jplee3

Hey all,

Total newb when it comes to anything ebike related but interested in exploring a bit more. We have a couple older bikes - mine is a Trek 7700FX and my wife has a Schwinn Sierra 7. Is a DIY ebike conversion on either of these bikes easily doable?

2old

Diamond frames suggest either is acceptable for mid-motor, but, considering the value of the bikes, you may be interested in a more cost effective hub conversion. Both are acceptable platforms for hub, but if the Trek has an aluminum fork, I wouldn't use the front. Read the tutorials at ebikesca for more info.

sloppy12

the Schwinn might be a step thru. Not that it changes things just use a rack style battery. just something to consider..

jplee3

Thanks guys. So something like these on the bikes (both are aluminum frames I believe):
https://www.amazon.com/ebikeling-Wat...dp/B07MY88HLV/
https://www.amazon.com/Voilamart-Ele.../dp/B07FVQPKYV

Also, what happens with the gearing on the bikes? Does the motor basically replace it all and the bike operates on a single chain? And do these motors operate fully independent of the pedal as well as with pedal assist (if you want?). What I'd be afraid of is if/when the motor or battery dies - will you be pedaling in 'fixed' gear and with heavier weight?

What about considerations for brakes and the front wheel set? Would this need to be upgraded to something beefier?
And how do you decide what wattage to go with? e.g. 1200w vs 1000w vs 700w, etc?

sloppy12

Aluminum frames make sure you get some pretty heavy duty torque arms. the ebikeling version comes with a decent torque arms. Personally I would avoid aluminum frames and direct drive motors, but since you have the frames just take the extra precautions.

nothing really happens with gearing. both of those are freewheel set ups, so you just use a 7 speed freewheel and thats it. You probably wouldn't want to set up single speed that would be more work.

both look to be PAS and throttle.

If battery/motor dies its gonna suck even with gears. but you will have some lower gearing to get home on its not impossible.

You have rim brakes on both bikes. Most people will advise having disks. You dont have that option from what I saw so either deal with the brakes you have or find new bikes.

wattage just to big a rabbit hole got ebikes.ca or endlessphere and just start reading. 750 watt is the legal max in the US (even this is a rabbit hole). so just go with whatever you want.

DowneasTTer

Check out the Swytch kits. They are front wheel drive, easy to install and have quite the following on Facebook. Seems they will work on any bike that doesn't have thru-axles. You can even find them from time to time on ebay and avoid the wait. https://www.swytchbike.com

2old

Also check ebay. There are kits like you're considering for about $200, although your choices are fine IMO. Depending on where you reside, you may need (or not) a waterproof system (not a bad idea even if you don't need them since they have better electrical connectors).

jplee3

What is the commonly used frame for ebikes anyway? I just looked at a Rad Bike and it says 6061 aluminum. Or is it the type of motor that matters in terms of safety when it comes to these frames? Like Mid-drive?

jplee3

What about sloppy's suggestion on avoid front drive motors with aluminum forks (well, at least on the Trek)? Would the Swytch/front wheel drive be OK and better on the Schwinn then?

DowneasTTer

Yes I believe so as it is only a small motor. If you still think it's a problem you could add one of these https://www.amazon.com/dp/B00K57N9II...roduct_details Have you looked at the swytch web site? Also check out the Facebook page (not a factory sponsored one just owners) found here. https://www.facebook.com/groups/2679153205653978

sloppy12

For a conversion steel is usually recommended. A bike built by a manufacturer from aluminum is engineered to have that extra load on the drop outs. For a mid drive steel or aluminum should both be totally fine. You seem to be looking at direct drive motors.

jplee3

Ah ok. Yea, I was looking at those initially based on the recommendation of them being lower cost. I'll probably take a look at mid drives. I hear mids are a more involved and complex install though, and I don't know a whole lot about bikes/bike maintenance/construction... maybe this is a good way to learn though!

jplee3

What are some good and low cost mid drive kits btw? BBS02?

2old

The best IMO; mine has been perfect for seven years of off road riding with no maintenance or repairs.

jplee3

The other consideration I haven't thought through much is the learning curve with riding these converted bikes coming from a place where I've never been on an ebike. I just saw a couple Youtube vids where, especially for mid drives, they were saying that you should be shifting gears in a particular order to avoid strain and damage to the motor. As it is, sometimes I'll just keep the bike in whatever gear I had it last and go as soon as I get on. I also need to probably replace the cables among other things... possibly even get a tune-up and inspection done on the bike since I don't know all that much about them or what to look out for. Anyway, is there one type of motor that is 'easier' to ride on compared to others?

2old

I've been riding a long time, so might not have a good perspective, but I have friends that were relatively new to biking and they adapted to "e" pretty easily. Hub motors are easier to convert (and ride, probably), but as long as you don't bog the motor, mid-drives aren't that esoteric. If you're considering this avenue, look at tutorials on YouTube. You need bottom bracket tools for these conversions. In general, mid-drives are preferred if your routes involve substantial hills, but hubs are great for relatively flat terrain.

jplee3

It's hilly in the area we live so it probably would be beneficial having something that would be longer lasting. At the same time, I'm not sure if there's a typical 'shelf life' on a given bike (frame, etc) given that the Trek is nearly 20 years old. I'm wondering if it would be worth the money to bring the bike into a shop and have it inspected and tuned up before I start doing this work on it. Unless the inspection/tune-up is something I really can and should just DIY... I wouldn't really know where to start or things to look for though, especially when it comes to potential damage on the frame or if the wheels aren't aligned or are bent out of shape. I would think those things are important factors to consider *before* doing an ebike conversion no?

2old

You can check your wheels by adjusting the brakes so the pads are close to the rims and spinning the wheel (works fine with the bike upside down). Look at the rim/brake interface to see if there's "wobble" (read at Sheldon Brown for this and how to true them, if necessary). You can check for frame problems yourself. I doubt either is defective unless they've been ridden hard. For me, an off road rider, 26" MTB's are nice platforms, even steel ones from the late 80's, early 90's. Depending on where you reside, they may be available on Craigslist for $200 or so, but only if in really good condition (not left outside etc).

simplygib

I'm in the same boat as you. I just ordered a bbs02 kit today to convert my 1998 Specialized Hard Rock mtb. I used this bike for touring until I decided to go light with a carbon road bike and bikepacking gear. So it has been collecting dust for over 3 years now.

Regarding getting your bike tuned up and checking the frame, etc., you might check around your area for any bicycle maintenance classes available. That might be a good way to learn and, who knows, maybe they'd even let you install the conversion kit with their supervision. Best of luck...

Doc_Wui

Drop a 500W ebikeline geared motor kit into the rear wheel on both bikes. They're about $350 on amazon. Add a downtube battery. You don't really need to worry about torque arms, but he used to include one in every kit, and if he still does, use it.

I'd simply avoid a front motor. It's a potential weak spot, easily eliminated by being to slip the chain around the gears when you install a rear wheel.

There will be a lot to learn about installing new handlebar levers, adjusting the derailleur, possibly moving the shifters around, but if you're setting out to do DIY, it's just bicycles. High school kids work at bike shops and do this stuff.




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jplee3

Jusf stumbled across this and its tempting:
https://slickdeals.net/share/android_app/fp/716461


Btw why wouldnt i be able to convert to disc brakes on either bike?
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jplee3

What battery(ies) do you suggest and also sizes btw? And what's the deal with the torque arms? Sloppy was saying earlier that it is a concern.

Looks like ebikeling has bundles and the 500w w/ a 36v 12.8AH bottle style battery is $689.99 so you save a bit buying both together:
https://www.amazon.com/EBIKELING-Wat...dp/B09F525V6D/

Not sure if that's a big enough battery or if I should look for something even larger. I'm not quite sure of our use cases thus far but I'm also envisioning potential rides to the beach/harbor and back which could get into the 20-30+mile range depending on route.

sloppy12

A torque are keeps the axle from rotating in the drop out. On a aluminum frame use should absolutely use one.

jplee3

Good to know - I'll keep it in mind. That Gotrax Traveler bike is awfully tempting at $630~ (shipped and after tax) currently. It would end up costing less than a full-on conversion (motor/kit/battery) of either of our current bikes! I know the components wouldn't be *as* good (like the control/display on the Gotrax is super basic non-LCD/screen) but it's quite appealing just to get something that's already set up...

2old

Take a look at Lectric's light, 20 mph, 46 pound, $795 model if you're thinking of a complete. The co-founder has been involved with e-bikes for a long time. However, you mentioned that you ride in a hilly area. This could present a problem for "hubbies" since if you're riding in steep areas with long ascents, the rule of thumb is to maintain about half the top speed of your bike or too much energy is transferred to heat and could ruin the motor.