You really
NEED to keep any Tire Size increase fairly proportional with the relationship between the (different rolling dia front to rear ) OE Tire Sizes & their relationship - so given a 5" increase in rim diameter, I'd guess that anything much larger than a fairly skinny tire with a max 35 profile up front is probably going to be too much for the 'Nanny' to handle over any significant distance! :shocked: Generally speaking, any increase much more than about a 1&1/2 inch increase in tire diameter on either end is going to be pushing the envelope of 'within the acceptable bounds' of variation for most VSS/Traction Control/Safety Systems (the 'Nanny') to manage....
So check the '
Revs per Mile' (or 'Revs per Km'
) info on your new 20" rim mounted front tires and match them to the OE Spec Kendas - if they aren't within just a few revs (maybe 10 or so?! :dontknow: ) then that could well be your problem
Uniekstylz (& maybe F3VE too?!) The difference in 'Revs per mile' and the tire's size increase due to the 5" larger dia rims
might juuust be '
within the acceptable bounds' with skinny enough low profile tires running at low speeds or even for short distances, but because the faster you go &/or the further you travel the greater the cumulative difference in 'revolutions turned' between the front and rear tires becomes, so the more likely you'll be to get these sorts of issues. :banghead:
The size increase on the rear is within the 'acceptable increase range' for the VSS etc
WITH NO OR MINIMAL TIRE SIZE CHANGE UP FRONT, but it might not be
enough of an increase to match the size increase up front due to the bigger rims! We really need to know more about the
TIRES & TIRE SIZE you've fitted up front, and ideally, also the 'revs per mile', the rolling circumference, &/or the 'rolling diameter' of those tires! If any of those are
significantly larger than the OE spec Kendas, then they just might be
TOO BIG or have
TOO MUCH of a difference for the 'Nanny' to handle; but if they are
juuuust a little bigger over-all, it comes back to how much of a tire size increase you've put on the rear! :lecturef_smilie:
Without knowing exactly which tire & the rest of that specific tire info mentioned above for
ALL the tires you've fitted,
AND without doing the actual calcs, I'd guess that you've probably only increased the actual rolling diameter on the rear of your Spyder by maybe as little as saaay, 1/2 to 3/4 of an inch, or possibly as much as a touch over 1 inch :dontknow: And that'd mean that if you've increased the rolling diameter of the front tires by anything much more than saaay 1 inch on the lower end of the scale or maybe 1 & 3/4 inches on the upper end (and I'd guess you're actually looking at an increase closer to at least 4"!! :yikes: ) then you're almost certainly running mis-matched tire sizes well beyond the Nanny's capabilities and you might need to re-consider your tire sizes on one or both ends!! :banghead: So by going from a
165 wide * 50 profile * R15 (the OE 165/50R15 Size?) to an
'anything much wider than saaay 125' * '35 profile or taller' * R20 tire up front, then you've probably exceeded that 'acceptable size increase limit'
significantly and you should
EXPECT these codes & Limp Home modes, if not immediately, then certainly as the cumulative revolutions per tire/end exceeds the Nanny's acceptable limits, despite the fact that 'she' is one of the best available & can 'learn' to handle most 'reasonable tire size changes'!! :shocked:
pps:
