kmxtornado
10 kW
I'm sharing in this thread what I think may be perhaps the perfect setup. I have yet to try this combination of a front geared hub or mid-drive and a rear cassette compatible IGH (internal gear hub). Key word is "cassette compatible IGH." I do have a lot of experience with IGH's on a non-electric recumbent trike and I imagine the setup married with a geared hub motor up front on an upright bicycle would simply be awesome. I'm getting starry eyed just thinking about it. If someone's already done this (if someone has, please share with everyone how great it is. I'm sure members could use a review). I'll post up my own review if I ever get this.
More info on my blog but I wanted to post it here b/c I think a lot of this will help the e-bike forum. I imagine more people here are knowledgeable in electronics and less so about bikes. Just wanted to share my insight from my bicycle knowledge. When equipped with both, you guys will rock!
I wanted to be a rebel and ride a recumbent tadpole trike (two wheels in the front) with 1,992 upright cyclists on a trip from SF to LA. My trike was 45lbs and the roadies had bikes ranging from 16-27lbs. I didn't want to be left behind or have to give up on the first day of a 7-day ride b/c of hills. I had 1 yr to plan and made full use of it. This is what I did and how it can help you
WAIT WAIT WAIT, THAT'S NICE BUT WHAT'S AN IGH?
It's a hub that has 3 gears inside of it. The type I'm discussing also allows you to put a standard freewheel/cassette on top of it. That multiplies your number of gears by 3! So if you have say, 6 speeds in the back, you'll now have 18 in the back. Multiply that by whatever number of chain rings you have and you could have up to 18x3 (number of chain rings) = 54.
It pretty much gives you underdrive and overdrive for your bike. The internal gear hub I have has 3 settings that can be engaged from a stationary position. Neutral for flats, underdrive for downhlls and overdrive for up hills. The hub has 3 gears inside of it and basically allows you to drop the range of your current setup by about 30% or increase it by 30% (depending on the specs of the hub). This means your lowest gear gets even lower. Your higher gear gets even higher.
Some IGH's replace cassettes and limit your rear to 3, 7 or 8 gears. Other ones like the one I mentioned however is a bit higher end, (the Sturmey Archer CS-RK3) and is cassette compatible. That means you get whatever you have now plus the overdrive and underdive capabilities. The only thing you sacrifice is a bit less than 3lbs of weight and the cost for putting this together. And did I mention that this hub is only about $115 shipped from a member here on Endless-Sphere? The great thing about this is that you can use standard shifters. No proprietary shifter needed like SRAM's equivalent, SRAM 3x7 IGH hub. PM me for the ES member's SN if you want to get one.
But first,
Perhaps consider an IGH (internal gear hub) from Sturmey Archer in the rear that's cassette compatible. You can match that with a geared hub motor in the front. This is my thought for my next setup until Sturmey Archer or SRAM come up with electric IGH's that are cassette/disk brake compatible for a full stealth look. Until then, my aforementioned setup might be a good thing for you. You'll be able to climb any hill with ease and the motor won't really have to be that strong. You'll have plenty of climbing capability with the IGH and cassette alone. Electrified, it'll be a bonus.
MY CURRENT BENT TRIKE SETUP IS A CLIMBING MONSTER:
My bent trike's got a Sturmey Archer CS-RK3 IGH in the rear matched with a 11-34T 8-speed megarange cassette. Combining this with a three chain ring setup in the front, 22/32/42, it's got 72 gears (overboard, I know), but allows me to get gear inches down to 8.9 on a 20" drive wheel. That pretty much means if trees were tall enough, I could climb one for hours. I've done something similar on my Aids Life Cycle ride, where I rode from SF to LA over the course of 7 days. I was paranoid about the 545 mile trek and spent a bit over a year and the above setup is what I came up with. No regrets. The hub itself is about $115. The expensive part was having the wheel custom laced by a shop since I don't really know how to do that stuff myself.
By improving the bike's drivetrain capabilities, you can rely less on the motor and therefore extend the use of your juice. With a cargo hauler, I assume you're going on more extended rides than the rest of us. I really recommend the above setup for that purpose. My trike's 45 lbs and it has no motor and no battery. It's heavy, but it certainly doesn't feel that way with the replacement drivetrain.
The best part of the IGH setup is that you don't sacrifice high gears to improve high climbing ability. Implementing this internal gear hub means you can up your high gears as well. You can check my trike blog for gear inch tables I made. If you're not much of a gear head and don't really care, just know that I went from a 76GI high to a 98GI high. It laymen's terms, that just means I can speed down hills faster than before.
PERFECT WHEN MATCHED WITH A MOTOR B/C:
1. Often times, the motor may not be strong enough to propel you at high downhill speeds. Gravity and momentum can be faster than motor speed. It's basically useless in this situation. An IGH will give you extra top gears for you to go faster. I rarely spin out going down hill on my trike. Unless I'm low 50mph (which I have, but don't recommend), there's always resistance which means you continue to have a high enough gear to bring you down hill at speed.
2. As I already mentioned, low gears are super important for uphill climbing - especially on a heavy weight bike such as yours. The motor should theoretically last long b/c you won't be using it as hard. The new drive train can do the work. Again, you can extend it's range by not utilizing as much (since the IGH when engaged in overdrive can drop all gears for improved hill climbing ability.
BENEFITS OF AN IGH SETUP:
1. Improves low gears for hill climbing
2. Improves high gears for hill descents
3. Perhaps lighter b/c you won't need as heavy duty of a motor to get up hills. The hub I have is about 3lbs.
4. Depending on exactly how you do this, you might break even or actually save money.
5. By improving your ability to climb hills by modifying the drivetrain, you won't need to rely on the motor. This will extend your battery range for sure.
6. This also means that if your motor/battery/controller craps out on you, you're still very capable of climbing hills
7. It's just plain cool. Not many people have IGH's or know what they are.
8. IGH's allow you to change gears at a stop. It pretty much raises or drops your entire gear range by a certain percentage. No more need to worry about forgetting to downshift when coming to a rest.
CONCLUSION:
I would recommend an IGH for most applications, but it's definitely not for everyone. If you're a downhill racer on a carbon fiber road bike, that extra 3lbs amounts to a lot! However, it's perfect for folks like you who are already hauling weight and hill climbing is already difficult. Two reasons NOT to go through this setup:
1. If you calculate the difference in a smaller motor size w/an IGH vs a larger motor w/o an IGH and the numbers don't make enough sense. Ask yourself how much more you'd be willing to spend to get the extra edge.
2. You don't need range on the ride.
3. If you can already take hills easily and slopes really aren't that big of a deal, then an IGH would be a waste. I can't imagine this is the case for you though b/c if you're looking at getting a motor, I'm assuming you're looking for some sort of needed assistance compared to what you have now. Those that don't have high grade slopes should do w/o the IGH. The extra money and weight aren't worth it. For you though, I'd definitely get an IGH, hands down.
---------------
DESIGNINGYOUR DRIVETRAIN:
I've laid out in my trike blog how I recommend designing your drivetrain with an IGH charts and all that fun stuff, but I can sum it up here.
The smaller the front chain ring, the easier it is to climb. The larger it is, the faster it will go down hill. But how small should your smallest chain ring be? And how large should the largest one be?
I found the easiest way to use a 3 internally geared hub is to use neutral for flats and only engage the underdrive or overdrive for downhills and uphills respectively. This makes it easier to know when you should be using what. Same with the front chain ring. Middle is for flats, small is for uphill and large is for downhill. Not everyone uses it this way, but it's ideal for me b/c it's simple and there's a rule to it. Plus, it's easier to explain to someone taking your ride for a test spin.
Step 1: Ride your bike now and determine what gear you need to start from a dead stop. Often times this will not be the first or second gear. Most likely it's the third or fourth gear that can comfortably get you going from a standstill. The idea now is to raise everything up so that you're in neutral of your IGH, in the middle chain ring and can start off from a stop at first gear of your freewheel/cassette (smallest cog). This way, when you engage the IGH to under drive, all cogs on your cassette/freewheel (speeds) can be used for the purpose of going downhill. Same for overdrive and uphill.
Step 2: To achieve this, you need to know how much bigger to make your chain ring. The easiest most objective way is to convert everything to gear inches or GI's. Sheldon Brown's website has a useful calculator for this. The reason you want to do this is b/c different combinations of front and rear size teeth can amount to the same GI. GI is a consistent way to do comparisons. So do the conversion and find out what GI you want/need to start from a stop in the above setup.
Step3:Plug into Sheldon's calculator different chain ring sizes to see what you get. It'll pretty much be trial and error to see what chain ring works for you.
THANK YOU:
This is sort of my thank you thread. I came from bentrideronline where I don't think anyone knew about the Flybikes Cobra sausage tubes for rear wheels that you guys had discussed here on Endless-sphere. I figure bringing info back and forth from one forum to another that is lacking can help a great deal. I've learned tons here and was looking to donate to the forum but Justin Le said there isn't anything set up at the moment. For now, this is my thank you contribution. I hope someone can take advantage of it and build a kick-@$$ ride.
More info on my blog but I wanted to post it here b/c I think a lot of this will help the e-bike forum. I imagine more people here are knowledgeable in electronics and less so about bikes. Just wanted to share my insight from my bicycle knowledge. When equipped with both, you guys will rock!
I wanted to be a rebel and ride a recumbent tadpole trike (two wheels in the front) with 1,992 upright cyclists on a trip from SF to LA. My trike was 45lbs and the roadies had bikes ranging from 16-27lbs. I didn't want to be left behind or have to give up on the first day of a 7-day ride b/c of hills. I had 1 yr to plan and made full use of it. This is what I did and how it can help you
WAIT WAIT WAIT, THAT'S NICE BUT WHAT'S AN IGH?
It's a hub that has 3 gears inside of it. The type I'm discussing also allows you to put a standard freewheel/cassette on top of it. That multiplies your number of gears by 3! So if you have say, 6 speeds in the back, you'll now have 18 in the back. Multiply that by whatever number of chain rings you have and you could have up to 18x3 (number of chain rings) = 54.
It pretty much gives you underdrive and overdrive for your bike. The internal gear hub I have has 3 settings that can be engaged from a stationary position. Neutral for flats, underdrive for downhlls and overdrive for up hills. The hub has 3 gears inside of it and basically allows you to drop the range of your current setup by about 30% or increase it by 30% (depending on the specs of the hub). This means your lowest gear gets even lower. Your higher gear gets even higher.
Some IGH's replace cassettes and limit your rear to 3, 7 or 8 gears. Other ones like the one I mentioned however is a bit higher end, (the Sturmey Archer CS-RK3) and is cassette compatible. That means you get whatever you have now plus the overdrive and underdive capabilities. The only thing you sacrifice is a bit less than 3lbs of weight and the cost for putting this together. And did I mention that this hub is only about $115 shipped from a member here on Endless-Sphere? The great thing about this is that you can use standard shifters. No proprietary shifter needed like SRAM's equivalent, SRAM 3x7 IGH hub. PM me for the ES member's SN if you want to get one.
But first,
Perhaps consider an IGH (internal gear hub) from Sturmey Archer in the rear that's cassette compatible. You can match that with a geared hub motor in the front. This is my thought for my next setup until Sturmey Archer or SRAM come up with electric IGH's that are cassette/disk brake compatible for a full stealth look. Until then, my aforementioned setup might be a good thing for you. You'll be able to climb any hill with ease and the motor won't really have to be that strong. You'll have plenty of climbing capability with the IGH and cassette alone. Electrified, it'll be a bonus.
MY CURRENT BENT TRIKE SETUP IS A CLIMBING MONSTER:
My bent trike's got a Sturmey Archer CS-RK3 IGH in the rear matched with a 11-34T 8-speed megarange cassette. Combining this with a three chain ring setup in the front, 22/32/42, it's got 72 gears (overboard, I know), but allows me to get gear inches down to 8.9 on a 20" drive wheel. That pretty much means if trees were tall enough, I could climb one for hours. I've done something similar on my Aids Life Cycle ride, where I rode from SF to LA over the course of 7 days. I was paranoid about the 545 mile trek and spent a bit over a year and the above setup is what I came up with. No regrets. The hub itself is about $115. The expensive part was having the wheel custom laced by a shop since I don't really know how to do that stuff myself.
By improving the bike's drivetrain capabilities, you can rely less on the motor and therefore extend the use of your juice. With a cargo hauler, I assume you're going on more extended rides than the rest of us. I really recommend the above setup for that purpose. My trike's 45 lbs and it has no motor and no battery. It's heavy, but it certainly doesn't feel that way with the replacement drivetrain.
The best part of the IGH setup is that you don't sacrifice high gears to improve high climbing ability. Implementing this internal gear hub means you can up your high gears as well. You can check my trike blog for gear inch tables I made. If you're not much of a gear head and don't really care, just know that I went from a 76GI high to a 98GI high. It laymen's terms, that just means I can speed down hills faster than before.
PERFECT WHEN MATCHED WITH A MOTOR B/C:
1. Often times, the motor may not be strong enough to propel you at high downhill speeds. Gravity and momentum can be faster than motor speed. It's basically useless in this situation. An IGH will give you extra top gears for you to go faster. I rarely spin out going down hill on my trike. Unless I'm low 50mph (which I have, but don't recommend), there's always resistance which means you continue to have a high enough gear to bring you down hill at speed.
2. As I already mentioned, low gears are super important for uphill climbing - especially on a heavy weight bike such as yours. The motor should theoretically last long b/c you won't be using it as hard. The new drive train can do the work. Again, you can extend it's range by not utilizing as much (since the IGH when engaged in overdrive can drop all gears for improved hill climbing ability.
BENEFITS OF AN IGH SETUP:
1. Improves low gears for hill climbing
2. Improves high gears for hill descents
3. Perhaps lighter b/c you won't need as heavy duty of a motor to get up hills. The hub I have is about 3lbs.
4. Depending on exactly how you do this, you might break even or actually save money.
5. By improving your ability to climb hills by modifying the drivetrain, you won't need to rely on the motor. This will extend your battery range for sure.
6. This also means that if your motor/battery/controller craps out on you, you're still very capable of climbing hills
7. It's just plain cool. Not many people have IGH's or know what they are.
8. IGH's allow you to change gears at a stop. It pretty much raises or drops your entire gear range by a certain percentage. No more need to worry about forgetting to downshift when coming to a rest.
CONCLUSION:
I would recommend an IGH for most applications, but it's definitely not for everyone. If you're a downhill racer on a carbon fiber road bike, that extra 3lbs amounts to a lot! However, it's perfect for folks like you who are already hauling weight and hill climbing is already difficult. Two reasons NOT to go through this setup:
1. If you calculate the difference in a smaller motor size w/an IGH vs a larger motor w/o an IGH and the numbers don't make enough sense. Ask yourself how much more you'd be willing to spend to get the extra edge.
2. You don't need range on the ride.
3. If you can already take hills easily and slopes really aren't that big of a deal, then an IGH would be a waste. I can't imagine this is the case for you though b/c if you're looking at getting a motor, I'm assuming you're looking for some sort of needed assistance compared to what you have now. Those that don't have high grade slopes should do w/o the IGH. The extra money and weight aren't worth it. For you though, I'd definitely get an IGH, hands down.
---------------
DESIGNINGYOUR DRIVETRAIN:
I've laid out in my trike blog how I recommend designing your drivetrain with an IGH charts and all that fun stuff, but I can sum it up here.
The smaller the front chain ring, the easier it is to climb. The larger it is, the faster it will go down hill. But how small should your smallest chain ring be? And how large should the largest one be?
I found the easiest way to use a 3 internally geared hub is to use neutral for flats and only engage the underdrive or overdrive for downhills and uphills respectively. This makes it easier to know when you should be using what. Same with the front chain ring. Middle is for flats, small is for uphill and large is for downhill. Not everyone uses it this way, but it's ideal for me b/c it's simple and there's a rule to it. Plus, it's easier to explain to someone taking your ride for a test spin.
Step 1: Ride your bike now and determine what gear you need to start from a dead stop. Often times this will not be the first or second gear. Most likely it's the third or fourth gear that can comfortably get you going from a standstill. The idea now is to raise everything up so that you're in neutral of your IGH, in the middle chain ring and can start off from a stop at first gear of your freewheel/cassette (smallest cog). This way, when you engage the IGH to under drive, all cogs on your cassette/freewheel (speeds) can be used for the purpose of going downhill. Same for overdrive and uphill.
Step 2: To achieve this, you need to know how much bigger to make your chain ring. The easiest most objective way is to convert everything to gear inches or GI's. Sheldon Brown's website has a useful calculator for this. The reason you want to do this is b/c different combinations of front and rear size teeth can amount to the same GI. GI is a consistent way to do comparisons. So do the conversion and find out what GI you want/need to start from a stop in the above setup.
Step3:Plug into Sheldon's calculator different chain ring sizes to see what you get. It'll pretty much be trial and error to see what chain ring works for you.
THANK YOU:
This is sort of my thank you thread. I came from bentrideronline where I don't think anyone knew about the Flybikes Cobra sausage tubes for rear wheels that you guys had discussed here on Endless-sphere. I figure bringing info back and forth from one forum to another that is lacking can help a great deal. I've learned tons here and was looking to donate to the forum but Justin Le said there isn't anything set up at the moment. For now, this is my thank you contribution. I hope someone can take advantage of it and build a kick-@$$ ride.
