Full suspension semi recumbent for long range

C

cwah

100 MW
Joined
Jul 24, 2011
Messages
4,256
Location
Between paris and london
I've finally completed my full suspension semi recumbent.
Specs:
- 48v40AH (15s14p ncr18650pf)
- phaserunner
- DD motor

Before:
https://www.dropbox.com/s/eraa4gvu4t798py/s-l1600.jpg?dl=0

After:
https://www.dropbox.com/s/7w9x5nyeu4k7qod/IMG_20180826_203302.jpg?dl=0


I'll try the bike when it stops raining. This is my long range bike. A quick ride seems did seem a bit awkward and not as stable as normal bike... Not sure if it's normal.

What else can I do to increase range or comfort?
 
cwah said:
A quick ride seems did seem a bit awkward and not as stable as normal bike... Not sure if it's normal.

What else can I do to increase range or comfort?
Click to expand...

Put the cogs and chain back on. Seriously, especially at slow speeds, pedaling gives me a much finer level of control that makes it feel more stable. (On my recumbent.) It keeps your circulation up, anyway, and it will increase your range, if you're traveling at moderate speed.
 
donn said:
cwah said:
A quick ride seems did seem a bit awkward and not as stable as normal bike... Not sure if it's normal.

What else can I do to increase range or comfort?
Click to expand...

Put the cogs and chain back on. Seriously, especially at slow speeds, pedaling gives me a much finer level of control that makes it feel more stable. (On my recumbent.) It keeps your circulation up, anyway, and it will increase your range, if you're traveling at moderate speed.
Click to expand...


I used to have it but I can't stand the noise of the freewheel. Tic tic tic tic tic... Maybe if I find a reliable and silent one I'll put it back
 
The only way a recumbent in Australia is going long range is plastered to the front of a truck.
 
Are you saying the front end is twitchy ?
if so then
A different fork for the next size up wheel. so if you have a 20 inch fork and wheel on the front put on a 24 or 26 inch fork, suspension fork with disc brake tabs with a 24 or 26 inch wheel.
or just put on a longer fork and use the same wheel.
either way you will rake the front end more, or what the Mountain Bike Mfg's are doing on most all the new MTB. they call it a Slacker head tube angle.
Also
A complete redesign of the rear of the bike, meaning a longer wheelbase, and suspension .

I get the best range when my average speed is 25 Kph and under .

How is it uncomfortable ?


cwah said:
A quick ride seems did seem a bit awkward and not as stable as normal bike... Not sure if it's normal.

What else can I do to increase range or comfort?
Click to expand...
 
Yes a bit twitchy but maybe it's because it's a semi recumbent. But also the weight quite high of the battery...

I'll have to drive a bit more to have a more accurate answer I think!

For comfort as well! I'll report next week after few rides
 
There is a video somewhere of someone in Russia that has a recumbent that is fast, in the video he is keeping up with traffic on a freeway.
I think it is the design of that recumbent that you have , is making it twitchy.

On my last bike build , that I have not put a motor on yet because it has the newer 12 x 142 mm through axle , I have put on a fork with 10mm more travel in order to slacken up the steering . I am considering this on all future bikes , unless I buy a e-bike specific frame that 200 mm of travel designed into it.
 
ScooterMan101 said:
I think it is the design of that recumbent that you have , is making it twitchy.
Click to expand...

Sure could. Mine is very stable at high speed, but there are all kinds of designs and each has its handling issues. I've been assuming that the problem appeared after the conversion and is maybe related to the change in forks and steering, but of course if it wasn't ever all that stable at high speed, then there probably isn't any fixing it. I think the simplified conventional wisdom might be, the shorter wheelbase designs are more squirrelly at high speed, just like uprights, but with direct control steering there's an extra complication as the front wheel moves farther out, in that you have a kind of "tiller" steering that at least takes some getting used to. Mine is an indirect mechanism with the handlebars under the seat, linked to the fork via a rod, so the bars can be installed where you want them and operate at whatever ratio you want.
 
cwah said:
What else can I do to increase range or comfort?
Click to expand...

Buy a welding machine and start working on the next one with a longer wheelbase for better weight distribution and a lower riding position. Except on large bumps my hardtail semi-recumbent with a much lower and more forward riding position (and battery placement) that has been in service for almost 10 years is probably more comfortable and efficient through the air as well as tracks like it's on rails up to 60mph. Plus it doubles as a cargo bike, so it's a very useful bike too.

With so little weight on your front wheel, you'll need to watch out for poor traction issues that will put you on the ground in a hurry in turns. Sitting on top of a bike with relatively little weight on the pedals is quite different than a more typical bike, but you'll quickly become accustomed to it. From the photo it looks like it has a good amount of trail, so I doubt it's "twitchy" due to a geometry standpoint and I'd hesitate about trying a larger wheel on front until you've measured the trail. A larger wheel seems likely to just make matters worse by putting your weight and the battery more over the rear wheel, and lightening the weight on the front, which I think is the handling difference you're feeling. How does it feel at very low speed? If it's a bit sluggish, ie you weave a bit at very low speed, then you definitely don't want to increase trail with a bigger wheel.
 
I just went back and took a closer look at your picture of the bike,
and sure enough it does look to have a good amount of trail, or what I am more familiar with more Rake . So John in CR has some good points there.

Also when looking closer at the picture it does not appear to have front suspension, is the stem a suspension stem of some sort ?

You say you want high speed, but with no front suspension I would not want to go very fast on that bike.

Is there a way to sell it and get a different bike that will be more stable at speed and have real suspension front and rear ?
Sometimes it is best to sell something and get something that will work better than to try and modify it.

Newer Down Hill Mountain Bikes not only have suspension front and rear and good suspension parts at that, they are also lower and slacker these days . We have Craigslist here in the U.S. to look for used ones if new is not in your budget.
Or even a e-bike specific frame. that would be best.
 
If you do want to modify that Giant Recumbent , besides doing what I and John in CR and others suggest which is to lengthen the wheelbase,
you could perhaps find someone to make a front suspension fork for you.

I like the type of fork that Moto Parilla uses on their carbon e-bike
for many reasons ,
One being that you can adjust the amount of Rake/Trail on it by making different length linkages , or make linkages with more than one hole where the bearings and pivot points are that experiment with different Rake and Trail Geometries .

I would like to find someone here in the S.F. Bay area to make one of that type of fork for my next conversion/e-bike build, using more affordable aluminium plates/sheets/rods , instead of carbon fiber legs .

https://www.youtube.com/watch?v=bAqDFOcErCo

http://www.motoparilla.it/
 
Thanks for your feedback very much appreciated.

It has front suspension as well just look carefully!

I've been on a ride on low speed (20mph) and all seems good so far:
https://www.dropbox.com/s/sfmtw7z2z2dld5q/IMG_20180828_160632.jpg?dl=0

I just had a try, it seems more efficient in general.

I just have 2 small issue:
- the crank would be better if further out... But it would need welding and I don't have the équipement.
- the backseat would be much better if it can have a lower angle, so I'd have a more aero position.

Not sure what would be the best option... But I may stick to that for now
 
donn said:
Put the cogs and chain back on. Seriously, especially at slow speeds, pedaling gives me a much finer level of control that makes it feel more stable. (On my recumbent.) It keeps your circulation up, anyway, and it will increase your range, if you're traveling at moderate speed.
Click to expand...

Yes! You do most of your balancing of your body through the feet. Put the chain on, and run in a high enough gear to apply pressure to the soles of your feet. Either that, or put foot pegs on it.
 
Warren said:
donn said:
Put the cogs and chain back on. Seriously, especially at slow speeds, pedaling gives me a much finer level of control that makes it feel more stable. (On my recumbent.) It keeps your circulation up, anyway, and it will increase your range, if you're traveling at moderate speed.
Click to expand...

Yes! You do most of your balancing of your body through the feet. Put the chain on, and run in a high enough gear to apply pressure to the soles of your feet. Either that, or put foot pegs on it.
Click to expand...

Any completely silent and reliable freewheel? The noisy of the freewheel is the reason I removed. It
 
For better comfort, I m thinking to remove the backrest and add replace it to another backrest here:
https://www.dropbox.com/s/ugx3293yrxkmed1/IMG_20180828_223647.jpg?dl=0

I'm thinking to buy this:
http://s.aliexpress.com/FruIfURF

Would that work?
 
cwah said:
Any completely silent and reliable freewheel? The noisy of the freewheel is the reason I removed. It
Click to expand...

This may help.

[youtube]SMYZewQoP4I[/youtube]

Shimano makes (made?) a silent freehub (Deore LX R080), but I don't know of a silent freewheel. Others discuss using grease to make a freewheel even quieter. I'd be concerned about whether that would affect the operation of the ratcheting mechanism or not. You'd probably have to hear from someone with more history and experience with doing that than I have.
 
cwah said:
Any completely silent and reliable freewheel? The noisy of the freewheel is the reason I removed. It
Click to expand...

That's the sound of the freewheel working. Lubricating it with heavier stuff can make it quieter, but if you follow that path too far the thing breaks because you stuck down the pawls. Note that not all freewheels make the same noise. There are a lot fewer of them to choose from these days than in the past, though.

Roller clutches are silent, but they fail more often and sooner than ratcheted freewheels. I don't know of a single one of those that came in a threaded freewheel format, either.

If you want this small and innocuous noise to stop, pedal. Simple.

And... I can't help but feel grossed out by scooter riders sponging off of bicyclists' privileges. There are separate responsibilities and rights of access for scooters, and you could abide by them. Then you wouldn't stain the reputation of e-bikers or irritate cyclists who are doing their thing honestly.
 
If you can share an ebay link to a very silent freewheel I would consider.

In the quest of having a more comfy and more aero position, I've added a car backrest on the bike.
https://www.dropbox.com/s/mbxf623qael8zj5/IMG_20180903_183352.jpg?dl=0

However I found out I also need a headrest. Can I use the initial backrest of the bike to make it a headrest? And if so, how best to install it? It has a 13.6mm hole.
https://www.dropbox.com/s/o1nrmshullk3kiu/IMG_20180903_231701.jpg?dl=0

https://www.dropbox.com/s/9wprxg6h27uql2q/IMG_20180903_231754.jpg?dl=0
Any idea?

Thanks
 
I've bolted it on now... But I'd like to lower it down... Any way I can bend the tube to lower it down easily?
https://www.dropbox.com/s/3934tjygihawr3a/IMG_20180904_124237.jpg?dl=0
 
Hey man.. you should share your photos directly to the forum in the future.
People don't wanna click on a link per pic.

Also, picture uploading on ES has changed. You can upload any size you want now, and the server takes it and generates a 1000 pixel wide thumbnail.

Cool build though. I rode a giant revive once and it was a dream. But wasn't really a fan of the design.
Not the most aerodynamic thing though. But nobody makes an aerodynamic semi recumbent that has suspension on either axle. It's a real shame and a half, because a half decent semi recumbent can reduce your air drag a ton.

Really extreme ones like this can lead to a 25-33% reduction in continuous wattage at high speeds.

rans_stratus_lg.jpg


A full recumbent is good for a >50% reduction :O
 
There are some commercially available recumbents out there with front and rear suspension, but I guess you're right, I can't think of one that's really a semi-recumbent. I think it has a lot to do with the wheelbase factor - it's the short wheelbases that get front suspension, because there's weight on the front. As the wheelbase gets longer, the weight on the front drops, and the suspension gets to be more trouble than it's worth. As the wheelbase gets shorter, your legs come up to clear the wheel, and it's no longer "semi" recumbent. I've thought about a suspension fork with mine, but it would need linkage bolted into the left crown shoulder for the steering, and for rarely exceeding 20mph it isn't worth it so far.

An optionally full suspension short wheelbase with (unusually) equal size 26 inch wheels, Azub "Max"
azub-max-360-degree-off.jpg
 
RE the twitchy ride, my RE Bike semi recumbent is similar. You just get used to it, mostly its bad at really slow speeds like under 5 mph.

Re the freewheel noise, pedaling makes that quiet. For longest range you would want slower travel anyway, like 15 mph in the highest gear the thing can pedal in. Above 15 mph, I just hear wind in my ears myself. But yeah, the cheaper freewheels often supplied with a hub motor can be noisy, compared to one taken off a good rear wheel. Lube with motor oil vs lighter oil will help.
 
dogman dan said:
Lube with motor oil vs lighter oil will help.
Click to expand...
Keep in mind the heavier the oil, the more crap sticks to it until it gums up and jams the freewheel pawls in one position or the other.

Packing it with grease also makes it quieter, but also makes it much more likely to jam the pawls.

Using a cassette version instead of freewheel takes the noise down quite a lot of notches if it's a good one; the one in the bigger Fusin geared hubmotor doesn't qualify as good, so it's about as noisy as a freewheel (and it's cassette bearings are so crappy that even though I almost never put any pedal power thru it to put a load on them, they disintegrated. )
 
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