Banshee Scream downhill MTB conversion

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Jan 4, 2019
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Looking for advice on motor and battery selection for my DH ride. I bought the banshee because it’s built tough, has large triangle for battery and has good brakes & suspension. I am not so mechanically inclined so not really sure where to start. I am not looking for speed but need power to get my 100kg plus bike up some steep inclines. Also would be good to get 50km ride distance out of battery. So to pick your brain to give me an idea where to start... would you recommend mid drive or front hub or back hub ? (with consideration of cost and ease to implement). Any particular brands? Also what power I.e wattage & volts. Any suggestions appreciated. Note: I am based in Australia but can import most gear pretty easily.

Desired max speed on level ground. 40 kph
Desired max range at what cruising speed. 40 kph
wheel size - 26"
Brake type of motor wheel - hydraulic disc
Rider weight - 100kg
Terrain. Exp: steep hills, road and cross country
Budget - undefined but have spent 1k on used bike and getting it running smoothly

I know these questions are common but with changes in technology and me being new to this I would appreciated any suggestions on where to start...
 
The bike has too much of a fork for the speed that you plan. Sell that Monster T and replace with a lighter fork. It does look mint, you can have a good price, for this particular late model of the Monster T is very interesting for those building fast bikes.

The bike is good to build, hub or BB drive. Hub would make it simple and more reliable, while BB drive would retain the bicycle feel.
 
Can you provide a % grade for what you consider steep? I’ve noticed that term seems to cover a wide range depending on where people live and the terrain they’re used to.


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Grantmac said:
How mechanically inclined and what is your budget?
Very basic mechanical knowledge but willing to take my time. Would prefer to spend under 1000$ on motor and battery.
 
MadRhino said:
The bike has too much of a fork for the speed that you plan. Sell that Monster T and replace with a lighter fork. It does look mint, you can have a good price, for this particular late model of the Monster T is very interesting for those building fast bikes.

The bike is good to build, hub or BB drive. Hub would make it simple and more reliable, while BB drive would retain the bicycle feel.
Front hub back hub?
 
E-HP said:
Can you provide a % grade for what you consider steep? I’ve noticed that term seems to cover a wide range depending on where people live and the terrain they’re used to.


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Good question. I live on a steep hill. 20% is my guess but hard to say. Every ride finishes with an uphill battle. Will be off road and on road use though.
 
MadRhino said:
Liquidbarrel said:
Front hub back hub?

Rear hub of course. Ideally a big hub, low Kv.
I have read some pros and cons for front versus rear. Looks like I have fork with steel dropouts so was thinking that would be easier option since I can remove/swap easily...but appreciate that rear us your suggestion... can I ask why? Safer? Can go more power at back?
 
Liquidbarrel said:
E-HP said:
Can you provide a % grade for what you consider steep? I’ve noticed that term seems to cover a wide range depending on where people live and the terrain they’re used to.


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Good question. I live on a steep hill. 20% is my guess but hard to say. Every ride finishes with an uphill battle. Will be off road and on road use though.

I'd say that's steep in most people's opinion. That grade may be OK for short spurts, but would be hard to maintain the kind of speeds necessary for keeping a direct drive motor from overheating.

I use Google Maps, and the bicycle route setting to check grades. Seems pretty accurate, and if you move the mouse over the route, you can see the elevation changes in the left margin.

https://www.google.com/maps/dir/-21.1361517,148.5103944/-21.1313078,148.4916668/@-21.1333759,148.4927575,15z/data=!3m1!4b1!4m2!4m1!3e1!5m2!1e3!1e4

You can also right click, and use distance feature to estimate grades. Then you can plug in grades into the e-bike motor sim tool, and see how hot the motor will get and how long it will take to overheat at different speeds.
https://www.ebikes.ca/tools/simulator.html

If, for instance, you chose a MXUX 3005, and attempted the 10% grade in the map without pedaling, you'd overheat in a little over 7 minutes. The same motor with Statorade and hub sinks, would make it all the way up the hill, or all day long, without overheating (100 degrees C cooler).
 
Liquidbarrel said:
Looks like I have fork with steel dropouts so was thinking that would be easier option since I can remove/swap easily...b
A quick image search on "Monster T DH fork" (based on MadRhino's post) finds that is a thru-axle fork, meaning that you'd probably have to build something to secure the hubmotor axle flats with on both sides of the fork, as none of the hubmotors (except one) are designed to work in that type of axle mount.

There is the Grin All-Axle front hub that can work there, from http://ebikes.ca , if it's enough power for what you're after.
 
amberwolf said:
Liquidbarrel said:
Looks like I have fork with steel dropouts so was thinking that would be easier option since I can remove/swap easily...b
A quick image search on "Monster T DH fork" (based on MadRhino's post) finds that is a thru-axle fork, meaning that you'd probably have to build something to secure the hubmotor axle flats with on both sides of the fork, as none of the hubmotors (except one) are designed to work in that type of axle mount.

There is the Grin All-Axle front hub that can work there, from http://ebikes.ca , if it's enough power for what you're after.
Thanks amber wolf but I think madrhino is suggesting not to use front hub but use back hub. But yes you are right it is a 2003 Marzocchi monster triple monster fork that I think has steel dropouts...
 
Liquidbarrel said:
amberwolf said:
Liquidbarrel said:
Looks like I have fork with steel dropouts so was thinking that would be easier option since I can remove/swap easily...b
A quick image search on "Monster T DH fork" (based on MadRhino's post) finds that is a thru-axle fork, meaning that you'd probably have to build something to secure the hubmotor axle flats with on both sides of the fork, as none of the hubmotors (except one) are designed to work in that type of axle mount.

There is the Grin All-Axle front hub that can work there, from http://ebikes.ca , if it's enough power for what you're after.
Thanks amber wolf but I think madrhino is suggesting not to use front hub but use back hub. But yes you are right it is a 2003 Marzocchi monster triple monster fork that I think has steel dropouts...
 
Climbing off road with a front motor is not a good idea, especially when it is steep. When you climb, traction is on the rear.

Also, mountain trails require a properly tuned suspension, that is impossible to achieve with a motor in the fork.

Front motors are suitable (not ideal but suitable) for low power street riding. Off road, climbing especially, does require good torque on the rear and lightness on the front.

I like riding a Monster T in my mountain trails, but that is because I ride much faster than your planned top speed. If I would build your speed, I would use a 7 lbs fork and save 5 lbs off the front.

The 2003 Monster T2 is Alu, like all other versions of Monster and Super Monster. Through axle, no dropouts. If yours has a QR skewer adapter, I suggest taking it off and use the DH standard 20mm axle, if you are gonna ride it. This particular model of the Monster T can fit many different Air spring cartridges, saving weight and improving tuning. It had been used on Trials motorcycles in the past, and still is sometimes. It is the stiffest fork ever made for bicycles, overkill for all but the hardcore freeriders out there. Many Chinese motorcycle forks are not as strong as a Monster T, despite weighting twice as much. It is a very good choice for heavy, or very fast ebikes.
 
Front hub definitely won't work, rear hub is questionable if you care about off road performance.
A mid drive would be best.

Realistically $1000 won't cut it unless you get creative/lucky.
 
Grantmac said:
Front hub definitely won't work, rear hub is questionable if you care about off road performance.
A mid drive would be best.

Realistically $1000 won't cut it unless you get creative/lucky.
Fair point. I have looked at the Bafang BBSHD. Do you think that would be compatible? BB is ISIS 118mm fully sealed. Any other motor choices?
 
MadRhino said:
Climbing off road with a front motor is not a good idea, especially when it is steep. When you climb, traction is on the rear.

Also, mountain trails require a properly tuned suspension, that is impossible to achieve with a motor in the fork.

Front motors are suitable (not ideal but suitable) for low power street riding. Off road, climbing especially, does require good torque on the rear and lightness on the front.

I like riding a Monster T in my mountain trails, but that is because I ride much faster than your planned top speed. If I would build your speed, I would use a 7 lbs fork and save 5 lbs off the front.

The 2003 Monster T2 is Alu, like all other versions of Monster and Super Monster. Through axle, no dropouts. If yours has a QR skewer adapter, I suggest taking it off and use the DH standard 20mm axle, if you are gonna ride it. This particular model of the Monster T can fit many different Air spring cartridges, saving weight and improving tuning. It had been used on Trials motorcycles in the past, and still is sometimes. It is the stiffest fork ever made for bicycles, overkill for all but the hardcore freeriders out there. Many Chinese motorcycle forks are not as strong as a Monster T, despite weighting twice as much. It is a very good choice for heavy, or very fast ebikes.
Makes sense and thanks for advice. 2003 Marzocchi monster triple monster fork With through axle...not sure if picture I posted implies a skewer adapter or not. I may well take your advice and go lighter fork.
I still need to decide on mid drive versus rear hub...Bafang bbshd seems suitable but may be complicated install to ISIS 118mm Bottom bracket. Any idea? Or do you think a rear hub motor is a safer and cheaper option? (Even though it won’t feel as balanced)
 
Liquidbarrel said:
Grantmac said:
Front hub definitely won't work, rear hub is questionable if you care about off road performance.
A mid drive would be best.

Realistically $1000 won't cut it unless you get creative/lucky.
Fair point. I have looked at the Bafang BBSHD. Do you think that would be compatible? BB is ISIS 118mm fully sealed. Any other motor choices?
1000$ is far from realistic, to build a good off road ebike. It is not impossible, but you would spend another 1000$ replacing stuff in the next year.

Hub or BB, is a matter of how technical the trails are, how long the steep climbs are, if there are jumps to do, and how important it is for you to retain the bicycle feel. It is about terrain and riding preference, to decide what is best for you.

Big hub builds are not riding like bicycles. They are much closer to motorcycle feel. They require high C rate batteries, better wheel building, better suspension. But, you don’t have to shift, and they are very low maintenance. In my trails, that are nice enough to speed, and where steep climbs are never very long, no BB drive can come close to follow me. I am at 50 Mph already before they shift half of their gear range. I have friends building powerful custom mid drives that are somewhat competitive, but they spend more time tempering with their bike than riding.
 
Liquidbarrel said:
Grantmac said:
Front hub definitely won't work, rear hub is questionable if you care about off road performance.
A mid drive would be best.

Realistically $1000 won't cut it unless you get creative/lucky.
Fair point. I have looked at the Bafang BBSHD. Do you think that would be compatible? BB is ISIS 118mm fully sealed. Any other motor choices?

Measure the width of the bike frame at the BB, not the total width of the BB.

I built using a Cyclone but it isn't exactly a turn-key option. The BBSHD is closer to that but the stock programming apparently isn't great and the chainline can be poor.
 
Eungella , isn't that a Hang Gliding Site ? Paragliding there these days ?

Living near hills, I am also in agreement with Rear Hub Motor, that is a slow wind / High Torque low Speed Version of what ever hub motor you get.
( There is someone who traveled from Canada to Mexico with a 12 t Mac motor )
Along with the Highest Torque Rear Hub motor you can buy, put it into 26 inch or even 24 inch wheel, and use 36 volts or so at 30-40 amps.

Note you can get a 24 inch rim, and change out that heavy fork for a single crown fork with a 26 inch wheel. often being able to buy a used fork and wheel that were sold together since many people are moving over to 27.5 inch forks and wheels that are throu axle.

Or

Build with a Mid Drive like the BBS02 / BBSHD or if you can wait a little while get the new GNG X1 Pro .




E-HP said:
I use Google Maps, and the bicycle route setting to check grades. Seems pretty accurate, and if you move the mouse over the route, you can see the elevation changes in the left margin.

https://www.google.com/maps/dir/-21.1361517,148.5103944/-21.1313078,148.4916668/@-21.1333759,148.4927575,15z/data=!3m1!4b1!4m2!4m1!3e1!5m2!1e3!1e4
 
Okay based on advice and some reading I am thinking that I will pursue the rear hub option (and swap fork for lighter front end). Can anyone recommend a high torque (low speed) rear hub motor suitable for climbing some hills on the banshee scream?
Note: I weigh 100kg and bike will be approx 20kg (plus motor)
 
I suggest this one: QS205 50H v3
It is a big hub, about 28lbs 150mm wide
It is available in a large variety of windings, to match wheel size/voltage to your desired top speed

http://www.cnqsmotor.com/en/article...ric High Power Bike Spoke Hub Motor/259.html

QS motor has a thread on ES, in the 'ITEMS OR SALE-NEW' section of the forum. You can contact Vito, who will direct you to the best contact to get full info, counseling, shipping cost and delay. Don't forget to mention that you want double drilling for the flange to fit bicycle spokes, for default drilling is motorcycle spoke size. They will drill another 36 holes for bicycle spokes. They are reliable. We are many here using their motors.

They can provide other items that you will need, or sell you a complete kit.
But, the controller I recommend is not from them. See Power Velocity for their 18fet 4110 sinewave controller.
 
With a heavy hub motor on a bicycle frame , I would have some custom made torque arms for each side, long enough to go far up the chain stays so as to lessen the torque loads on a bicycle's small , thin, drop outs.
 
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