Build of Recumbent with RS 35cc

[Lee_K]

In the last few days I rode the bike (without engine) 25 miles and it was fun to ride. It's back in my basement and I am working on a jackshaft, pulley, and idlers.

I will be using this trigger shifter as a throttle control. The three positions will be for idle, 1/3 throttle, and 2/3 throttle. I do not expect to need more than 2/3 throttle, but I can always change that.

The shifter has a total stroke about twice what is needed. So this pulley reduces the cable stroke to the throttle. The other pulley does the same change for the rear brake because the brake levers have the leverage for V-brakes and I am using a drum brake. On the right side I use a pulley with equal diameters as a way to splice the cable for the 8-speed shifter.

This is the first try at an idler pulley for the belt. Also it shows a helper spring to add tension to the throttle cable.

 

[srdavo]

 

[Lee_K]

Just added an idler sprocket for the chain that runs between the two jackshafts. Then I took it for the first ride with motor power, it worked. There are a few areas that need improvement.

 

[perilous]

It Works, that's awesome. I was hoping somebody would ask this first so I don't sound silly but what is the deal is with the wooden driven pulley? is it just for prototyping purposes? I'm not used to seeing wood on motorised bikes

1 Belt and 4 chains must sound cool. What a machine! Looking forward to seeing more progress.

 

[Lee_K]

I've been away from home for a few days and did not have a chance to post or work on the bike. The wood idler arm is a prototype, but the pulley is wood because it's a cheap material and easy for me to make. It is attached to a steel flange with 6 screws so it can be replaced to change the gear ratios.

With the motor turned off, the pedaling is still going thru 3 chains with one freewheel ratcheting and it is very quiet. With the motor idling it is still quiet. With the motor running at aprrox 1/3 throttle it pulls really good, but vibrates a little and gets noisier. Also, I have to pedal very fast to keep up with the motor.

So I will be making these changes:
1--replace the 44 tooth chainring with a 53 to slow down my pedaling
2--Eliminate the O-ringed motor mounts and make solid mounts
The soft motor mounts might be contributing to the vibration under load.

 

[Lee_K]

I have made these changes:
Replaced the 44t chainring with a 53t chainring
Re-machined the engine pulley to reduce its diameter by approx 10%
Replaced the drive belt and made a new slightly larger driven pulley.

The new pulley is still wood, I painted it so it would not stand out so much. I also painted the engine shroud black. These changes give me a pedaling cadence of 64 with the engine at 5000 rpm which is good for me.

I had problems with the original belt being thrown off. It seemed to be due to a misalignment of the idler pulley. Eliminating that pulley has solved the problem.

I replaced the belt with a slightly smaller one, then made a new slightly larger pulley so no idler pulley is needed. I got the belt to fit by making the pulley oversize, and machining it smaller in steps until it just fit.

I have over 200 miles and am starting to have more confidence that it won't strand me. Next I will be working on a kill switch that will activate with the front brake.

 

[Lee_K]

It's been awhile since I last posted. I have been busy riding and fixing little issues. I mostly use the rear brake because it is a drum brake that is silent, has good feel, and most of the weight is on the rear. So I added a kill switch to the front brake to kill the motor in cases where I need to stop fast. I have another kill switch on the top tube which I normally use, but I need to reach for that one.

I have over 500 miles now (about halve with the motor off by choice) and every thing is working well. I think I will put off clean up and painting until next winter so I can take the time to do a good job, right now I would rather ride.

So if all goes well I won't have anything new to post here for a long time. I will post photos after it is painted and I will jump in on other threads.

 

[perilous]

That's great that the bike has been going so well. Certainly something to be proud of. Maybe after its painted you might consider doing an on board video I would love to see what it's like from the riders perspective. I think the brake kill switch is a great idea in populated areas I find that my bike attracts more attention than I'm comfortable with. I have to reach down for the kill switch which is potentially a tad dangerous and could be a real problem if the throttle got stuck or something, I like how you implement that.

So far I have only managed just over 200km on my bike due to lack of free time but no real problems. I'm looking forward to a ride this weekend . I'm finding that my Subaru engine is pretty much fully run in now and is just going so smooth. I have pushed it really hard up some long steep hills and I keep thinking to my self that I should stop and give it a rest but my temperature gauge doesn't indicate that its even starting to get hot. I remember the Honda gx31 on my old bike used to get really hot to the point of burning oil and not wanting to idle.

 

[Lee_K]

Here's a clip of me riding. Good thing for that kill switch or I might have run over the camera woman.

 

[John Titcomb]

Lee,

Please how goes the torsion bar rear suspension that is housed partly in the top tube? Been working up to making something w/ torsion bars, too.

Thanks,
John Titcomb