The seat of the problem on my new V20

Pcmousley

Member
So it's early days trying to get to grips on my new V20, it's unlike anything I've ever ridden and whilst at each outing confidence and proficiency improves I still cannot envisage climbing and descending real steep stuff and only a few weeks to go before we depart for Lanzarotte taking the V with us, getting it wrong there has real consequence as its all volcanic with solid lava on the roadsides.

I've found that in traffic and in town, and we have a lot of both here in the UK, I've wanted to sit up, rather than the real laid back position, this offers its own problems if trying to sit up for several miles, I thought of putting in some form of wedge in the backrest but then that doesn't get me adapted to the reclined position which is of course is going to be the fastest and most comfortable place to be.

So out came the pencil and eraser and decided to make a backrest that moves from its laid back to about 40 degrees up, this needed to be able to be done underway and pretty instant in both directions, considered using a small hydraulic or pneumatic cylinder and then settled on a MTB adjustable seat post. Fabricated a 3mm backrest, contemplated cutting the actual seat but went off that idea, put pivot hinges on the front edge under the Seat base, got a six inch lift at the rear edge and realised that the MTB seat post idea was a no goer and found relative simple solution down at the local boat shop.

I have to say the end result is fantastic the seat defaults to its more upright position and is very solid, take the weight off it depress the lever and just lean back, as soon as you want to sit up again the seat back follows you and locks, now I really feel I have the best of both and should I want to spend all of my rides in the laid back position it is readily undo able.

Now if I can figure out how to attach a couple of photos I can share this with you but at the moment it's not showing me the attachment option.
 

Wannabe

Well-Known Member
Wind tunnel tests or similar

It would be nice to have some concrete evidence of aerodynamic effects from 20 to 27 degree lean. I am thinking that part of the increased speed of the V over the S is due to bike weight as well as stiffer front triangle. I realize that Aero trumps all. Indeed, after certain speeds, aero makes up for most of the effort required to attain speeds over ~15 mph. Of course head winds add to the effort if they are present.

The aerodynamic drag experienced by a DF rider compared to a S or V is significant. But from a Silvio to a Vendetta, maybe not so much?
 

Rick Youngblood

CarbonCraft Master
Pcmousley ~ Very creative

Pcmousley ~ Very creative idea ~ Please post some pic's when you go on holiday in a few weeks. "I still cannot envisage climbing and descending real steep stuff" Once you get proficient on the flats start doing small hills. It all comes together in time.

Wannabe ~ Correct the aero difference between S and V are not as drastic as a DF to most any recumbent. The aero advantage between V and S becomes more significance with speed probably over 20 mph. On a steep downhill I coasted the V at a top speed of 48+, the S got 45+ on the same hill...there is no wind in this area due to it being up in the mountain canyons. Also I noticed the V will accelerate faster (a lot faster) while coasting down hills too...this is all due to aero. Now I noticed the V has faster acceleration from say a dead stop than the S, this is due to combination of stiffness and it being lighter.

The thing we do a lot on this board is compare the V to the S a lot, and we are mostly just comparing speed between these two. The Silvio is a darn fast bike compared to most DF and other recumbents, and I think faster than a lot of the other highracer recumbent bikes...the MBB-FWD system is just so incredibly efficient taking my power and transferring it to the drive wheel.
 

telephd

Guru
more info please pcmousley

pcmousley that looks like a really slick installation. Ive just received my new V20 frameset and would like some more information regarding your seat angle solution. Specifically what kind of hinges did you use and where did you attach them? What is the mechanism that raises the seat? What material did you use for the fabricated seat back? How much. if any, did you change the lay-back angle of the seat when down with the mechanism attached? More pics please!
 

ratz

Wielder of the Rubber Mallet
Video time

I'm assuming the extra brake handle serves to "release" the seat to change position in the non-ratched direction? Video would be good.

Rick's right my betting $ are on the fact that eventually you will use this less and less. BUT I have driven on many UK roads for business. I can definitely think of places that being up right and supported by the seat would be a plus. When I go from the V to the S; I feel like I'm sitting bolt upright. It comes surprisingly fast in the early miles. 30-20 would probably be the max range I would used but I'm pretty darn comfortable with 20 now. First time I saw someone else sit on a V; I was thinking wow that's crazy. Now it seems normal.

 

Rick Youngblood

CarbonCraft Master
Bob..."I'm pretty darn

Bob..."I'm pretty darn comfortable with 20 now"...
Yeah, I feel the same...but it's not like that out of the box...the confidence comes with time and practice. I started with the Silvio back in Feb-2014, bought the bike for it's suspension as a supplemental bike to my Metabike, not as a go fast bike. But to my surprise it was not only more comfortable on the rough roads, but faster than my Metabike, I was not expecting that. Then Bob went out and got a Vendetta, I liked the idea of a Silvio on 'roids, so I sold the Metabike and purchased a Vendetta as a bike for centuries and fast rides...not sure what the lower recline was going to be like. BTW, I don't have a local recumbent source, so I have buy to try. So with that mentality, I'm expecting a learning curve with any recumbent I buy. Now after about 2500 miles on the Vendetta I feel confident in the most extreme situations that I thought I would never be able to ride the V. For example, the Sacramento River Trail is just a block away from my home. It gets extremely congested with, kids, dogs, 30' dog leashes, tootsie rolls, and people just not paying attention. So riding the trail is challenging, but fun, because it really hones in your slow speed and maneuvering skills of avoiding last second surprises. At this point 100% confident riding the trail, but I had to build up to. I expect my skills will continue, I don't think you are ever done refining your skills.

My only dilemma is I want to just ride the Vendetta and not as much the Silvio. I know poor me
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!
 

Rampa

Guru
I wonder if an air bladder between hinged panels would work?

Might have to much give though. You could have a little bulb beneath the seat to inflate it with.
 

Pcmousley

Member
V20 Seat

Here is the link to the video, will try another one but Dropbox takes ages to upload.

https://www.dropbox.com/sh/9hdafw6mzsg14zk/AAAnFuClF4GHM9XXTZkPjZ3la?dl=0
 

richa

Active Member
This looks really really


This looks really really great; I can see this being beneficial in several instances. Those leery about laid-back position can now start off more upright (which it's evidently easier to learn on), and those wanting a more upright position in traffic have it. And can lay back when they get going. The best of both worlds.

I don't know of any other recumbent with an on-the-fly adjustable seat. A great innovation IMO. Even if after awhile you use it less and less, it's there when you need it.

I'd really like to see some views from the side to see your recline angle and relationship to the bars. And would be interested in details about what raises the seat. Is it a spring or pressure on the lever on the bars?

Thanks in advance,

Rich

 

Pcmousley

Member
V20 Seat Mod

Rich, Hopefully this is the info you need, and I got another 30 miles in today in very windy conditions climbed a number of pretty good hills and the seat in its upright position was rock solid I definitely would not want to be without this now as it just gives you options on seat position.
So the seat back was fabricated from 3mm aluminium sheet, and was cold formed for the hinge section, I traced the shape from the seat cushion and went from the top of the rear of the cushion forward for 16" this made the two holes in the V20 seat that I believe we're meant for bottle cages (but I could not get them to fit without large packers) the point for the hinge and I used the rearmost of these. I traced the hinge from a 5mm penny washer and allowed 3mm for the seat base thickness and another 3mm to allow for the fold, I did not drill the holes until later. Then the fold was made on both sides ensuring they were parrallel, and did make a mock from a offcut to see how the fold went and where the crease line needed to be, the actual folds went well and lined up well either side of the existing bottle holes. Positioning the seat either of the holes and ensuring it was square I marked the slots and drilled and filed until they were the correct length. If you look at the very front of the new seat back the front edge has to be trimmed along the front edge between the pivots points to allow for it to lift. I then folded two of the stainless steel flats (a Seasure part) to match with the hole and trimmed to length so it cleared the frame, I used the exsiting hole in the plate for the pivot point and then aligned the plate to the inside edge of the slot and marked the position of the Bottle cage hole removed it and drilled the hole. Once you have these formed bolt them in place, lower in the new seat back, adjust the folds if need be and once you are ok with the fit place a small shim or card over the bolt heads for a little clearance ensure the new seat back is aligned and square and then mark and drill the pivot holes, I used 5mm stainless with nylocs and did one at a time, the slot may need slight adjustment but you should end up with a smooth movement and just over a 6 inch lift at the back end. The actual lift mech is a Seasure stainless Hasp & Staple 97mm SKU # 23.04 this is used for locking hatches on boats, Seasure is a UK company but I think have USA outlets, but if you really want to do this and have trouble finding one I could mail one to you. Apart from a small hole for the release cable the piece was as is. The hole nearest the hinge was aligned to the front edge of the rearmost hole in the V20 frame with the washer and nut under, in the front two holes I used counter sink head bolts and as these would now fowl the frame were countersunk into the seat base and nuts on the top,
 

Pcmousley

Member
V20 Seat Mod

Charles, I did shoot a video seat tour and left it for hours to upload to Dropbox and then gave up on it, do you know of a better way ?
 

Pcmousley

Member
V20 Seat Mod

Rich, the second part of this seems to have not been posted if it doesn't appear I will rewrite it over the next couple of days.
 

Pcmousley

Member
V20 Rest of Mod

I wanted to get the hinge as far forward as possible for the max lift which is just over six inches at the back end, but did not want to make any mods to the frame hence why two bolts are up and one down. From the offcut of the longer stainless plate I made the over centre stop and bolted this on the hinge, the spring mech is simply a piece of elastic Bungy cord led through the slot that was there for the staple to fit into, which you don't use, put on a stainless washer and a stop knot, the Bungy was the led forward under the front of the new seat back, which I filed a half hole into so it would not get trapped and drilled a hole in the seat in a position where the first hole is in the frame is, added a stop bead and stop knot, the Bungy is about three eights. The release mech was a Avid brake lever I had spare, followed the brake cable around to the seat added some clips and fitted a permanent bend at the back end. I did find that the inner release cable did not return and the outer cable then came out of the lever housing and the seat then would not lock, a further smaller Bungy cord on the inner cured this. From the onset I thought that this would involve some form of custom hinge but this Seasure product works so well why bother, unless you wanted to incorporate a 'mouse trap' type hinge into it, I did play around with one but without being able to control the spring gave up. Apart from anodising the seat back which I will do, they is nothing I would change, is works so fast, locks solid, and you don't feel any resistance when fully reclined, unless you used a piece of Bungy for jumping off bridges. And for sure I now wouldn't want the bike without it, however used to the fully reclined postion I get I do want to use this bike for long distance touring and for the towns and cities I am pretty sure how I want to be sat through heavy traffic. I do find that on some steep accents I also get more control sat up and I think a piece more pressure on the pedals but that might just be my amateur status on a V20 at the moment.

Holla if you want anything else, I will attempt to put up a video on YouTube.

Phillip
 

currystomper

Well-Known Member
S20/45

I'm just thinking that if Cruzbike upgrade the Silivo with this idea we could be looking at a Silivio going from 20 Degs to 45.

Now that may get me to sell my S1.5 and get a new one!!

CS
 

currystomper

Well-Known Member
Video uploaded to Youtube.....

Philip: that's your video up on youtube at

https://www.youtube.com/watch?v=AvGkcKHol-8&feature=youtu.be

if you get it uploaded at a later stage I'll delete this vesion

CS
 

Romagjack

Well-Known Member
Great Idea

I'm always changing the seat angle for comfort in my car on long drives. How great would it be to change the seat angle while riding on my Cruzbike!
 
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