Multipurpose mountain e-bike for mixed use?

rdkaz

New Member
Hello everyone:

A 65 year old casual weekend warrior needs some e-bike selection assistance.

I live in N, Georgia; and occasionally ride on unpaved mountain Forest Service roads; and steep paved paths.
In addition, I like to bring my bike on vacations to explore the cities. My body says its time to get some electric assistance.

I have spent days reading and watching the e-Bike reviews on this website; educating myself. The information contained here is excellent!

Based on my research, it appears a mid-drive full suspension; capable of city touring fits the bill.
The bikes I am considering include: Focus Thron Impulse, Felt DualE, Lapierre Overvolt FS, Haibike Xduro FS RX, Grace MX II; and hardtails of the same brands with a seat post suspension; to save money. Based on the reviews, these are all excellent bikes.

The #1 bike for my needs seems to be the Focus Thron Impulse. It is also the most expensive. I would love to fine a lower cost version; without too many compromises. Hopefully you can offer some suggestions.

The hardest decision for me is whether to choose a pedelec or a speed pedelec. I have read about the legality issues of over 20 mph; but don't want to be short sited; and wish I had purchased the speed pedelec.
Unfortunately, I can't find any e-bike dealers in the Atlanta area; that have the e-bikes in stock. Based on my
planned uses; your suggestions are appreciated.

Secondly, If I choose a hard tail; I may have to settle for a 250 watt motor instead of 350 watt. Will they get me up mountain hills? How well does the seat post suspension work?

Another consideration is the amp hour rating on the battery. The Focus bike seems to have the advantage here by a wide margin.

Other less important considerations include the ability to attach a water bottle, bike rack; kick stand and lights.

Any other comments and suggestions are welcome.

Thanks.
 

Mike leroy

Active Member
Do you know the steepness in percent grade? Every 2.5% increase from 5 to 20% is significant. A center-mounted motor will generate more torque. The minimum speed is crucial. Wobble speed is 9mph. You will need a wide gear ratio, e.g., 400-500% above 10% grade.

The best way to understand motor power requirement is to acquaint yourself With Strava bicycle rides. I believe you can obtain the ride wattage from racers on Strava.

Torque, rather than Watts, is your relevant measure for hills. The tipping point is above 10% grade. Roughly, 5Nm per percent grade.

5oNm should be ok to 10%, depending upon total weight and desired speed. 15% and higher, above wobble speed (9mph) for 200 pounds will require at least 90Nm of torque.

Suspension will affect endurance and comfort. If you need a rear rack, a hardtail is the better choice.

Over 25mph, you reach the point of diminishing returns due to wind resistance. The battery will drain faster. You start paying heavily above 25mph and 48V is better. My personal choice is 20mph, 48V.

The choices you list are all good and expensive. My personal approach is to start with the battery, the weakest link in the system. You will need to replace the battery is a few years. The proprietary batteries are unjustifiabialy expensive. My bias is towards 5 year time frame, so a 48V battey is my bias. 36V are common, but will be old tech in 5 years.
 
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rdkaz

New Member
Mike:

Thanks for the advice.

I am not sure of the hill grades; but the bikes I am considering offer 60 - 70 Nm of torque; and 36 volt batteries. Can the OEM batteries be replaced with 48 volt batteries. Do you know of other bikes to consider?

Thanks.
 

Mike leroy

Active Member
Mike:

Thanks for the advice.

I am not sure of the hill grades; but the bikes I am considering offer 60 - 70 Nm of torque; and 36 volt batteries. Can the OEM batteries be replaced with 48 volt batteries. Do you know of other bikes to consider?

Thanks.
No, 48v used on a 36v will fry the controller (computer connecting bAttery and motor).

What is the start and end point of your steepest ride? I can tell you the grade.

I need to know the distance, grade, desired speed and total weight, before I can give you any kind of accurate advice.

Do you have any idea of a target heart rate, I.e., how hard you want to pedal? did you know some bike motors can be controlled by a heart monitor? I believe the Kahlkoff offers a heart monitor.

You could limit your rides to less than 10% grade. Estimating 5Nm per percent grade will work in a very general sense. Any of the bikes will work.
 
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Mike leroy

Active Member
How stealthy do want to be? I prefer the bike to more concealed, like the Volton Alation. I think the 48V, 500W option at $2600, is a better value than the bikes you listed. Note you need to go their web site to find the 500W option. It probably is 90Nm.


I have a hard time with so much detailed text. I prefer star plot diagrams to illustrate the Cost-Benefit ratios. I rated Thorn Benefits as 2.8 and Volton 500W as 3.7 on a scale from 1 to 5. I rated the Cost-Benefit ratios as 0.6 and 1.8, respectively. Diagramming took all of two minutes.

Thorn.png
Volton500W.png

http://electricbikereview.com/volton/alation-mid-drive-350/

Georgia law is like Calif. http://en.m.wikipedia.org/wiki/Electric_bicycle_laws#Georgia

I would ask about 48V x 20A = 980W, if the hills are very steep. Also ask about a torque sensor, to ease gear shifting. 8Fun advertises one on their web site.

Gear shifting is less smooth. I would ask about an internally geared hub option, like Rohloff 14, but that adds $1400.

https://voltonbicycles.com/
 
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