Buddy Higher Top Speed After Zippy Tires Replacemnt

mattsyd · Post by **mattsyd** » Thu Aug 23, 2018 7:38 pm

I just put on my Zippy 1 tires (front & rear) on my Buddy 125 (which had stock tires on it). Iâ€™m very happy them! Great traction in the dry, and I look forward to testing them out in the wet as soon as it rains.

On to the problem:

I stayed with stock size (3.5x10) after much deliberation, so the the tires should be almost identical in size to the originals. Whatâ€™s interesting is that my speedometer is showing that my top speed has increased by about 5 mph (thatâ€™s an estimate after one quick ride), and just from riding experience it seems to me that the speedometer is reading more optimistic (by 3-5mph) than it was before the tire change.

There are a few things that could be going on: (1) the tires could be a slightly different size causing a change in speedometer reading, but I think this is very unlikely; (2) The bike feels more stable now than it did with the original tires at high speeds. So maybe the original tires werenâ€™t balanced good, and now the bike does actually have a slightly higher top speed and I just think Iâ€™m going slower at certain speedometer mph because Iâ€™m not used to such a smooth ride; (3) I messed up speedometer thingy (canâ€™t think of the name of it right now) when I put back on the front wheel.

Any thoughts?

Thanks everyone!

Stanza · Post by **Stanza** » Thu Aug 23, 2018 7:59 pm

Stiffer compound, with the tire riding more on the centerline vs squishing the rubber down for a wider contact patch.

jrsjr · Post by **jrsjr** » Thu Aug 23, 2018 8:49 pm

It's possible that it's a bit of both because rolling resistance is a small part of what limits top speed. Far more likely is that a size differential is causing your speedo to read a bit more optimistically. Still, if the ride feels more stable, that is a big bonus, so win-win IMHO.

GregsBuddy · Post by **GregsBuddy** » Thu Aug 23, 2018 9:22 pm

Tire pressure can make that much difference.

BuddyRaton · Post by **BuddyRaton** » Thu Aug 23, 2018 9:45 pm

New tires are like a new paint job...they both make a scooter faster!

mattsyd · Post by **mattsyd** » Fri Aug 24, 2018 1:19 pm

BuddyRaton wrote:New tires are like a new paint job...they both make a scooter faster!

Well, my scooters red, so itâ€™s already as fast as paint can make it ðŸ˜œ

mattsyd · Post by **mattsyd** » Fri Aug 24, 2018 1:21 pm

GregsBuddy wrote:Tire pressure can make that much difference.

Yeahâ€¦ I thought about that, but I was pretty good about being sure my tires or at the right pressure.

mattsyd · Post by **mattsyd** » Fri Aug 24, 2018 1:23 pm

jrsjr wrote:It's possible that it's a bit of both because rolling resistance is a small part of what limits top speed. Far more likely is that a size differential is causing your speedo to read a bit more optimistically. Still, if the ride feels more stable, that is a big bonus, so win-win IMHO.

Yeah, it could be both. And Iâ€™m very, very happy with the great traction, and overall better ride quality.

mattsyd · Post by **mattsyd** » Fri Aug 24, 2018 1:23 pm

Stanza wrote:Stiffer compound, with the tire riding more on the centerline vs squishing the rubber down for a wider contact patch.

Interesting point! I never even thought about that.

mattsyd · Post by **mattsyd** » Fri Aug 24, 2018 2:47 pm

Stanza wrote:Stiffer compound, with the tire riding more on the centerline vs squishing the rubber down for a wider contact patch.

Interesting point! I never even thought about that.

BuddyRaton · Post by **BuddyRaton** » Fri Aug 24, 2018 3:53 pm

And less contact patch on a new tire than old so less rolling resistance. I think it's a case of taking care of your ride and it taking care of you!

GregsBuddy · Post by **GregsBuddy** » Fri Aug 24, 2018 4:31 pm

mattsyd · Post by **mattsyd** » Fri Aug 24, 2018 4:31 pm

BuddyRaton wrote:And less contact patch on a new tire than old so less rolling resistance. I think it's a case of taking care of your ride and it taking care of you!

Yeah...contact patch is another thing I didnâ€™t think about. Good point.

Point37 · Post by **Point37** » Thu Aug 30, 2018 2:06 pm

i agree with these guys...you're going from an old set of tires that have been worn down (mostly in the middle typically) to a new set which aren't worn so the actual profile of the tire is different...the profiles of all tires can also be designed differently as well for different purposes/reasons...the steeper the profile the quicker the turn in...the flatter the profile the more stable and the bike will want to go straight

a speedo is calibrated by the factory based on new oem tires with oem pressures...so in theory as your tires wear (smaller circumference) your speedo will gradually read faster due to the smaller tire circumference and it will spin more times (or lower pressure creating a smaller circumference)...

in your case if your speeds are faster with new tires that would mean that your circumference is smaller than your old tires so either the pressures are lower or the tire profile is flatter...the only way you can tell is to measure it out on the ground with the old tires at pressure vs the new tires at pressure...align the valve stem at the bottom of the tire make a mark on the ground roll out one full rotation and mark the end on the ground and measure it with a tape measure...and then compare the measurements