I know. Here's the basic design/look of their swingarms:



Also available in a bare finish. They also make a a companion chain guard.

If making a CBX-specific unit is a lot pricier than the GS1100 one that they make, what would be involved in fitting it?

[EMS]

What has to happen to a GS1100 swinger to fit the CBX? , what would be involved in fitting it?

The GS swinger is longer than even the CBX Prolink swingarm. The flanges in the rear that hold the axle need to be cut and the moved forward. Or, you can use it as is. The swingarm axle is the same as on your '80. I had to get a sleeve made to fit a 14mm swingarm axle from my 79.

Here is a picture of the Multistrada front end side by side with a modern USD from a ZX-R. From the bottom triple to the axle is not much difference on first sight, but you have to consider that the ZXR forks would need a longer stem, which would move the lower triple down. The Duc stem is almost the same length as the CBX stem, even a tad longer. And there is room to move the tubes down in the trees.

[Syscrush]

Plus there are mounts for handlebars.

A Duke 690 front end would probably work even better as it has sportbike-like suspension travel and must be similar length to the Multi. But only one fork end has a brake mount, so that would need to be taken care of.

A buddy of mine is Rick from Cogent Dynamics. I've asked him for some advice on my front end options - whatever we decide on, he'll be the one handling the springing, valving, and any other mods. The more I think about it, the more I want a nice USD with radial 4-pots, but I have to decide how much that's worth to me - especially if I'd be looking for an oddball set of forks from an ADV bike.

[EMS]

It is raining....lot's of time to post..(although most people won't give a sh..t)

Checking through my records, I was wrong with the GS1100 swingarm. It is not really longer than the Prolink arm, pretty much the same length.
Here are some swingarm possiblities I considered, from bottom to top:

- Prolink swingarm. Needs shock mounts. Longer than stock 79/80
- GS1100 swingarm. Has shock mounts. Longer than stock 79/80. Perfect when shortened a bit
- CB1100F swingarm. Longer than stock 79/80. Also steel. Was dismissed
- CB1100/1300 "Big One" swingarm. Awsome piece, but too much work. Really long and too wide between frame. Difficult to modify.

[Syscrush]

As impressed as I am with that swingarm collection, I think I'm even more impressed with that peek at your carb bank collection! :)

Rare as they may be, I did find a set of Duke 690 forks & triples on ebay... And I see radial-brake GSX-R fork assemblies for $300-400 with calipers & master cylinder. If the GSX-R setup could donate the fork bottoms and brake components I could sell off what's unused from both assemblies and make out OK.

Gonna call the guy I sold my 690 to and ask him to measure fork length, and my suspension guy to see if he can find out if those non-WP fork bottoms will screw onto the WP forks.

[EMS]

As impressed as I am with that swingarm collection, I think I'm even more impressed with that peek at your carb bank collection! :)

Rare as they may be, I did find a set of Duke 690 forks & triples on ebay... And I see radial-brake GSX-R fork assemblies for $300-400 with calipers & master cylinder. If the GSX-R setup could donate the fork bottoms and brake components I could sell off what's unused from both assemblies and make out OK.

Gonna call the guy I sold my 690 to and ask him to measure fork length, and my suspension guy to see if he can find out if those non-WP fork bottoms will screw onto the WP forks.

Sorry, Phil, I had the picture cropped. Here is a better look.
There are so many projects, it is always good to have a few spares....

[EMS]

....and, of course, tanks come in handy too....



..as well as exhausts....

[steve murdoch icoa #5322]

Quit showing off, Mike.
Your stash is better than what i have on the bike.
BTW, can you send me your address and when you will be heading out of town again. haha.

[steve murdoch icoa #5322]

My seat of the pants review of the GS1100 swingarm was positive.
It just felt more solid in the rear.
I did not notice the extra length affecting handling in a negative way. There was no extra effort required nor did it feel slower to turn in.

[EMS]

My seat of the pants review of the GS1100 swingarm was positive.
It just felt more solid in the rear.
I did not notice the extra length affecting handling in a negative way. There was no extra effort required nor did it feel slower to turn in.

That's good to know, Steve. Considering that it is virtually the same length as the Prolink, the expense for shortening it, is probably not necessary.