Oversize tire for 170i

[GregsBuddy]

Hola,
Yes, I did a search but didn't find what I'm looking for.
It's about time to change the rear tire on the 170i. I'd like to use an oversize tire, not for additional width but to change the final gear ratio for more "relaxed" 55-60 MPH riding. At these speeds the engine is spinning pretty quickly. The scoot' has plenty of power for low speed acceleration but I'd like more upper speed power available. (I know aero drag is the largest loss at high speeds. Also, I like the handling at upper speeds and find the scoot' plenty stable.)
Anyone else change to a larger tire for this reason?
If so, what size tire have you tried?
Thanks!

[DeeDee]

viewtopic.php?t=23429&highlight=130+7010

[GregsBuddy]

Thanks!
I'm going to try the 130/70, Continental Zippy-1's as a replacement for the 3.50-10 originals. I'm only looking for a final ratio improvement and hope the extra width doesn't mess up the handling.
Hmmm, maybe the 120/70-10 is a better size to keep the width close and still gain higher final ratio.

[DeeDee]

I ran a 130/70-10 on the rear of my 170i for a while. I wasn't that impressed. It wore out really fast. Below is a chart so you can compare sizes.

Be aware of the speed rating. I'm pretty sure the stock tires are rated at 57mph which is a bit under the scooter's top speed.

[jd]

I ran a 130/70-10 on the rear of my 170i for a while. I wasn't that impressed. It wore out really fast. Below is a chart so you can compare sizes.

Be aware of the speed rating. I'm pretty sure the stock tires are rated at 57mph which is a bit under the scooter's top speed.

If that's true, then I suspect the rating is significantly under top speed on a 170i. My Blackjack 150 does 68-69 MPH GPS with a 160 lbs. rider aboard (tested in both directions on an expressway). I imagine a 170i would do at least 4-5 MPH better than that!

[GregsBuddy]

On the Heidenau Specification Sheet both tire sizes (3.50-10 & 130/70-10) have a 118 MPH rating.
Did your tire wear in the center rapidly?
The sheet indicates a maximum load of 243 & 551 pounds respectively. The wheel width is not compatible in the sheet. I don't think I know better that the manufacturer but I really want the higher final drive ratio.

[350kmi]

I actually did a similar tire size upgrade on my Honda Elite 110cc. The top speed the Elite is limited by engine rpm/governor rather than drag. When I took the Elite to work would it spend about half the trip sitting on the governor, so I figured the engine had plenty for power to pull a higher ratio.

The Elite 110 uses same the stock 100/90-10 (or 3.50-10) tire size as my 170i. I went up to a 4.00 - 10 sized Bridgestone ML16 on the Elite, it's slightly wider than the stock but most of the difference is in diameter. It was a tight fit sliding the tire/wheel assemble back onto the rear axle due the exhaust bosses on the back side of the engine, but once in place on the everything cleared fine. (Airing down the tire helped.) The scoot still bumps the governor, but the top speed has gone up by 3 MPH (48 to 51) so there might be a similar gearing change for your cruising on the Buddy.

I haven't tried the 4.00 - 10 size on my 170i, so I can't say it will work, but since both scoots start with the same stock size its possible.

[DeeDee]

The 4 x 10 is taller than the 130/70-10. I don't know if there is enough clearance on the rear fender to run a 4 x10 on the Buddy. The 130/70-10 was a pretty tight fit. 4 x 10 is a fairly rare tire size. Not a lot of options out there.

[GregsBuddy]

The new Conti Zippy-1, 130/70-10 tire arrived and is quite a bit wider and about 6% taller.
I'm looking forward to trying it when the stock Conti wears out.

[iamryan25]

I've been running a 130/70-10 for at least 3,000 miles now. There was a noticed difference in ride comfort with the larger tire. Rolling over bumps improved from very noticeable (on the 3.5-10) to not bad with the 130/70-10. Rolling into turns became very smooth and fun.

After having ridden in wet, cold, and slippery conditions (including ice and snow) with the 130-70 as well as the 3.5-10 rear tires, there is an obvious loss of traction on turns with the larger rear tire. I'm concerned about the mismatched tire sizes between the front (110-80) and the rear (130-70) being the cause of this issue.

There is a noticed feeling of loss of traction during turning on anything except for dry road. I've even felt this loss of traction during cornering on sandy/dirty dry roads, with less concern as the dry roads are far more forgiving. I am confident the issue I'm experiencing is related to mismatched tire sizes.

I expect the squirrelly feeling I'm experiencing to go away once I install matching tire sizes once again. Has anyone else noticed what I'm describing? Anyone returned to matching sizes after having mismatched sizes?

[paracer]

So, what would be the proper front tire size to go with a 130/70-10 rear? The obvious answer is 13/70-10, but will it fit?

[wheelbender6]

Concerns about speedometer error prevent riders from changing front tire size. My Buddy speedo is around 5 mph optomistic from the factory. Maybe somebody will discover a tire size that will make the speedo More accurate.

[iamryan25]

So, what would be the proper front tire size to go with a 130/70-10 rear? The obvious answer is 13/70-10, but will it fit?

The 130/70 fits the rear only. I believe 110/80-10 is the largest you can match on the front and the rear [without any additional modification to the scooter]

Concerns about speedometer error prevent riders from changing front tire size. My Buddy speedo is around 5 mph optomistic from the factory. Maybe somebody will discover a tire size that will make the speedo More accurate.

If you wan't accurate more speedometers, you'd need a smaller front tire -- however GPS is the only way to get the most accurate speeds on these Buddy scooters.

I used https://www.tacomaworld.com/tirecalc to find out what the differences were.

It will also tell you what the change in speedometer reading will be.

This is a comparison between a 90/90-10(nearly 3.5-10) and 110/80-10.

Speedometer Difference
Speedo Reading Actual Speed
20 mph (32.19 km/h) 20.67 mph (33.27 km/h)
25 mph (40.23 km/h) 25.84 mph (41.59 km/h)
30 mph (48.28 km/h) 31.01 mph (49.91 km/h)
35 mph (56.33 km/h) 36.18 mph (58.22 km/h)
40 mph (64.37 km/h) 41.35 mph (66.54 km/h)
45 mph (72.42 km/h) 46.51 mph (74.86 km/h)
50 mph (80.47 km/h) 51.68 mph (83.18 km/h)
55 mph (88.51 km/h) 56.85 mph (91.49 km/h)
60 mph (96.56 km/h) 62.02 mph (99.81 km/h)
65 mph (104.61 km/h) 67.19 mph (108.13 km/h)

Differences between 1-2 miles per hour when going to the 110/80. So you're adding 1 or 2 miles per hour to the error with this tire size -- not much difference at all.

[Iowa Racer]

I just installed the Michelin S1 tires 130/70-10 rear 110/80 -10 front. They are a perfect fit. I will ride them for a while and report. 28 psi rear 26 psi front.

[babblefish]

Concerns about speedometer error prevent riders from changing front tire size. My Buddy speedo is around 5 mph optomistic from the factory. Maybe somebody will discover a tire size that will make the speedo More accurate.

While the speedo may be inaccurate, the odometer is just about spot on. Since both are driven off the front wheel, doing anything that makes the speed reading more accurate will cause errors in the odometer reading. So I guess one has to decide which reading is more important.

[paracer]

So, what would be the proper front tire size to go with a 130/70-10 rear? The obvious answer is 13/70-10, but will it fit?

The 130/70 fits the rear only. I believe 110/80-10 is the largest you can match on the front and the rear [without any additional modification to the scooter]

Thanks! I'm not concerned about the speedo or the odo. I want the scooter to perform its best.

[iamryan25]

Thanks! I'm not concerned about the speedo or the odo. I want the scooter to perform its best.

I'm with you! After feeling the way the tires don't seem to track properly on turns I'm excited to return to matching sizes. I'll be running the Michelin S1 110/80 in the front and the rear. This seems to have a wider profile and is slightly larger than stock.

[w6euh]

I just installed the Michelin S1 tires 130/70-10 rear 110/80 -10 front. They are a perfect fit. I will ride them for a while and report. 28 psi rear 26 psi front.

I know this thread is old, but this subject is still interesting to many of us.
Iowa Racer, what's your opinion on the Michelin S1's after all this time?

Any other alternative, anyone? (These particular Michelin ones are out of stock everywhere in the US, apparently)

Thanks, ride safe!

Marcelo

[scootERIK]

I just installed the Michelin S1 tires 130/70-10 rear 110/80 -10 front. They are a perfect fit. I will ride them for a while and report. 28 psi rear 26 psi front.

I know this thread is old, but this subject is still interesting to many of us.
Iowa Racer, what's your opinion on the Michelin S1's after all this time?

Any other alternative, anyone? (These particular Michelin ones are out of stock everywhere in the US, apparently)

Thanks, ride safe!

Marcelo

I ran a few oversized rear tires(the Michelin S1 and Kenda K413) and I wasn't impressed. I felt like the rear tire was slipping a little when corning. Plus one of them rubbed the CVT side of the rear fender. I'm now back on 3.50-10 front and rear and much happier with the cornering(100/90-10 is good too but 3.50-10 is usually cheaper*.) My current favorite tire is the Pirelli Angel.


*I always check the price of both the 3.50-10 and 100/90-10 and buy the cheaper one.

[DeeDee]

I saw a stripped down Buddy 125 parked at Sportique earlier this week with a 130/90-10 on the rear. It was mounted on a stock wheel. It had rubbed the rear fender completely through in one spot. I remember there was a thread on here years back about a fellow swapping a Buddy 125 engine into a Ruckus. He had to grind off part of the engine case for the 120/90-10 tire to clear. I can't imagie what that big of rear tire does to your speed off the line. I don't want any more top speed, so I don't see the point to it. All I care about is cents/per mile for the tires. I'll often throw a used take off onto the rear of mine to squeeze a couple thousand free miles out of it.

[Therealslimshaggy]

What a coincidence I came across this post at the same time cycle gear sent me a notification that the 120 70 10 Michelin city grip tires are now back in stock. These sell out quick as they come stock on many vespas. I really want to try this size on the rear of my buddy 170 but one things stopping me from pulling the trigger, lack of photos of anything large mounted on the buddy 170 rear. I have googled and searched this forum but found nothing image wise of any larger tires mounted on the buddy 125,150 or 170. The main reason I want a picture so bad is because currently I have a 100 90 10 tire on the rear and it looks like nothing a milimeter bigger would fit without rubbing. Pretty shocked people on this forum are talking about how they ran a 130 tire on the rear. Let’s see it. Post the pictures. My buddy 170 currently sits collecting dust while my roughhouse 50 gets used daily and makes me wish it had the 170 engine. Why? Because the roughhouse is just way way more comfortable. I got a 130 rear and 120 front Michelin hopper baloon tires. They really help smooth out the road. If I’m ever going to turn my 170 into a daily ride it’s going to be in desperate need of bigger tires that flex more. Not like the op poster who wants bigger tires for better top speed cruising. I simply want the bigger tires for acceptable comfort over the rough stuff as of right now a daily ride on it will result in lower back pain while an all day ride on the roughhouse 50 will not result in lower back pain.