Is this bicycle, a Scott Sub 20 hybrid, a good candidate for conversion to E-bike?

Busse Woods

Member
Region
USA
A dork disk is required on a bike of that vintage. Funny my other bike is a Miyata Nine 14 that I purchased new sometime in the 80's. Fortunately it is in black but it still has its dork disk. It's still in great shape as I mostly rode my other bikes. I'll use the Nine 14 if I want to ride unassisted. Great bikes.
 

Busse Woods

Member
Region
USA
Received my TSDZ2 unit. I would like to remove the chainguard but if I do that I cannot tighten the chainring using the supplied bolts. Do I need to obtain different chainring bolts?
 

EMGX

Well-Known Member
Shorter bolts or washers under the bolt head or spacers sold specifically as chainring spacers or chainring tabs like this
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Busse Woods

Member
Region
USA
Have started the removal/installation. My observation is that the you tube videos make this project look much easier than it typically is.:) Some difficulty getting pedals, cranks and bottom bracket off. But eventually managed. If one does these things on a somewhat regular basis and has good quality tools it's probably much easier. Lesson learned.

Now routing of shifter cable is an issue. I removed the plastic cable guide from the bottom of the bracket. I used a dremel tool to cut off the taller guide and tried using the shorter part of the guide. I tried to make the guide protrude as little as possible but its still won't allow me to install the motor. Do I have to route the cable and locate the guide somewhere other than it's original location? I welcome suggestions.

Edit: looks like I may have to use cable housing, the cables are bare now, and route the cable somewhere other than below the bottom bracket.
 
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EMGX

Well-Known Member
Cable and housing is widely available and inexpensive (I've purchased mine from Amazon for fast shipping). I had to run cable over the top of the bottom bracket on one bike that I tried a TSDZ2 motor on. Consider making the rear derailleur cable longer if you think that you would ever want a handlebar riser stem - they look pretty short on the linked image of your model bike that you posted. That way you would only have to replace the brake cables in the future if you needed longer for a riser stem.

Edit:
Long ago I found that a bicycle cable cutting tool was worthwhile to add to the bike tool chest. For me they worked better than standard diagonal cutters on both the cable and cable housing.
 
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PedalUma

Well-Known Member
Region
USA
City
Petaluma, CA
@Busse Woods,
Yes the cable can go over the BB or you can run it over the top and down the seat stay. @EMXG is correct, run continuous housing. You get what you pay for with housings and cables. The better ones are so much better. I am doing it with white housing on a spanking new bike that came in today. It has never been ridden. It is a Public V7. A second conversion for the same family. The wife has had her bike for three years, now it is his turn.
 

Busse Woods

Member
Region
USA
Thanks for the advise and quick response. I was hoping to keep the bike the same as much as possible. I will go with the covered cable and route it above the bottom bracket. Yes I need to get a quality cable cutter. Cutting cables can be a pain. I hope to be riding in a few days. Will post my hopefully finished product then.
 

Busse Woods

Member
Region
USA
One more question. Wish I had asked earlier. I have heard of these motor making creaking or other noises if they are somewhat loose. Should I be using locktite or doing anything else to avoid that?
 

EMGX

Well-Known Member
I think any of these mid drives fasteners can loosen up over time, I've re-torqued my yamaha a couple of times. I do check the fasteners on the TSDZ2s once in a while. The 36v 500w currently on my Dahon Jack has never had a loose fastener, I don't use the rear chainstay anti-rotation device on that one - the motor housing is just rotated forward on the down tube. That device has been loose a couple times on my 48v 750w version, as has the bottom bracket lock ring. I think that when the chainstay device loosened up and allowed the motor to rotate forward it resulted in the bottom bracket lock ring loosening. The bottom bracket lock ring hasn't loosened as long as I have kept the chainstay device tightened - I haven't used locktite but maybe I will at some point. As you probably know, you have to remove the left pedal to be able to use the tongsheng supplied lock ring tool, so instead I have used a bottom bracket spanner tool to tighten the lock ring. It isn't a perfect fit but the one tooth part of the spanner worked fine for me to check tightness as well as tighten it up without having to remove the pedal.

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PedalUma

Well-Known Member
Region
USA
City
Petaluma, CA
One more question. Wish I had asked earlier. I have heard of these motor making creaking or other noises if they are somewhat loose. Should I be using locktite or doing anything else to avoid that?
It is not just a matter of red Loctite on everything. Thin aluminum shims need to be cut and used around the portion that goes through the bottom bracket shell and the shell needs to be packed with grease. The grease cannot compress, sort of like hydraulic fluid. This will stabilize the motor. The amount of shim material is different for each bike. Even the same model and model year. It has got to be tight. It took me over a year to figure this out. It makes all the difference. No creaks.
 

Busse Woods

Member
Region
USA
Thanks PedalUma. I have already installed the motor without doing any of those things. At this point I will hope for the best and consider reinstalling the motor using your suggestions if I have any issues with noise. All I have left is to do is install a new shift cable and connect all the wiring. Any suggestions as to how much slack to leave in the wiring or how best to hide the wiring to have a clean install? If all goes well I should be able to go for my first ride in a day or two.

As much as I am looking forward to riding my throttle-less conversion bike, I'm already thinking that in the future, I may want to purchase a fat tire E-bike with a very powerful battery for days when I don't feel like pedaling at all. Those look like a whole lot of fun. A fat tire E-Bike may also allow me to ride more often in the winter maybe even in the snow.
 

PedalUma

Well-Known Member
Region
USA
City
Petaluma, CA
Thanks PedalUma. I have already installed the motor without doing any of those things. At this point I will hope for the best and consider reinstalling the motor using your suggestions if I have any issues with noise. All I have left is to do is install a new shift cable and connect all the wiring. Any suggestions as to how much slack to leave in the wiring or how best to hide the wiring to have a clean install? If all goes well I should be able to go for my first ride in a day or two.

As much as I am looking forward to riding my throttle-less conversion bike, I'm already thinking that in the future, I may want to purchase a fat tire E-bike with a very powerful battery for days when I don't feel like pedaling at all. Those look like a whole lot of fun. A fat tire E-Bike may also allow me to ride more often in the winter maybe even in the snow.
I worked on a fat bike today. What a nightmare. A rear flat took forever. One part is the rims do not support the tire bead well. That is just one part. Problem after problem. It is a gimmick for marketing. Yes, it sells. The guy thought is was a mountain bike! It would not survive in the wild: Can't go off a curb without getting a flat. Can't climb a hill. It was new with 20 miles. He rode one of my bikes with Schwalbe 50's and is going to sell the heavy monster. Rout cables before installation of the motor and battery. This is hard because you need to first visualize the whole at inception. Which cannot be done on your first dozen builds. Here is one example from today, its in process. Next the shimming. It is well worth pulling the motor to start fresh. Note that this example bike has all white cables and wires. The contiguous shifter housing goes over the BB. This bike is new, that makes things much better.
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PedalUma

Well-Known Member
Region
USA
City
Petaluma, CA
That is Top Secret. I share a lot of clues of how to approach a problem, but cannot share all of my tuition. This is hard spent money. No one else has it. That is why people in this Bay Area bring bikes to me. I will show a photo when the new V7 is done. Improvise until you find a working solution. One with no wiggle, before it is locked down. Solid in the BB.
 

Busse Woods

Member
Region
USA
I understand. I'll see what I can do so there is no wiggle.

How about cable tie downs I'm trying to get a clean installation and use as few tie wraps as possible. Although my bike is black so tie wraps probably wont be all that noticeable. Has anyone tried something like these?




 

Genetics

Member
Region
USA
Thanks, I like the idea of keeping the weight down. Should make the bike easier to haul. I saw a video that said many E-bike accidents are similar to motorcycle accidents. So I want my E-Bike to continue to be more like a regular bike as far as speed is concerned. I don't see a reason for a lots of power unless one wants to go fast or tackle steep hills. I'm only looking to make my recreational rides longer and more enjoyable. Not to mention with rim brakes, fairly skinny tires and no suspension I probably don't want too much speed.

The Bafang or Tongsheng mid drive motors both appear to be 750W. Would something lower powered be more appropriate?
Is my Scott hybrid bike a good choice for a conversion?
What is typically the most difficult part of doing a conversion?
Thanks all.
True, many e-bike accidents are like motorcycle accidents. What’s really bothered me about e-biking after buying my first e-bike a little over a year ago is that it’s twice as dangerous as a regular bike because #1 People don’t expect you to be covering so much ground so quickly, I can’t tell you how many times I’ll be coming down the road and have someone pull out in front of me… You can see the deer in the headlights look drivers get when they realize they just cut you off and misjudged your speed or #2 Drivers are impatient and they will hurry to try and get around you, once again misjudging your speed and creating dangerous situations.

I get what you’re saying about the speed thing tho, for awhile now I’ve wanted to upgrade mine to get some better performance but after reading your post it’s given me a little better idea about what I want/don't want in my bike. I think 25 mph is plenty fast for me, I just want to get there quick …..
 

EMGX

Well-Known Member
OK thanks I'll go with the shims, grease and locktite. Where can I get the shims and what size?
FWIW none of the 6 bikes that I installed the tsdz2 on had any detectable wiggle or looseness in the bottom bracket that I could tell. I did try shims made from strips of pop/beer can but there was no clearance to allow for even a single strip. All of the bikes have aluminum frames. I'll try again when I install on a '70s steel frame bike. I'd guess that different bikes might have different clearances, YMMV.
 

PedalUma

Well-Known Member
Region
USA
City
Petaluma, CA
On some Al frames I need to mill slag out of the BB shell. These tend to be big box bikes such as GTs.
I was just reading about the flight response of deer in the new book 'Fuzz'. Most animals use distance from a threat and not the rate at which it looms larger. For deer this distance, not speed, is about 100 feet. Put a dog at about 100 feet and a deer will run off. More than that, better to continue eating someone's yummy gardening. Freezing is a way of hiding against the bushes and their eyes are radically different than ours. Human children are particularly bad at jugging speed. They will walk into the front of a speeding truck.
When cars speed up I know that they are then about to slam on the brakes and do a right hook in front of me.