pattonme

suspension damping frequency and loading bias is more likely to be a contributing factor than tires. Not to say that cupping doesn't also contribute to the front's wandering. I've had some BT and Avons do some very odd things... Any proper tourer has by definition a relaxed rake and longish trail. Yamaha is WAY off the reservation with the FJ09. I don't know why they thought it was a good idea.

@rocky5000100 those were measurements you had done? The stats I'm seeing says 96@25d for the 05R6 which is perfectly in line with pretty much every sport bike of the last 15 years across all brands. The '05 GSXR750 had 23.8deg rake with short trail and Traxxion makes extended length fork caps for that series to get the Rake back under control (somewhere around 24.5). I'm not saying 100@24 is guaranteed under any and all designs to be a problem, there's more to it than that. But it's a very questionable design choice for anything that isn't a full-tilt sportbike. So if your bike is properly balanced, and you like going really fast and especially with luggage, and you want to push past the weave/wobbles, you probably want a damper. Just don't expect it to save you once you go over the inflection point.

I think I've found the culprit for the 'not stable' at speed. If the 'Internet' is right, it's the ridiculous rake and trail numbers. 100mm@24deg. The FZ09 has sane values of 103@25. Now admittedly swingarm pivot and other factors come into play but 102@24 was the reason why the '04 ZX10 required a steering damper installed from the factory. The FZ1 runs 109@25 as do a slew of others in the low hundreds and 25deg. The most recent R1 (not the new one) runs 102@24. So Yamaha gave a mid-weight budget tourer more aggressive steering than an R1?!?!

those are max pressures. Now if you're putting 500lbs on the bike (rider, passenger, luggage or some combo) then yes running max might be advised. If the bike was 600lbs or 800lbs instead of 450, I would run higher than 33/33 as well. Owner's manuals have as much mis-information as they have accurate and useful information. Recommended tire inflation is one of those perennially wrong entries. but feel free to experiment.

@buz11, you can run whatever pressures you like up to whatever is max on the side-wall. If 35/41 is what you want, have at it. It might improve mileage but there are multiple factors to contend with. What you will doubtless observe in the near future is accelerated wear in the middle of the rear tire of a relatively narrow width. Unless you happen to spend a lot of time on the side of the tire because you're blessed with curvy roads.

your tires are overinflated @buz11. 33 front/rear modulo load is plenty. Also, it helps if you're talking clicks/turns of settings that you indicate from fully in (aka hard). It's not clear if that's what you meant.

> the adjuster says "TEN" that's short for 'tension' aka rebound. > needs setting up for each individual rider especially if they are big / heavy because heavy is way outside the design brief of the suspension. It was no doubt evaluated by and configured for a 150lb Japanese male. > Yamaha dealers need to get hold of this issue I'm afraid it will be a rare dealer indeed who knows even how to set sag properly. The ignorance of service departments never ceases to amaze and the sales guys are hopeless.

You guys with Racetech upgrades if you could chime in with SKU, pricing etc.

Links updated by @koth442 in March of 2020. Please make sure the link takes you to the correct motorcycle before purchasing. I'm not responsible if you buy the wrong thing! -- Springs -- Sonic : $84.95 product info [ul type=disc][*]Forks-by-Matt : $70[*]Stoltec Moto[/ul] -- Cartridges -- Complete control of slow-compression and rebound circuits. Fast-compression adjustment via shim stack re-valving. A couple of clicks covers temperature effects, passenger loads, as well as Touring vs Sporty vs Track riding profiles. Use of light-weight oil greatly diminishes temperature sensitivity. Easy front sag setting via preload adjustable fork caps to handle varying loads, tune the stroke range, and influence overall behavior. Andreani Group 105/Y07 : 480E, $535USD Europe: Benvenuti nel sito ufficiale di Andreani Group International Specialisti sospensioni auto, moto e mtb. Distributori dei marchi... Anybody know the United States Distributor?? Andreani Install guide: Buy Matris Motorcycle F12 Series Fork Cartridge Kit - F12Y124S | Demon Tweeks Hydraulic fork cartridge kit that completely replace all the existing... AK-20 Axxion Cartridge Kit (AK20Y-FJ09) - Traxxion Dynamics Traxxion Dynamics is proud to introduce the next revolution in... Race Tech Yamaha FZ-09 / MT-09 2014-2016 Gold Valve Fork Kits Purchase the Race Tech Yamaha FZ-09 / MT-09 2014-2016 Gold... NOT A COMPLETE KIT, SOME ASSEMBLY REQUIRED. See review below. Race Tech Yamaha FZ-09 / MT-09 2014-2016 Gold Valve Fork Kits Purchase the Race Tech Yamaha FZ-09 / MT-09 2014-2016 Gold... Ohlins NIX30 Cartridge Kit Yamaha FZ-09 / FJ-09 / XSR900 Developed and tested with leading World Supersport and... There's supposed to be a cheaper "street" version made by Ohlins, but I haven't found anything. GP Suspension, 25mm Cartridge Kit DIY valving like the RaceTech kit above GP Suspension Fork Re-Valve Kit GP valve kit, pre-assembled into a kit https://stoltecmoto.com/shop/yamaha/fz-09/14-16fz-09-drop-in-cartridge-kit/ Alternative to Matt's forks DMr Applications – Yamaha – DMr Performance Suspension Having trouble viewing the table below? Download the pdf here...

Updated listing for full-feature set Ohlins shock offered by Andreani Group. US distributor is Fast Bike Industries.

fixed, sorry about the wrong value.

They make a fantastic product IMO. Admittedly that was on different bikes with differently shaped screens. No FZ09 experience.

There is something VERY wrong with RT's shock spring calculator for the FZ1. Either the OEM rate isn't remotely right or the formula is wrong. I compared with a Triumph 1050 and was also getting surprising rates even at low rider weight so either the leverage ratio is incredible or the formula for that one is wrong too. It wouldn't be the first time. I would ask Penske/Traxxion for their input. I would believe something on the order of 20% stiffer rate for every 100lbs over 150.

stock on the FZ09 and (reasonably sure) FJ09 is 550. Racetech claims the FZ1 came stock with 12.0kg/mm == 670lb/in stock. So when you put 500lbs of rider and gear on that subframe (was it even rated for that kind of weight?) you only went up to a 700 spring? I would agree with your other forum members, a 750 isn't unreasonable. The only thing the FZ1 has in common with the FZ/FJ09 is the sticker that says Yamaha on it. If you're going to put the same 500lbs on the FJ I'd carefully read the weight limit disclosure. And if I had to guess, a 650 spring.

@brprider, why a 700lb/in spring? If 'baseline' is 550, that's one heck of a step up. I could believe a 600 or maybe 625 if you're a 250+lb rider. What spring calculator spit out that number? Unless you can show the linkage ratios are the same what some other bike uses for spring rate is utterly irrelevant.

Added Eibach part reference. Just use the same series coilover. I've been doing this for years and not infrequently a third or half the price of "motorcycle specific" product application.

An official Givi response: the most recent Monokey information booklet that has a maximum recommended speed limitation of 120km/75mph (see page 4). GIVI is an advocate of safe riding, although our European pamphlet has the above maximum recommendation, which is probably more relative to their own highway speed limitations, our US customers would be advised to not exceed the posted speed of any public road and or highway.

> Most of the air hitting the rad thankfully passes through it to stop our engines overheating Not to step into it a second time but no, the radiator is only capable of passing about 25mph worth of air. Over that speed it might as well be a piece of wood. Pressure does build against the radiator and any flat'ish portions of front cross section. Since the forks are angled, this force will necessarily result in an upward component. I do not wish to speculate how much of that is countered by a downward component generated by the windscreen or fairing components to include the winglets on the bars.

I hereby recind the aero-theory and apologize for the tangent. I can't find it now but I was using a Google image of an FJ cockpit that had blanking plates contoured around the fork legs as the premise. I'll shut up and stick to suspension.

the issue with lift isn't that the fairing is "flying" or acting as a foil. I don't have access to a 120+mph wind tunnel but there isn't "huge amount of daylight" between the forks and the bodywork - Yamaha put blanking panels in there to keep the cockpit area calm but the side-effect is it traps air. It is my contention that the lift is coming from what amounts to a 'ball' of high-pressure air trapped in the nose to radiator section. Look at the FZ1, the FZ8, the versys 1000, sv1000. Only the FJ has such large vertical distance between fender and fairing nose. The others also have downward sloping noses which helps to reduce the build-up. The 1st gen FZ6 has an upward angled fairing like the FJ and modest side-curtains so from an aero perspective it probably has similar tendencies. I'm not sure how my words got twisted into that the FJ was dangerous to ride. ANY bike ridden at the edge of it's stability envelope and with objects producing dirty-air is no longer safe. I could put side or top cases on a CBR600 and the results at 120mph+ probably wouldn't be pretty. The point was that over 100mph aero forces really start to assert themselves. It is therefore no wonder that introducing hard cases, top boxes, or unbalanced suspension that things can go from just fine, to iffy or worse in a moment of time. I mentioned the triumph situation simply to point out that had I been running clean, I probably wouldn't have crashed. Yes the bike was inherently unstable. But without the bags, the turbulence coming off the side cases would not have induced shakes into the chassis, nor the weight caused rear squat nor some degree of weight transfer fore and aft. All of it combined to lead to a nasty crash. Perhaps my word of caution is over-blown. Take it or ignore it. The reason I chimed in in the first place was that it one shouldn't mask handling and chassis dynamics problems with a steering stabilizer.

head stock bearings could very well be a contributing factor - it's not like there haven't been other 'huh?!?' headscratchers. The FJ/FZ have shorter wheelbases than Ducati Monsters but longer than the SV650 and CBR600 but I don't know the relationship of the swing-arm length. There's also chain angle to consider. If you have a copy of Tony Foal's chassis dynamics software, we could punch those numbers in and see what it says. Anyway the point is these factors and the torque of the motor, many owners have first-hand experience with the front to get light/wheelie-prone, more so than many bikes currently on the market. It makes for lively, responsive handling around town but not a good thing for high-speed stability or when under heavy acceleration. If you moseyed from 85-105 I expect you wouldn't get so much as a twitch unless the rider trying to hang on while being blown about was introducing steering inputs. Yes, I agree Yamaha purposely designed it to be wheelie-friendly - who doesn't like to hoon, right? And the press will make a big point of selling that to all the "young kids" who think that's how you earn your coolness badge. Or maybe they assigned the design to a young, inexperienced team (the FZ07 just reeks of neophyte engineers getting their first crack at design, and sourcing crap metallurgy parts from cut-rate suppliers) that has no hard-earned knowledge about designing in stability. I'm slightly tempted to chalk it up to the latter. The -09 engine, however, was clearly done by guys who know what they are doing. This series of Yam FZ/FJ07 and 09 have IMO such badly done suspension both front and rear such that somebody over in Japan Inc. should be banished into the mountains for bringing such 'haji' to the company. Even with revised suspension, properly torqued headstock bearings, and proper balance, I doubt the headshake tendencies at 100+mph and earnest throttle application will change that much. For the FJ I'd rip that plastic out because I expect that will make a perceptible difference. And put a longer swing-arm on it.

In Japan if it's not class-based licensing limits (ie bikes between 600 and nana-han), general certification limits, I'm sure it's nationally imposed top-speed limits. I don't know why the limiter in the USA aside from the fact that unlike every rational country, we don't have mandatory and rigorous rider training.

It was the Givi rep's suggestion that the advisory be drawn at 75mph, not mine. You're misreading my posts to somehow conclude I said the FJ was necessarily unstable at 75mph with luggage. The closest statement I made to that figure was that I doubted the bags were certified for anything higher than 70 (certified != disaster if you exceed), and that if going 90+ it's a bad idea to do so with luggage. And if you're going to ride like that anyway, that one needs to make sure the bike is balanced and suspension adjusted to compensate properly for the weight, and that you can probably help matters by getting rid of the panels that are trapping air. Well, at least we now know that dual Kappa 40's on your bike are fine up to 120mph. Speed away!

I eagerly await your experience riding a luggage equipped FJ09 at 140mph with accompanying video footage of the fork action. With or without a stabilizer.

Ok, so I called Givi and no, there isn't an official speed limit on the cases but he did say that yes, they used to mold a "don't exceed speed" into the lid and that if they don't anymore, 75mph should be considered that advisory limit. "I personally ride faster than that and haven't had a problem". So, to your point @wessie, I wasn't saying "YOU'RE GONNA DIE" but that you should think good and hard because you're opening yourself up to the aerodynamics making everything go pear-shaped in a real hurry.