The Ultimate Brakeless/Front/Rear/How many brakes? thread

might need to showing your workings on the risers (more weight over back wheel) reducing effectiveness over riding in drops (less weight over back wheel)

Risers make the CG higher relative to the fulcrum point, so load transfer to the front wheel is greater for a given deceleration. It's possible that risers also move the CG back, which would somewhat counter the effect of raising it, since what matters is the angle of the line from CG to fulcrum point.

Risers make the CG higher relative to the fulcrum point, so load transfer to the front wheel is greater for a given deceleration. It's possible that risers also move the CG back, which would somewhat counter the effect of raising it, since what matters is the angle of the line from CG to fulcrum point.

still wanna see those workings

Do your own workings using the science Linc provided. The great thing about mathematical models is that you can use them to model different scenarios simply by using different values for the variables.

It's an interesting one though. Going back to the lo-pro question on the last page, it does feel like you're overbalanced further forward and are more likely to go over the handle bars as you're leaning forwards so much. I suspect that you actually shift your centre of gravity downwards by a greater proportion than you shift it forwards compared with a normal riding position as you're basically just rotating down around your hips. Counterintuitively this would make it more stable than normal. Don't know if that's actually the case though.

I will just use my assumption based physics (what can go wrong with that)

A body of weight further away from the point where the front wheel touches the ground is going to take more effort to lift due to basic leverage. Centre of Gravity doesn't matter as it still as lifting 2mm is lifting 2mm (or enough to make back brake redundant)
If the rider sat 100 metres back from the front wheel it doesn't matter how much higher they are sitting, they are not going to be lifted as easily.

I will just use my assumption based physics (what can go wrong with that)
If you read the post then it won't be assumption based!

This is the reason I wrote it in the first place because you are only seeing half the effect. The second half is not quite as obvious and is entirely dependant of the height of COG.

A body of weight further away from the point where the front wheel touches the ground is going to take more effort to lift due to basic leverage.
Right

Centre of Gravity doesn't matter
Wrong! You've just told me it does matter (horizontally) in your last statement.

If the rider sat 100 metres back from the front wheel it doesn't matter how much higher they are sitting, they are not going to be lifted as easily.
Wrong. If the seat was 200m high then it would be considereably less stable than a normal bike.

There is only 1 equation to compare the different situations (the first equation for deceleration in the post), and it's very simple (calculates acceleration/ deceleration but that's essentially the same as stopping distance).

brakers gonna brake

good debate guys, whilst braking with the front IS more effective, IMO I found myself getting alot more cocky with the brake so i would put myself in the position where i would need to brake harder, and on a couple of occasions, emergency stop. so i came to the decision to to take it off. cliched/hipster answer but i like the connection between the drive train and my legs, i can manage the speed a lot better and i never put myself in a dangerous position UNLESS im feeling adventurous. I welcome grief but...

BRAKERS GONNA BRAKE!

Wrong. If the seat was 200m high then it would be considereably less stable than a normal bike.

Yes, it would be less stable but if it were the seat were 100M further back then it still wouldn't lift up under front braking so centre of gravity is irrelevant isn't it.
Bike A. Rider sat 1m from front wheel axle at height of 1m
Bike B. Rider sat 100m from front wheel axle at height of 10m

With same front braking force rider of bike A will be over the bars before rider of bike B has any rear wheel lift.

Bike A. Rider sat 1m from front wheel axle at height of 1m
Bike B. Rider sat 100m from front wheel axle at height of 100m.

Each has exactly the same limiting deceleration before initiating tipping. The height of the CG above the fulcrum matters just as much as the horizontal distance.

Each has exactly the same limiting deceleration before initiating tipping. The height of the CG above the fulcrum matters just as much as the horizontal distance.

Yes they are the same when changing the height to 100M which isn't what I was using as an example where the height above fulcrum changed less than the horizontal distance.

All things to bear in mid next time I slam the brakes on but it has come back to me why I didn't take Physics past O level (apart from not being allowed to)

Weeeeeeeeeeeeeeeeeee..................

When I went out in the snow, I was doing hipster front wheel skids with my brake.

Try doing that brakeless.

And no, I don't own the bike anymore and no, there was no damage to the forks.

/csb

I skidded the front wheel of a boris bike the other day, it wasn't even raining!

im skidding the shit out of boris bikes, the tyre supply is infinite or at least this is how i see it.

good debate guys, whilst braking with the front IS more effective, IMO I found myself getting alot more cocky with the brake so i would put myself in the position where i would need to brake harder, and on a couple of occasions, emergency stop.

Then learn how to ride properly.

When I went out in the snow, I was doing hipster front wheel skids with my brake.

Try doing that brakeless.

And no, I don't own the bike anymore and no, there was no damage to the forks.

/csb

Ha. When I went out in the snow I was doing wheelspins and two-wheel skidding. It was totally intended.

i never put myself in a dangerous position UNLESS im feeling adventurous. I welcome grief but...

BRAKERS GONNA BRAKE!

You welcome grief?

Good Grief.

When I went out in the snow, I was doing hipster front wheel skids with my brake.

I skidded the front wheel of a boris bike the other day, it wasn't even raining!

Ha. When I went out in the snow I was doing wheelspins and two-wheel skidding. It was totally intended.

Do you ever take it off any sweet jumps?

Yet another reason to install brakeless...

[ame="http://www.worldstarhiphop.com/videos/video.php?v=wshhsA3OpfUpT5f53gfX"]Video: 15-Year-Old Girl Hits A Pothole & Has To Get This Bicycle Brake Handle Removed Deep Inside Her Leg![/ame]

Wait a sec... Aren't brake handles usually facing outwards?

How?

doing a leg-over-bar skid

Even then it would be more likely to have gone into the back of her thigh than the front as the video shows. What's also puzzling is the apparent lack of any bruising around the entry wound. I'd have expected to see some marking from the bars.

As for the brake debate - I ride F&R when fixed. Went to front only and had a crash when my worn SPD cleat unclipped whilst pulling a skid stop, grabbed the front brake and went over the bars resulting in a broken scaphoid. Since then I'll only ride with two brakes. It may not be cool, but then I never was to begin with.

Front only for me, as I want my knees to not be fucked from skidding fixed all the time!