Trek 4500 Conversion short commute

[etrainmd]

Howdy all,

I have been searching the forums for several hours now and must admit that I find myself perhaps more confused than when I started. So please forgive me if this is a waste of forum space...

I'm looking to convert my mid-2000s Trek 4500 to electric. I would mainly like to use it to get to work with less sweat that I currently do (darn Texas summers), and part of me just wants to try it out because it seems so cool. I have about a 6 mile commute to work one way, and I'm out in West Texas so it is completely flat. I can recharge at work if necessary/helpful. I'd definitely like to have something that wouldn't be too much of a beast for me to do most of the peddling on the way home if I wanted. My trek has caliper brakes and Armadillo road tires. I have attached a couple of pictures for whatever they're worth. Let me know if you need more info on the bike and I'll try to supply.

I'm a big boy at 6'8 and 275 lbs, so I realize I may need something a bit more than the average bear. However because of my fairly modest distance requirement, I was hoping I wouldn't have to spend several large on batteries. I've flown electric RC for several years so I'm not completely ignorant of batteries, esc, and motors, but nothing in the bike world. Budget's not really an issue, but I'm not looking to spend money just to overkill it. 20 mph and 6-12 miles is probably going to be plenty on the streets I ride on.

All that being said, anyone want to make some recommendations for my specific bike? I think I lean toward an entire kit rather than piecing something together, but I'm flexible. I really appreciate any and all input.

Thanks!

 

[john7700]

Really, the biggest decision usually comes down to battery. Even though you have some lipo experience, if you are going to use it as a commuter with a short commute, no hills and a desired speed of around 20mph,the plug and play of Lifepo, to me, is the way to go. A Ping 36v 15AH mounted in the triangle gives decent handling and will give you ~23 mph and ~17 or so miles per charge on an average/fast wind motor giving you plenty of distance without having to charge at work. If on the other hand, you want to treat your bike more like a hobby and are willing to put the time and effort in to the complexity and more time consuming care of lipo, you will get much more performance (speed and energy density). My suggestion given your parameters stated, would be to start with lifepo4 for a plug and play commuter and if you enjoy e-biking make a second high performance, perhaps full suspension hobby bike.

As for motor kits, I like to plug our home team here and recommend Grinn at Ebikes.ca. They offer great products and have proven customer service from a North American supplier. I am running their fast wind 9C and I think it would make a fine kit for you. It can also handle more power if you should get bit by the speed bug in the future. What ever kit you end up with be sure to spend the money on one of Grinns Cycle Analyst. They are a really helpful tool.

Best of luck on your build and enjoy your E-bike GrinnN

 

[BikeFanatic]

you will love your commute on the electric bike.

I agree , 9Continent from EBIKES.CA- and You could go Lipo on the battery, a light weight 2x 6 Series batteries, 8000MAH will get you 15 miles.
For about $200 plus a charger that you may already own.

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=20647

 

[wesnewell]

http://www.yescomusa.com/product.php?productid=729&cat=48&page=2
Probably won't be in stock for 30 days, but it's only 4-5 days shipping from US, not China. When in stock you can get them on ebay cheaper.
http://www.hobbyking.com/hobbyking/store/__18631__Turnigy_5000mAh_4S1P_14_8v_20C_hardcase_pack_USA_Warehouse_.html
Six of these will get you 10ah 12s, which is perfect for the controller that come with the above kit. Should get you 20 miles at 20mph.With a top speed of ~28mph.
I'm also 275lbs, but a lot shorter. Unless you have some really good roads out there, I'd suggest upgrading your tires to CST cyclops for a lot smoother ride, assuming they'll fit your bike.

 

[dogman dan]

Perfect bike for the first one.

Even with your weight and size, the lack of hills makes this one easy. Nearly any complete direct drive rear hubmotor kit will work fine for you. The only tricky bit might be the torque arms for the rear dropouts, that tend to work best if you cut your own custom torque plates. That issue easier if you have a steel frame, I couldn't tell from the pics. At lower power, just one torque plate on the non gear side will do.

36v should be enough. 10s in RC lipo, but the suggestion of a pingbattery 36v 15 ah battery is spot on. Carry it in a bag or small toolbox in the front frame triangle area. If you go RC lipo, then check out the for sale new thread from Icecube 57, on charging and discharging harnesses that make it easy.

Whatever battery you choose, a Cycleanalyst from Grin Cyclery is a battery monitoring tool you will love. They also have a new universal rear torque arm you should get if it's in stock. The stand alone CA will be fine for your needs, if you choose a kit that is not CA ready.

Since budget is flexible, you might consider getting a deluxe kit setup entirely from Grin. Justin is the best kit retailer in the world, great CS, and inventor of the CA and other stuff the rest immediately copy if they can. A 2808 motor will be a tad slower, as you say you want, but take off from the stop signs nicer.

Don't worry about the pedaling, you will still get all the pedaling you want, or don't want. Set throttle to speed you like, then pedal till going 1 mph faster for a good workout. For a nice easy workout, just spin the pedals adding less than 1 mph to your speed. Both great for the heart lung.

 

[etrainmd]

Thank you all for the very helpful replies.

Dogman, the frame is aluminum. I am attaching photos of my dropouts below. I'll ad the torque arms / plates to my reading list hehe. It does have a steel front fork, if that would be a better option? It does not run rain much out here, so wet streets are not a problems. For some reason I just feel like the drive should be under me, however.

Seems like Grin is the place to go. I like the idea of starting with the LiFePO4 to get my feet wet (although Grin is out of them right now). Based on my RC experience, I'm not sure I'm ready to manage lipos on something that I hope to use everyday to get to work. I must admit however that most of my rc lipos are fairly old (as is my charger/balancer). The Cycleanalyst looks really cool - the nerd in me will definitely go for that.

Regarding the 9C - I notice that Grin says the wheel quality is "poor"? Again, being a big fellow, should I be worried about this? Would the Crystalyte be a better option? I assume the 20A Infineon Controller will adequate for now.

Final question (for this post), are my caliper brakes going to be adequate? Grin says they don't fit well on the 9C, I'm wondering if upgrading to disc would be good idea in general anyway.

Thanks you!

 

[motomech]

I use dual mini-motors, no torque arms required.

 

[john7700]

I personally like having my power at the rear wheel. It just feels more intuitive to me. Some people like front wheel and it makes it easier to get the wheel on and off. If you get the itch, and start upgrading you will definitely want rear wheel for more power and speed.

The go to recomendation around here and the route I went was a battery from Ping. A good known Chinese vendor with good prices and known good customer service. If I had the money, I would go for A123 cells that can be had here in the for sale by vendor cell man. He can make a custom pack that will have a higher discharge rate and better cell density (smaller for same power) than regular Lifepo pouch style batteries but are still plug and play lifepo. He also offers a triangle bag that could work out well for you for battery mounting.

I am not a fan of the wheel build on the 9c. If you go with a laced one, it will need to be trued and tightened by some one who knows how right out of the box. If I was to do it again, I would order the kit with an unlaced motor (cost a little less) and build it myself (or have your local shop do it). I just finished replacing my stock wheel with a Rhino light rim and John Rob Holmes custom spokes for around $85 total and it feels much more solid. Stock kit controllers are matched by grin so you'll be fine at 36V.

At the speeds we are talking, V breaks are totally adequate. The only time I had problems with V's was when the rims used to ice up. Probably not an issue for you. But, disk are nice. If you have upgraditis, go for them. You will be well off to change your rubber. Start looking for some fat tires like a 2.4 . I am running the Holly Roller right now, but there are several options. You can add tires to your "reading up on list".

Keep asking questions and best of luck!

John

 

[Drunkskunk]

Welcome to the forum. Good choice on bike.

The Armadillos are good tires but generaly skinny. I've got many miles on mine, and I kind of like the perversion of Specalized Tires on a Trek. You may find you prefer A larger tire with the added weight, speed, and power of an E conversion.

A 9 Continents motor is exactly what you need. Good and light weight but with enough power for your size. A Crystalyte HS3540 world be overkill for flat west Texas roads. If you were going off road or had some steep hills that would be diffrent, But otherwise it's just dead weight. A 2807 should be good. 2806 would be faster but with Texas heat, Its better to go faster with more volts instead of a faster wind.


Ebikes.ca is the best place to get what you need for motor, controller, and the Cycle Analyst. I highly recomend that last part. It moniters everything you'll need to know about your bike.

For the battery, If you're comfortable with RC Lipo, then batteries from Hobby King are they way to go. 36V, or 10S worth at 10,000ma, - 10 Amp hours will be more than enough to get you one way. 15AH would be more than enough to do it round trip, in a headwind if needed.
And if you want more speed later, most 36-48 volt controllers can take 15S of Lipo, though that pushes them to the edge.

If you're less thrilled about Lipo, you can go with LiFePO4. Ping is a good sorce, so is Cell_Man. The advantage is Cell_man sells a triangle pack that will fit in the frame.

 

[Ykick]

All in all good choice of bike. Sure, a front disc would be better and not hard to upgrade later with another fork. Rear V brake is fine and more than enough IMO.

I'm 240lbs and my original 9C rear wheel eventually died from pothole strike. It was always needing truing every few weeks too. Went with a Mammoth Fat rim and 13/14ga spokes from JRH and haven't touched a spoke wrench since the rebuild in Dec. Approaching 2K miles daily riding very rough roads.

Even as an amateur wheel builder, decent rim and quality spokes do a make a major difference. Trouble is, loose hub motor's a major PITA to ship so most people start with the Chinese wheel build and rebuild it when needed. If you don't ride extremely harsh roads, stock may be all you ever need...

I run 30A 9C 2807 in 26" wheel on aluminum dropouts with one torque arm. About 4k miles and no sign of any axle twisting/movement. No regen though.

I'd do RC Lipo in a triangle bag for your battery.

Good luck!

 

[etrainmd]

I'm not going to lie, going lipo and getting to buy a new charger is quite tempting.

My wife is going to be thrilled!

 

[wesnewell]

Frankly, I wouldn't use that bike. Aluminum dropouts suck for powerful hub motors, and you can tell that those are so shallow that a hub motor axle isn't going to fit all the way in to the dropout. Do yourself a favor and get a cheap bike with steel dropouts. There are lots of new ones for about $100 or less. Properly installed in steel dropouts, torque arms/plates aren't needed. I've got about 5k miles on mine using up to 4000W on rear motor.

 

[etrainmd]

Thank you for the feedback wesnewell. I guess I don't mind buying a new bike, it would just be handy to use the one I already have. I wonder with the lower speed I'm looking for and the torque arms if it would be alright. Are my dropouts a good bit more shallow than what is typical? Again thanks for the feedback.

 

[Ykick]

I probably do a little more power than you're planning with the 9C 2807, 26" wheel with a single torque arm LH side. My derailer hanger happens to be Ti22 and many seem to be hard steel. As long as you stay away from regen and ensure dropouts fully handle the axle flat you're gonna be fine.

Just look around this site and you'll find many fine builds based on a similar frame as your Trek.

 

[e-beach]

Howdy all,

I have been searching the forums for several hours now and must admit that I find myself perhaps more confused than when I started. So please forgive me if this is a waste of forum space...Thanks!

Nube e-bike questions are never a waist of space on this forum IMHO.

As I have said before,...I am not the most expert on the subject of e-bikes but there is something I know for sure; "You have to build an e-bile to know how to build one."

My 2¢ is this:

Keep the first build simple and cheap and safe.

Go with a inexpensive (within your budget) rear wheel drive motor.

Front disk brakes are really good for a heavy man!!!!!

48v at 1000k is a good configuration for your size.

Forget the lipo's...who needs to babysit batteries every day, especially at work. If one self-immolates at work will everyone be happy with you?

Go for a LiFePo4 pack. Safer and almost as long lasting. People around her like: http://www.pingbattery.com, http://www.emissions-free.com and http://ebikes.ca/

All the above are good venders.

Personally. I have been running a Yescomusa.com 34v 800w front hub motor on 3 12ah sla's for the last 6 months.
I got it off of ebay for $250

My sla pack cost me $115 and has lasted me 6 months at about 6 miles per day on average. I went with sla's just to get my bike going. They are now dying on the hills and I am upgrading to a Headway 15ah LiFePo4 pack as I write this. My sla's still work fine on the flats.

If you are going to spend money get a fast (high amp) charger.

Mount the batteries in the tangle of your bike for the best balance. (Putting the batteries on your rack will leave you riding down the road moving like a duck due to the weight and perhaps leading to a crash.)

I have a 4 inch limit to the width of my battery pack. Anything larger am my legs rub. Your width will differ.

Your dropouts are shallow so use a torque arm as Dogman suggested. Consider one on each side. Having a motor crack out of the frame while moving at speed is a dangerous thing.

Welcome and have fun with it!

 

[wesnewell]

It depends on the type of dropouts you have. While the vertical ones make it easy to install/remove the wheel, they all tend to be shallow. Ands that's fine with a 10x10mm normal round axle that has very little torque and it doesn't matter if they slip in the dropouts because they will just turn inside it. But a Hub motor is 10x14mm with the flat part fitting in the 10mm dropout. And it needs at least a 14mm depth on both side of the axle. Now you can make it work in what you have, but have something come loose and and put too much torque on it and you've got a major repair job. Just not worth the hassle if you ask me. You can probably find a cheap used bike for next to nothing to use. I prefer the horizontal dropouts as seen in the middle of this page http://sheldonbrown.com/gloss_dr-z.html because there's plenty of adjustment room and the axle will be solid on them and there's plenty of room for using torque washers that fit into the dropout.

 

[dogman dan]

Steel dropouts on a bike do make things easier, but all too often the price you pay for it is an old but quality frame that is hard to upgrade, or a newer one that is not a quality frame.

Stick with that one I say, if it has a 1 1/8" headset that allows a good disk ready fork to be added later. You got a good frame. With one torque arm on the left, you will be fine.

Wes is correct that higher power needs more. But 20-25 mph only takes 1000w. Your alu frame will be fine.

You will be able to adjust a good set of v brakes enough to make them work fine with the 9c wheel and rim. Old school calipers can have less range of adjustment. The stock rims on kit motors are not that great. You might want to have an unlaced motor sent to Holmes Hobby. He's the USA expert who specializes in quality hubmotor wheel building. Worth every penny. Personally, I just have so many 9c motors laying around, I just swap to a good on as needed, and relace a motor later on, maybe. If you can true a wheel a bit, you'll be ok enough with stock. You will need to learn to at least snug up loose spokes. They will stretch out for the first 100 miles or so.

It's typical to shave a few more mm deeper on steel or aluminum dropouts that are vertical. The idea is to get the center of the motor axle exactly where the center of the original axle was. Just a quick file job that is easy.

Your ride is short enough to build a hobby king battery that gets you there and back, eliminating the need to charge at work, or worry much. But you might find it so nice to have a large battery, and go for longer rides running errands on the way home, to want a bigger pack that can charge at work. Ping 15 ah or so.

You realize of course, that you will quickly get hooked on ebikes, and be building a much faster bike for fun rides very soon? So you could lipo that one.