2LikesWhy are 4wd front carpet/turf tires much smaller than rears?
12-07-2021, 07:40 PM
#1
Why are 4wd front carpet/turf tires much smaller than rears?
Any input on this? Specifically the diameter.
12-07-2021, 08:05 PM
#2
^Specifically which tyre are you referring to? Off road tyres frequently vary in diameters between models of the same brand, unlike on road tyres which are broadly similar. IME, astro tyres have been the same diameters front to rear IIRC. The fronts are much thinner width wise to reduce steering and prevent traction roll......
12-07-2021, 08:22 PM
#3
Schumacher cactus, Proline hexon and prizm rears - with their front cactus, fusion and prizm. They are all about 4 to 6mm smaller in diameter. Probably not a huge deal if running a center diff, but I prefer a slipper on carpet. The only front I've seen recently that matches closely is the Schumacher wide stagger rib.
12-07-2021, 09:08 PM
#4
Tech Master
iTrader: (16)
Schumacher cactus, Proline hexon and prizm rears - with their front cactus, fusion and prizm. They are all about 4 to 6mm smaller in diameter. Probably not a huge deal if running a center diff, but I prefer a slipper on carpet. The only front I've seen recently that matches closely is the Schumacher wide stagger rib.
Of course, that's a guess and I could be wrong.
12-08-2021, 01:01 AM
#5
I suspect it is just because Schumacher made the original low profile Cut Stagger smaller because it was meant for a 2wd car, and then when it worked well, versions of it were made for 4wd. Why change the diameter of something that works?
12-08-2021, 06:59 AM
#6
There are too many variables to address every possible option, but generally all the choices are to handle various desired tuning options for grip/handing.
There was a shift to remove foam inserts from the front which improves tire wear and increases grip at the same time, however older design sidewalls are too flexible and require inserts for proper support, the lower profile sidewall doesn't need inserts to get these gains. Another added benefit with a reduced diameter on front is called "overdrive" so the front wheels spin faster and "pull" the car through the corners.
Many years ago (on a clay track) I experimented with recycling front 2wd tires on my 2WD buggy and installed them on my 4WD for quals. I was surprised with the results and started a local trend because this lightened the rotating mass and improved acceleration. I also found that stretching 2WD tires on 4WD wheels also created the same effect described above with the benefits of reducing the diameter . This caused a stink and I contacted ROAR to verify what I was doing was within the rules which only state max dimensions there are no minimums in the specs. It was just a matter of time before the manufactures effectively made equivalent of what I already learned an effective tuning option on clay but did this for turf.
There was a shift to remove foam inserts from the front which improves tire wear and increases grip at the same time, however older design sidewalls are too flexible and require inserts for proper support, the lower profile sidewall doesn't need inserts to get these gains. Another added benefit with a reduced diameter on front is called "overdrive" so the front wheels spin faster and "pull" the car through the corners.
Many years ago (on a clay track) I experimented with recycling front 2wd tires on my 2WD buggy and installed them on my 4WD for quals. I was surprised with the results and started a local trend because this lightened the rotating mass and improved acceleration. I also found that stretching 2WD tires on 4WD wheels also created the same effect described above with the benefits of reducing the diameter . This caused a stink and I contacted ROAR to verify what I was doing was within the rules which only state max dimensions there are no minimums in the specs. It was just a matter of time before the manufactures effectively made equivalent of what I already learned an effective tuning option on clay but did this for turf.
12-08-2021, 08:12 AM
#7
Tech Master
iTrader: (16)
There are too many variables to address every possible option, but generally all the choices are to handle various desired tuning options for grip/handing.
There was a shift to remove foam inserts from the front which improves tire wear and increases grip at the same time, however older design sidewalls are too flexible and require inserts for proper support, the lower profile sidewall doesn't need inserts to get these gains. Another added benefit with a reduced diameter on front is called "overdrive" so the front wheels spin faster and "pull" the car through the corners.
Many years ago (on a clay track) I experimented with recycling front 2wd tires on my 2WD buggy and installed them on my 4WD for quals. I was surprised with the results and started a local trend because this lightened the rotating mass and improved acceleration. I also found that stretching 2WD tires on 4WD wheels also created the same effect described above with the benefits of reducing the diameter . This caused a stink and I contacted ROAR to verify what I was doing was within the rules which only state max dimensions there are no minimums in the specs. It was just a matter of time before the manufactures effectively made equivalent of what I already learned an effective tuning option on clay but did this for turf.
There was a shift to remove foam inserts from the front which improves tire wear and increases grip at the same time, however older design sidewalls are too flexible and require inserts for proper support, the lower profile sidewall doesn't need inserts to get these gains. Another added benefit with a reduced diameter on front is called "overdrive" so the front wheels spin faster and "pull" the car through the corners.
Many years ago (on a clay track) I experimented with recycling front 2wd tires on my 2WD buggy and installed them on my 4WD for quals. I was surprised with the results and started a local trend because this lightened the rotating mass and improved acceleration. I also found that stretching 2WD tires on 4WD wheels also created the same effect described above with the benefits of reducing the diameter . This caused a stink and I contacted ROAR to verify what I was doing was within the rules which only state max dimensions there are no minimums in the specs. It was just a matter of time before the manufactures effectively made equivalent of what I already learned an effective tuning option on clay but did this for turf.
12-08-2021, 08:58 AM
#8
That all makes sense except for the smaller diameter causing overdrive. Would the smaller front not cause underdrive as the rollout will be less with a smaller diameter. A local guy here will try old 2wd fronts on his 4wd on occasion. It's a tuning tool for sure. Lots of ways to use tires and rims to create different handling effects.
So in my mind, the smaller the diameter, the more revolutions the wheel will spin and this is what makes me believe this is called overdrive.... it's been too long for me to recall the change in handling I was experiencing, but there a pretty good explanation here on the effects:
Underdrive and Overdrive
12-08-2021, 09:00 AM
#9
That all makes sense except for the smaller diameter causing overdrive. Would the smaller front not cause underdrive as the rollout will be less with a smaller diameter. A local guy here will try old 2wd fronts on his 4wd on occasion. It's a tuning tool for sure. Lots of ways to use tires and rims to create different handling effects.
12-08-2021, 12:05 PM
#10
Exactly. The front and back tires would be fighting each other. On full size cars this will almost keep a car from moving if it has a lockable transfer case. If running a slipper, It has to cause significant drag. I'm working on narrowing some rear tires to mount on front rims and see if there's a noticeable speed/handling difference. The lowest profile rear tires I have are prizms. Anyone know of smaller diameter rear carpet tires?
12-08-2021, 12:07 PM
#11
Tech Rookie
Schumacher cactus, Proline hexon and prizm rears - with their front cactus, fusion and prizm. They are all about 4 to 6mm smaller in diameter. Probably not a huge deal if running a center diff, but I prefer a slipper on carpet. The only front I've seen recently that matches closely is the Schumacher wide stagger rib.
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