Confused about tire pressure

[VegasDan]

2021 RT Limited. Im a big boy - and most of the time my wife rides with me.
I have the tires at 19 front - 26 rear.
But the bike feels squirrely in turns (to me).
Do I go up in pressure - go lower?
Everything I read says lower - but from an automotive background - sidewall flex is not conducive to handling.
Help me out.

[2dogs]

You don't say how long you've owned the spyder or how many miles you've ridden on the new machine. Try relaxing your grip would be my first suggestion, if you are a new rider. Heavier sway bar or stiffer shocks could help but without further info, your question is a bit difficult to diagnose and answer. Hang tight, you're going a lot of answers here in just a short time. PSI doesn't seem to be that far off.

[Little Blue]

2021 RT Limited. Im a big boy - and most of the time my wife rides with me.
I have the tires at 19 front - 26 rear.
But the bike feels squirrely in turns (to me).
Do I go up in pressure - go lower?
Everything I read says lower - but from an automotive background - sidewall flex is not conducive to handling.
Help me out.

Do you still have the OEMS (Kenda tires)? If so your tire pressures are good. A lot of Forum Members have changed to an Automobile Tire on their Spyders.
Not sure about your problem.
More information is needed.
Please post up any comments you have and someone will give you some ideas.....

[Peter Aawen]

Are you still running the OE Kendas, or after market tires Vegas Dan?? If the former, see above; if the latter, what tires, & what sizes??

Given the good feedback you've already got from others, and that we really need to know all that info requested above (by me & others! ) in order to provide any specific feedback/advice, as a general comment, many people who complain about 'their Spyders feeling squirrely in turns' can't really tell us exactly what makes them think that?! . You need to understand that there could be a number of reasons for that feeling.... some may be your riding style as above; but have you checked your suspension components lately?? Had a wheel alignment? Is everything up to spec & in good nick?? Do you know if the 'squirrely' feeling is feedback from the steering, in which case it could be that the front tires are over-inflated; if it's a movement from the rear tire part way thru the corner, it could be under-inflated; OR (& this is surprisingly, at least to me, after quite a few years working in the industry, far more common than it should be... ) both/either could be that many people have simply become used to riding (&/or driving) on over-inflated tires, and they are simply not used to the sidewall flex that SHOULD be present when they are running radial construction tires, and what they THINK is 'not conducive to handling' (both for their car & their Spyder!) is actually providing greater traction than if that sidewall flex was not there!

Radial tires work best if they are run at a pressure that best keeps the entirety of the tire tread/contact patch on the road; too much pressure marginally increases how 'direct' the steering may feel, but significantly decreases the amount of tread that remains in contact with the road surface, which MASSIVELY reduces traction, ride comfort, handling, resistance to punctures or catastophic failure from road debris, tire life, and the list goes on! And if you're old enough to have learnt to drive on cross ply tires/have always ridden on cross ply 2 wheel motorcycle tires and become used to that feel & ride etc, or if you've become used to riding/driving on hard/over-inflated radial tires that would not only feel softer & a bit squirmy-er at their optimal presure, but they MUST feel a bit like that to perform at their best in order to serve you best, then it will probably take some time riding/driving on tires that are run at a more appropriate pressure to get used to that! But if you persist, you'll gain confidence over time due to the greater traction, better ride, handling, improved tire wear, etc etc etc that running radials at or near their ideal pressure will give you..... but if that's your addition & you want to cure it/get better everything from your tires, then you'll HAVE to persist long enough to recover from the addiction to over-inflating your tires!

Admittedly, there's a fairly fine line between over-inflation & under-inflation, and those drivers who simply set & forget their tire pressures for months on end (if not forever! ) are far more likely to be running under-inflated tires than over-inflated tires, but if you regularly check your tire pressures & pay attention to the changes that should occur in their pressure over time and as you ride, then you shouldn't have any real issues. FOBO &/or similar Tire Pressure Monitoring Systems make it easy to keep an eye on your pressures, but you should still make a practice of checking your tire pressures and their condition at least monthly, if not weekly or even more often if you do a lot of miles!

That said, a good 'Rule of Thumb' to use to help you get your tire pressures close to the ideal pressures for YOU, the loads YOU carry in/on your vehicles, and the way YOU ride/drive in YOUR current ambient conditions & on the surfaces YOU are riding/driving on is 'the 4psi Rule'. There are others, chalking, measuring footprint length, actually doing the calculations for the load/conditions/major variables that might impact, & a whole bunch more, but for the time & effort it takes, the 4psi Rule is quite easily done, repeatable, and will get you very close to ideal pressure taking ALL of the variables into account for the riding/driving you've just done so that it gives you a fairly good guide for what's coming; and if you use it regularly then over time, then you will likely learn very quickly to get pretty good at estimating what changes you'll need to make for the riding/driving you are about to do - altho for our lightweight Spyders, any changes are likely to be minimal at best - which is why the 'about 18 psi for a/mkt tires across the board is always going to be pretty close!!

How do you apply this 4psi Rule - start by checking your cold start pressures before you ride/drive anywhere for the day, and then head off & ride for an hour or so (or as long as your regular ride/commute might be ) The aim is to see/achieve a 4psi increase in tire pressure after an hour's worth of riding/driving (or whatever/however long your regular ride/commute might be/take. ) An increase of MORE than 4psi means your cold start pressure was too LOW, add some air pressure NOW; while an increase of LESS than 4psi means your cold start pressure was too HIGH, reduce your cold start pressure before you next ride/drive. When you know which to do, add or subtract air as appropriate, it's a good idea to only change your pressures by 1/2 of the pressure difference between what your pressure actually got to after an hour's ride/drive and what it should have been if it went up by 4psi - and there's no real point in adjusting pressures by anything less than one whole pound of pressure! Any adjustment of less than 1psi is simply chasing your tail into the endless minutae of ever increasing but overall quite meaningless accuracy! So if you are within 1 psi of that 4psi increase, that's probably close enough for most riders/drivers, even if you might see the F1 Teams or other regular racers &/or professionals making smaller adjustments - for most of us, if the pressure is 1 psi LOWER than the 4psi, it's easier just to brake a little later, corner a little harder, or drive/ride maybe as much as 5mph faster; and if it's just 1 psi HIGHER than the 4psi, simply knock 5 mph off your speed & drive/ride accordingly. The point is that the 4psi thing is simply a gude to make it easier for you to get closer to the ideal/optimum pressure for your driving/riding, load, conditions etc, and there's no point in worrying about anythong nthat requires an adjustment of less than 1psi, it's really not going to make that much difference!

Sorry about the epic tome, but you did ask, and it's sorta hard to condense years of study & learning, experience, etc into a quick description.... . To be any more specific in answering YOUR question Vegas Dan, we really need that info I asked for at the top.

Over to y'all!

[VegasDan]

About 1500 miles on the new toy. Years of 2 wheel. I just seem to have issues with keeping a steady "set" thru a turn.
I turn into a corner and once the tire loads - it feels like it slips/ wobbles - unloads and Im chasing the nose.

[Little Blue]

....OEMS?
Do the Tips that Peter Aawen has Posted above.
The 4psi deal is worth a try. .....

[Peter Aawen]

About 1500 miles on the new toy. Years of 2 wheel. I just seem to have issues with keeping a steady "set" thru a turn.
I turn into a corner and once the tire loads - it feels like it slips/ wobbles - unloads and Im chasing the nose.

That sounds a whooole lot like you're still on the Kendas, and you REALLY NEED to keep them at the (higher) pressures the manual calls for! . That said, the Kendas WILL be the limiting factor for most Spyder riders who expect similar handling to their 2 wheelers; and it'll only be once you get rid of them that you'll realise how much BETTER than any 2 wheeler your Spyder can be! Sure, it'll be different in a lot of ways too, & not necessarily always as 'good', but when it comes to cornering and braking, especially in the twisties & short straights, if you are prepared to put in the effort to learn & do it right, your Spyder IS capable of significantly out performing anything on 2 wheels & most things on 4 to boot!

[VegasDan]

Yes still on Kendas. Brand new bike - hard to justify to myself dumping brand new tires when the issue may indeed be me.

[BLUEKNIGHT911]

About 1500 miles on the new toy. Years of 2 wheel. I just seem to have issues with keeping a steady "set" thru a turn.
I turn into a corner and once the tire loads - it feels like it slips/ wobbles - unloads and Im chasing the nose.

Dan, the Spyders are classified as Motorcycles for LEGAL reasons .... However they Don't, Won't and CAN'T respond to inputs like a two wheeler will. .... People who have bought Spyders and NEVER rode a two wheeler often learn how to drive a Spyder much sooner than those coming up from the two wheeler crowd. OE Kenda's are MARGINAL even for low weight Spyders, and until very recently were very prone to being Defective for a few different reasons. Good luck, & get auto tires when yours wear out ..... Mike

[Bfromla]

Yes still on Kendas. Brand new bike - hard to justify to myself dumping brand new tires when the issue may indeed be me.

part of learning curve. Get whatever life you can out of oem while researching/deciding upgrade replacements.
& alignment laser preferred. It may not have a drastic impact, but will be noticeable enjoy

[Piratezz]

Run those kenda's hard, and you'll need new AUTO Tyres, in just about 4500 miles, replace them with a good brand tyre, there's so much info on this site, you can't fantom that.
I run a Hankook RS4 tyre now, and it's making a huge difference, I read you are in the learning curve with your new spyder, loosen your grip, point the spyder in the right direction, hit the throttle, and in mid corner, you'll see what Spyders are all about.
Try on a open road, or a parking space, til you are formilar with the bike. It took me about 1000km's to get used to the Spyders behavior, and you can bring anything you want. The Spyder is very, very capable in the twisties, read my signature, and you'll see what I have done to improve my spyder

Don't change anything yet, not before you are completely comfortable on your spyder, then start with swaybar, auto tyres, if you are happy with that, don't forget the Shocks and a laser alligment, and the Spyder will reward you with miles of smiles!

[K80Shooter]

For what it's worth, here's my advice. Get the BaJa Ron sway bar, install it and then ride it for a while.

[FrogmanDave]

My dealer (and the BRP area rep) recommended I run my stock Kendas at 15 front and 26 rear. He even told me 13 may be more in line. According to the rep, Kenda changed the sidewalls a couple of years ago. I have read more about tires on this forum that I care to and none of it is good about the stock Kendas. I wonder if a lot of the information is based on some old tire composition/sidewall stiffness that no longer applies?

[WDAVEY]

About 1500 miles on the new toy. Years of 2 wheel. I just seem to have issues with keeping a steady "set" thru a turn.
I turn into a corner and once the tire loads - it feels like it slips/ wobbles - unloads and Im chasing the nose.

Dan, One other suggestion: push your outside leg into the floorboard when going through the curve. I found that my upper body was moving back and forth through the curve, causing inadvertent push/pull (unintentional) on the handlebars. My upper body motion was causing the bike to wobble.

[CloverHillCrawler]

Yes still on Kendas. Brand new bike - hard to justify to myself dumping brand new tires when the issue may indeed be me.

If you are still on kenda's it will not be long before you need a replacement anyway. My rear oem kenda was wasted at 6K miles. Love my new Quatrac's that I replaced the kendas with. Also take up the others recommendation on the baja ron sway bar. It does wonders for your riding pleasure!

[Peter Aawen]

My dealer (and the BRP area rep) recommended I run my stock Kendas at 15 front and 26 rear. He even told me 13 may be more in line. According to the rep, Kenda changed the sidewalls a couple of years ago. I have read more about tires on this forum that I care to and none of it is good about the stock Kendas. I wonder if a lot of the information is based on some old tire composition/sidewall stiffness that no longer applies?

Yeah, NO!

The latest Kendas that I've been hearing complaints about, seeing, & dissecting have had fairly recent date codes on them, and AFAI can see/measure, there's no obvious changes in the threads & plies of the tread or sidewalls (not yet, anyway!?), altho there have been some changes (improvements?? ) to the tread compound layers - they are a small percentage harder than they used to be and the various layers have been more carefully applied with fewer overlaps &/or misalignments than in previous years! . And that sorta leads on to the biggest change I've seen in Kendas over recent years, which has been a noticeable improvement in their quality control, such that more of their tires (but not yet ALL of them) appear to be fairly well made without anywhere near the former number of major defects built in - still lotsa little stuff tho, but at least there's not anywhere near the number of big bumps, bulges, out-of-round, de-laminations, &/or tread layers misaligned/sliding into the sidewalls than there used to be!

And in all fairness, I must admit that the Kanines have always been 'a little' better than the OE Spec Kendas (probably due to their slightly harder tread compound & thicker construction layers ) and these latest improvements have been reflected in the number of complaints about & failures being reported in any of the Kendas &/or their clones - the rate of both complaints & failures has been slowly dropping over the last few years, but that rate is still somewhat higher than for any other comparable style/size/price range 'normal' auto tires.

Still'n all, while the latest OE spec Kendas & their clones are quids ahead of what they were 10-12 years back, you hafta remember that they had MEGA-quids to catch up on, and even tho they are now 'a little' better than they were, they are still pretty crappy and are STILL the major drawback & limiting factor on your Spyder's rideability, road holding, and performance etc! . And that's fine if you're not asking too much of them, if you rarely ride (knowingly! ) anywhere near the limits you might expect them to be able to manage (but be warned, those limits are nowhere near as good as you might expect! ) so for some of the more conservative riders out there, they might even work reasonably well & last maybe as long as some of the really expensive high performance tires available.... but they are still pretty expensive for what you get/how long they last and I strongly believe they STILL ARE the biggest limiting factor on the performance of your Spyder!

Just Sayin'

[sdcatman]

I raised my front tires to 24 PSI and the handling improved dramatically.
2021 RT Limited
I am also a big boy 300#