AMERICANS: Would you buy a 125cc motorcycle for the street?

[Xringer]

Why two spark plugs? I've heard of a redundant spark plug on an ultra-lite airplane,
but motorbikes don't crash if a spark plug fails..

[redpoint5]

Somehow most of the information you'd want to know about a motorcycle isn't to be found on manufacturers websites anymore. I just looked at what the big 4 had to offer, and not a single HP or speed rating was listed on any bike for any manufacturer. Top speed is very relevant for the lower displacement bikes.

Anyhow, I found Suzuki had a 200cc bike, but other sites that reviewed it said it had a top speed of 65, and didn't get particularly good fuel economy.

No idea why the 250s weigh more than my 17 year old CB600. You can probably find my bike for $2k used. It would get 75 MPG if you geared it taller and drove it like a granny.

First time I've looked at bikes in over a decade, and there are way more options available now, but very few 250 options, and even less below that. This should be an indication of the demand for these displacements. If a bike requires a motorcycle endorsement, then it should also be capable of achieving the speed limits of the state. A 50cc scooter doesn't require an endorsement and will do about 40 MPH.

I get the appeal of small and light bikes. The most fun I had in my motorcycle tour through Peru wasn't on the CRF 450 bikes we rode, but an afternoon tearing around on a 125cc dual sport. This was due to the attention and skill required to get it up a steep, dry riverbed. Driving a 125 at it's limit isn't likely to get you killed like a more powerful machine. That said, I'd still be in Peru if I had to do the whole trip on a 125 (and the policia would have extorted all my money).

Finally, I agree with taking the back roads as often as possible, which I do. That's exactly the place I want to ride fast. I especially have no patience being stuck behind someone that wants to go slow through the curves. Being able to pass anyone in 2 seconds means I never get stuck behind someone.

[woodsrat]

Originally Posted by Xringer

Why two spark plugs? I've heard of a redundant spark plug on an ultra-lite airplane,
but motorbikes don't crash if a spark plug fails..

In the days of big dome pistons and low octane gas it was a way to create a dual flame front so the air-fuel mixture didn't get blocked away from the spark plug by the piston's dome. To be honest with the flat top/dished/low dome pistons used nowadays I'm not sure why they went with a dual plug setup unless it's a way to help eliminate pre-ignition (knocking) in markets with really low octane gasoline.

[jkv357]

Originally Posted by Xringer

Why two spark plugs? I've heard of a redundant spark plug on an ultra-lite airplane,
but motorbikes don't crash if a spark plug fails..

Pretty sure it's just to reduce emissions by ensuring more complete combustion. There's no power gain to be had.

The SV650 went to 2 plugs per cyl in 2007, and I'm pretty sure it didn't bump HP but may have increase MPG slightly.

[Xringer]

Thanks guys. I had a suspicion it had something to do with the EPA.
I wonder if 2 plugs last longer than one plug.?. Longer time between changes?

[cRiPpLe_rOoStEr]

Originally Posted by Xringer

I wonder if 2 plugs last longer than one plug.?. Longer time between changes?

It's more likely to not affect the longevity of the spark plugs.

[Daschicken]

Holy cow, never ridden a road legal bike this slow. It was perfectly fine at 25 mph, but when you get on 55+ mph roads it doesn't feel like enough. 'Cruising' at 55 is about 90-95% throttle. Fully tucked down it would go about 57 mph without a drafting buddy. I also went into the superman pose, which it would get up to around 60 mph. Doing the superman pose and drafting the car in front of me I was able to get up to 66 mph(flat ground!) on a stock grom.

Ignore the non-riding pants and boots...





The wheelbase is super short, which makes the bike twitchy, especially since it is so light. The seating position puts you perfectly upright, any further 'upright' and you would start leaning backwards. Sitting on the passenger seat felt perfectly natural and gives a sportier riding position other than the pegs being more forward.

I feel like an aerodynamic bike with 15 horsepower would be just about perfect for what I want. 9 horsepower and terrible aero just isn't enough.

[19bonestock88]

What about doing a fairing and maybe some “power mods”(pipe and such)? I mean, a sub-60 top speed seems way too slow except for city commuting or a similar use

[MetroMPG]

But was it fun?

[Daschicken]

Originally Posted by MetroMPG

But was it fun?

I didn't go on the right kinds of roads to truly enjoy what that bike is about, but it was fun.

The four speed transmission definitely limited fun, part of why I like low power bikes is being able to run through the gears, and quickly. With its wide ratio four speed it didn't give that sense of running through the gears that I wanted. My first ride on the bike I was pretty nervous since it was so twitchy, but that second ride was where I got more daring and decided to go superman. I also discovered that the bike is light enough that I could pop the front end up a few inches just by bouncing it. Add a little throttle and you could have a dank wheelie, but I wasn't about to go stunting on a borrowed bike. (That and i'm not good at MOTORCYCLE wheelies). I could definitely see myself getting into stunting if I got a grom, which isn't really a good thing. Then I would want to wheelie all the time!

Originally Posted by 19bonestock88

What about doing a fairing and maybe some “power mods”(pipe and such)? I mean, a sub-60 top speed seems way too slow except for city commuting or a similar use

There are plenty of mods out there to boost the top speed of the grom to acceptable levels, but yes I agree the stock top speed is too slow. If you get lucky when accelerating and get a slow and tolerant car, you could draft up to 60+ mph, but then mechanical sympathy kicks in because it is so close to the rev limiter at those speeds. There appears to be a one tooth taller front sprocket available, which would help at those higher speeds assuming it could get up there in the first place. I don't know if it would actually fit though.

Disclaimer: Bike had less than 400 miles on it, so top speed would likely improve with further use. I was also about 4400 feet above sea level, which doesn’t help for power.