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eskimo
Starting Member

USA
15 Posts

Posted - 04/23/2017 :  14:57:33  Show Profile  Reply with Quote
I have a Sun EZ-1 old style. I am 6'1 260 lbs and the thing is too squirrley. Weight distribution is my suspicion. Is there any way I can fix this?

Joseph J. Quinn III

warren
human power expert

USA
6052 Posts

Posted - 04/24/2017 :  06:28:03  Show Profile  Visit warren's Homepage  Reply with Quote
Yes, they are a bit squirrely. They are actually better than the old Bike-E's in that respect. After you ride it several times you will get used to it and it will feel normal.

Warren
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eskimo
Starting Member

USA
15 Posts

Posted - 04/24/2017 :  18:17:53  Show Profile  Reply with Quote
So there are no mods to get a little more weight to the front or change the forks or put the steering goose-neck 180 degrees around like it should be? Kinda terrifying to mingle with cars on this thing!

Joseph J. Quinn III
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eskimo
Starting Member

USA
15 Posts

Posted - 04/25/2017 :  17:23:50  Show Profile  Reply with Quote
Warren! I tried one of the mods I was tslking about and it made an amazing difference in my Sun EZ-1! I rotsted the gooseneck 180 degrees.I thought that it would shift the weight distribution forward and I believe I have achieved my purpose. It is much more managable.



Joseph J. Quinn III
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warren
human power expert

USA
6052 Posts

Posted - 04/25/2017 :  18:26:20  Show Profile  Visit warren's Homepage  Reply with Quote
Hey great! Is the gooseneck the part between the steerer tube and the handlebars?
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Larry Lem
human power expert

South Sandwich Islands
2523 Posts

Posted - 04/26/2017 :  08:43:08  Show Profile  Reply with Quote
Quill stems were commonly referred to as goosenecks in the 70s and less so in the 80s and now, many folks don't know what a quill stem is with the advent of threadless steerer tubes and headsets.

Larry Lem
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DougC
Starting Member

USA
10 Posts

Posted - 04/26/2017 :  09:37:46  Show Profile  Reply with Quote
One mod you could try is changing the 16" front wheel & fork out for a 20", and then using a fatter tire in the front. That would give a bit more gyro stability.

Changing the stem around doesn't really matter much, since on a recumbent you don't lean on the handlebars anyway.
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Balor
recumbent guru

Russia
512 Posts

Posted - 05/01/2017 :  10:12:12  Show Profile  Reply with Quote
quote:
Originally posted by eskimo

Warren! I tried one of the mods I was tslking about and it made an amazing difference in my Sun EZ-1! I rotsted the gooseneck 180 degrees.I thought that it would shift the weight distribution forward and I believe I have achieved my purpose. It is much more managable.



Joseph J. Quinn III



It has nothing to do with weight distribution, you've simply reduced tiller to more manageable levels.
Too much tiller results in onset of steering inertia of your own hands swinging in a large arc, and muscles that move hands side to side are weak, hence you need to relearn your steering pattens to turn the handlebars smoothly, so you will not overshoot.

Tiller being distance from steering axis to centerline of your bar handles (but located on the other side of the forks, as opposed to uprights)

Edited by - Balor on 05/01/2017 10:13:11
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eskimo
Starting Member

USA
15 Posts

Posted - 05/02/2017 :  20:02:51  Show Profile  Reply with Quote
Thank you all for your comments. When I first posted to this thread I only had a couple of short rides on the bike. I rode it quite a bit today (after almost a week of monsoon rain} and got more familiar with it.

Balor: This tiller action you are talking about is very intriguing and I will have to study your post more to get a handle on it but... I can't help believing that weight distribution is still a problem. Before I rotated the Gooseneck/quill/headset the front tire was actually sliding back and forth under certain riding conditions. I think it was slow uphill stuff. Almost like the front wheel was lifting. I'm getting used to starts but the first couple of pedal turns on slight uphill inclines always result in a drastic turn! (right I think)

Joseph J. Quinn III
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eskimo
Starting Member

USA
15 Posts

Posted - 05/02/2017 :  20:23:17  Show Profile  Reply with Quote
I had a fast down hill today and it was terrifying! Alot of side to side front end movement. It still feels like the frontend is light although its better than before!

DougC: I read a post by Warren and he said that mod made his bike more squirrely. Am I correct Warren? I couldn't locate it again to verify.

I like the bike well enough to try some things!

Joseph J. Quinn III
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eskimo
Starting Member

USA
15 Posts

Posted - 05/02/2017 :  20:40:32  Show Profile  Reply with Quote
Balor said "Tiller being distance from steering axis to centerline of your bar handles (but located on the other side of the forks, as opposed to uprights)"

So if my handle bars were right on top of the fork post (so the centerline of my handle bars were lined up with the fork post) would that reduce the tiller sensitivity?

PS I promise to look at some diagram naming the parts of a recumbent bike so I can name them better in my posts!

Joseph J. Quinn III
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roster
Starting Member

USA
16 Posts

Posted - 05/03/2017 :  16:31:26  Show Profile  Reply with Quote
I have a KMX Viper and the same reaction in steering at first , but after some mile, 100, got used to steering being squirrely.
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Balor
recumbent guru

Russia
512 Posts

Posted - 05/04/2017 :  07:09:30  Show Profile  Reply with Quote
quote:
Originally posted by eskimo

So if my handle bars were right on top of the fork post (so the centerline of my handle bars were lined up with the fork post) would that reduce the tiller sensitivity?




Yea, but you are unlikely to reach the bars (if you bent was designed with some tiller in mind) this way.
And you may actually lose some stability, because when you pull on the bars (as you do on a bent by simply holding onto them), when there is some tiller - it results in a stable equilibrium and extra self-centering force.

You WILL learn how to deal with all this, it will just take some time.
'Squirreleness' is just a vague impression we have about perceived lack of control (that includes proper damping of unwanted corrections and over-corrections) over the bars.

Moving bottom brackets bents, for instance, are invariably considered BOTH squirrely and unresponsive at first - due to a ton of steering inertia and some unstable equilibriums involved.

By the way, you may notice that you cannot ride no-hands on a bent. This is somewhat unavoidable:
You need some tiller for relaxed cruising, but for a bike to be rideable w/o hands for an average person, not a circus acrobat, it must self-steer into a lean.
You cannot have that on a bike with a tiller, unless it is also an MBB - but USUALLY on MBB it results in 'too much of a good thing', front end being so heavy and floppy it simply flops over on its own very fast unless you correct it with your bar input or, in case of expert riders, leg input.

You may want to see this video why mass distribution, in addition to trail and gyroscopic forces, is very important for bike stability:
https://www.youtube.com/watch?v=NcZCzr9ExKk

Edited by - Balor on 05/04/2017 07:10:56
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eskimo
Starting Member

USA
15 Posts

Posted - 05/04/2017 :  07:36:18  Show Profile  Reply with Quote
Balor: Thank you so much for all the detail! It is very interesting! I am going to analyse this info and get back to you.

Thanks again

Joseph J. Quinn III
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eskimo
Starting Member

USA
15 Posts

Posted - 05/25/2017 :  14:34:37  Show Profile  Reply with Quote
Thank you all for posting and giving me feedback.
This quote from "Bicycle and motorcycle dynamics" PKU http://www2.coe.pku.edu.cn/tpic/file/20160122/20160122085792739273.pdf
explains my experience with the EZ-1 very well.
"The farther forward (closer to front wheel) the center of mass of the combined bike and rider, the less the front wheel has to move laterally in order to maintain balance. Conversely, the further back (closer to the rear wheel) the center of mass is located, the more front wheel lateral movement or bike forward motion will be required to regain balance. This can be noticeable on long-wheelbase recumbents, choppers, and wheelie bikes.

It can also be an issue for touring bikes with a heavy load of gear over or even behind the rear wheel. Mass over the rear wheel can be more easily controlled if it is lower than mass over the front wheel."

So when I start (from a dead stop) the bike is a real handful until I get some momentum. I have learned to lean right so the bike doesn't dart out into traffic.

I have gotten more comfortable with higher speed except in controll situations. (ie...close riding in traffic) I have to steer more to keep it straight. Riding alone without cars around is actually quite nice.

Have any of you ridden SWB bents? What has been your experience with them?

Joseph J. Quinn III
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warren
human power expert

USA
6052 Posts

Posted - 05/28/2017 :  07:40:10  Show Profile  Visit warren's Homepage  Reply with Quote
I think most of us have ridden SWB recumbent bikes. They handle nicely in my opinion.
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Balor
recumbent guru

Russia
512 Posts

Posted - 05/28/2017 :  13:32:17  Show Profile  Reply with Quote
I've yet to pilot an SWB bent that handles close to DF, but most are more than rideable and can be used even in heavy traffic.
Even my first MBB, which is a real pig to handle can be manuevered somewhat in congested traffic - it comes with practice. Few designs are actually unrideable no matter what, it takes a lot of skill to make one, actually :) (provided they are mechanically sound and have adequate means of control, that is... or even without one, like Pythons that are usually ridden no-hands).
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eskimo
Starting Member

USA
15 Posts

Posted - 05/31/2017 :  15:01:27  Show Profile  Reply with Quote
I am getting more comfortable with my EZ-1 although it is kind of a tank. Is the EZ-! lite a significant difference? I read Bicycleman's take which was about 2 MPH difference, but what about the wear on the human engine? Does it take any less force or a substancially less force? So are pythons and flevos the same?

Joseph J. Quinn III
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eskimo
Starting Member

USA
15 Posts

Posted - 05/31/2017 :  15:04:43  Show Profile  Reply with Quote
Have you ridden a EZ-! in traffic?

Joseph J. Quinn III
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warren
human power expert

USA
6052 Posts

Posted - 06/01/2017 :  07:26:24  Show Profile  Visit warren's Homepage  Reply with Quote
The EZ-1 is about the cheapest recumbent you can buy. It's heavy and slow and does not handle well (IMO), but it's fine for tooling around on a bike trail. If you are looking for something more yes, I'd suggest an SWB recumbent. The ones with a a 20" front wheel generally are more docile that the ones with two big wheels. I can't recommend Pythons and Flevos and other bikes without headtube steering.
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PUGZCAT
recumbent enthusiast

Canada
459 Posts

Posted - 06/03/2017 :  06:51:13  Show Profile  Reply with Quote
Hmm, might be time for experimentation, unscrew the valve on the tire tube and remove the air, screw the valve back in, put a hand pump in a pail of water, reinstall empty tube and fill the tire with water instead of air. See how greatly increased rotating weight effects handling. Another easy option is an 18 inch wheel with a 1.75 tire or smaller will likely fit in the fork. This will increase trail because of the increased radius and slackening the head angle a little from raising the front end 3/4 of a inch.
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Richard Myers
recumbent enthusiast

USA
206 Posts

Posted - 06/22/2017 :  15:29:36  Show Profile  Reply with Quote
The EZ-1 does not fit you I am 5'6 162 and my EZ-1 light in equipped
with a 20" Durano front tire running at 115 psi and a Kojack running at 95 psi on the rear. The bars are 4" narrower then the stock and after a couple cranks it is stable. Heavy front tires will not work, your best bet is to sell the EZ-1 to someone it will fit and find yourself a recumbent that does fit you. Generally all recumbents are a bit twitchy but with experience comes stability.

Richard from Ohio
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eskimo
Starting Member

USA
15 Posts

Posted - 07/22/2017 :  11:02:27  Show Profile  Reply with Quote
Thank you Richard Meyers for your observation. I have been suspicious that I am too tall for my Sun EZ-1 but I did measure myself before I bought it. I think my weight amplifies the steering problems.

Update: I am fairly comfortable with fast straight runs and I can balance the bike at a creeping pace (provided it was moving already) but starting (from a dead stop) and high speed turns are still problems. I enjoy the bike much more if I just take it easy. As all the reading I have done has said that is the type of riding the bike was designed for.

Regards
Joe

Joseph J. Quinn III
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Tom Hering
Starting Member

USA
15 Posts

Posted - 08/26/2017 :  21:01:34  Show Profile  Reply with Quote
I bought a 2001 Sun EZ-1 last year. I had control problems at first, and was constantly running into the curb. But after about 10 hours on the bike, I was riding one-handed with no problems. I learned to keep my hands, arms, shoulders, and upper body relaxed - a lot of twitchiness I blamed on the bike was actually caused by my own tense body. I also learned to let the bike wobble a little bit (which it naturally wants to do), rather than trying to make it track straight as an arrow. As for getting going again from a dead stop, I learned not to rush it. Slowly push on one pedal in the power position, while at the same time kicking off with the other foot that's on the ground.

Edited by - Tom Hering on 08/26/2017 21:13:33
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eskimo
Starting Member

USA
15 Posts

Posted - 08/30/2017 :  11:25:30  Show Profile  Reply with Quote
Thanks Tom! I learned that starting technique even before I bought my EZ-1 through watching YouTube. On the flat it works fine but if there is any incline the difficulty increases exponentially. Weaving on Springfield Missouri streets is a death wish! There is no weight on the front wheel therefore no traction! I can especially feel the bike losing grip on mild inclines (going up of course)

I think Richard Myers has the right idea (selling)! I found another issue with the bike that isn't a handling problem when I laid it down the other day to avoid getting hit. Seat construction! I wonder if I should start a new thread since that is off topic?

Thanks again Tom

Joseph J. Quinn III
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