Bandit 1250 Suspension & Power Comments

I purchased a 2007 Bandit 1250S with 19k miles in early Sept ‘16 to replace my ’97 Bandit 1200S with 80k miles that was totaled in a deer crash. It was mine and the bike’s 2nd deer tangle over 18 years. Now that I’ve had a chance to fix the 1250’s issues, I’ll do a quick comparison. In short, I like the 1250 better than the 1200 – less vibration and better, smoother low end power, peak power about the same, FI instead of carbs , equally crappy front suspension, 1250 shock worlds better.

Both bikes had/have very large airbox holes (~2”x 6”), K&N filter, PC-V vs Factory Pro jet kit, Delkevic full exhaust vs a Yosh can on the Gen1. The 1250 was tuned on a DJ 250i with Tuning Link. Both had PAIR systems removed and blocked. The 1250 has the secondaries removed. I rode the 1250 with secondaries in, and it had as good of throttle response as the modified bike does now. I removed them to get rid of the high rpm throttling they do.

Both bikes were dyno’d, but directly comparing a 17 year old inertia dyno result to a current DJ250i is not too accurate. My 1250 is right in there with others that have done similar changes. I agree with others to just leave the stock header with CAT as really the best thing, and that Dale Walker makes some rather bodacious claims. The full header is causing a bit of a dip in torque from 3,500 to 4,500 rpm (from 75 #-ft to 72 #-ft) instead of being nice and flat. The Delkevic system has a slightly higher pitched, raspier tone vs the deep tone of the Yosh can on the Gen1. I prefer the deeper tone of the Yosh. As others have noted, the Delkevic header can be a b*tch to mount, but does look good installed and drops ~12 #’s. The Delkevic Tri Oval 17” can is ~4-1/2#’s lighter than oem.

The Gen1 had a Works Performance Ultra shock with remote res, rebound and compression adj, and the forks had Racetech 1.0 kg/mm springs and I revalved the forks compression stack. The 1250 has Racetech 1.0 kg/mm springs and I revalved the forks compression stack as well (details to follow). The Gen1 had shop made dogbones raising the rear 1-1/4”. Currently the 1250 has shop made dogbones raising the rear ¾”, with a Wilber’s shock on order with length adjustment. The stock shock works surprisingly well, even with the now 20k miles on it. It is a bit weak for loading up for touring and/or 2 up, though. I’m about 265, and with just me, no luggage, and with stock rear ride ht it needed preload #6 for proper sag ( ~32mm). With ¾” lift, I backed it off to #5. The shock has a bit too much high speed compression damping, but works surprisingly well once properly tuned in.

The stock forks and damping are crap. Replace the springs with straight wound proper rate Racetech. Don’t buy anyone’s BS about progressive wound springs. Even if you are small replace the springs. As for damping, a set of Racetech Gold Valves are a good option, but you can save ~$150 by revalving the stock stack. Perhaps someone else has done so, but my searches turned up nothing. One can argue that the Gold Valves flow more oil with the shims wide open when hitting a sharp bump, and I won’t argue too much, but it isn’t a lot. Examine the stock valve body and pics of the Gold Valve body – there isn’t a lot of room to expand the porting. You can always try the revalve and if not pleased then spend your $. The procedure for fork disassembly for both revalving the stock bodies or the Gold valves is the same, so I won’t cover that. The only difference is removing the bolt that holds the shims in the stock valve body, which is done with an allen wrench. I’ve successfully revalved my Gen1 Bandit and ’02 DL-1000, so I wasn’t starting from “0”. I used Silkolene 02 Synthetic Fork Fluid (5wt/ISO 22 equiv) up to 112 mm from the top of the tube. I wanted more airspring, but it may be too much. I plan to drop to 120mm as Racetech recommends and compare.

Stock, my 1250 had different stacks in each fork. Starting from the valve body, here’s the shim stack for each leg. Included is what shims to reassemble with. Also included are the before and after shim stacks for the Gen 1 1200 (I tried to get the table to show correctly but gave up):

Gen3 1250
Right Side # of Shims OD x Thickness
Stock

The great thing about this info is not just the data, but the context. Much appreciated! For example, I keep hearing how heavy the stock exhaust system is, but the NET weight loss (after you put the aftermarket stuff back on) rarely gets posted.

I am assuming the different left/right 1250 legs are because one is compression and the other is rebound; is that right? The Suzuki parts fiche does not seem to distinguish.

(removed broken PB link)

I also found the Gold Valves a waste of money for the type riding my old body does. Softening the stockers and 5 wt oil would have of done just a good I'm thinking. As for the rear shock, still the same stock one with over 80K miles on it. Keep thinking I'll go to a Busa shock but has not happened yet. I can always build new links for the ride height adjustment .

I guess I'm just an old fart that doesn't know any better, but I'm perfectly happy with the stock suspension as is...and the engine too.

I'm 64 yrs. young and started riding motorcycles in 1963, of all the different bikes I've owned through the years the Bandit is overall my favorite bike.

I must be missing out on a lot...........................

Horses for courses, Rob. Some people enjoy the upgrade process itself. It's not necessarily that they can't tolerate the stock bike.

Mine's all stock too, but with over 30k miles now I figure I may have to refresh the suspenders sooner or later... so I am constantly reading threads like these. And I thought I wanted a slip-on can... but I am not sure 5lbs is worth $200, and I don't mind a quiet bike.

In general, the 1250 seems to be a textbook UJM: does a lot out of the box, yet is relatively understressed so there's loads of upgrade potential.

Dances - no, both are for compression, located at the bottom of each cartridge tube. The rebound valve body is attached to the end of the "damper rod" that screws to the fork cap. The drawing shows the catridge tube, valve bodies, etc as one assembly, #15. Easy to disassemble. There is a circlip at the bottom of each tube. Push the valve body up, remove the circlip, the use the damper rod to push the valve body out.

As for those happy with the stock forks - I actually found them almost dangerous, the springs are so soft. Granted I'm larger than most at 265, but I had to just putt-putt through corners with them. The bike would not take anything close to aggressive cornering. If you're happy you're happy, but you also don't know what you don't know, i.e. how much better the bike handles with proper fork springs and damping - it is a night and day difference if you want to corner above the posted corner speed. Reducing the compression damping also improves comfort by reducing the jolt from sharp bumps. The same modifications are good for touring or sport riding. Properly tuned suspension works well for both. For more of a touring ride some may want slightly more sag and slightly less compression damping, but there really isn't a lot of difference.

This is an old but interesting post. Can you explain the effect of removing the shims? I currently have .95 springs, 5 wt bel ray and stock valving but it feels like it could use more damping.


Gen3 1250
Right Side # of Shims OD x Thickness
Stock

I too am perfectly happy with mostly a stock bike..suspension is stock as is the engine..the Delkevic slip on is problably to only mod for performance...
I just completed a 270 mile day that was all twists and turns..in W.NC and N.GA and into E.TN as well and back to W.NC. My suspension settings were fine. and I couln't be happier. A big deal is to be made for the new Michelin PR2s as well..they stuck to everything and hooked me into and out of corners like nobody's business...
Theres no doubt theres more to be had ..if that is what ya want..personally..it aint necessary....

Indeed a old thread resurrected for good reason.
All Bandits have sub par suspension, expected with their given price point.
The 1250 benefits greatly with stiffer straight wound fork springs and lighter fork oil to help with the undersprung over damped stock set up.
From there a fork brace (Dale Walker) and changing the valve stack, a fairly major job. Are the next level though worth the effort if you are going to keep it.

Interesting point about fork oil: I went with a certain gold valve stack combo, 35 as I recall, and thought I may want to soften it up a bit more.
Had a bad fork seal and decided to change the fluid from bel-ray 5 wt. to Silcolene 5 wt., a much lighter looking viscosity fork oil.
I read a article about differences in manufactures true viscosity.
Sure enough the valving is perfect without having to pull the Gold valves out again.