Giant Revive Semi Recumbent

[LewTwo]

Spotted this on the local Craig's list (Giant Revive DX):


Now there are at least one or two opinionated individuals on this forum and I am seeking an opinion(s)

Someone here once said that the best way to get a smooth ride was a long rear swing arm. I reckon this thing qualifies in that regard. It is also crank forward, flat footed, step through ... all features I desire. The wheels a bit smaller than I would prefer (20x1.75) and the rider weight is a bit farther to the rear than I would prefer but like popeye, "it is what it is".

What do you think of the idea of putting a BBS02 mid drive on one of these

 

[E-HP]

Spotted this on the local Craig's list (Giant Revive DX):
revive 02.jpg

Now there are at least one or two opinionated individuals on this forum and I am seeking an opinion(s)

Someone here once said that the best way to get a smooth ride was a long rear swing arm. I reckon this thing qualifies in that regard. It is also crank forward, flat footed, step through ... all features I desire. The wheels a bit smaller than I would prefer (20x1.75) and the rider weight is a bit farther to the rear than I would prefer but like popeye, "it is what it is".

What do you think of the idea of putting a BBS02 mid drive on one of these

Other pics online seem to show the bottom bracket is part of the swingarm, and the pivot is just ahead of it. If there's an issue, it seems like it would depend on how the motor tucks up against the frame, which is usually against the downtube, and may not work. So, as long as you're OK with the motor hanging down, it should be fine:

 

[LewTwo]

... So, as long as you're OK with the motor hanging down, it should be fine:

I believe that may be the LX model but the same problem.
However it would only be ridden on the street so as long as there are no overly high speed bumps ....

 

[LewTwo]

Well I got it ... damn but those tires are tiny (47-406). Rims are only 26.5mm wide (outside). that would make the bead about about 24mm ... yes/no ? Good news is that there is plenty of room for wider tires ... maybe even a 24 inch wheel in back ... front would need another fork.

The good news is I can adjust it so my legs do not have be doubled up all the time, one of the few frames I have seen that will fit a full grown adult. The bad news is that Giant used a 600 pound suspension spring. I ran it down to the minimum preload (just enough to keep the spring from rattling) and backed the dampener screw out all the way. When I sat my 130 pounds on it there was no change what so ever. The suspension is designed for a 300 pound sumo wrestler. Everyone else gets a hard tail, rigid frame. Seems to be a common problem for spring based suspension systems ... the designers assume everyone is extremely obese. Another pet peace is that Giant installed the spring upside down on the shock. I have not yet figured how to completely disassemble the shock. Replacing that bloody shock is going to be among the highest priorities..

The entire bike as it sits now weighs 18.8 kg (40 pounds).

I have to say I am a bit disappointed. I thought "Giant" was a quality brand. Turns out they are just another manufacturer of big-box store BSOs (bicycle shaped objects).


EDIT UPDATE:
Managed to find some specifications for this shock:

Material: Hard chromed shock shaft.
Finish: ANODIZED
Use: MTB
Spring type: Coil Spring
Adjustment: Rebound / Preload
Spring rates: 600 lb/in
Eye to eye: 165mm (6.5 inches)
Travel length: 4 inch - 5.0 inch adjustable travel
Width (Top): 32mm
Width (Botttom): 29mm
Eyehole diameter: 6mm
Weight: 510g (include pivot)
Range weight rider: 70~90 kg (154~198 lb)

Now I need to locate a replacement.

 

[99t4]

Seems to be a common problem for spring based suspension systems ... the designers assume everyone is extremely obese.

I am not so sure about this, in my experiences.

For your build plans: Don't forget to include the added weight of battery/controller/wiring/misc. You may find the (now) overly strong spring turns out to be just about right once all the additional components are mounted.

Also, that is not really a MTB or DH bike so common rule of thumb about aiming for 2-3" of sag when setting up the shock might not apply here.

Should be trivial to reverse the shock orientation if it bothers you. I did one easily (to accomodate locating a tight-fitting battery).

 

[amberwolf]

The bad news is that Giant used a 600 pound suspension spring. I ran it down to the minimum preload (just enough to keep the spring from rattling) and backed the dampener screw out all the way. When I sat my 130 pounds on it there was no change what so ever. The suspension is designed for a 300 pound sumo wrestler. Everyone else gets a hard tail, rigid frame. Seems to be a common problem for spring based suspension systems ... the designers assume everyone is extremely obese. Another pet peace is that Giant installed the spring upside down on the shock.

I have some springs that will probably fit that shock that I think are 300 or 400lb rating. I'll have to dig them out and get some pics and measurements. If I do, then you can have them for cost of shipping, which ought to be pretty cheap. (the shocks they came on were garbage and broken so I don't have those, just the springs).

 

[E-HP]

The bad news is that Giant used a 600 pound suspension spring. I ran it down to the minimum preload (just enough to keep the spring from rattling) and backed the dampener screw out all the way. When I sat my 130 pounds on it there was no change what so ever. The suspension is designed for a 300 pound sumo wrestler.

How does that silver bracket and the bottom attach to the swingarm? You might be able to either relocate it, or attach some type of bracket to allow you to change the angle of the shock relative to top pivot point, instead of changing the spring rate. Add a few holes for fine tuning.

 

[LewTwo]

I have some springs that will probably fit that shock that I think are 300 or 400lb rating. I'll have to dig them out and get some pics and measurements. If I do, then you can have them for cost of shipping, which ought to be pretty cheap. (the shocks they came on were garbage and broken so I don't have those, just the springs).

Thanks for the offer. FOX makes/sales springs in various ratings.
https://www.ridefox.com/fox17/help.php?m=bike&id=672

They sale for about $40 each on Amazon. I have a 300 pound/inch spring on order. That may have been a bit much but I figure I might be able to add some preload to it. It appears the shock disassembles by unscrewing the bottom end from the central body. Difficultly will be getting a thin wrench to fit between the spring coils and hold the central body. I have a few tool wrenches (for routers and such) that may be suitable .... otherwise I may have to rig something.

Another option is to install a 165 mm air shock. Long term I am going to look into that. 'Tis a subject I need to get educated on :wink:

I also ordered a 20x2.25 tire for the rear. I realize that is only 1/2 inch increase but I measured the actual tire width for the 20x1.75 tires. It was only 1.6 inches. I have to see how that will work out with the narrow rims and cantilever brakes. I also ordered two new tubes to replace the two-year old "Slime" filled tubes. I have read that they begin to "setup" after a period of two years .... especially if the bike has not been ridden much.

 

[LewTwo]

How does that silver bracket and the bottom attach to the swingarm? You might be able to either relocate it, or attach some type of bracket to allow you to change the angle of the shock relative to top pivot point, instead of changing the spring rate. Add a few holes for fine tuning.

It is a machined aluminum block that bolts to a plate welded between the swing arms (same plate is used to mount the kick stand). That is a bit of an oddball shock. It uses smaller pivot bolts (6 vs 8 mm) than other common shocks. The mounting bushings are also non-standard widths (29 and 32 mm wide x 16 mm diameter). A new aluminum block would likely need to be fabricated. An air shock might be a more practical solution.

EDIT: change diameter of shock bushings from 12 to 16 mm

 

[LewTwo]

Don't forget to include the added weight of battery/controller/wiring/misc. You may find the (now) overly strong spring turns out to be just about right once all the additional components are mounted.

The battery (about 10 to 12 pounds) would mount to the frame (sprung weight). I am thinking on the frame tube as far forward as possible. The mid drive motor (about 12 pounds) would be installed in the bottom bracket (un-sprung weight). However I doubt that short lever arm (distance to pivot point) would have much effect.

For your build plans: ...

Also, that is not really a MTB or DH bike so common rule of thumb about aiming for 2-3" of sag when setting up the shock might not apply here.

Now that is an understatement! It will also ONLY be ridden on street pavements (though in Houston that might be considered worse than some back wood trails).

I am working on line drawings for the long term plans. I will start a build thread when I get further along. It will be a long term, ongoing project. Some options to consider: replace rims (24 inch)? ... Front air fork? ... spare rack mount battery? ... Brakes? ...IGH rear hub? How will any of this (all of this) affect the handling which is already a bit quirky.

 

[E-HP]

How does that silver bracket and the bottom attach to the swingarm? You might be able to either relocate it, or attach some type of bracket to allow you to change the angle of the shock relative to top pivot point, instead of changing the spring rate. Add a few holes for fine tuning.

It is a machined aluminum block that bolts to a plate welded between the swing arms (same plate is used to mount the kick stand). That is a bit of an oddball shock. It uses smaller pivot bolts (6 vs 8 mm) than other common shocks. The mounting bushings are also non-standard widths (29 and 32 mm wide x 12 mm diameter). A new aluminum block would likely need to be fabricated. An air shock might be a more practical solution.

Even better that it's bolted on. You use the same part, but add a piece of steel flat bar that bolts to the existing hole, with additional holes to bolt the bracket to. You'd need a hacksaw, drill, and Home Depot. Changing the angle reduces the spring compression relative to the swingarm travel, which is the same effect as reducing the spring rate. An hour plus $5 to make a prototype to see if it makes a change in the right direction, then make the final version. Depending on the width you could also replace the bracket with a piece of C or U channel steel.

 

[LewTwo]

You use the same part, but add a piece of steel flat bar that bolts to the existing hole, with additional holes to bolt the bracket to....

That block is sitting in a recessed slot in the cross piece (may be hard to see). It would likely be more practical to do something with the upper mounting hole although I do not believe I can achieve a much better angle.

 

[Hillhater]

What do you think of the idea of putting a BBS02 mid drive on one of these…

Since you wont be “off roading” or racing much with that frame set up,… a think a nice compact 500-1kw hub motor in a 24” rim, would be a better option !
PS… you dont need to spend “Fox” level dollars for a better spring… check Ebay etc.

 

[LewTwo]

Since you wont be “off roading” or racing much with that frame set up,… a think a nice compact 500-1kw hub motor in a 24” rim, would be a better option !
PS… you dont need to spend “Fox” level dollars for a better spring… check Ebay etc.

You are correct ... no racing. About 25 MPH maximum suits me just fine. Also a ten foot change in elevation passes for a hill here.

I was about to respond that a mid-drive offers two distinct advantage: 1) the ability to use an IGH hub and 2) less unsprung weight. Then it occurred to me that in this case the mid drive is also mounted on the swing arm. However the CG for the motor will be so close to the swing arm pivot point that it should not require much force to move it up or down a centimeter or so.

As far as the spring is concerned, it is already shipped. However I may take you advice if it turns out I went too light on the spring weight.

P.S. Making a accurate line drawing of this frame is proving to be somewhat of a challenge.

 

[LewTwo]

Well Shit !!! That wee bit of red in the picture below is the interference between the BBS02 motor and the swing arm.

I will check the dimension again in the light of day but I think that I am in serious need of a plan "B".

 

[Cowardlyduck]

Hey nice to see another Giant revive conversion!

Why don't you join the rest of us and you might get some better feedback:
https://endless-sphere.com/forums/viewtopic.php?f=6&t=114664&p=1696320#p1696320

I am in the process of ordering parts to convert mine to a fat electric bike. Should be interesting. I also recently changed the rear shock. Initially I tried a super long DH spring shock (DNM) bit it was too hard so I swapped over to an old air shock I had lying around. Seems great so far.
Once I convert it to electric and add a tone of batteries...i.e. weight I might switch back to the DH shock and see how it rides.

Cheers

 

[LewTwo]

Hey nice to see another Giant revive conversion!

I am losing interest fairly fast.
1) Too light in the front for a front hub motor
2) mid-drive will likely require TIG and machining to add a new BB below the original (too expensive)
3) rear hub would mean no IGH and I really do not like derailleurs

I will see how it feels with a 20x2.25 tire and a lighter shock but it may be time to cut my losses

 

[PaPaSteve]

Wouldn't adding a motor to the front be an advantage in balancing the front to rear weights ?

 

[Chalo]

The suspension is designed for a 300 pound sumo wrestler. Everyone else gets a hard tail, rigid frame. Seems to be a common problem for spring based suspension systems ... the designers assume everyone is extremely obese.

Is it not obvious to you what kind of buyer this abomination of a bike was made for?

If the spring is too hard, the bike will still ride, and the suspension will still move when you hit a hole or a bump. If the spring is too soft, the typical fatty who buys a bike like this will bottom it out on a test ride and decide not to buy it.

 

[LewTwo]

Wouldn't adding a motor to the front be an advantage in balancing the front to rear weights ?

Some but not much, examples:
Bafang fast wind G311: 2.26 kg (5 pounds)
Shengyi fast wind SX1: 2.95 kg (6.5 pounds)
That is not much compared to the rider weigh which is nearly all over the rear wheel (even a pencil thin person like me at 130 pounds). The problem as I see it, is a lack of traction (the standard 20x1.75 tire is only 1.6 inches wide). Might be able to fit a 20x2.25 with the stock wheel, cantilever brake and fork. Otherwise new fork, wheel, brake etc.

I have two front wheel drive bikes now ... I really did want a mid drive. Optimum solution (IMHO) would be to have a new bottom bracket welded to the swing arm directly below the existing one.

 

[LewTwo]

Is it not obvious to you what kind of buyer this abomination of a bike was made for?

If the spring is too hard, the bike will still ride, and the suspension will still move when you hit a hole or a bump. If the spring is too soft, the typical fatty who buys a bike like this will bottom it out on a test ride and decide not to buy it.

There is another old proverb .... best I recall it pertains to a "fool and his/her legal tender" ... yep, they saw me coming.

 

[PaPaSteve]

[/quote]
Some but not much, examples:
Bafang fast wind G311: 2.26 kg (5 pounds)
Shengyi fast wind SX1: 2.95 kg (6.5 pounds)
That is not much compared to the rider weigh which is nearly all over the rear wheel (even a pencil thin person like me at 130 pounds). The problem as I see it, is a lack of traction (the standard 20x1.75 tire is only 1.6 inches wide). Might be able to fit a 20x2.25 with the stock wheel, cantilever brake and fork. Otherwise new fork, wheel, brake etc.

I have two front wheel drive bikes now ... I really did want a mid drive. Optimum solution (IMHO) would be to have a new bottom bracket welded to the swing arm directly below the existing one.
[/quote]

Welding aluminum softens the area reducing the strength considerably so should have a post heat treatment to reduce the chance for an unexpected frame failure.
Heat treatment adds cost and complexity.
A stronger method without undue complications would be removing some metal to fit the motor and then adding brackets between the frame and motor.
Sort of a "stressed engine" concept as used on race cars, motorcycles and the like.

BTW ... Recumbents are my specialty. Bike in the avatar won the production class at the World Solar Ralley in Akita Japan

 

[99t4]

What about this orientation?

You're planning to run a larger rear wheel anyway? Wouldn't that raise the ground clearance?

 

[PaPaSteve]

Reviewing goggle images there appears to be two distinctive swing arm designs for the Giant Revive.
One will accept a mid-drive motor easily, the other ... not so much.
BikeE recumbent was made by Giant the last three years before the company suddenly closed.
"Revive" was Giant's attempt to fill the void left by BikeE.

 

[LewTwo]

What about this orientation?

That is a different model (it also has horizontal rear dropouts). There were at least three models of the Giant Revive (possibly four). There was a "Revive", "Revive DX" and "Revive LX". The one that I have is the original (as far as I can determine). There was also one with an electric motor.

You're planning to run a larger rear wheel anyway? Wouldn't that raise the ground clearance?

Thought about it until I got the drawing done but not to raise the ground clearance. To mount a set of 24 inch wheels would require using a 190mm shock in the rear and a 24 inch fork in front. That would raise the rider height by at least 3 inches (best case). Starts to defeat the purpose because to lower the seat height brings the seat forward as well (shortening the leg extension).