Felt Like A Good Time To Swap Engines

Here's my latest incarnation. Swapped the Subaru Robin EH035 engine for the 97cc Lifan 2.5 HP engine on the downhill MTB. It runs out strong & has more power everywhere. Too bad its over the cc & hp limit of State MB laws.
As long as I keep it under 30 & pedal along in high gear, I might fly under the radar.
Anybody know of a good looking readily available 49cc replacement sticker?
-Lowracer-

 

[lowracer]

Added Aerobars for some more testing

I put on the straight MTB handlebars again, but added some time trial style clip-ons to get my hands out forward (as I ride on my road bikes).
On my pedal bikes I can maintain a 2-3 mph advantage using time trial style aero bars & power along all day at 23-26 mph.
I am still playing with seat height & distance to get my back more horizontal on the MB, but it definitely adds a few mph to the MB experience & is quite comfy for me (I'm used to the position).
I also added an extra throttle trigger to be able to swap the cable from one to the other depending on where & how I'm riding. If I am going into a headwind, the aero position helps even more.
See what you think from the pics.
-Lowracer-

 

[bangblow]

can you post close up pictures of how its mounted and works?

 

[lowracer]

bangblow,
Which detail pictures would you like to see?
Thanks
-lowracer-

 

[ibdennyak]

Hey lowracer, finally get a face to attach to your name. Actually, you don't fit the mental picture I had. Wonder how many other people I have an incorrect perception of. (dangling participle or something)

Anyway, nice bike there. Got all the stuff to build my version of your rim drive....if it ever gets above freezing here. Shorts....****, I'm jealous.

 

[lowracer]

ibdennyak,
This newest setup is friction drive, but 'The Beast' is rim pulley drive. It hasn't given me a lick of trouble & has some miles on it now.
Supposed to get colder here this week highs in the low 60's.
-lowracer-

 

[ibdennyak]

ibdennyak,
This newest setup is friction drive, but 'The Beast' is rim pulley drive. It hasn't given me a lick of trouble & has some miles on it now.
Supposed to get colder here this week highs in the low 60's.
-lowracer-

Aaargh, rub a little more salt in the wound. 12 degrees with 35-50 mph wind. Downwind is easy.....upwind, I have to work on my aero tuck a bit more. Rode the peddle bike the other day.....came around a corner and the wind hit me. Shift cable was frozen, so I couldn't down shift. I actually stopped, and the wind started to move me backward. Then the back tire spun on the ice and I fell over. Takes the joy out of biking.

 

[lowracer]

I hooked up the speedo today & carefully did the rollout measurement with my bodyweight on the bike & tires pumped up to 50psi. I also had my wife ride with me in the car to double check the speedo. Its fairly accurate & was able to hit 34 mph today in the aero position on the Robin Subaru powered BMP friction drive bike (without pedaling).
-Lowracer-

 

[lowracer]

2 Up

And here is a pic of my daughter & I riding 2 Up on 'The Beast'. She loves going around the block on 'The Motor Bike' as she calls it
-Lowracer-

 

[lowracer]

Rocky Mountain Flow - Rear Friction Drive

Well,
I went back to less agressive gearing on the friction drive bike. Now I'm running a 39/14 singlespeed. I installed a nice double leg kickstand to eliminate the 'Leaning Against Things' method of parking. I've got two throttle triggers on the bike. One in the normal location, & another up on the aerobars. If I'm riding into headwinds or on a windy day, I prefer to ride in the comfy aero position resting my upper body weight on my forearms (look ma, no numb hands). Its easy to pull the throttle cable out of one throttle & switch positions while the engine is off. I also recently bought a wider MTB riser bar that I installed flipped & inverted.
See Pics
-Lowracer-

 

[5-7HEAVEN]

my next build is going to be a fat tired bike with front and rear engine two wheel drive. I'm going with twin Staton 7 speed chain drives. I need to sell some motorcyles to drum up some extra money for this project. I want a "Rokon" like woods trail bike. That big Pugsley bike would be exellant for this application but its really too pricey for me. I have a dual throttle adapter already that ties the throttles together. Staton's have freewheels so one engine can be shut down if I wanted to in some situations. Dual redundancy. But mostly they would be run together. I can't wait to get started on it.

You really don't need to tie the throttles together. In fact, for safety purposes, ya might want to keep them separate, in case one of them jams. The only time you'd need to synchronize throttles is if you were driving two separate rear tires. With tandem drive, one engine could actually be idling or off, while the other engine drives the bike.

I ran separate throttles on my twin-engined beast w/front and rear staton drive. Front was friction drive, rear was chain drive. Gear ratios were different. When you throttled the front engine then switched to rear drive, it sounded like a gear shift from first to second gear.That was on my no-suspension bike. On my front-suspension girlie bike, I used Staton friction drive on front and rear. Also, with separate throttles, you'd be able to finesse the exact amount of power needed, especially at low speed and around pedestrians and vehicles. Engine speeds don't need to be synchronized, but I bet you'll be on both throttles as much as feasible. I know I was on both throttles 95% of the time.

I also used a 4-liter Happy Time fuel tank to feed into both engines' saddle tanks. My Mitsubishi tanks were a bear to fill. I had to literally run the bike up a tree to fill them to the max, and then they'd spill over. With the central tank, only the HT tank needed to be filled, then it would distribute into the saddle tanks. The front tank was at a higher position because I was using a girlie bike, so sometimes it'd run outa gas at high speed. I even tried using a 12-volt VW electric fuel pump to solve that high speed fuel starvation.