Need help with drivetrain selection...

[cruzer]

Shopping for first ebikes and looking for some feedback, especially on some of the new drivetrains available.

I live in SoCal in the foothills, close to the beach with a 4000' mountain range behind. Unless cruising the beach everywhere we go has hills. I'm in my 50's, and have the need for speed of a 24yo adrenaline junky and the knees and back of a 70yo I grew up on dirt bikes, but I'm not a strong peddler.

I think we will use the bike something like: 40% roads and paths, 5% beach at low tide, 25% fire roads and 30% trails and single track. I'm 6'-2' and 205#, wife 5'-8" and 135#
We will live within the capabilities of whatever we buy, but if we can find strong hill climbing bikes there are some incredible rides nearby.

Given my weight, bad knees, hilly location, and budget I think the Bafang m620 setup is the way to for me, but:

- Concerned about the durability of the derailleur and cassette with the torque of the m620....how have drivelines been holding up with with mid-drives? Does the "pause while shifting" feature help? I don't mind upgrading to a better derailleur chain, cassette after 500 or 600 miles (i.e. alibaba bike) but I wouldn't want continuous problems, or failures far from home.

- Wondering if my 135# wife could get away with a geared hub drive ?? I'm a gear head/engineer this is really easy on machinery, but she is more of a gear grinder on uphill climbs. (I assume direct drive is out?..unless looking at 5K-10K watt "enduro" bikes with huge batteries) If it's best to stay with mid-drive, thats fine...she will learn fine and we'll just keep the derailleur adjusted, etc..

- The new Gates belt drive looks promising...if they can get an IGH to hold up to the m620 torque. Does anyone have much experience yet with the Sturmey-Archer RX-RK5, or other IGH and M620 yet?

- Given my beat-up back and occasional sand and sandy trail riding, I'm thinking fat tire & full suspension bike is the way to go. Hoping the comfort and stability of the fat tires will make up for the loss of efficiency. Is that mistake? Do the 4"+ tires add too much weight for trail riding or sacrifice too much performance?

- This is not one of my main hobbies (and buying 2 bikes) so i think the upper limit on price is +/- $2500 each. i.e something like the upcoming Sondors Rockstar.

- I have a business account on Alibaba and have looked at tons of bikes there . Seems like I could find something in the $1600-$2100 range + shipping, but I'd gladly support a US marketing company if I can find something in my range (i.e. Rockstar). I'm comfortable buying on Alibaba, especially if I can trace one of the well respected "US brand" back to the original manufacturer, or get a recommendation for a trusted manufacturer from the forum. I can do all of my own set-up and repair.

- FWIW, I won't work over a US supplier for info and/or try and set up a demo ride, only to buy direct from china..that's just not cool. So I will be doing lot's of research and probably buying sight unseen, so really appreciate any feedback this forum can offer.

Thanks to all!

 

[AHicks]

Direct drive is out for sure!

With the big hills, you might get away with a bigger gear drive (750w+) for the wife if she's not going to be up for the need to keep a mid drive in the right gear. I think that's what I would do for my wife for the same reason.

Hearing mixed messages regarding the gear sensors.

Regarding tire size, the 3" wide tires are a good off road compromise, but for a hybrid that will be on the pavement most of the time, tires in the 2-2.5" will often work well.

4" are about ride, flotation over soft surfaces, and traction. Bikes on pavement are a tough call regarding the available ride, don't need flotation or traction. Also to be considered are the noise levels.

Not big on rear suspensions here, but I have a hundred pounds on you. Just consider the best suspension is going to be junk unless you can get it set up for your 'druthers. I'm fine with a good suspension seat post.

 

[CdnShaun]

Hey there cruzer, welcome to EBR.

Just some thoughts to help you with what you are seeking. For quick reference I'm 6'0, 270#, early 40's and have a small fleet of ebikes to compare to for you.

-95% of what you are looking for works perfectly with a bike having 50-60mm (1.9" to 2.35") tires that can be mounted on 26", 27.5", 29" and 700C size rims. The 5% that these tires do not do well in is beach sand.

When I go to the beach or ride in snow (up here in Canada) I take out the 3.8" to 5.0" fat tire bike. These bikes can also work well on rough dirt trails but (assuming with some decent knobbies) do not ride well on pavement for extended periods.

I have a road going bike with 50mm tires on 700C rims that handle the smoothest of roads up to rough/worn roads, fire roads and single track. If I'm only going on trails I will take my mountain bike with 50mm tires mounted on 27.5" rims, more so for the front suspension and handlebar installed, and yes I'm lucky to have multiple bikes to choose from.

-adrenaline junky = need for speed. Most fat tire bikes (OEM and conversions) have only a 36T chain ring up front and limit you to 20mph spinning at 100-110 rpm cadence. If I'm correct on you having a need for speed make sure you do the math on the chain ring(s) you are considering to know what your cadence/speeds will be.

www.bikecalc.com is awesome for this type of quick calculation and review.


-I currently have a total riding weight (bike, batteries, tools, fluids and rider) of 400lbs when I go out for long rides. My 500watt/50nm Bionx D500 rear Direct-Drive motor moves me along as fast as I want and I can climb 14% grade hills - this is in reference to your consideration of options for your wife.

A geared hub will have even better climbing ability with her overall riding weight.

Geared hubs are awesome for off the line torque and up to a target speed (depending on the motor), direct drive hub motors do well off the line (see my stats for example), have better top end speed and longer range as they are more efficient at higher speeds.

-Mid-drive versus Direct Drive/Geared Hub Motors - no wrong answer here. This can be as much as personal preference as technical reason to choose one over the other. I started out and will be staying with Direct Drive motors in my fleet for these reasons:
-If I break a chain I can still get to safety, possibly home (throttle all the way) without having to walk.
-If I break the motor I can still get to safety, possible home (human only power) without having to walk.
-Longest range per Wh from my research
-Quietest riding experience when compared to geared hub motors and mid-drives (yes both categories have improved a lot the last few years).

Even for yourself a hub motor (geared or DD) might be a better fit for you, something your research will clearly flush out. Either way, you will love the ebike life.

-Last thought/suggestion. OEM vs conversion. Each year we are seeing more and more amazing OEM options on the market. I suspect within the next 2-3 years I will purchase my first OEM bike to have and enjoy.

If you do want to consider a conversion approach, what you gain is you get to purchase the bikes that are best for you and your wife and then add the ideal motor/battery/controller/display setup to it. Yes the conversion approach is not as 'clean' looking as OEM (but can come close with a little effort) and does require more up front effort -

but you get exactly what you want, easily upgrade down the road in the years to come and can be much less costly to repair/replace elements that wear out over time. Food for thought.

Cheers!
Shaun

 

[cruzer]

Thanks for the replies guys...

Was thinking hub drive for out for my weight, but do wonder what kind of grade I could conquer with a 750watt-1000watt hub drive? Or maybe even 1000-1500 watt direct drive?

We don't plan on taking rides much longer than 20-25 miles, so I could live with shorter range and higher powered hub.

I had been leaning towards fat bikes, for cushier ride, and more stability on the some of the sandy trails we ride..but Shaun brings up an interesting point about conversions. I have a like-new 15 year old Jamis Dakar full suspension MTB I could use as a donor. It was probably a near entry level MTB at the time, but I'm guessing (and its just a guess) that the Shimano Deore XT components and Mavic rims are better gear than the $2500 e-bikes i've been looking at?

Question still remains if I go the conversion route...rear hub motor, or mid-drive (most likely BaFang BBSHD) ?? Simplicity of the hub-drives appeals, but think we could get to some cool places if we had assisted climbing ability.

Haven't been able to find much about the ride drive Gates belt + Sturmey-Archer RX-RK5 combo yet...maybe still too new?

 

[KLamond]

Hi Cruzer,

The one thing I can comment on is the fat tire ebike, as I've just got one and have done several rides on it. I found that the fat tire ebike works fine on a variety terrain. You get a bit less mileage out of the battery, but it works just fine. I've done street, gravel, and a little off-road with it and it handled all of it just fine. Now my bike only has a front suspension, but it with the fat tires I wasn't missing the rear suspension.

The fat tires do add weight, especially if you get one with mag wheels, but it will still be quite capable for trail riding.

As for speed, I found the gear ratio of the top gear is the limiting factor when it comes to speed. I can't comfortably pedal fast enough to go past 23 mph on my bike. Several times I found myself wishing I had a higher gear I could go to for a little more speed. Now if you are building your own, you can set the gearing however you like.

My weight is close to yours and the 750 watt hub drive does fine for me, even on hills. With the assist level at 3 out of 5, I found myself passing some non electric bike cyclists on hills.

 

[AdilDesai]

Take a look at Watt Wagons. They are a little out of your price range, but all the components that you're asking about can be found on their bikes. If you do go mid-drive, then the new Archon X1 controller is a must.

In the midst of my research, someone on the forum pointed me to their bikes, and after doing a lot of research, I ended up buying one.