On the Adjustable Suspension and Front Tyre Pressure

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mcatrophy

Privileged to ride a 2018 FJR1300AS
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Ok, probably destined for NEPRTdom, but might be of interest to someone.

Nomenclature: Because off Yamaha's curious naming differences between markets (see here), let me firstly say that my Gen III AS has the adjustable suspension of the FJR1300ES in America and Canada (and possibly other areas). So for probably most readers, this applies to riders of the FJR1300ES.

When I got my 2014 FJR1300AS, I rode it the 9 miles home from the dealer, with the suspension set for "Rider only, Standard". I was somewhat taken aback by the very poor comfort level, my best description was that the front and back of the bike seemed totally out of touch with each other, and the ride was very harsh.

My first thoughts were "What the hell have I done, buying this?" Particularly knowing that most riders talk about the FJR's suspension as under-sprung. I've been very happy on both of my Gen IIs, weighing in at a mere 145 pounds (plus gear), maybe I'm simply not heavy enough for my Gen II AS? Most riders appear to have significantly more weight than me.

Over the next few rides, I started to play around with the settings, and I found that the "Hard" setting gave probably the best balance between front and back, but still a very harsh ride. However, on the plus side, from when I first had it, the bike gave me far more confidence on the road. Most noticeable was that, without thinking, i was taking corners significantly faster than with my Gen IIs.

Anyway, today I went out for a ride (SWMBO is away for a couple of days, so I can play a little). Before I went, I checked the tyre pressures (as I generally do once a week or before any significant ride). They were 40 front, 42 rear.

Since new, I've never put air into the front tyre. Every time I've checked it it's been 40 or over (depending on temperature I suppose). Anyway, I've known from first reading the Driver's Manual for this bike that Yamaha recommends 36 PSI whereas for my Gen IIs the recommendation was 39. Presumably what my dealer assumed for my Gen III. Most comments on this forum have said "Run 40 front, 43 rear" or similar, except for some (all?) years of the Gen I. So I've been leaving mine at this pressure.

Today, I decided to drop the pressure to the nominal 36. Then off I go for a 115-odd mile loop, through some nice twisty roads, nice autumnal scenery, nice weather - a perfect way to fill a few hours (2:50, actually).

What a transformation! All that teeth-rattling juddering has gone. Front and back move together. There's something approaching my Gen IIs' comfort levels available. The "Hard", "Standard" and "Soft" settings all feel better.

Downsides? Perhaps not quite as pointy in the front, maybe that front rail it was riding on has become a groove it rides in. Still very good handling, though. Also, possibly a bit more noise from the front tyre when braking hard.

Seems to me that Yamaha might actually know what that pressure should be, after all it is one of the suspension design parameters.

Don't yet know what affect this might have on wet roadholding or wear, but I'm going to run it at 36 or near from now on.

Who knows, this might be the point when acquaintance turns into lurve
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I have noticed similar results, except that I found that I am setting the rear preload lower than one might expect to get the compliance I was looking for. I weigh in at 225 lbs and I am running on single rider preload and low or mid damping depending on the road surface. Then when with my both my 100 lb wife and all of our luggage loaded for a weekend ride, I found the 1 plus luggage or two up no luggage were adequate, with damping still kept on the soft side. And, yes... I have been running at 40F - 42R also.

Considering that the front preload is non-adjustable, you may be onto something, that the front spring rate is a bit higher than would be optimal when running a higher tire pressure.

My fear is that the tires will scallop severely when run at the recommended lower tire pressures, as my first hand experience shows they will, especially Bridgestones. And most certainly they will wear considerably faster due to the higher temps those lower pressures will induce.

The hot setup may be to investigate a means of reducing the spring preload up front to better match the rear spring settings when the front tire pressure is raised up to the FJR weight, nominal 40 psi.

 
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On our last trip we had 3 FJR's, 2 '13s & 1 '14. 2 of us were running 40 in the front and 1 of the '13s was running 36. At the end of the 3500 mile trip the one running 36 was scalloped and the other 2 were wearing evenly. All 3 bikes started out with new tires with about 1000 miles on them. Since then the owner of the scalloped tires has upped his pressure. He is running PR4's.

 
Once you have a couple thousand miles, report back regarding front tire wear and feel. Maybe there's a balance between tire life and ride quality that's livable.

--G

 
I'm 145lbs and have been running 39-40psi front and 42psi rear since new. Now at 9K the front tire is wearing evenly and has 3/32 tread, no cupping or flat center . I have always been an advocate of higher psi for better tire wear.

Suspension settings for me is one-up no bags, std-0 setting when day riding. When on road trips one-up with bags and std-0 setting unless in the twisties then set on Hard-0. Bike handles well and yes, I seem to find myself going faster in the turns than on the Genii's.

 
I'm 145lbs and have been running 39-40psi front and 42psi rear since new. Now at 9K the front tire is wearing evenly and has 3/32 tread, no cupping or flat center . I have always been an advocate of higher psi for better tire wear.
Suspension settings for me is one-up no bags, std-0 setting when day riding. When on road trips one-up with bags and std-0 setting unless in the twisties then set on Hard-0. Bike handles well and yes, I seem to find myself going faster in the turns than on the Genii's.
How do you find the comfort level compared with the Gen II? That's my real issue.
 
I do not find any difference in the comfort level as it relates to general road surface. I really appreciate the cruise control feature and find the suspension allows faster turns. I believe if you keep the tire pressure at recommended levels and play with the suspension setting you will find the correct settings for your weight and riding style.

 
I do not find any difference in the comfort level as it relates to general road surface. I really appreciate the cruise control feature and find the suspension allows faster turns. I believe if you keep the tire pressure at recommended levels and play with the suspension setting you will find the correct settings for your weight and riding style.
Ok, thank you. But I notice you run your front pressure higher than reccomended for a Gen III.
Different subject, but anyway - curiously, I never like leaving the cruise control active when cornering (other than a motorway, where lean angle is minimal). I always prefer to have manual control, even if I'm not changing speed noticeably.

 
I run 1up preload, Soft -2 when on slab or rough city streets, Std 0 on wide sweepers and Hard +2 on tight curves. When my 135# wife is on the back, we run 2up or 2up with luggage if appropriate. Tire pressure is 39-40 front and 42-43 rear. These settings provide smooth rides on slab and great control of suspension travel on curves. The ride is similar to my '08AE with 17k miles but my ES no longer bottoms out on small bumps when we are 2up, unlike what the Gen2 did.

I'm on my second front tire and third rear now that I have 16.5k miles. They have all been BT-023s. The first set were run at 36F and 39R psi for the first 4k miles and the front started to scallop and caused a head shake. I increased the pressures to 39/42 and the headshake reduced through the full 9.2k miles the tire lasted. My current front has been set at 39-40 psi since the beginning and has not scalloped. I've had no headshake during its 7.3k miles and it appears to be about half-way through its life.

I suggest playing around with the + and - on the Soft and Hard settings to see if it helps with the smoothness and stability you seek when running at the higher pressures.

Good luck!

 
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I run 1up preload, Soft -2 when on slab or rough city streets, Std 0 on wide sweepers and Hard +2 on tight curves. When my 135# wife is on the back, we run 2up or 2up with luggage if appropriate. Tire pressure is 39-40 front and 42-43 rear. These settings provide smooth rides on slab and great control of suspension travel on curves. The ride is similar to my '08AE with 17k miles but my ES no longer bottoms out on small bumps when we are 2up, unlike what the Gen2 did.
I'm on my second front tire and third rear now that I have 16.5k miles. They have all been BT-023s. The first set were run at 36F and 39R psi for the first 4k miles and the front started to scallop and caused a head shake. I increased the pressures to 39/42 and the headshake reduced through the full 9.2k miles the tire lasted. My current front has been set at 39-40 psi since the beginning and has not scalloped. I've had no headshake during its 7.3k miles and it appears to be about half-way through its life.

I suggest playing around with the + and - on the Soft and Hard settings to see if it helps with the smoothness and stability you seek when running at the higher pressures.

Good luck!
Thanks, useful input.

I'm beginning to wonder if there's something wrong with my front end. Trouble is, I know my dealer has no real experience of setting up "normal" suspension, let alone electrically adjustable.

 
Good point. I wonder if there are some mechanical adjustments that can be made that would influence what the electric motor ranges are on the damping adjusters. Time to crack that section of the manual open and investigate!

 
Hmm. Think I'll pay a visit to my dealer, see what they and their manual say.

 
Using tire pressure to adjust suspension settings is probably not the best idea. It's gonna lead to excessive front tire wear after some miles. I don't run 41 because of suspension, I run 41 psi in the front because of tire wear. Mostly due to the weight of the bike.

As always, you'll have to find what makes you happy with wear and feel.

 
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I never like leaving the cruise control active when cornering (other than a motorway, where lean angle is minimal). I always prefer to have manual control, even if I'm not changing speed noticeably.
The most effective and safe way to attack bends on a public road is "slow in, fast out". That is different to a track where you accelerate right to the braking point then hard on the brakes and finally tip in to the apex.

You can't do that on the road because you have zero margin for error, and you need that safety margin to allow for slow moving or stopped vehicles, pedestrians, gravel on the apex and a million other things that don't exist on the track.

The consequence is that when you slow for the corner, the brake shifts the CC to standby, so it disengages without you having to think about it. You then can make the corner under full manual, and hit "resume" when you have powered out.

All that said, I have never really used the CC on roads that require much "corner planning". Usually I'm having too much fun :) Cruise helps me relax on long, high-speed cruises. One useful and under-reported feature of CC is that it allows you to pick your preferred speed (limit + a bit), and not go OVER it. This can be wallet saving on a bike that will hit three figure speeds without any apparent discomfort.

 
Using tire pressure to adjust suspension sett8ngs is probably not the best idea. It's gonna lead to excessive front tire wear after some miles. I don't run 41 because of suspension, I run 41 psi in the front because of tire wear. Mostly due to the weight of the bike.
As always, you'll have to find what makes you happy with wear and feel.
Remember your "41" is only 2 psi above Yamaha's recommendation for your 2007, whereas it would be 6 psi above for my 2014.

Still don't know why they changed the recommendation between Gen Is and Gen IIs, nor back again for Gen IIIs.

 
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Using tire pressure to adjust suspension sett8ngs is probably not the best idea. It's gonna lead to excessive front tire wear after some miles. I don't run 41 because of suspension, I run 41 psi in the front because of tire wear. Mostly due to the weight of the bike.

As always, you'll have to find what makes you happy with wear and feel.
Remember your "41" is only 2 psi above Yamaha's recommendation for your 2007, whereas it would be 6 psi above for my 2014.

Still don't know why they changed the recommendation between Gen Is and Gen IIs, nor back again for Gen IIIs.
I totally get the recommendations have changed, but I don't know why, as the tires haven't changed. I don't see enough difference in the bike to bring PSI down 3. I figure with the same tires and weight, PSI should be about the same, regardless of what the stickers say. Of course I could be FUBAR. I still think at 36 PSI, you're gonna get bad front wear and cupping, but I also weigh 100 lbs more than you. That could be all the difference!
 
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I agree. There is no logical reason to have changed the tire pressure spec from Gen 1 to Gen 2, or from Gen 2 to Gen 3.

Unless... it is not coming from Yamaha, but rather from whoever is the chosen OEM tire supplier at that point in time. I think that this has some real likelihood as they do seem to switch vendors on a regular basis.

But, anyone who has any experience riding any FJR with any of the available ST tires on them will know first hand that the front tires will cup, scallop and wear rapidly if run at much less than about 39 psi.

Of course since we are talking tires, YMMV!
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I would be reluctant to follow the GIII tire pressure specs given other egregious misinformation in both owners and service manuals. Typical example: 31 lb-ft torque for the oil drain bolt. I think there are others, and know there are some absurd procedural directions in the FSM.

Perhaps some tire manufacturers could shed some light. Also, I seem to recall inflation recommendations provided on some tire manufactures websites..

 
... Also, I seem to recall inflation recommendations provided on some tire manufactures websites..
As far as I can tell, Bridgestone on their UK site recommend 2.5 bar (36 psi) for all models of FJR, although selecting the actual FJR model/year is a bit of guesswork.

You selected : Tyres for YAMAHA FJR 1300 / AS RP 23 (5) ab 2013
or

You selected : Tyres for YAMAHA FJR 1300 / A RP 04 / RP 08 / RP11 / RP13


 
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