rear tire size 225/50/15 or 215/60/16 or?

[ARCTIC]

I see that many who have replaced the rear tire with a car tire have gone with a 215/60/15 versus the stock tire size of 225/50/15. Is the reason for the different size only to get the specific brand/model of tire that you prefer? I ran a tire size calculator and the 215/60/15 is a larger diameter than the stock tire.

[jerpinoy]

Is there any adverse effect to use it vice the oem tire?

[Bob Denman]

Can anybody tell me what is wrong with the stock sizes?

[ARCTIC]

Can anybody tell me what is wrong with the stock sizes?

The only thing I can see is that you're limited on tire selection in the 225/50/15 size according to tirerack.com's inventory. The only low priced tire is the Kumho Escsta at $67 otherwise they're all $150+ in that size. The 215/60/15's do have a large selection but you're increasing the diameter of the tire. The miata.net calculator shows 5.4% larger so at 60mph you're actually going 63.1mph. That would be damn close to fixing my speedometer because it reads high all the time so when it says 62mph, I'm going 60. I'm leery of changing tire size because I think I have an extra sensitive nanny at the reigns of my spyder.

[reverendg]

I imagine changing all three tires at once with a similar change in diameters would negate any possible nanny problems.

[Bob Denman]

Tirerack ain't the only place selling tires...
I've had three shoes out back on mine...
The OEM
Falken ZE 192
Kumho Ecsta
The OEM ogt spin-happy as it wore; it'd lose traction on a dog turd as the end grew near...
The Falken got a bit lossey-goosey in the wet once it was worn about out...
The Kumho sitll is pretty new; it needs a bit more testing...

[ARCTIC]

I imagine changing all three tires at once with a similar change in diameters would negate any possible nanny problems.

I'm not going to swap out the front tires that have TONS of useful life left in them and bear that expense for the speedo correction.

Tirerack ain't the only place selling tires...
I've had three shoes out back on mine...
The OEM
Falken ZE 192
Kumho Ecsta
The OEM ogt spin-happy as it wore; it'd lose traction on a dog turd as the end grew near...
The Falken got a bit lossey-goosey in the wet once it was worn about out...
The Kumho sitll is pretty new; it needs a bit more testing...

Are you using 225/50/15's? I just used tirerack because it's easily searchable and a large retailer. This give a good "feel" of the selection that's available. I wont buy my tires from them when I purchase (soon)

[ARCTIC]

I just got to thinking..... if the spyder reads the speed for the speedometer from the front wheels, the rear tire size will have no affect on the speedometer.... so does anyone know where the speed is picked up?

[Bob Denman]

We need somebdoy brave enough to find out; we need a bike taken out to a safe place, and have the rear tire lit up on take-off! If the rider notices freaky speedometer readings; we'll know that it's pulled from the rear wheel...
If all remains calm and normal; it's taken from the fronts.

[reverendg]

All you need is someone with an SM5 to pop the clutch and watch the speedo while the tire spins, or an se5 on some slick pavement.

[Bob Denman]

Any takers out there??

[reverendg]

Its the rear tire. Spun it up on the dirt on our apron, was barely moving forward and speedo read 20 mph

[Bob Denman]

That sure sounds as if it's taking the reading from the rear tire...
Thanks, Reverendg!

[ARCTIC]

I could just put mine on the Jack and fire it up to see if the speedometer moves BUT I'm all for tire smoke and fun such as that

[ARCTIC]

What size tire are u running Bob?

[OldCowboy]

When does changing the rear tire size cause Nanny to think either the rear tire is spinning too fast or the front tires are? At some point won't the TCS think the relative tire speeds between front and rear are out of whack and kick in some corrective measures?

[ARCTIC]

When does changing the rear tire size cause Nanny to think either the rear tire is spinning too fast or the front tires are? At some point won't the TCS think the relative tire speeds between front and rear are out of whack and kick in some corrective measures?

Yeah, I think so. Probably be more sensitive in turns?

[r1100rider]

I see that many who have replaced the rear tire with a car tire have gone with a 215/60/15 versus the stock tire size of 225/50/15. Is the reason for the different size only to get the specific brand/model of tire that you prefer? I ran a tire size calculator and the 215/60/15 is a larger diameter than the stock tire.

I'm running the 215/60/15 on 2 spyders no problems yes more choices in tires than the stock size and its very close in diameter but a 1/4 in less tread face width the wear of the hydro edge is amazing the toyo proxies didn't wear any better than stock do what you want but I love my hydro edge and it looks like it mite just be my last tire ill have to buy that was one of the things I was looking forward to with a spyder over my bike ,getting car tire like wear instead of a new rear tire every 3000 miles but the stock tires disappointed just put a high mileage Michelin on and forget about tires and ride instead. IMHO

[Bob Denman]

I'm runing OEM-sized tires...
225/50-r15

[BLUEKNIGHT911]

IRE

I see that many who have replaced the rear tire with a car tire have gone with a 215/60/15 versus the stock tire size of 225/50/15. Is the reason for the different size only to get the specific brand/model of tire that you prefer? I ran a tire size calculator and the 215/60/15 is a larger diameter than the stock tire.

I know the answer to this I've posted it a SAJILLION times so I'm not going to tell you.......Do the SEARCH THING......Mike .....................But I will advise you this ABSOLUTELY ....DO NOT MOUNT A 16 INCH TIRE ON YOUR OEM RIM

[Bob Denman]

[reverendg]

IRE

I know the answer to this I've posted it a SAJILLION times so I'm not going to tell you.......Do the SEARCH THING......Mike .....................But I will advise you this ABSOLUTELY ....DO NOT MOUNT A 16 INCH TIRE ON YOUR OEM RIM

GO ahead, let him try....I don't see it hurting anything. No way you could get it to seat and take air anyways.

[ARCTIC]

IRE

I know the answer to this I've posted it a SAJILLION times so I'm not going to tell you.......Do the SEARCH THING......Mike .....................But I will advise you this ABSOLUTELY ....DO NOT MOUNT A 16 INCH TIRE ON YOUR OEM RIM

So I hit the "dumb question" that wont be answered because I can't find it in a search?

[BLUEKNIGHT911]

So I hit the "dumb question" that wont be answered because I can't find it in a search?

To be most accurate I will use revolutions per mile to show you just how close in size these TWO sizes are.......the 225/50-15 goes 869 revs per mile......the 215/60-15 ( and I'm sure you meant 15 not 16 )goes from 827 to 828 for four tires I checked ...two others were 837 & a FUSION at 845 but these were the exception..........Soooooooooooooo this small a difference would not be noticed by the seat of your pants ....or the " NANNY " .....it will effectively lower (?) your gearing ....Like giving you an extra tooth on the SPROCKET so to speak............I hope this Helps you out....Mike...

[ulflyer]

I've had two of the 215's on mine: first was a General Altimax and second on now is Pirelli P4. First one ran 1 MPH over indicated, based on GPS; second runs about 1 1/2 MPH over. Swapped out the General Altimax at just over 10,000 but it still had a couple thousand or more left. Pirelli now has 7K plus and still looks new running 20lb air since new with no discernable center wear.

FWIW, I swapped out the OEM at 10K but it had a couple or more thousand left on it.

I got both car tires from Discount Tire and had them dealer mounted who charges 1 hr labor.