A few more mph.

Alb brajn · Post by **Alb brajn** » Thu Sep 06, 2012 4:50 am

I've got just under 5,000 miles on my buddy 125. On a good day my top speed is 63bmph and 55bmph on a bad day. Sometimes it feels like I need a bit more. What are the cheapest and easiest ways to increase the top speed to maybe 70bmph? Is it even reasonably possible? Thanks for your help guys.

Skootz Kabootz · Post by **Skootz Kabootz** » Thu Sep 06, 2012 5:10 am

The 161 cylinder kit would be the way to go for the speed I think you are looking for.

michelle_7728 · Post by **michelle_7728** » Thu Sep 06, 2012 5:58 am

Get a windshield.

.

Both of my Buddy's are stock 125s, both have windshields, and both can achieve 62 (GPS, not 'indicated') on flat and level ground.

Howardr · Post by **Howardr** » Thu Sep 06, 2012 4:56 pm

michelle_7728 wrote:Get a windshield. .

Both of my Buddy's are stock 125s, both have windshields, and both can achieve 62 (GPS, not 'indicated') on flat and level ground.

+1 for the windscreen. Simplest way to get 3-5 more BMPH. Get the medium sized one.

The 161 kit will also get you a few more bmph, but it is considerably more $ to do so.

Howard

JettaKnight · Post by **JettaKnight** » Thu Sep 06, 2012 5:25 pm

Windshield is the cheapest in terms of installation and operational cost. Second would be a Prima muffler.

New cylinder kit is the most fun!

Playing around with the CVT might buy you a little bit, but really it's a power vs. drag issue. Either add more power or reduce drag.

Alb brajn · Post by **Alb brajn** » Thu Sep 06, 2012 8:10 pm

Thanks guys. I have not put on a windshield because I like the look without it but if it helps reduce the drag it may be just what I want. The cylinder kit cost more then I want to spend. Maybe in the future I'll upgrade to a 170.

MYSCTR · Post by **MYSCTR** » Fri Sep 07, 2012 2:40 am

Ride downhill he he

Your top end sounds low unless you are carrying a lot of weight.

We ride two 150's and one 125 and all three have hit buddy speeds over 70 mph. The fastest was my wife's factory original 2009 Italia 150 at 78 mph.

After mods, mine has fluctuated - tried different springs etc. and about a week ago hit 75 bmph twice on the same ride and I am right at 190 pounds. This is a 2008 150 with 19,000 miles on it. Of course the larger tire had something to do with that I am sure. But that would be another subject.

Oh - we all three ride with the windshields.

rick71454 · Post by **rick71454** » Fri Sep 07, 2012 4:36 am

Hello MYSCTR:

Try heavier roller weights for top end speed. Might have to do trial and error with more than one set. I believe he stock Buddy 125 has 11g roller weights, check that out first before you decide which ones to install.

I am the Buddy 125 owner that started the recent thread about upgrading my 2009 Buddy 125 to have a Prima Big Bore 161cc kit as a stand alone upgrade. My indicated speedometer speed went from 60MPH to 42MPH.
I believe the shop messed up on the upgrade so be concerned the shop does yours right.

Rick71454

Skootz Kabootz · Post by **Skootz Kabootz** » Fri Sep 07, 2012 2:20 pm

A word about increasing the top end speed of any scooter... since I'm awake in the middle of the night with nothing to do.

To use the Buddy as an example, the potential top end of all three Buddys, the 125, 150, and 170, is always going to be roughly the same. Top end ultimately is determined by the gearing of the scooter which is the same in all three scooters. If you had a 300cc Buddy with the same gearing the top end would be roughly the same too.

What more cc's change is how much power the scooter has - how much oomph its got to get up to to its top speed, its ability to hold that speed under load, uphill etc., and how much it strains while doing so.

A windshield or tucking or doing anything to help with aerodynamics will not give you more speed but will stop you from losing speed by reducing the air resistance.

Heavier/lighter roller/slider weights will change how the engines power is applied - like adjusting what gear you are using, you can favor shifting it earlier in the power ramp for more off the line pickup (lighter weights = a lower gear) or later (heavier weights = a higher gear) for less strained top end performance (notice I didn't say increased top end performance). Heavier weights could also potentially help to increase the belts travel on the variator if it is not already getting full travel. This will feel like adding an extra gear.

A performance variator might give you an extra mph or two if it has a larger working size that allows the belt more travel (again kind of like like adding an extra gear). Its ramp will also likely improve the scooters powerband - how evenly the scooter accelerates from low to high speed.

But the max top end is determined by the gearing in the rear of the scooter. Once the Buddy's engine, or any scooters engine, is at max rpm's and the belt has full travel, and you've cut down wind resistance as best you can, what speed you've got is what speed you've got. And its the gearing that determines that potential speed.

OK, going back to bed now...

SYMbionic Duo · Post by **SYMbionic Duo** » Fri Sep 07, 2012 4:23 pm

Final gearing and belt travel only determine ratios of engine speed to wheel speed. You will always be able to go faster with more RPMs, provided a) your belt doesn't slip, and b) your engine doesn't explode.

A performance CDI can help the engine get more RPMs, but it also needs the power to reach those RPMs.

Big bore kits can provide the power, and transmission tweaking can change the load on the engine, so that it hits max power at a higher RPM range.

Aerodynamics always help at speed. The faster you go, the more the air pushes back at you; and this is exponential, not linear. If you had some type of custom fairing that significantly reduced your drag, your engine would be much less strained, and would be able to reach higher RPMs. Your fuel economy would also jump, big time.

That said, Windshield ($70-$100)1st, heavier weights + CDI ($50-$60) 2nd, BBK ($180) 3rd, Pipe ($200) 4th.

BuddyLicious · Post by **BuddyLicious** » Fri Sep 07, 2012 6:42 pm

Alb brajn,

You may need to up that speed to at least 85 mph since your State is raising the speed limit on a 41 mile stretch of highway.

"The Texas Transportation Commission has approved a speed limit of 85 miles per hour for a 41-mile toll road several miles east of the increasingly crowded Interstate 35 corridor between Austin and San Antonio"

Ok you probably never ride that area so your ok.

Good luck and above all have a reputable mechanic do the work.

Post by **ericalm** » Fri Sep 07, 2012 6:42 pm

SYMbionic Duo wrote:Final gearing and belt travel only determine ratios of engine speed to wheel speed. You will always be able to go faster with more RPMs, provided a) your belt doesn't slip, and b) your engine doesn't explode.

Yep. Kind of got to disagree with Skootz on this one. Gearing is a huge part of it, but turning those gears faster = more top speed.

The variator doesn't limit RPMs, just the gear ratio at the highest RPMs. This is why some scooters have rev limiters.

Add displacement, you will usually get a boost in top speed. I haven't touched the gearing in my LX and the top speed is much higher (10-15+ mph) than it was stock. That's with windshield, 190 kit, performance variator, 9g/12g mixed weights, stiffer clutch spring.

SYMbionic Duo · Post by **SYMbionic Duo** » Fri Sep 07, 2012 6:46 pm

Eric,
the mixed weights, is that to get 10.5 or does it give some of the benefits of both? ie quicker acceleration in the low end and lower rpms in the upper?

MYSCTR · Post by **MYSCTR** » Fri Sep 07, 2012 11:04 pm

This was under the photo page yet here is what we have done to the engine since 10,000 miles:

Mechanical adds:
171.3 Cylinder Kit (61mm)
Sliders (Dr Pulley 11g 18 x 14)
Iridium Plug
Variator
Clutch Arm Springs (1500 yellow)
Clutch Compression Spring (1500 yellow)
BANDO CDI & Coil
Stator
Sprag Clutch Replacement (little springs gave out @ 13,300 miles)

We tried a few spring combinations and landed on the 1500 rpm clutch and compression springs which seemed to still get a great take off yet not cut the high end.

If we were to do it again - we would take the sound advise we were given and do everything but the bb kit. By the time you are up and running and it is tuned properly you will have spent three time what was shown above if not more.

So maybe we do need to step up to slightly heavier rollers? At 20K miles we will make some changes - just not sure where to go. Want to check into the performance transmission we have read about.

We do spray ourselves with 'Pam' before every ride to help get less wind resistance too. Not too sure how that is working... he he

Post by **ericalm** » Fri Sep 07, 2012 11:10 pm

SYMbionic Duo wrote:Eric,
the mixed weights, is that to get 10.5 or does it give some of the benefits of both? ie quicker acceleration in the low end and lower rpms in the upper?

It's a bit of both. Some folks like a very smooth acceleration curve, which is what you get with sliders. I like a little punch off the line, smooth mid and a little more punch on the high end. I was running 14g/9g for a while and while I had some great high speeds, I was losing power on long inclines. Went back down to 12s and it seems better, but I'll know for sure when I head up into the mountains next weekend. The clutch spring is new, too, and that's changed the behavior again. Now, it's a little sluggish right off the line from a dead stop, but after a little hesitation, accelerates quite well. The transmissions a little noisy too, with new weights, so I may go back in and make sure everything's buttoned up tight.

Skootz Kabootz · Post by **Skootz Kabootz** » Mon Sep 10, 2012 4:45 am

SYMbionic Duo wrote:Final gearing and belt travel only determine ratios of engine speed to wheel speed. You will always be able to go faster with more RPMs, provided a) your belt doesn't slip, and b) your engine doesn't explode.

ericalm wrote:Yep. Kind of got to disagree with Skootz on this one. Gearing is a huge part of it, but turning those gears faster = more top speed.

Hey... last line of my post says "Once the Buddy's engine, or any scooters engine, is at max rpm's and the belt has full travel, and you've cut down wind resistance as best you can, what speed you've got is what speed you've got. And its the gearing that determines that potential speed."

Sure max RPM's can be increased up to a point with various mods. But the gearing is still the gearing and once your scooters max RPM's are reached, you aint goin' no faster unless you change the gearing.

I stand by my statement and welcome anyone to prove to me it is not true. (this aughta be entertaining

)

Rusty Shackleford · Post by **Rusty Shackleford** » Mon Sep 10, 2012 4:48 am

Skootz Kabootz wrote:To use the Buddy as an example, the potential top end of all three Buddys, the 125, 150, and 170, is always going to be roughly the same. Top end ultimately is determined by the gearing of the scooter which is the same in all three scooters. If you had a 300cc Buddy with the same gearing the top end would be roughly the same too.

What more cc's change is how much power the scooter has - how much oomph its got to get up to to its top speed, its ability to hold that speed under load, uphill etc., and how much it strains while doing so.

A windshield or tucking or doing anything to help with aerodynamics will not give you more speed but will stop you from losing speed by reducing the air resistance.

This is probably the best advice I've seen. Gearing is ultimately what determines top speed. Once you hit the rev limiter, that's it. You'd need taller gearing in order to hit higher speeds at that point, and aero drag would overcome the loss in rear wheel torque, hence the need for larger displacement to account for it. What speed are you getting? Do you tuck? I just sustained 65mph on flat ground with throttle to go a few minutes ago, but I was tucked. With only 125cc's, you gotta minimize the wind drag, especially over 55mph or so. It adds up exponentially.