oh my... low psi on car tire on Spyder works...

[aka1004]

I've been on here a long time but could not bring myself to low(to me) psi for car tires on Spyder.
mostly because under-inflation is a cardinal sin in my job but I finally went to low psi and my.... it works
I went to 14 in front and 18 in rear with all car tires(name left out on purpose)...
much better grip and no more of floating feeling on hard curves.

[Peacekeeper6]

I've been on here a long time but could not bring myself to low(to me) psi for car tires on Spyder.
mostly because under-inflation is a cardinal sin in my job but I finally went to low psi and my.... it works
I went to 14 in front and 18 in rear with all car tires(name left out on purpose)...
much better grip and no more of floating feeling on hard curves.

That's because your Spyder weighs A LOT less than your typical car.

And why would you leave out the name of the tire ?? Wouldn't you want to share your experiences to others who are wondering if that tire is right for them ??

[BLUEKNIGHT911]

I've been on here a long time but could not bring myself to low(to me) psi for car tires on Spyder.
mostly because under-inflation is a cardinal sin in my job but I finally went to low psi and my.... it works
I went to 14 in front and 18 in rear with all car tires(name left out on purpose)...
much better grip and no more of floating feeling on hard curves.

Well glad you are on board ..... However do you think Peter and I have been making up the " Tire Science " ..... IMHO 14 psi FRONT is ok for casual riding but I keep mine at 17 psi ,.. because I like it better in the " Twistie's " when I'm usually Pi**ing off Ms. Nanny :roflblack:.... Mike :thumbup:

[aka1004]

what was the consensus psi? front and back with car tires? I am definitely on aggressive side.

[aka1004]

That's because your Spyder weighs A LOT less than your typical car.

And why would you leave out the name of the tire ?? Wouldn't you want to share your experiences to others who are wondering if that tire is right for them ??

it was to not to start tire side of story but I have quatrac in 165 which I am sure most people here are familiar with in front and continental in rear( I don't remember which and hate, it came highly recommended but that may have been good for RT but not for RS)

[BLUEKNIGHT911]

it was to not to start tire side of story but I have quatrac in 165 which I am sure most people here are familiar with in front and continental in rear( I don't remember which and hate, it came highly recommended but that may have been good for RT but not for RS)

" Continental " .... I have Not recommended that brand for a few reasons .... the TWO best choices currently are the Quatrac and the Michelien Cross Climate ..... Mike :thumbup: .... TIRE psi .... AUTO tires only = 15 to 17 front & 18 rear ..... Mike :thumbup:

[Peter Aawen]

I've been on here a long time but could not bring myself to low(to me) psi for car tires on Spyder.
mostly because under-inflation is a cardinal sin in my job but I finally went to low psi and my.... it works
I went to 14 in front and 18 in rear with all car tires(name left out on purpose)...
much better grip and no more of floating feeling on hard curves.

That's still a sin aka, it's just that like Peacekeeper & others have said, your Spyder weighs a whole LOT less than the average car! :shocked:

Just keep in mind that while a really heavy stretch limo might need saay 45psi in the car tires it runs to do the necessary job under the heavy load the limo imposes; putting the very same tire on a much lighter Ford Focus means that you won't need anywhere near 45 psi in those same tires to carry the significantly lighter load imposed by the Focus cos it weighs in at about 1/2 the weight of the stretch limo - instead you'll likely only need something closer to saaay, 28-30psi.... :lecturef_smilie: . In a similar vein, taking that very same car tire that needs something like 30psi to carry the Ford Focus & putting it on a Spyder that weighs a LOT less again means that it just isn't going to need 30psi in it to carry the even lighter load of the Spyder - and running lower pressures like the 14/18 psi you have under your Spyder ISN'T under-inflating those tires, it's just that the lighter load of your Spyder doesn't need as much air pressure in those car tires as they would need if they were carrying a much heavier car or an even heavier stretch limo! :rolleyes:

That said, like Mike, I usually run my tires a little higher in the front when I'm working it hard in the twisties, but I still wouldn't generally recommend going too much below 12-14psi in any car tire fitted to a Spyder, cos not only would it likely start costing you in terms of getting noticeably fewer miles per gallon, but pressures any lower than that very likely WOULD be under-inflating them, especially for running anything much more than saaay 30 mins at hwy speeds on the open road, &/or if you are working it hard thru the twisties. But now you've tried them, those lower pressures in car tires really do work pretty well under your Spyder, don't they?! :ohyea:

[Isopedella]

While I dont usually ride aggressively there are the odd Ye Ha moments when I get into a corner maybe a bit hot.
Bit of practice is time well spent so there are no surprises and you know within yourself, well its not really a big deal.

Watching with interest.

[Piratezz]

I for one, was also sceptical bout the lower pressure, but after biting the bullet :) I run 1.2 Bar (17.5 psi) in the fronts, Michelin Cross Climate's - rear 2.4 bar (34 psi) still on the crapenda :(
AND I JUST LOVE IT.....

[RudyB]

" Continental " .... I have Not recommended that brand for a few reasons .... the TWO best choices currently are the Quatrac and the Michelien Cross Climate ..... Mike :thumbup: .... TIRE psi .... AUTO tires only = 15 to 17 front & 18 rear ..... Mike :thumbup:

What’s your reason for not recommending Continentals I have them on my Spyder 50000miles so far still plenty of tread left

[troop]

Hell .. I just set my new Fobo II numbers to 18/18/18. I'll stick with it unless something feels wonky :)

[Navydad]

Hell .. I just set my new Fobo II numbers to 18/18/18. I'll stick with it unless something feels wonky :)

I run 18 all the way around. Lots of two up riding and hit the twisties pretty hard. 18 in all three works for me and it's easy to remember.

[oldgoat]

REAR TIRE:-

I had 17.5psi in my Kumho Ecsta for 4 seasons. The centre of the tread was wearing down faster than the outsides.

This season I have 15psi in the hope of making it last longer.

[BLUEKNIGHT911]

What’s your reason for not recommending Continentals I have them on my Spyder 50000miles so far still plenty of tread left

Well 50,000 + miles ..." and plenty of tread left " .... would be reason #1, ...... that reports that it isn't very good in the wet ...or dry for that matter ....would be #2 .... and taking the advice of those who rely on " Butt theory " would be #3 .... etc etc .... JMHO .... Mike :thumbup:

[troop]

What’s your reason for not recommending Continentals I have them on my Spyder 50000miles so far still plenty of tread left

50K miles on the same tire? That tire compound has to be hard as a rock.

[T.P.]

Hell .. I just set my new Fobo II numbers to 18/18/18. I'll stick with it unless something feels wonky :)

I just installed our FOBO's this week and they all got set at 17.7 fronts and rears. Q5's on mine Q's on the MRS.
Will adjust as the outside temps increase during the Summer.

T.P.

[2dogs]

Hell .. I just set my new Fobo II numbers to 18/18/18. I'll stick with it unless something feels wonky :)

18 seems to be the up and coming magic number for PSI all the way around. I'm using almost the same settings, but if you have FOBO's you can watch those numbers change by the hour, they're nonstatic for many reasons. I'm pretty anal about my PSI MPG and PSA. So I'm glad to see we all seem to be in the same ballpark at least for safety reasons anyway.

[sledge]

I just put 3 new car tires on my RTS ( Kumho Escta 225/50R15 ) & ( Sincera 165/65R14 ) about 2 weeks ago ... I put 20 lbs. in each of them , have only put maybe 200 miles on it so far , but... handles and rides really good . good for me anyway.

[CloverHillCrawler]

I have put the new Quatrac's on the Front/Back.

165/60/15 on the front

205/60/15 on the rear.

16 is the magic number all of the way around for me and if I go to 17-18 my rear tire starts chirping when going around corners.

[BLUEKNIGHT911]

I have put the new Quatrac's on the Front/Back.

165/60/15 on the front

205/60/15 on the rear.

16 is the magic number all of the way around for me and if I go to 17-18 my rear tire starts chirping when going around corners.

IMHO " chirping " = Traction .... not a bad thing ..... Mike :thumbup:

[Mikey]

Chirping is the sound you get to tell you that you are on the hairy edge, of that tire's traction for the set up! Push it any harder and you will see where you been instead of where you are going! Driving Autocross taught me that, I have done a few loopy loops!! Hell of a lot of fun with a car, not so much with a BIKE!

[Sarge707]

I have 22-23 in my Kumho Ecsta rear on my F3 and it slips when I downshift pretty easy. Wears great but stock tire was better. IMO

[BLUEKNIGHT911]

I have 22-23 in my Kumho Ecsta rear on my F3 and it slips when I downshift pretty easy. Wears great but stock tire was better. IMO

Because that Kumho is a Car tire at your PSI ....it's 4 to 5 lbs psi to high ..... Ask Peter .... Mike :thumbup:

[Wahrsuul]

Many people seem to think that the Max Inflation listed on the tire is what they're supposed to be at. I've gotten into arguments with people over that when I tell them to use the decal inside the driver's door (usually). Tire manufacturer's don't know what vehicle that tire is going on or for what use.

If you want to get really precise, do the chalk or water test to set the pressures.

[2dogs]

So few folks know about the water or chalk test. It's so simple and quick.

[sledge]

I have put the new Quatrac's on the Front/Back.

165/60/15 on the front

205/60/15 on the rear.

16 is the magic number all of the way around for me and if I go to 17-18 my rear tire starts chirping when going around corners.

Well...... this is the first thing I have heard or seen about this, I have been hearing a little chirping noise when pulling out and cornering ... I thought it was the drive belt.
But now that you've said this, I am pretty sure that's what I am hearing too... Thank you for the Info.

[Knizar]

Well...... this is the first thing I have heard or seen about this, I have been hearing a little chirping noise when pulling out and cornering ... I thought it was the drive belt.
But now that you've said this, I am pretty sure that's what I am hearing too... Thank you for the Info.

The chirping could also be your wheel bearings! "Just something to think about".......:thumbup:...Bill

[Frankf]

So few folks know about the water or chalk test. It's so simple and quick.

Explain.....

[2dogs]

Explain.....

Make a chalk line across your tire in the area of the valve stem. (Makes it easier to find.) Drive a short distance and check the line. It should disappear evenly. If not adjust PSI so it does.

[BLUEKNIGHT911]

what was the consensus psi? front and back with car tires? I am definitely on aggressive side.

" Consensus " - Do you think at a race track they poll the Entire Pit crew to decide what PSI they will use. ... To me " consensus is similar to S.W.A.G. ..... good luck ....Mike :thumbup:

[Peter Aawen]

Make a chalk line across your tire in the area of the valve stem. (Makes it easier to find.) Drive a short distance and check the line. It should disappear evenly. If not adjust PSI so it does.

I generally recommend a big wide band of chalk instead of just a line, 2dogs - preferably at least covering 3 tread blocks width at the circumference & extending from those 3 blocks right across the tread face! ;)

This is to also show the wear pattern on the tread blocks themselves; cos if you just put a line across a single tread block, especially one on the edge of the tread face, the wear pattern on the edge blocks in particular may 'heel/toe' or 'scallop', and that could mean the narrow strip of that tread block where the line is just gets completely missed, making the viewer think their pressure is still too high when it may not be; or vice versa!! :shocked: . With a big wide band of chalk mark across the tread face, you'll be able to see PDQ what your tread wear pattern is doing on any of those tread blocks, and if you do that soon enough after fitting new tires, that might mean you catch the developing wear pattern rather than an established wear pattern, so you juuust might be early enough to rectify things & save that tire or set of tires from early retirement due to abnormal tread wear!! :banghead:

Just Sayin' :thumbup:

[PW2013STL]

So few folks know about the water or chalk test. It's so simple and quick.

I told someone at Spyderfest how to do this and he was amazed.

[ButterSmooth]

Using the 'load and load rating' method I arrived at somewhat different pressures.

Rear with a Yoko 92H (1400# rating @51psi) and 450# load (road scale) calculates to ~16psi. 1400 / 51 = 27.45 #load per psi. 450# / 27.45 = 16.39psi.

Front Vredstein 980# rating @51#, 375# load (750# on front) calculates to 19.5psi. 980 / 51 = 19.21# load per psi. 375# / 19.21 = 19.5psi.

The smaller front tires with the higher front load require more pressure. At 16psi my fronts seemed fine, but emergency maneuvers (rock dodge) made them collapse under the load. 14psi sounds scary soft to me.

[2dogs]

I generally recommend a big wide band of chalk instead of just a line, 2dogs - preferably at least covering 3 tread blocks width at the circumference & extending from those 3 blocks right across the tread face! ;)

This is to also show the wear pattern on the tread blocks themselves; cos if you just put a line across a single tread block, especially one on the edge of the tread face, the wear pattern on the edge blocks in particular may 'heel/toe' or 'scallop', and that could mean the narrow strip of that tread block where the line is just gets completely missed, making the viewer think their pressure is still too high when it may not be; or vice versa!! :shocked: . With a big wide band of chalk mark across the tread face, you'll be able to see PDQ what your tread wear pattern is doing on any of those tread blocks, and if you do that soon enough after fitting new tires, that might mean you catch the developing wear pattern rather than an established wear pattern, so you juuust might be early enough to rectify things & save that tire or set of tires from early retirement due to abnormal tread wear!! :banghead:

Just Sayin' :thumbup:

My father-in-law showed me that trick years ago. He used to build custom trailers and to determine the PSI to recommend to his customers he used the chalk method. He did use a large piece of chalk the size kids use on sidewalk games. That piece of chalk is still sitting on a shelf in the shop. I wonder about using a wide strip of white spray paint. He told me he was told about that chalk method back during WWII when you had to use ration stamps to purchase tires. Tires had to last a long long time between purchases so you didn't want to wear them out too soon.

[Wahrsuul]

Spray paint might work too, but then you have paint down in the tread till it wears off, and paint on the driveway when it comes off the tire. If you have a concrete driveway, a thin layer of water work too. A thin layer of water on the concrete, ride through slowly and see what the tread pattern looks like.

[newdave]

Spray paint might work too, but then you have paint down in the tread till it wears off, and paint on the driveway when it comes off the tire. If you have a concrete driveway, a thin layer of water work too. A thin layer of water on the concrete, ride through slowly and see what the tread pattern looks like.

Grandpa showed me this one in the '70s. Works every time!

[2dogs]

Spray paint might work too, but then you have paint down in the tread till it wears off, and paint on the driveway when it comes off the tire. If you have a concrete driveway, a thin layer of water work too. A thin layer of water on the concrete, ride through slowly and see what the tread pattern looks like.

Yes, concrete. Not blacktop. Blacktop is not smooth enough and do it in the shade because the water evaporates fast.

[FrogmanDave]

I generally recommend a big wide band of chalk instead of just a line, 2dogs - preferably at least covering 3 tread blocks width at the circumference & extending from those 3 blocks right across the tread face! ;)

That's some darn good information there!

[Peter Aawen]

Using the 'load and load rating' method I arrived at somewhat different pressures.

Rear with a Yoko 92H (1400# rating @51psi) and 450# load (road scale) calculates to ~16psi. 1400 / 51 = 27.45 #load per psi. 450# / 27.45 = 16.39psi.

Front Vredstein 980# rating @51#, 375# load (750# on front) calculates to 19.5psi. 980 / 51 = 19.21# load per psi. 375# / 19.21 = 19.5psi.

The smaller front tires with the higher front load require more pressure. At 16psi my fronts seemed fine, but emergency maneuvers (rock dodge) made them collapse under the load. 14psi sounds scary soft to me.

Don't forget that's for your loads & your choice of tires/tire size, Butters - other peoples may be different! :lecturef_smilie:

And it's probably worth bearing in mind that the tire itself (not incl the tread! ;) ) is effectively just a bag that carries the load put on it - use a smaller bag for a given load & it'll need more pressure than a larger bag asked to carry that same given load! :thumbup: . So if you go bigger (or stronger ;) ) in the tire you're running, you'll likely need a lower pressure; wheras if you go smaller (or weaker ;) ) you'll generally need a higher pressure! :ohyea: ..... And only then can you start to work on the problem of how to get the tread up to its operating temp for it to provide the traction you need! :rolleyes:

Simples, innit?! :cheers:

[ButterSmooth]

Don't forget that's for your loads & your choice of tires/tire size, Butters - other peoples may be different! :lecturef_smilie:

And it's probably worth bearing in mind that the tire itself (not incl the tread! ;) ) is effectively just a bag that carries the load put on it - use a smaller bag for a given load & it'll need more pressure than a larger bag asked to carry that same given load! :thumbup: . So if you go bigger (or stronger ;) ) in the tire you're running, you'll likely need a lower pressure; wheras if you go smaller (or weaker ;) ) you'll generally need a higher pressure! :ohyea: ..... And only then can you start to work on the problem of how to get the tread up to its operating temp for it to provide the traction you need! :rolleyes:

Simples, innit?! :cheers:
:bowdown::bowdown::bowdown: Couldn't agree more... I just can't afford that many words! Thanks for filling in the gaps!:thumbup: