2nd 100cc APS build

[Koncretekid]

You do realize that piloting that thing at 140 mph or whatever is not exactly like sitting still on the garage floor, don't you?  Get someone, or two people if necessary to pick up the back of the bike about six inches off the floor and drop it about 100 times to try to get the sensation of speed.  You might want to at least add some knee cups to try to preserve the otherwise very sensitive parts or your anatomy.  I ended up putting the foot pegs up under my hips (not easy to get into) so I could get some leg support.

You'll also probably want a chin support to keep your head up.

Tom

[sofadriver]

You do realize that piloting that thing at 140 mph or whatever is not exactly like sitting still on the garage floor, don't you?  Get someone, or two people if necessary to pick up the back of the bike about six inches off the floor and drop it about 100 times to try to get the sensation of speed.  

Tom

  That's funny! Probably true, but funny anyhow.

Yes, I'm anticipating some bruising and a trip to the chiropractor.  But it could be worse............... https://www.youtube.com/watch?v=D8T1Nnmw4hA

That little box under the chin of my helmet will be replaced by support padding. The frame will be padded under my torso and hips. Thigh supports, too.

[Hoody]

You do realize that piloting that thing at 140 mph or whatever is not exactly like sitting still on the garage floor, don't you?  Get someone, or two people if necessary to pick up the back of the bike about six inches off the floor and drop it about 100 times to try to get the sensation of speed.  You might want to at least add some knee cups to try to preserve the otherwise very sensitive parts or your anatomy.  I ended up putting the foot pegs up under my hips (not easy to get into) so I could get some leg support.

You'll also probably want a chin support to keep your head up.

Tom

On a similar note given the elbow/shoulder position in those images just how easy will it be to hold the bike if it goes into a speed wobble?

[bak189]

Build a small displacement LSR M/C so the rider is in a kneeling position.....low profile....good control......and Yes, I ran the salt when they had the black line.......and Yes, it was better then the flags............................

[55chevr]

The first configuration of the laydown Sportster was similar to what you are planning.  I tested before Bonneville and found that I had to move my body forward to have more arm movement.   It will be difficult to control with your arms extended.


Joe

[Nortonist 592]

That's why I lay on my back in my sidecar.  I didn't want to become a member of the Bolshoi Ballet and wind up dancing the Nutcracker across the salt.

[sofadriver]

The first configuration of the laydown Sportster was similar to what you are planning.  I tested before Bonneville and found that I had to move my body forward to have more arm movement.   It will be difficult to control with your arms extended.


Joe

We'll see. Haven't adjusted the bars yet. They'll be further back.

[SaltPeter]

The first configuration of the laydown Sportster was similar to what you are planning.  I tested before Bonneville and found that I had to move my body forward to have more arm movement.   It will be difficult to control with your arms extended.


Joe

Hi Sofa

While my V Twin 250cc APS Bike is not a Lay Down Bike, I set it up with my arms extended and found the same thing as Joe  .... it was very unstable and difficult to control ....

Moved myself forward 65mm/2 1/2" and it transformed the Handling/Control ...

I am sure that a small/lighter engine in the Bike means that the Rider position has a greater effect on the Front/Rear Load Distribution than the larger Engined Bikes and therefore the Handling/Rider Control ...

Pete 

[55chevr]

The original seating position had my arms  extended similar to your frame.   It limited the leverage I had steering at low speed.  It was a bit concerning.  It was almost evil.  After I moved forward 6" it was like a different bike.  I also moved the foot pegs forward which made it easier to use my legs to shift weight.  You will need to apply body "English" as speed increases.  Tom's bike is about the best balance for a small motor that I have seen. 

Joe

[bones]

Hey Sofa

   I think feet under your hips is a better idea-- but it depends how flexible you are.
 
With your feet out the back the fairing will be wider and you will also need a huge cutout to be able to see your legs. Bad aero
 With your feet under your hips the whole of the tail is faired.
 I think you need to be in a position like a road race sidecar-- hey Bak.
 You may have restricted ankle movement--  but you only have to change up gears and the brake can be on the handle bars

My mate who rides my bike is not as flexible as me and has to add 4" to the seat height to get his feet on the pegs

  cheers    Bones

[sofadriver]

Hey Sofa

   I think feet under your hips is a better idea-- but it depends how flexible you are.
 

I agree with you guys 110% (especially the aeros).  But my flexibility IS the big problem.   I can get my knees under my chest but that arches my back which changes the angle of my neck.    I've had some vertebrae fused together in my neck so I can't tilt my head back very far.   That means I can't see under the lower fork tree (which is the whole design concept).

The foot pegs are still only tacked so I'm not committed to the riding position.   I'm thinking the only way I'm going to get my eyes under the fork trees AND my knees under me is to use longer forks.   Even if they were, say, 4" longer the overall height would still only be 35".   That's acceptable.  It would add about 50 sq inches more frontal area but the aerodynamic benefits at the tail would be huge.

I'll work on it today.

[Jessechop]

All of this talk about rider position. This is one of the better riding styles out there, and for whatever reason he is faster than everyone else on the same bike

The second picture is poor position on the same bike....sorry Joe

[salt27]

Jesse, nice comparison in positions.

 Don

[bak189]

Also if you are racing a small displacement or low horse power M/C, it pay not to use a hydraulic disc brake
to much drag.......use drum brake.....or if you are using a disc, use a manual cable operated "caliper" like used on go-karts......no drag.........After all most of the time there is plenty of room to stop...(maybe not on airport run-ways events.... don't know never did LSR on them)
Again small M/C.....ride in a kneeler position....if I had to do it again that is the way to go.....never did build one to ride in that position.....(except in our LSR sidecars)......Live and learn..........................................

[55chevr]

Cliff is lean, very flexible and 21 years old.   I am overweight, not flexible and 69 years old.  I have to raise my shoulders to compensate for the lack of flexibility in my neck.   I can see why he is 3 mph than I am.  But he is also 3 mph faster than everyone on their own bike when he rides it.  Nice catch on the photos Jesse.