Bromptons Downhill

[Kell]

I've had mine up to 44 mph on a pretty steep hill near me. In fact, I do it every morning as it's part of my commute.

I do have slightly wider bars on mine and it's much more stable than you'd think.

However, the wheels don't generate anything like the gyroscopic forces that bigger wheels do so there's no way it feels as stable as a 'proper' bike.

For what it's worth, I've been down there on my road bike and also on a full size Dahon and I didn't go any faster on either of those (I have the aerodynamic abilities of a beachball) but they definitely feel more stable.

The biggest worry with that sort of speed (on any bike) is what you do if you need to slow down quickly. I only go that fast on that hill when:

• visibility is good
• it's not raining
• traffic is light

View: https://www.youtube.com/watch?v=1wNkVZltMfw

 

[12boy]

I find Kell's video terrifying. A year ago I missed seeing a crevice and found myself with a pelvis broken in 3 places. As with riding in poorly lit conditions, I don't like to go faster than I can see. On a known road with good visibility I can go 40 without feeling any shimmy, especially if I have some weight in the front bag. However, unexpected gravel, ice or other hazards could leave you in a world of hurt.

 

[Drago]

Even Evel Knieval turned down a million quid to ride a Brommie downhill at 50 MPH. Too dangerous, he reckoned

 

[CopperBrompton]

40mph is the fastest I've been yet, but that was the limit of the hill and the engine rather than the bike. It felt fine to me at that speed.

 

[kais01]

if you angle the m handlebars forward, steering will get heavier and stability increase. s handlebars are already in a more forward position.

its equivalent to fitting a longer stem on an ordinary bike.

wider bars make it easier to handle gyroscopic forces, jerks and self-steering, but the power of all three are minimal on a brompton because of the small wheels. already ordinary brompton bars are overly wide considering this.