Slo Ride

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BiggKidd

100 W
Joined
Oct 15, 2024
Messages
143
Location
South Central Virginia
Started acquiring parts for a new build facetiously "dubbed" Slo Ride. I'm going to need a lot of info and help finding parts if you good folks would be willing to help.

The starting piece ordered yesterday is a tiny little German made motor smaller than a Mason jar that packs a punch! I also ordered a weld in 120mm BB shell and the 120mm BB.

What I am envisioning here is a large fat tire simi chopper build with a stretched frame. I want to build it rock solid with full suspension and a minimum of 7 pedal speeds more would be better. With a belt drive from the mid mount motor on the left and possibly a hub motor in the front. I want the pedals way out on the front of the frame with a low seating position that will let me be flat footed while sitting yet still have proper leg geometry for pedaling. The battery will likely be at minimum of 100AH and for longevity I'm leaning toward LifePO4 cells even though they are large and heavy. A 26x4 or wider rear tire with either a 29x2.25 or 26x3 up front and a good bit of rake on the forks but not to the point of being a full on chopper. Hydraulic disk brakes are a must.

Need some help finding sources for the forks and head tube. Along with a belt drive that can handle 25-30kw pullies and all. One major stumbling block is the motor will have to have a very small drive pulley. The motor is water cooled and there isn't much space for a larger pulley because the water cooling tubes come out very close to the shaft. The motor drive gearing needs to be around 11.5 or 12 to 1.

Also looking for 72V 300-500A water cooled controller options with a display and something that can work with a throttle as well as pedal assist and regen is a must have! It also needs to be programable and switchable between power settings. More than just low medium and high would be nice with PAS usable in all power settings. Needs provisions for lights etc. too.

This is not going to be an over night build as with the motor I have to buy pieces as I can afford them. The motor I just ordered cost as much as my 6 month old dual 1000w motor E-bike did delivered!

Thanks for any info and help you may be able to provide!
 
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bananu7 said:
If you plan to ride a 25kW+ vehicle around people, you really, really should have insurance. And noone will insure a vehicle with no tag or registration.
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Actually there are companies insuring E-bikes now.

I seldom ride around people or traffic. I live way way out in the sticks where the towns have one stoplight and it's over 25 miles to a walmart!
 
LMAO
The first piece just came in, no it's not the motor. Still haven't even gotten tracking info on the motor so who knows when it'll ship. Good thing I'm not in a hurry. lol
What did come in is the old Kawasaki 454LTD rear hub & pulley assembly. Other than being heavy as heck it should be near perfect. It's just slightly less than 12" dia. It's likely considered a 12" and that is just about what I will need, I think. haha
 
BiggKidd said:
LMAO
The first piece just came in, no it's not the motor. Still haven't even gotten tracking info on the motor so who knows when it'll ship. Good thing I'm not in a hurry. lol
What did come in is the old Kawasaki 454LTD rear hub & pulley assembly. Other than being heavy as heck it should be near perfect. It's just slightly less than 12" dia. It's likely considered a 12" and that is just about what I will need, I think. haha
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Drum or disc? I know I'd prefer a drum despite somewhat increased weight, though either would be overkill for your project.
 
Drum but as you said to much for my build. I just wanted the ring / pulley I'll mount a new center in it. The motor I ordered is stupid high RPM! Which is why I needed such a large pulley. I still need a one inch or as close as I can get for the driver pulley and I need to figure out wheels too. I'm going to want MC tires at the speeds this will be capable of. Something about the size of the LTD wheel & tire would be good but I need bike hubs so I can run a cassette so it almost has to be spoke wheels. Any suggestions for strong rims & hub and good a rear tire for mostly street but must be able to handle mud as I live couple miles from the road... This thing will likely run around at 5-10% power 99% of the time but I want to be able to safely get the power to the ground when the itch hits!
 
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BiggKidd said:
good a rear tire for mostly street but must be able to handle mud
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This is a very hard requirement to satisfy. I think your best bet would be a 40-60 adventure tyre, such as Mitas Enduro Trail XT (old E-10). Anything with denser knobs or even a pad tyre will be hopeless in mud.
BiggKidd said:
This thing will likely run around at 5-10% power 99% of the time but I want to be able to safely get the power to the ground when the itch hits!
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Have you considered building two separate vehicles? Optimizing for 5% of total power use almost certainly won't give you satisfactory results as you will end up with an overbuilt construction that will feel heavy and boring most of the time.
 
bananu7 said:
This is a very hard requirement to satisfy. I think your best bet would be a 40-60 adventure tyre, such as Mitas Enduro Trail XT (old E-10). Anything with denser knobs or even a pad tyre will be hopeless in mud.

Have you considered building two separate vehicles? Optimizing for 5% of total power use almost certainly won't give you satisfactory results as you will end up with an overbuilt construction that will feel heavy and boring most of the time.
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Mitas Enduro Trail XT I think that's a bit more traction off road and less on road than I'm after, they might work without being to noisy or crazy vibrations. Something with tread more like the Heb Allscape tires should be enough. I'm not sure they would handle the top end though. This thing should go well in to the triple digits if the rider is crazy enough!

The bike should come out at a decent weight unless I actually use LifePO4 cells. Besides even at minimum power were still talking over 1,000W and it's going to have strong gearing. The final gear ratio should be around 11:1 or 12:1.
 
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BiggKidd said:
Mitas Enduro Trail XT I think that's a bit more traction off road and less on road than I'm after, they might work without being to noisy or crazy vibrations. Something with tread more like the Heb Allscape tires should be enough. I'm not sure they would handle the top end though. This thing should go well in to the triple digits if the rider is crazy enough!

The bike should come out at a decent weight unless I actually use LifePO4 cells. Besides even at minimum power were still talking over 1,000W and it's going to have strong gearing. The final gear ratio should be around 11:1 or 12:1.
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I very much doubt that eMTB fat tyres will have appropriate speed rating for triple digit speeds. Sounds very risky. There's also no chance they won't immediately pack up with sticky mud and turn into two perfectly round donuts.

If you think the XT is too "offroady" for you (which I don't, this tyre handles just fine on pavement as long as it's dry, but it's indeed noisy) there's a swath of options available for you. Even something like a narrow size TKC 80 could work - but again, if you actually do need the vehicle to handle mud and provide actual traction, then TKC 80 (or mitas equivalent Enduro Trail / Enduro Trail+) clog up very fast and become slippery. You need appropriate knob spacing for the tyre to be able to clean itself, and the dense ones optimized for street mileage just don't have it. All of those tyres can handle speeds of up to 140km/h, which should leave a reasonable safety margin.
 
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bananu7 said:
I very much doubt that eMTB fat tyres will have appropriate speed rating for triple digit speeds. Sounds very risky. There's also no chance they won't immediately pack up with sticky mud and turn into two perfectly round donuts.

If you think the XT is too "offroady" for you (which I don't, this tyre handles just fine on pavement as long as it's dry, but it's indeed noisy) there's a swath of options available for you. Even something like a narrow size TKC 80 could work - but again, if you actually do need the vehicle to handle mud and provide actual traction, then TKC 80 (or mitas equivalent Enduro Trail / Enduro Trail+) clog up very fast and become slippery. You need appropriate knob spacing for the tyre to be able to clean itself, and the dense ones optimized for street mileage just don't have it. All of those tyres can handle speeds of up to 140km/h, which should leave a reasonable safety margin.
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I agree about any bicycle tires not handling 100+MPH speeds. If I have the gearing etc. figured correctly that is. Riding on street tread tires packed full of mud is nothing new but it is a little easier when the tires have some traction. Many many years ago a friend and I rode hundreds maybe even thousands of miles on mid powered street bikes with crap tires through mud, dust and every other thing you can imagine. So tires that don't fly apart at high speed are more important to me than the tread pattern as long as they ride smooth and quiet and aren't to heavy.
 
BiggKidd said:
I agree about any bicycle tires not handling 100+MPH speeds. If I have the gearing etc. figured correctly that is. Riding on street tread tires packed full of mud is nothing new but it is a little easier when the tires have some traction. Many many years ago a friend and I rode hundreds maybe even thousands of miles on mid powered street bikes with crap tires through mud, dust and every other thing you can imagine. So tires that don't fly apart at high speed are more important to me than the tread pattern as long as they ride smooth and quiet and aren't to heavy.
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In my experience, soft-compound tyres like TKC 80 or Shinko 804/805 handle just fine on pavement under both heavy and lighter motorbikes. For a 25-30kW peak power and a 72V 100Ah battery, we're realistically looking at a 120-140kg machine, and the smallest size of TKC80 on offer is actually a quite narrow 3.25-18, with a load index of 59, and speed index S (180km/h, 112mph). This seems to check all your boxes and would be appropriate for a very lightweight machine.

Of course pedalling is pretty much out of question, as I've already mentioned. It's going to be a very much motorcycle-sized motorcycle, and there's no point whatsoever of putting human-powered drivetrain on it.

While you could go down with thread to a 30-70 tyre like TKC 70 or Shinko equivalent, I'd advise against that if you do indeed plan on riding in the mud. I have a set of TKC 70 as my "street set" and love them, but they really only work in dry conditions.
 
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Got a message from the motor seller this morning saying it should be here by end of week. Which is awesome even though it'll be awhile before I get all the other pieces together to even test it much less build the bike.

This leads me to another question I need a little help deciding about. That is do I really need to try and use a CVT or can I run without. The gearing I have is about 12:1 so I'm thinking the CVT isn't absolutly needed. The motors "working" range is 2,000-20,000 RPM. Depending on the tire size I opt to go with that puts 2,000 motor RPM equaling 12-15 MPH which is about as slow as I ever ride anyway. My question is do I NEED the CVT or would one even be helpful? Especially if you consider it's going to add another 15-25lbs to the bike not to mention the size and space needed for it.

Opinions please!
 
I haven't read all the considerations and probably can't envision the gearing, but with that much power, I think a SS is adequate even if it's not a drag racer.
 
2old said:
I haven't read all the considerations and probably can't envision the gearing, but with that much power, I think a SS is adequate even if it's not a drag racer.
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By SS I assume you are meaning single speed?

I will likely take it to the strip at least once just to see what's what. I just don't want to burn the motor with to much torque at low RPM I highly doubt it'll have trouble pulling off but I do worry about trying to ride slower than 2,000 motor rpm since that's listed as the lowest "working" rpm. Then again I seldom try and ride slower than ten mph.

Thanks for your reply!
 
With a water-cooled motor, i wouldn't worry about that. Slow speeds can be problematic, e.g. on uphills, because you need a lot of power and you're getting almost no airflow, but if you can dump the heat into the radiators, you'll extend the low-speed high-current capability by a factor of 5 (in time units) at least.

Can you link the motor you're getting? Also, how are you achieving 1:12?
 
bananu7 said:
With a water-cooled motor, i wouldn't worry about that. Slow speeds can be problematic, e.g. on uphills, because you need a lot of power and you're getting almost no airflow, but if you can dump the heat into the radiators, you'll extend the low-speed high-current capability by a factor of 5 (in time units) at least.

Can you link the motor you're getting? Also, how are you achieving 1:12?
Click to expand...
Thank you for the cooling info!

Torqstar 3 (7050) - Lehner Motoren Technik

Torqstar 3 (7050): Weight: ca. 1900g Operating instruction and specifications RPM table outrunners under load RPM table outrunners idle speed --> ...
www.lehner-shop.com www.lehner-shop.com

I am using the rear wheel belt drive pulley from a Kawasaki 454 LTD which is 12 inches and making a custom 1" ish front pulley.

This build is going to take some time as almost everything is custom and I can only afford to buy parts so fast. Wheels tires and forks are the biggest problems I am facing. I want a rake of roughly 28* and the wheels and tires need to be able to take triple digit mph speeds.
 
BiggKidd said:
Wheels tires and forks are the biggest problems I am facing. I want a rake of roughly 28* and the wheels and tires need to be able to take triple digit mph speeds.
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Any good reason why you won't use an existing motorcycle frame with wheels? You'd get everything that fits together and is plenty strong, leaving you just with mounting the motor and the battery. Also, I feel like this thread should be in the e-motorcycles category in the first place.

There are lighter-weight vehicles out there in the 70-85kg category, but I wouldn't trust any of those at 160km/h - not just because they don't have the power for it, but because going that fast requires an overall much more solid construction. For example, suspension loads at those speeds mean that something that feels plush and comfy at low speeds is out of question, and you need a lot of damping to cope with the bumps at that speed without losing stability.

If you go with the TKC80 tyres, then those will be fine at those speeds, but you definitely need to keep a close eye at pressures, as that will massively impact stability. To low and you'll introduce wiggle and oscillations and that's plain dangerous. I'd honestly upsize them to at least 120mm in the back for stability as well.

I've just realized that you wanted a low sitting position with forward pegs, kinda like a chopper - keep in mind that most motorcycles built in that style don't really go that fast. A reasonable top speed of a spirited ride on one of those might be 120km/h. Anything past that and you start feeling the limits of short, too soft suspension, the footpegs don't allow you to absorb bumps (like the pegs below the rider do) and because of the upright position the wind hits you straight on, which at that speeds actually becomes a considerable force. Have you actually ridden a motorcycle at such speeds before?

You'll also want proper brakes - at least one huge disc or prefferrably double disc setup, which you can only mount on a motorcycle fork anyway, so it's not like you can shed any weight or complexity here.

BiggKidd said:

Torqstar 3 (7050) - Lehner Motoren Technik

Torqstar 3 (7050): Weight: ca. 1900g Operating instruction and specifications RPM table outrunners under load RPM table outrunners idle speed --> ...
www.lehner-shop.com www.lehner-shop.com
Click to expand...
That's a fun little motor! Power-to-weight ratio seems really crazy, but I wonder how much the balance changes when you include the weight of the cooling system, fluid, radiators, pump etc.
 
You are right on several points. Then again I never do the things others do I usually break & make my own trails! Here with this build I know just what I want to build and yeah it is crazy and that's just this old mans way. I have been doing my thing my way for 50 years and I'll just keep on scootin along.
I have been toying with the idea of using MC forks. The added weight up front might help more than hinder. Just as I've been toying with the idea of adding a geared hub motor up front as much for the off road ability as the added weight to help hold the front end down.
 
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