The fantastic brakes made me miss a kid

[JonB]

Hi

Today i rode almost 40 km, toke me just under 2 hours. I was tired, but i still want to go more, More, MORE, just keep rolling rolling rolling rolling http://youtube.com/watch?v=nupIl1UTLk0

A few km's from home, going down a long hill, a kid suddenly ran out on the bike lane EMERGENCY BRAKING!!! I have wanted to test emergency braking, but never got arround it. It works very well though. I applied both brakes. The back wheel locked up and skid along during the braking, but the front brake was fantastic. Very short stopping length at that speed. It probably helped that i leaned forward and put my feet on the ground as the bike lifted itself upwards in the back, and i managed to stop several meters from the kid. I dont think i could have avoided a hit on my upright, but i probably wouldnt drive so fast in the city on my upright. Having feet first makes me less scared.


I got to use the full gear range, climbing some short, but steep hills. Some even required 1. gear, and i dont think i need lower gears, because if i go slower i loose my balance. Downhill i could use 1, maybe 2 higher gears.



JonB

 

[Hotdog]

I'm glad you managed to avoid the accident. In the event of future emergency braking I'd recommend you leave the rear brake alone though, and just use the front. You'll stop just as quickly this way, but under more control as the rear wheel won't be skidding. See here.

Provided they're fitted with good brakes recumbents can generally stop quicker than upright bikes. On a decent road which gives plenty of tyre traction the maximum deceleration of an upright is limited by how hard you can brake without going over the handlebars. The lower centre of gravity of a recumbent makes it much harder to tip forwards, so you can brake harder.

 

[Rick Harker]

Hi Guys,

Braking is something I have been experimenting with lately. I have almost come to the conclusion that the rear brake could be thrown away. Except for law ... and common sense (front cable snaps).
I have also tried some fish-tailing with only the rear brake in wet grass and find the bike wants to track straight. Safe but less pose factor. Strangely enough though the Kenda tyres slip easily on tar and stone surfaces when they are pumped up to 90-100psi. At 60 rear and 80 front they become more stable in corners on this type of surface. On asphalt 100psi is OK to almost lay the bike over to scary angles.
And... Whilst the feet are up I cannot get the back wheel off the ground under hard braking.

Rick.

 

[migo]

I'm reading through Sheldon's site right now. I found the bit on braking with a fixed gear bike quite interesting. He mentions that a rear brake is unnecessary with a fixed gear bike, of course that's with a RWD bike. I'm wondering if any of this would change at all given the Cruzbike is a FWD.

 

[John Tolhurst]

Fishtailing is a hoot, while it wants to track straight you can induce a bit of wag. On a very loose surface you won't brake anywhere near enough to unload the rear, so the rear brake is then indispensable.

The EU braking standard works out to a deacceleration of 0.5 g, which requires a (from the horozontal) 60 deg angle from centre of gravity to front wheel contact path.

Absolutely agree on adjusting pressures to suit surfaces, a must in fact. I nearly specified 26 x 1.25 tyres. Then thought more about surfaces other than good roads and ended up on 26 x 1.5. With this set up, the bike really will go just about anywhere.

 

[Kamatu]

Hmmm, I'll check the fishtailing, haven't tried that yet. I agree, even under hard front brake, the back tire stays down. At least until I swing my feet down just before I stop then it comes right up....

 

[JonB]

johntolhurst wrote: Absolutely agree on adjusting pressures to suit surfaces, a must in fact. I nearly specified 26 x 1.25 tyres. Then thought more about surfaces other than good roads and ended up on 26 x 1.5. With this set up, the bike really will go just about anywhere.

And then some of us ruins your thinking by putting Schwalbe Big Apple on the bike at the earliest possible time ;-)