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Speedometer accuracy

Posted: Fri Apr 09, 2010 4:19 pm
by Hipnerd
How accurate is the Buddy's speedometer?

I'm still breaking my St. Tropez in I have <50 miles on it so far. On my very first trip the left mirror bent inwards from the wind. The dealer didn't tighten it enough. I needed to get over into the left-hand lane though, and a guy was camping in my blind spot, so I gave it some gas to get past him.

When I merged over, I glanced down at the speedometer and it said I was going 55+ mph in a 35 mph zone. Oops.

I told this story to an old guy on a Vespa that flagged me down yesterday to talk scooters, and he said that I was probably only going 44 mph because the speedometers were inaccurate. I don't really care one way or the other except I do want to have a decent idea of how fast I am going so I don't make other drivers angry or get a ticket.

So, did I hit 55 mph? Or do I need to subtract 10 mph at higher speeds?

Posted: Fri Apr 09, 2010 4:26 pm
by brape
This comes up all the time, I recommend doing a search.

This was the last occurrence I could find: viewtopic.php?t=13651&highlight=speedometer

Posted: Fri Apr 09, 2010 4:30 pm
by lmyers
The speedometer is to give you a very vague idea that you're going... at some speed. You can get a GPS and find out how fast you're really going, but most are off anywhere from 10 to 15%.

Posted: Fri Apr 09, 2010 4:31 pm
by pugbuddy
Speedometer? I don't need no stinkin' speedometer! :lol:

Posted: Fri Apr 09, 2010 4:36 pm
by gr8dog
Speedometer accuracy seems to vary a little from bike to bike. My speedometer is highly optimistic. According to my GPS the scooter speedometer reads a little more than 15% high at any given speed. To compensate I just add 20% to the posted speed limit and do that or a bit under. 25 posted becomes 30 Buddy. 45 posted becomes 54 Buddy. You get the idea. Those are the speeds I will use when there is little other traffic on the road. Otherwise the speed I go is mostly dictated by the other vehicles. I want to move with traffic and not be a hinderance to traffic flow. One of the large causes of accidents is variation of speed between vehicles.

Regarding your mirror, it will likely come loose occasionally. Some people have used loc-tite (the blue stuff) to keep the mirrors from coming loose. I tried that and it didn't work for me, they came loose anyway. I keep a crescent wrench in my pet carrier to tighten the mirrors when necessary.

Have fun with that St. Tropez and ride safe.

Posted: Fri Apr 09, 2010 6:45 pm
by bpatrick5
My 150 St. Tropez is about 10% overstated, based on a GPS test. My girlfriends 50 Italia also is about 10% overstated. I like it though. I basically do the speed limit on my speedometer and feel good knowing I'm just under. Autos probably aren't happy with it, but I haven't had any problems so far.

Re: Speedometer accuracy

Posted: Fri Apr 09, 2010 6:48 pm
by BuddyRaton
Hipnerd wrote:How accurate is the Buddy's speedometer?
WHY RED IS RED!

Posted: Sat Apr 10, 2010 2:31 am
by nissanman
Red is red... and it's safe to say most 2 wheeled transportation vehicles are about 10% optimistic. You're off buy 1 mph at 10mph, 5mph at 50 mph. It's not a set number like 5mph, but a percentage. As your tires wear it will change and increase the percentage off.

Posted: Sun Apr 11, 2010 9:48 pm
by ScootLemont
"Speedometer accuracy" :rofl:

Posted: Mon Apr 12, 2010 5:21 am
by Cheshire
Between several "you're going this fast" boards and that one trooper that let me off with a tongue-lashing :oops: ...I know my Buddy 125's 10% optimistic across the board. From what I hear and read, both spoken and online, it's pretty standard for just about anything on 2 wheels. Many motorcycle people talk about the same up-to-15% optimistic speedometers.

10% is a good rule of thumb. It's definately a lot easier and faster to do the math on 10% in my head! :P

Posted: Mon Apr 12, 2010 5:53 am
by ericalm
This is actually in the FAQ!

topic10818.html#139168

Posted: Mon Apr 12, 2010 1:03 pm
by Lostmycage
ericalm wrote:This is actually in the FAQ!

topic10818.html#139168
Yeah, but that's like a year old, ppffftt! :P

Posted: Mon Apr 12, 2010 5:57 pm
by polianarchy
Lostmycage wrote:
ericalm wrote:This is actually in the FAQ!

topic10818.html#139168
Yeah, but that's like a year old, ppffftt! :P
I love that you're heckling your own work. HAAAAY BATTA BATTA! :lol: