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4 day Giant Revive RC build for my wife.........


1 GW
Apr 19, 2008
On Earth right now. That can change at any time, t
Hey Guys,

Some of you may remember I asked about an ideal platform to build my wife a basic mountainbike. Well, after some research, I decided, instead, to electrify her Giant Revive. I decided this for a few reasons;

#1 We already have the bike. No need to purchase something else that will take up garage space.

#2 She LOVES the Revive!

#3 The only downside to that bike is poor hill climbing. That is easily taken care of with a drive. :)

The only reason I did not want to move in that direct previously was based on difficulty mounting a drive. I wanted something I could just bolt one of my reductions to and color it done. But, I decided to weld together a simple sub-frame that would bolt to the Revive swingarm to hold the drive. This is the simplest and most elegent solution.

Now, my wife just left (5 minutes ago) to take her mother back to Minnesota. She took the kids and will be back Friday night or Saturday. So, with that in mind, I am taking the Revive to the shop to build it as a surprise to her when she returns.

Here is the spec list;

2006 (I think) Giant Revive
Astro 3210 10 turn
V3 reduction with torque limiter (this will be mounted in front of the rear wheel on the swingarm)
HV160 (what else?) :mrgreen:
Magura twist grip throttle
4 Turnigy 6S packs (12S2P) mounted in a couple of my CNC machined battery boxes
Watts-Up meter
36 spoke, 2 inch wide rear rim laced to a disc brake hub for left side drive purposes
Rear 203mm disc brake

The labor list is a bit heavy for such a short build;

I need to weld together a swingarm subframe, lace together and true a rear wheel, machine a caliper to fit with the rear sprocket, fab a caliper mount, fabricate a chain guide, mount battery boxes and misc electrical items, and do all other basic stuff like move the shifter to the left bar to make room for the throttle, etc.

The cool thing is, I have every single item on hand other than 2 of the 4 packs. So, I will merely set it up, innitially, at 5ah to get everything running well, then order the other 2 packs.

I decided to add a rear disc brake to aid in stopping with the additional speed this setup will deliver versus he normal pedaling speed. A rear disc is best rather than a front because the Revive is a very rear weight heavy bike with precious little weight on the front wheel. So, adding braking power is best done at the rear on this bike. Plus, I can add the caliper mount to the subframe I am welding together.

Now, I only have 4 days for this (after work). I will take tomorrow off to put a solid 10 hours or so into the bike. But, it will still be tough to meet my time frame. But, what I plan to do is build up all the mechanicals first, and do the wiring at home at the very end. It is really too cold to ride anyway. So, as long as it looks complete, I can present it to her when she comes home.

One cool thing about this build is, I plan to built it street legal. This is a first for me. :wink: :mrgreen: In fact, I think 15mph would be plenty for her. But, the reduction I have here and the motor I will be using puts it right at about 20mph. I doubt she will want to go any faster than that to begin with, though that may change later on.

I will post pictures as I have them.

Matt, I look forward to the build, that was one recombant design I could see myself riding on. I like the high seating position. Great for riding in traffic.
Hey Matt,

Sounds like a good challenge. I'm sure she will be very happy with it. I don't know why I didn't think of it before, but a K2 Easy Street, or any of that range might be good as well.k2.jpg It isn't a full suspension, but the bottom bracket is forward of the seat position quite a bit. It is designed so you do not have to get off the seat when you come to a stop, but you can get a full leg extension while pedaling. I sold lots of them when I worked in Minocqua. They are a very comfortable and classy beach cruiser style ride. Food for thought.

Hi Matt,

recumpence said:
I will post pictures as I have them.
Looking forward to the pictures!

recumpence said:
One cool thing about this build is, I plan to built it street legal. This is a first for me. :wink: :mrgreen: In fact, I think 15mph would be plenty for her. But, the reduction I have here and the motor I will be using puts it right at about 20mph. I doubt she will want to go any faster than that to begin with, though that may change later on.
What's cool about that :p :mrgreen:?
Its good that you can get all of the family involved in your hobby. My wife loves her ebike and it certainly makes convincing them to go for a ride a lot easer. I seem to get less protesting about spending $ on this hobby now :D .My daughter has been riding around on ebikes with me from one year old.

I think you are on the right track with keeping it tame and street legal to begin with. Nothing worse than creating a monster and having them fall off never to return.

Comfort, reliability, simplicity and practicality were high on the agenda with my wife's bike. Although she has now come to appreciate importance of power/torque for hill climbing. My wife rode my recumbent trike for the first time the other day and now she wants one to. I told her I will get mine going first iron out all the bugs then build her one.

Looking forward to following the build and seeing if you pull it off in 4 days.

Wheazel said:
Matt, what are your opinions about choosing between an Astro 3210 and a 3220.
When would you go to a 3220?

It is all about budget and expectations. I normally just quote a drive system for a customer with a 3210, unless they either are over 200 pounds, or do alot of hill climbing, or want speed over 30mph. Of course, if they just want stupid power, I lean them toward a 3220 also. :wink:

Actually, the best option in many situations is a 3215. It is not nearly as costly as a 3220, and has more "Headroom" than a 3210.

I am at home now. I will build the rear wheel tonight (assuming I have enough of the correct length spokes). Tomorrow the bike goes to the shop. I hope to have the bulk of the fabrication finished tomorrow with mechanical details to finish up Thursday and finally wiring on Friday.

I just spent the last 3 hours building the rear wheel. I had to unlace two entire wheels to get the rim, spoke, and hub combination I needed. Talk about time consuming. But, tomorrow I will be at the shop at 6 AM and begin working. I have two customer orders to fill. So, I need to make sure I give myself enough time to get their orders out and build my wife's bike.

Man, I have to fill those two orders, true the wheel and mount it on the bike, make a run to the welding shop to pick up a tank of gas for my MIG welder, pick up some box steel for the subframe, make the subframe, machine a pulley for the torque limiter, configure the drive, mount the drive, modify the rear disc brake caliper for sprocket clearance, run the chain, mount the battery boxes, reconfigure the bars for the Magura, run wiring, etc. Oh, and I have a very important lunch meeting as well.

Sheesh, this is going to be a long few days...........

If one of the orders is mine Matt relax and just get your wife's surprise build done.I am not in a hurry

I most likely cant take delivery until after Easter as I am going away for two weeks


I have most of your components sitting here. The pulley shop is 2 weeks out on the first run of the new style pulleys. :)

I am setting up a torque limiter for a twin 3220 trike customer in a unique situation. I also have a basic chain drive 3220 (single motor) system to finish for one of our very own posters. :mrgreen:

Here are come picture to gaze upon.

I put 3 hours into the rear wheel yesterday and 10 hours if fab work into the bike today.

There are a couple minor details to correct on the subframe along with adding the caliper bracket. That work will be done tomorrow. Hopefully I will have all mechanical work finished tomorrow along with some lettering for the frame "Cheryl's Hot-Rod". :wink:

The rear wheel is 2 inches wide. It has the stock tire. The wider rim really makes the rear of the bike take on a cool look.

I will post more pictures as I have them.



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Top notch Matt!
Hi Matt,

Excellent work!

I'm a little disappointed that you aren't using a Sprague clutch with a Polychain belt for the final drive :wink: :mrgreen:.
Sorry to pollute the thread, but I am not very educated on the RC motors. I have a question Matt. Will that bike climb grades better with that motor than say a 400W Kollmorgen going through the gears will? Assuming volts and amps are the same? I am working on a Bike E (similiar to a Revive, trying to keep it somewhat on topic :wink: ) and am planning on using the Koll as a mid-drive. I am wanting around 27mph, but I want it to climb decent grades with relative ease. I'm not looking for a burnout machine, I want a good commuter/climber. I know with the square frame on the Bike E mounting one of your drives shouldn't be too difficult, but I have some concerns regarding climbing ability and simplicity/dependability. Do the amp draws on those motors pretty much dictate LiPo a must or can you use a high rate LiFePo? If this is better discussed (or if it has already been discussed) in another thread please let me know.
That is a really good question. Here's the deal;

Driving through the gears can, indeed, give a relatively weak motor the ability to climb some serious hills (though slowly). I like the idea of running through the gears. There are two drawbacks to that, however, that have kept me away from it;

#1 Complexity
#2 inefficiency

This type of setup will climb hills just fine. However, there are also two drawbacks to this as well;

#1 You need to run more wattage (alot more) to get the same climbing ability and good speed with a single ratio.
#2 You need to charge up a hill, not creep up it, with a setup like this to keep the phase current in the controller at a reasonable level.

Basically, each setup has its benefits and drawbacks.

This particular setup will be setup for about 1,500 watts. I will set the torque limiter to slip at that point. That is 35 amps. RC setups normally draw at least that much, or much more, depending on the setup. So, that is what you need to consider when purchasing a battery pack.


I am all sold out of Polychain final drives. :wink: :mrgreen:

That subframe looks like a very clean addition, looks like it was meant to go there! Any ideas on paint colours?

Yes, I do have an idea of paint color! :mrgreen:

OK, alot of stuff happened today, but not a huge amount to show. I did alot of detail work. Here is the list of what I did;

#1 Finish welding and bracing the subframe as well as cleaning up all the welds.
#2 Drop off the subframe at the powder coater. I called him at 11:30 and asked if he could finish this today. I picked it up at 4:00. :mrgreen: They are a great shop to deal with.........
#3 Stopped by my local sign shop for some lettering. Brian is cutting come vinyl letters in blue for me that say "Cheryl's Hot-Rod". Her name will be in script, while the Hot-Rod lettering will be block letters. That will be 12 inches long on each side of the frame.
#4 Mount the shifter to the left bar instead of the right.
#5 Install the throttle and run the wire through the handlebar tiller.
#6 Machine (narrow) a Tektro caliper for the rear brake. Make and mount the caliper mount.

I will pick up the vinyl in the morning. Then I have a nearly full day of appliance work. My wife may not come home until Saturday. So, that would give me another day to work on the bike.

At this point, all I have left to do is run a longer brake cable and do the wiring (oh, I need 2 more packs and a battery box from Mouser). But, I can "Deliver" the bike to my wife without being runable. It is really too cold to ride anyway. She will be totally floored when she sees it. This thing is so "Her". :)

I think I have about 4 hours of whork left to get it running and another hour to fine tune everything.

I did make one mistake, however. I miscalculated the subframe and the pedal chain just barely touches the subframe in first gear only. It is already powder coated, so I am stuck with that. There are a few options to fix this;

#1 I can just adjust the limit screw on the derailer to make second gear the lowest. This I did for now.
#2 I can run a chain tube right there. That will keep the chain from touching and jingling at the frame in that spot. This may be the best and easiest permanent solution.
#3 I can get a road bike cassette. The largest cog would be much smaller than the 30 tooth it has now. That would drop the chain and keep it away from the frame there.

Odds are I will run a piece of chain tube eventually. For now, locking out first gear is easiest. Lefts face it, with a drive, the bike will never see first gear anyway. :wink:



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This frame will cost roughly $100 to powder coat once the paint is stripped. Eventually this entire bike will be a brilliant blue. That is my wife's favorite color. That will probably be next winter's project. For now, I want to make sure everything runs well and is safe for her. I can pimp it out and speed it up for her later. :)