How Do You Manage To Pedal At High Speed?

[Lyen]

I have upgraded my motor & controller & battery a couple days ago. Last night I rode my new setup to work & back between San Francisco & Brisbane city in California. I have noticed pedaling at 33MPH is hard to balanced due to higher speed and wind in addiction to going over pot holes and rails. My typical speed before the upgrade was between 20-25MPH with a MAC 600W motor + 33V DC9360. Now I am somewhere between 25-33MPH with a MAC 750W motor + 48V LifePO4. The crank gear ratio on the bike is capable of going up to 41MPH. So my question is how do you guys pedal & balance at high speed while controlling the throttle at the same time?

 

[dogman dan]

I thought this was about the gearing being too low for pedaling at 30 mph. But high cadence pedaling does take some getting used to. Most of my life I just pulled huge gears with brute strength at low cadence. Then Lance showed me the beauty of high cadence riding. At first I could harldy do it, but now it seems natural. Just ride till your body catches on. You do get real set in the groove with a particular bike or car or tool. But a bit of practice and it seems like you always used the thing.

If your bike has no suspension, I found that above 15 mph I find shocks help a lot, especially with the extra weight of the battery and motor. FS of course, does open a whole new can of worms for battery mounting and stuff though.

 

[Little-Acorn]

I installed an 11-32 7-speed rear cluster from www.sdelectricbike.com. Now I can crank at MY cadence (that is, slow) at 30mph.

Problem solved.

 

[Lyen]

I installed an 11-32 7-speed rear cluster from http://www.sdelectricbike.com. Now I can crank at MY cadence (that is, slow) at 30mph.

Problem solved.

I apologize if I have misleaded & confused you. My cadence/RPM ratio gear is fine for to up 41MPH. What I meant was when I ride at high speed my body will sway left & right causing me hard to balance on a straight line. My bike is a 2007 Dahon Cadenza with aluminum triangle frame with 700c/25 rims/tires and no suspenion of any kind.

 

[mrzed]

Sounds more like bike fit and possibly riding style than anything else.

Your fit from seat->pedals could be off. Or you may just need to learn to ride smoother (no offense intended). Swerving left and right means you're centre of gravity is probably shifting all over the place - this could be the result of a seat too high or low, too far back, or any number of other things. There are plenty of fit guides online, or bike shops can help you.

Other thing that helps is clipless pedals - I doubt many e-bikers use them, but by allowing you to pull the pedal through the entire stroke, it can really smooth out your ride, especially at higher cadence. Also requires a learning curve.

Of course, over 40mph is also pretty fast. I've only ever done that on a bike down long grades and my recollection is that things can get pretty squirrelly on little road bike tires. How does it feel when you are not pedaling at the same speed?

 

[RTLSHIP]

What you have is about 52 tooth front sprocket and 11 teeth in the rear cog
(i.e. a higher gear ratio)?. Both my bikes have one 40 or 44 tooth front sprocket and require an unreasonably high pedaling after 23-25 mph. It's probably not too safe too be pedaling at higher speeds, especially in bumpy conditions.
Control over bike is more important than top speed. top speed is just for testing.
Based on theory and experience, pedaling (with e-power) is most practical in acceleration/take-offs, and up hills.
Presently, I mostly use the pedals w/ throttle when accelerating. This saves energy.
Also, I try to make a habit of being ready to pedal through intersections because it's dangerous to overly rely on battery and motor. Easy pedaling is essential for take-offs.
It makes little or no sense to get up to 30 or 35 mph on elec power and vigorously pedal assist, unless you are in remote areas with smooth roads etc.

 

[dogman dan]

Hell, even with my 58 tooth front and 14 rear my cadence would be pretty fast at 40 mph. On other bikes that only have 48 -14 the pedaling gets cartoon fast by 30 mph, but I won't go faster that that on a bike with a weak frame. I find most bike frames start bending around a lot once you get above 30 mph or so, untill you get into really strong (heavier or more expensive) frame designs. So you may have a problem of both things, difficulty keeping the pedaling smoooth at higher cadence and and body movements causing the beginings of a high speed wobble.

Practice a smoother riding style, and if the frame is wobbling, upgrade the frame or limit your speed to what the frame can handle. I'm building a new commuter right now, on a stronger frame with better suspension to be ready when my 48v battery arrives.

 

[Dingo2024]

just a thought.....take a look at the saddle height...dropping it by only a couple of mm's can be enough to stop your hips rolling when spinning fast

Ian

 

[JennyB]

What you have is about 52 tooth front sprocket and 11 teeth in the rear cog
(i.e. a higher gear ratio)?. Both my bikes have one 40 or 44 tooth front sprocket and require an unreasonably high pedaling after 23-25 mph. It's probably not too safe too be pedaling at higher speeds, especially in bumpy conditions.
Control over bike is more important than top speed. top speed is just for testing.
Based on theory and experience, pedaling (with e-power) is most practical in acceleration/take-offs, and up hills.
Presently, I mostly use the pedals w/ throttle when accelerating. This saves energy.
Also, I try to make a habit of being ready to pedal through intersections because it's dangerous to overly rely on battery and motor. Easy pedaling is essential for take-offs.
It makes little or no sense to get up to 30 or 35 mph on elec power and vigorously pedal assist, unless you are in remote areas with smooth roads etc.

At that sort of speed (unless you are very fit) the amount of power you can generate is offset by the extra drag of all that leg-flapping, and you might be better off just tucking and gliding. Perhaps the guys with more powerful ebikes could test that theory and report back - at what speed does pedalling make no further improvement in top speed?

As for position, you have got it about right if you can ride "hands-off" with your heels on the pedals. The classic ways to achieve a smooth pedalling style are to ride rollers or to ride fixed (no freewheel) - especially downhill!

 

[mabman]

I have noticed pedaling at 33MPH is hard to balanced due to higher speed and wind in addiction to going over pot holes and rails.
My bike is a 2007 Dahon Cadenza with aluminum triangle frame with 700c/25 rims/tires and no suspenion of any kind.

If I was heading for a pot hole or railroad tracks at 30+ mph on 25c tires, an aluminum frame and no suspension I would be more interested in the brakes, not the pedals. For that type of speed, conditions and the extra weight of your motor battery system you would do well with some tires that have lots more volume.

 

[dontsendbubbamail]

Sounds more like bike fit and possibly riding style than anything else.

Your fit from seat->pedals could be off. Or you may just need to learn to ride smoother (no offense intended).
quote]

I think mrzed is correct. One way to learn to ride smooth is to get a set of rollers. Get the kind that have straight drums and do not dip down in the middle. You have to ride smooth in order to say on them.

Bubba

 

[NeezyDeezy]

At that sort of speed (unless you are very fit) the amount of power you can generate is offset by the extra drag of all that leg-flapping, and you might be better off just tucking and gliding. Perhaps the guys with more powerful ebikes could test that theory and report back - at what speed does pedalling make no further improvement in top speed?

As for position, you have got it about right if you can ride "hands-off" with your heels on the pedals. The classic ways to achieve a smooth pedalling style are to ride rollers or to ride fixed (no freewheel) - especially downhill!

yeah

 

[Lyen]

I have figured what my problem is. The 48V10AH LifePO4 battery is mounted above the seat level. It was mounted too high so a tiny swerve would cause the bike lose its balance and more pronounce at higher speed. I have then lower my seat-post rack and the issue seems to be less. My next think is to find a way to mount the battery inside the triangle frame or creatively find another suitable mounting location. Thanks you for all your comments.

 

[dogman dan]

Ahh yes, the rest of the story. I have just switched my commuter setup to a different bike. The new frame seemed substantially stiffer than the cheap wallbike I've been riding for 5,500 miles. But as soon as I put all the panniers on the stiff bike, I found I had the same frame wobble as before.

Oh well, I suppose I really need a cargo bike but for now I do try to pedal smooth so I don't start the wobble. I keep the speeds at 25 mph or less.

 

[amberwolf]

@dogman: IIRC, your panniers have no frame behind them that ties them down to keep them from wiggling horizontally, right?

If you create a frame that does this, and tie them to it even if just with bungee cords wrapped all the way around, it should help minimize any "sloshing" of their mass, and that'll help tremendously with the wobble.

This is one other reason (aside from theft deterrence) I opted for the metal boxes on my CrazyBike2, since they won't wobble with the stiff frame they're bolted to, as long as I have the contents packed to prevent movement.

 

[amberwolf]

@lyen: You should take a look at my old DayGlo Avenger side-panel / cargo pod. Even with just the one pod on the left side, since it is stiffly mounted to the frame and it is very low (box centered around axle) it does not wobble around while pedalling, even with heavy cargo in it under pedal-power-only.

IIRC from the pic showing the flashlight battery mounts, your bike is a hardtail so you have no problem with fastening things directly to the triangle frame.

If you take some flat pieces of metal, draw lines on them matching your triangle's stay tubes, cut slits on either side of where the tubes would be, and use hose clamps to secure the flat metal to the stays, you can then bolt anything you like on the flat metal and it won't shift around or bang into the wheel or get caught in spokes.


Here's what I did, to replace a set of old wire baskets, which wiggled around lots, and were not theft-resistant at all.
View attachment 9
I started with an old discarded rackmount networking box, which had big aluminum rack ears:

I took the ears off and clamped them to the bike frame:

and drew lines on them to mark where the frame was behind it.

The first time around I drilled holes to bolt directly to the frame, and that ended up a bad idea. Cutting slits parallel to and either side of the frame lines, and putting hose clamps thru and around the frame works much better.

The other side I clamped to the frame and set a piece of flat metal across the top to line it up with the first side I did:

Note that I left the rack ears themselves facing outward, so they could also be used to later bolt a plate to for above-the-wheel storage.


Those pics show the cargo pod itself attached, which later got a lid with a lock, as seen in the pics below, which also show how much cargo could fit stably on top of it, plus about that same weight inside it, at least.