hopping ?

[Don Templeton]

I hear from a number of good boaters that if a rigger hops then you should lower your rear sponsons. I thought a rigger hops because the prop is climbing out of the water and I don't understand why lowering the rear sponsons will help.

I'd like to hear some comments,

Don

 

[Chris Wood]

try flatting out the strut, or put more pitch in the prop.

chris

 

[Don Ferrette]

I hear from a number of good boaters that if a rigger hops then you should lower your rear sponsons. I thought a rigger hops because the prop is climbing out of the water and I don't understand why lowering the rear sponsons will help.
I'd like to hear some comments,

Don

Like Chris just said, look at the strut angle & the prop first. If it pulls the prop that's on it easily then you can add some cup to it which also reduces lift. B)

 

[Buckshot]

Don,

I haven't read or heard about lowering the rear spoonsons to cure a hopping hydro so I can't comment on that, but I will agree with Chris and Don F. about adding cup or pitch to reduce the lift of the prop and flaten the strut.



-Buck-

 

[GRoth265]

If you are using a prop that has been (worked) are you sure both blades are the same? It can cause a nasty hop. Greg

 

[steve wood]

i think lowering the rears would be a band aid to fix something else. check your prop and make sure you don't have a bent blade either

 

[aaron alberico]

if the prop is on the limit already with pitch\cup

back cut the blades, will reduce lift and unload it.

regards Aaron

 

[mark holton jr]

i had a cat once that hopped in the water bad but after he stoped biting i didnt have through him in the lake anymore lol

 

[shadow]

Definately look at your prop and maybe try a couple of others. Last year at a race one of our local guys had the same problem. Mark Grim spent probly about an hour and a half on his prop for him and it started to settle down a little.

There used to be and maybe still are some rigger hydros that didn't even have rear sponsons, they just ran on the strut and prop. So I would definately look more into the prop and less into the rear sponsons.

Cliff

 

[Grimracer]

Don,

make sure you check the flatness of the front sponsons riding pads first..

Also if you have the rear sponsons at to high a AOA the boat can hopp.

Regards

Grimracer

 

[SayMikey]

Don,
make sure you check the flatness of the front sponsons riding pads first..

Also if you have the rear sponsons at to high a AOA the boat can hopp.

Regards

Grimracer

Don what prop are you using?

 

[user 115]

Definitely check the prop blades as mentioned by Greg and others.. I had a prop from a reputable prop guru and it made my 21 rigger hop something fierce. Turns out blades were way off... Sharpness of the blades was a factor too.

Charley

 

[Ron Olson]

One idea stolen from one of John Finch's book it that you may not have enough weight on the rear as that can cause hopping with lifting props.

 

[Don Templeton]

Thanks for the input guys.

Actually, I totally agree with each and every one of you! :lol: I really can't remember where I recently read the comments on the rear sponsons. Maybe on another forum but it didn't make any since at all to me. <_<

I run a 12 rigger with a 1640 highly cupped. It launches with ease, runs with good speed and turns in almost any radius I want,

but I discern a small high frequency hop on the straight mainly from the sound.

My fronts are a little high on AOA at 4.5 degrees and my rears are set high off the water at no more than 1 degree max, the same as the strut.

Now the real problem, my strut is a center sponson and not adjustable! (NO BODY SAY ANYTHING, I'M AN OLD BOATER) :lol:

Anyway, I really think the easyest answere to my problem is a new set of fronts with a more forward trailing edge which should increase the weight on the strut with out adding weight to the boat.

Any comments?

Don

 

[aaron alberico]

Don,

if it was me i would cut the lift out of the prop to start with,

then try a longer after plane,

regards Aaron