Can I and should I do this

Hi everyone. New here and need your help.
I have an older (mid 1990s) Dean Titanium Bicycle that weighs about 12 lbs loaded.
I’m thinking of making it an e bike.
Questions:
1. It has 26” tires on it now but would like to put 20” on it. I am older and want to have my feet on the ground and also have trouble swinging my leg over as my balance isn’t what it use to be. Can I safely put 20” tires on it? Will I need to change out the front suspension to something meant for a smaller bike?
2. It currently has cantilever brakes on it. Should I replace with discs?
3. Will the electric hub fit in a bike not made for one?

This is all new to me so forgive my ignorance, please

I have lots more question but thought I would start with the feasibility of the whole thing

I have a Rad Mini now but would love to build my own

Thanks for reading and hope you can help

Bikejunkie said:

Hi everyone. New here and need your help.
I have an older (mid 1990s) Dean Titanium Bicycle that weighs about 12 lbs loaded.
I’m thinking of making it an e bike.
Questions:
1. It has 26” tires on it now but would like to put 20” on it. I am older and want to have my feet on the ground and also have trouble swinging my leg over as my balance isn’t what it use to be. Can I safely put 20” tires on it? Will I need to change out the front suspension to something meant for a smaller bike?
2. It currently has cantilever brakes on it. Should I replace with discs?
3. Will the electric hub fit in a bike not made for one?

This is all new to me so forgive my ignorance, please

I have lots more question but thought I would start with the feasibility of the whole thing

I have a Rad Mini now but would love to build my own

Thanks for reading and hope you can help

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I love those older titanium frames.

1. The 20" rear question is not ebike specific, but bicycle geometry. It will result in a slacker head tube angle, and slower steering but could also result more stability at higher speeds to a point. You could go with a smaller front wheel, like 24" so the geometry is affected less. I would be more concerned about pedal strikes depending on your crank arm lengths.
2. I don't think the early Dean frames had bosses to mount disc brakes, unless you mean discs on the front only.
3. Yes, older frames have a 135mm dropout width, and most basic hub motors have that width (135mm-140mm).

Welcome to the forum :thumb:

Bikejunkie said:

Questions:
1. It has 26” tires on it now but would like to put 20” on it. I am older and want to have my feet on the ground and also have trouble swinging my leg over as my balance isn’t what it use to be. Can I safely put 20” tires on it? Will I need to change out the front suspension to something meant for a smaller bike?

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You may encounter pedal strike and may snag the chainwheel over obstructions, as the BB will be approx 3 inches lower.

Bikejunkie said:

2. It currently has cantilever brakes on it. Should I replace with discs?

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The current cantilever mounts are not located in the proper position for 20" wheels. Unless the frame and fork has suitable mounting bosses for the calipers, replacing cantilevers with disc brakes will not be trivial. It is possible, yet expensive, to add disc brake mounting bosses to a TI frame.

Bikejunkie said:

3. Will the electric hub fit in a bike not made for one?

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Easiest if the rear dropout width is close to the common 135mm.

Bikejunkie said:

I have lots more question but thought I would start with the feasibility of the whole thing

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Are you willing to modify your Ti frame? Twelve lbs. sounds like a real nice one.

Bikejunkie said:

I have a Rad Mini now but would love to build my own

Click to expand...

Suggest starting with an inexpensive used bike (with disc brakes) as a base. OR modify your Rad Mini to your liking, if its size and ergonomics are agreeable to you.

Hey Bikejunkie! Welcome to ES. From one "I'm older" to another, the answer is yes, you can put 20" wheels on a bike made for 26" with some caveats. How did Ross Perot so famously put it......."The devil is in the details."

It goes like this. Obviously you will need brakes. However older frames, despite a nice big triangle to put your battery in, have no way to attach disk brakes. However, if you have a 1 1/8 inch head tube, you can purchase a suspension fork with a disk mount quite readily. If the head tube is narrower then 1 1/8 inch, well good luck to you.

Also, if the rear seat stay doesn't have a disk brake mount, then you will need an adapter.

As for the rims, you will need to find a rear rim that can take 12 gauge spokes to suit the motor, or find a motor that can handle 14 gauge spokes. Or you will need to adapt things like a lot of us do around here.

Or you can get a "girls" bike frame with a step through frame and not worry so much about the adaptions.

It all depends on how good you are at making your own stuff

I didn't ask if you plan on pedaling or not. If not, and are just going to occasionally turn the cranks, then I would go with a MXUS 3K hub, set up for a single speed freewheel. The pedal drop is more like 2", since the bottom bracket is located about 60/40 between front and rear axles. You could put a 36 tooth front sprocket on and some shorter cranks.
As already mentioned, you can fill that big triangle with 72V of Sony VCT6 cells (20S10P), add a suitable programable controller, with proportional regen, a decent throttle, and a cycle analyst to tame it.
If your front fork doesn't have brake bosses, and your frame has a 1" head tube, you may have limited choices for adding front discs. You have to decide on a much heavier cheap fork with disc brakes, or keep what you have. If the current front brakes and rear regen aren't enough, then there are a few cheap front suspension forks available with shorter travel, like your existing frame is built for (before the smaller rear wheel). If you go that route, get 203mm discs and dual piston calipers and you'll have plenty of stopping power.
Buy or make a good set of torque arms to protect the frame. The titanium will at least soften the ride a little, but you may be able to stuff a fatter tire on the rear too, and add a good suspension seatpost and you're all set.
Does it look like this one??

If it were me, I'd stick with the stock fork and brakes. Regen works pretty well. I barely ever use my brakes riding around most of the time, only using them from around 6-7 mph down to stop if I need to actually stop. You'll need brakes for steep hills though.

e-beach said:

As for the rims, you will need to find a rear rim that can take 12 gauge spokes to suit the motor, or find a motor that can handle 14 gauge spokes. Or you will need to adapt things like a lot of us do around here.

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I've re-laced 3 direct drive motors that came with 12 gauge spokes and used 14 gauge spokes. Also one geared hub motor and rim that came with 13 gauge spokes replaced with 14 gauge. The J-bend is of course offset in the larger hole, but wouldn't be able to pull through. I've not noticed any problems after 2 years of usage. Is there something specific that I should look out for?

Bikejunkie said:

Hi everyone. New here and need your help.
I have an older (mid 1990s) Dean Titanium Bicycle that weighs about 12 lbs loaded.

Click to expand...

No, it doesn't.

I’m thinking of making it an e bike.

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Don't do that. You'll only screw up a nice pedal bike, and not enjoy any of its nicer qualities after your convert it. If you don't want to ride it and don't want to keep it the way it is, sell it to someone who appreciates it and use the money something to buy a more suitable bike.

Get a sturdy chromoly steel frame made of straight round tubes, with disc mounts if you must have disc brakes (they don't improve anything except your bike's cleanliness). Whatever wheel size you want to use, get a bike designed for that wheel size.

Here's one made for 20" wheels:
https://velo-orange.com/collections/neutrino-mini-velo/products/neutrino-minivelo

with disc mounts if you must have disc brakes (they don't improve anything except your bike's cleanliness).

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Not to restart that old argument, but it depends on what you are starting with. Take a spin on an EZIP trails with rim brakes, and you will appreciate disks more. Even perfectly adjusted, those brakes are just adequate - and for only about a week before needing readjustment. I've been riding with disks (one bike hydraulic, one mechanical) after many years with rim brakes, and I would never go back.

I wish that my bike were really light, loaded...

LeftieBiker said:

with disc mounts if you must have disc brakes (they don't improve anything except your bike's cleanliness).

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Not to restart that old argument, but it depends on what you are starting with. Take a spin on an EZIP trails with rim brakes, and you will appreciate disks more.

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I've dealt with cheap and awful early cable discs that were about as effective as dragging a brick on a string. That isn't characteristic of good discs, just like the garbage that comes on an e-BSO isn't characteristic of good linear pull brakes.

If you have $50 to spend, you can set up a kickass rim brake, or a just-okay disc brake.

E-HP said:

The pedal drop is more like 2", since the bottom bracket is located about 60/40 between front and rear axles. You could put a 36 tooth front sprocket on and some shorter cranks.

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Are you sure the OP wants to keep the 26" on the front? Looked to me like OP wants to go 20" on both F/R:

Bikejunkie said:

1. It has 26” tires on it now but would like to put 20” on it. I am older and want to have my feet on the ground and also have trouble swinging my leg over as my balance isn’t what it use to be. Can I safely put 20” tires on it? Will I need to change out the front suspension to something meant for a smaller bike?

Click to expand...

Hopefully OP will return to clarify.

99t4 said:

Are you sure the OP wants to keep the 26" on the front? Looked to me like OP wants to go 20" on both F/R:

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Ahh, that makes more sense. I think when I saw the part about changing out the fork to a smaller one, I got thrown off, since that would change the geometry. Cranks will need to be pretty short. Maybe 24" would be a good compromise.

LeftieBiker said:

with disc mounts if you must have disc brakes (they don't improve anything except your bike's cleanliness).

Click to expand...

Not to restart that old argument, but it depends on what you are starting with. Take a spin on an EZIP trails with rim brakes, and you will appreciate disks more. Even perfectly adjusted, those brakes are just adequate - and for only about a week before needing readjustment. I've been riding with disks (one bike hydraulic, one mechanical) after many years with rim brakes, and I would never go back.

I wish that my bike were really light, loaded...

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Just consider the rim to be a really large diameter disk :wink:

I've re-laced 3 direct drive motors that came with 12 gauge spokes and used 14 gauge spokes. Also one geared hub motor and rim that came with 13 gauge spokes replaced with 14 gauge. The J-bend is of course offset in the larger hole, but wouldn't be able to pull through. I've not noticed any problems after 2 years of usage. Is there something specific that I should look out for
[/quote]

Others on this board have not been as lucky as you have without using washers to insure no "pulling through" at the hub.

[youtube]FJe99BjV8bM[/youtube]

markz said:

[youtube]FJe99BjV8bM[/youtube]

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Typical weak disc brake stuff. The limitation on braking for most of my bikes is the integrity of the fork (and most of mine use rim brakes). Discs, especially hydros, bite hard with modest lever effort, but they don't follow through when things get serious.

I think even my BB7 disc braked bike would likely bend the fork in a panic stop before the brake ran out of juice. Of course, I'm sticking that bike to the ground twice as hard as the average bear. Nobody of normal weight needs to get more deeply into it than Kool Stop Salmon pads for rim brakes or fully metallic pads for discs. Slick die-drawn stainless steel cables if you like yourself.

Chalo said:

Slick die-drawn stainless steel cables if you like yourself.

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Yessssssss :thumb: but how do you find this stuff?

Bikejunkie said:

1. It has 26” tires on it now but would like to put 20” on it. I am older and want to have my feet on the ground and also have trouble swinging my leg over as my balance isn’t what it use to be. Can I safely put 20” tires on it? Will I need to change out the front suspension to something meant for a smaller bike?

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No. Just just a different bike with lower standover height.

99t4 said:

Chalo said:

Slick die-drawn stainless steel cables if you like yourself.

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Yessssssss :thumb: but how do you find this stuff?

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Your local bike shop has such things. Or if not, there's online retail:

https://www.ebay.com/itm/Jagwire-Sport-Brake-Cable-1-5x2000mm-Slick-Stainless-SRAM-Shimano-MTB/303542695329

Thanks Chalo. Previously, I didn't know it made that much of a difference, or that it was that easily available. Any specific housing that it works best with?

OP hasn't been back in over a month, just made the one initial post and that's been it.

99t4 said:

Thanks Chalo. Previously, I didn't know it made that much of a difference, or that it was that easily available. Any specific housing that it works best with?

OP hasn't been back in over a month, just made the one initial post and that's been it.

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Plastic lined housing is a must for decent brake and shifter feel, but that's almost anything that isn't horribly cheap these days. Jagwire housing that has -SL appended to its name contains lubrication (but you can add your own to any housing by lubing the cable before you run it through).

So called "compressionless" brake housing is basically shift housing with a strong Kevlar jacket to keep it from bursting. It does make the brakes feel better, but I only use it for brakes that are finicky, like drum brakes. The disadvantage to compressionless housing is that it's very stiff compared to traditional Bowden brake housing, and can bias the bike's steering.