ed 

I really hate drops to flat, but Kansas isn't known for transitions.

So I was out doing a little urban session and there's just not a whole lot of "fun terrain" around here. I found a progressive ledge to flat grass and was wondering how big of a drop to flat can I get away with w/o damaging my crap too much?

This one was 40" to flat and I sucked it up pretty well with my arms/legs and fork. I still had about 10mm of fork travel to spare according to my zip-tie. My wheels are still true and I don't see any signs of stress anywhere.

I think the weak links could possibly be my pedal spindles Candy C's and rims 5.1d.

What's the consensus?

ca7erham

I've ridden off of loading docks (around 3-3.5 feet) with no issues, and that was with the dart. Well, I guess I did destroy my rear wheel (but that was trying a tail whip to flat), and I think that killed the rebound in my dart, but that was bound to happen. Drops to flat just arent that fun IMO.

pnj

It is subjective. A skilled rider can do less damage then an unskilled rider. Also, going faster can be softer, as the impact is less harsh.

rankin116

Thinking about this from a (very limited, I must admit) physics angle, the velocity forward has no relation to the velocity down. Gravity is gravity, regadless of how fast you are travelling forward.

cryptid01

That would be the case if the rider landed instantaneously...but the load is actually distributed over an area delineated in time from when the tires first touch until the rider finishes absorbing the impact. The faster the rider is going, the greater the area the load is spread over resulting in a lower peak load.

Definitely.

rankin116

That certainly makes sense. I've definitely felt the difference too, just never was sure why.

And let me just point out that, yes, I am a nerd.

sscyco

I have done 6 foot drops to flat at ~ 20 mph (on a DH bike) with very little compression - I've also done a 3 foot drop to flat and bottomed - almost no speed wheelie drop. However, I have done ~ 6-7 foot drop at ~ 10 mph (on a 22# ti had tail) with a perfect transition - with barely and compression - Spokanites know this drop as "Rushmore"

sscyco

One more thing - on all my bikes - dh, cx and xc - I run SS eggbeaters - never had a spindle break.

ed 

What model beaters?

How much U weigh?

sscyco

I know them as the Eggbeater SS (stainless steel) I have several sets -

About 155 (not kilos) soaking wet

dminor 

I have to man up this year and hit Rushmore. No excuse. Now Girthmore on the other hand . . . that sucker looks big from any angle.

scrublover

ttiwwp!

mtnbiker66

Drops to flat are the best. The biggest I've ever hit is 22 feet.

sscyco

The first time it's best to follow somone off it - but it really is a nice smooth drop.

dminor 

That would be good - - would help me gauge my approach speed. Knowing me, otherwise I might overcook the corner. Don't want to do what Robby Johnson did off it.

Still looking for Rushmore, scrub. In the meantime, here's a local boosting Girthmore. It is bigger than it looks in the pic and run-in is sketchy:



Rushmore vid:

https://profile.myspace.com/index.cfm?fuseaction=vids.individual&VideoID=20752517

sscyco

The first time I dropped Rushmore was on my HT - a week after Robby broke his leg - of course I did not know that until after I did it.

born2bahick

My left tibia snapped in two, just reading that!

dminor 

Pffft! I had to schedule a hip replacement.

ProFail

I guess you have to start somewhere. Get good enough and maybe you can ride with me.

junkyard

Looking for another go through the warranty process?


Please note that XC guys know nothing about drops...

ed 

Actually...just the opposite. After much reading...I'm gaining confidence in the durability of this one. My wheelset doesn't come with a warranty though, so that's my concern. (that and the pedal spindles)

We'll see, I guess. I really do hate drops to flat. There's just not much for drops to tranny in mah'hood.

dminor 

I realized I never answered your original question, Ed. (So what else is new? - - there were bad jokes to be made and off-topic photos to post).

I consider 4'-5' to flat to be the limit of abuse I want to heap on parts when I'm just messing around; and the 5-footer should have some speed so that you don't just drop like a rock. But that's just me.

mx_599

pics?

mx

dminor 

junkyard

I read the last line quickly and saw "tranny" and what I thought was "manhood". I got nervous for you.