How fast is too fast for you?

[Mr. Coffee]

So this is a question that came up amongst friends recently. How fast on a downhill is too fast? Of course, a lot of variables go into that so go ahead and explain it all to me.

For me, typically my comfort zone is around 20-25 mph on unpaved roads and 30-35 mph on paved roads. But this can vary quite a bit depending on the condition of my tires and brakes, the actual road surface, weather, and traffic.

I've also noticed that on very long downhills, my average speed is quite a bit higher in the very lower fraction than in the upper parts. Also, for clarification, my definition of "very long downhill" is usually on the order of ten miles and 2500+ feet of elevation loss.

In great conditions with new tires and brakes I've hit 35 mph on unpaved roads a handful of times.

For absolute fastest speeds ever for me, on an arrow-straight section of very lonesome highway in Eastern Washington with brand new butter-smooth asphalt, no traffic and no wind I hit 48 mph through a very broad valley.
This was on new tires and new brakes as well. Unfortunately, such optimum karma only occurs once or twice per year.

 

[Taylor57]

So this is a question that came up amongst friends recently. How fast on a downhill is too fast? Of course, a lot of variables go into that so go ahead and explain it all to me.

For me, typically my comfort zone is around 20-25 mph on unpaved roads and 30-35 mph on paved roads. But this can vary quite a bit depending on the condition of my tires and brakes, the actual road surface, weather, and traffic.

I've also noticed that on very long downhills, my average speed is quite a bit higher in the very lower fraction than in the upper parts. Also, for clarification, my definition of "very long downhill" is usually on the order of ten miles and 2500+ feet of elevation loss.

In great conditions with new tires and brakes I've hit 35 mph on unpaved roads a handful of times.

For absolute fastest speeds ever for me, on an arrow-straight section of very lonesome highway in Eastern Washington with brand new butter-smooth asphalts, no traffic and no wind I hit 48 mph through a very broad valley.
This was on new tires and new brakes as well. Unfortunately, such optimum karma only occurs once or twice per year.

In a car?

 

[Mr. Coffee]

In a car?

No silly, on a bike.

 

[RabH]

I regularly go faster than 40 mph and always feel safe, my bike is extremely stable at speed! This was from todays ride, my Wahoo actually showed a top speed of 44.6mph! My current top speed on my e bike is 48mph also!

 

[theemartymac]

I have a highway median route home that I use on my commute some days when the traffic is light. It is a slight downhill for the middle 7 miles or so, and I regularly maintain 40mph easily. I upgraded my front chainring specifically to meet that need, and I can sustain that at a brisk, but not frantic cadence. My 1000w mid-drive with fat 26" tires handles it as well as my 1000cc motorcycle - acknowledging the bicycles hydraulic brakes are adequate, but not superb at those speeds. If I did it more often, a 4-piston premium upgrade would be mandatory IMHO, and I wouldn't expect a bicycle brake system to manage more than a couple of hard stops without overheating the system.

As for peak 'possible' speeds, in my MTB days I regularly approached 60mph on some downhill courses on my 'premium for the day' full-suspension bike. With quality equipment, and the right environment and skill, the speed limits can be very high. In the city, in all practicality, I find I rarely exceed 25mph when mixed in with any amount of vehicle traffic or pedestrian/mixed use routes.

 

[Taylor57]

I think I was able to get the Frey CC up to 38 throttle only flat ground and that was plenty. I typically like to keep my bike speed around 15-18 mph...

 

[fooferdoggie]

under 30 just not brave enough anymore. Plus it freaks my wife out.

 

[JES2020]

Speed does not scare me !
It's the sudden stops that do the damage , no matter what you're riding.

Pretty sure everyone here has done 500 MPH and felt very safe, that is until it's time to land!
Then the anxiety in the cabin ticks up dramatically.

If I had an open road (freeway) and the capability to do 80 mph on a ebike, I would dress for the occasion and go for it. I have gone way faster than that on a motorcycle and loved it !

 

[m@Robertson]

Riding in the Lower Sierras on an analog road bike I regularly (as in every morning) hit terminal velocity on a bike with 700x23C tires. That was in the early 1980's. Terminal velocity without anything like a Zzipper front fairing is going to be in the high 50's. I did the same thing riding down Big Basin Way from the summit on Skyline Blvd down into Saratoga CA in the 1970's. Your body's drag is the limiting factor. There are some crazy positions you can get into that kick you up into the mid 60's.

So all this 'ooh ebikes are too fast' stuff I hear from some people has always struck me as a bit silly. High speed on bicycle parts is not anything new. Of course crashing has always sucked.

On an ebike on flat ground I have had my Bullitt up to around 36 with a tailwind. On a bike that size, thats plenty.

Absolute speed isn't really anything worth talking about though. What is, is speed based on conditions. 10 mph can be blazing fast depending on where you are riding.

 

[Roamers]

Although I used MC and not be concerned about 70 mph, I don't trust bike tires and brake at 30 going downhill. The thought of gravity continueing me rolling down a hill once no longer rolling on an upright bike has always scared me.

 

[Bubba zanetti]

I’ve crashed a motorcycle at well over 100 kph and under 15 kph. Both times the resulting injuries took me to the hospital the fast one in an ambulance . The low speed one was the result of hitting a diesel spill, by a construction site and sliding shoulder first into a square curb. 3rd degree separation of shoulder with all ligaments torn. It hurt devilishly. Yes I had great gear and CE armour.
Point being … it depends on what you hit. I’ve had my ebike over 60 kmh just to see. I stay below 50 now though, wear a helmet, motorcycle gloves and light armour. I have a good Gyro MIPS helmet but it is open face.

 

[Gordon71]

25 on paved roads and 15 on gravel trails is about my max.

 

[chunk]

This, bicycles are far too twitchy I've found for my comfort level. 20 MPH or so gives me a good feeling of control. I hit 40 on the speedo once and that seemed to limit out the display, it reverted back to zero until I reset it. Going downhill of course.

 

[JES2020]

I’ve crashed a motorcycle at well over 100 kph and under 15 kph. Both times the resulting injuries took me to the hospital the fast one in an ambulance . The low speed one was the result of hitting a diesel spill, by a construction site and sliding shoulder first into a square curb. 3rd degree separation of shoulder with all ligaments torn. It hurt devilishly. Yes I had great gear and CE armour.
Point being … it depends on what you hit. I’ve had my ebike over 60 kmh just to see. I stay below 50 now though, wear a helmet, motorcycle gloves and light armour. I have a good Gyro MIPS helmet but it is open face.

My point exactly..it's not the speed it the sudden stops! Consider even, crashing at 80 mph into a wall vs crashing onto a flat ice covered field.
You ever see the riders crash at 100 mph, on race tracks and just skidding on thier leather to a stop?

 

[RabH]

My GPS only showed 47.5mph that day....

 

[indianajo]

36 mph on good pavement with no rocks water or mud. We have deer here that tend to sprint across the road suddenly at the bottom of the hill. Stupid as bunny rabbits (that I've run over). Come right into town sometimes: there was a news shot of a deer on 3rd street in downtown Louisville near Galt House. At least the bears stay in the suburbs. Really, I'd hate to hit a ground hog or raccoon at that speed.

 

[JES2020]

View attachment 123837

My GPS only showed 47.5mph that day....

What you got in that beast? Or was it off a cliff?

 

[RabH]

What you got in that beast? Or was it off a cliff?

Its UK spec so restricted to 15.5 mph and 250W, I just have lots of big hills all around me!

 

[FatChance]

You only left out all of the information someone would need to give you a a good answerm

 

[FrankR]

I'm a former motorcycle rider, but, 30 mph is about it for me on an ebike. Plus, I have learned, I enjoy the ebike much more at a Slower speed. More enjoyable, more exercise, more battery life.

I started out cruising near 20 to 25 often, but I'm down to about a 12 mph average now. Much better for me.