How Fast Can You Go App?

[csmith12]

Seen this over at the CSS forums and thought I would share.

http://www.howfastcanigo.com/

[lgk]

just went through deals gap in kneedragger mode.

17555 Tapoco Road, Robbinsville, NC 28771
7801 Happy Valley Rd Tallassee, TN

surprising how many curves have to be negotiated at lower than 40mph.

[csmith12]

Yea, I did part of my normal route. Interesting results compared to what I normally do vs. what others "say" they do. I routinely say "it's a challenge to take this route @ 55mph the whole way". According to this app, it's not possible at 40 degrees, in which I agree. Now if you increase the lean..... different story. I will have to change my story next season. Veteran riders: "Try to take it at 55mph but there are a few corners you must slow down for".

Willow KY
Falmouth KY
40 degree
55mph limit

[subxero]

I played around with it on a few roads, one i have never taken on my bike. I am assuming red circles are speed? despite me saying 95mph speed limit it says 120+? in some? I am guessing it is just stating max speed possible for lean angle despite listed speed limit?

Regardless, it had one killer turn listed at 21mph which i agree with, but then another at 40mph which is probably close to being right but would definitely be pushing it

But then i did a small section of my daily commute, and it listed one turn at 31mph..... I routinely take it at 35-40mph with out serious lean and have taken it faster when riding aggressive. So it tells me that the program is most likely limited by google maps and how accurate of a depiction it gives of the turn/curve.

But fun little program either way.

[csmith12]

Yea, red circles are the speed in which that corner can be negotiated at the parameters set; max speed and max lean angle. Given the vagueness of google maps (maps in general), I would expect it to be off every now and then. No substitute for knowing the route first hand.

His goal is to create an app that can guide you down unfamiliar routes. For this to be of any real value a "margin of error" must be built in and somehow not overestimate a corner, ie. error on the side of caution at the very least.

[lgk]

Originally Posted by subxero

So it tells me that the program is most likely limited by google maps and how accurate of a depiction it gives of the turn/curve.

But fun little program either way.

as far as i can tell,
it can't determine banking of the road and vertical slope changes, but it still accurate for 90% of curves in my commute, since the land is flat here.

the deal gap scenario is probably off by a good margin, lol.

[Nny]

Nice find, Chris!
This site may become a staple in how I find new roads during the winter.

Now take what you want from what I am about to say...
Either I ride like an asshat while I am on my almost 700lbs cruiser with a 30 degree lean angle...
This site is off...
Or this site will give you a general idea on an unfamiliar road...
...but, I did punch in one of my favorite stretches of road. 45mph speed limit, 20-25mph posted signs, site says as low as 30mph on some of the turns but I know for a fact I dont fall below the speed limit on this road.

[csmith12]

One of the biggest factors is missing from his math in the app is camber. Since the google map data only gives elevation for a given gps point, 90 degrees is hard coded into the formulas for any given speed, lean and radius of the turn. Most all experience riders know that good camber can call for faster speeds.

Anyway... don't take the speeds as 100% (see my margin of error comment above). Also, there are at least 50+ factors that can be added to an equation that will result in different speeds for any given corner.

I see it similar to you, I see a twisty road on a map but when I ride it.... It's sometimes is less than I expected. Hopefully this will help weed out some of those trips. But then again... I have seen some very cool things and made some new friends in unexpected places.

[bdavison]

Um....ok, so here's my local fun spot.

Start Position: GPS Lat/Lng, street address or intersection.
32.648517,-83.760388
End Position: GPS Lat/Lng, street address or intersection.
32.724079,-83.986616

There is NO way you can take the Jordan Chapel turn doing 110.
I'm currently the fastest on that corner, and 80 is tops, with the knees dragging, and the rear right on the verge of sidewall. I don't care what bike you do it with. And you'd better have your apex spot on too, right at the 35mph max sign or you're in the corn.

The rest of the track sounds about right, with the exception of the turn right before causey, which is a corner where it starts 5 positive, and switches to a 8 negative camber, and any nutcase that tried it at 90 is dead. Literally.

The last guy to try it, went to his funeral headless...they found it a couple of days later.

This section of road is deceiving...it looks like a few long straights with just long sweepers, but they are tricky decreasing radius corners, and with oddball cambers that change mid-turn. You'll come in at 100+, everything's going fine, and then it tightens up on you, and changes camber....crap bricks for the newbs.