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Messages - handlebar

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1
General Chat / Re: RAD CITY 5+ HANDLEBARS
« on: March 27, 2024, 05:31:12 PM »
Before derailleurs were common, handlebars were typically high enough to stand and pedal. Derailleurs had enough gears to maintain 20 mph or faster, but that required leaning low to reduce air resistance. Leaning over for low bars put too much weight on the hands, so seats were moved forward. (Schwinn moved seats forward in 1932 for another reason: to make their bicycles look more like American motorcycles.)

Moving the seat forward meant the knee was bent more sharply with the pedal at top dead center, and you can't pedal very well with a knee bent more than 90 degrees. As a result, riders don't typically apply much torque except between 2 and 4 o'clock, viewing the right pedal. That limits the power they can apply per revolution. It's also inefficient. On each revolution, the knee has to move up and down 14 inches, while the ankle has to move 14 inches up and down and 14 inches back and forth, all to apply torque for 7 inches.

It was proved in 1885 that if you move the seat farther back (maybe 12 to 18 inches behind the bottom bracket, depending on the length of the rider's legs), you can get a much longer power stroke by starting it at top dead center. You have to lean forward somewhat to concentrate your weight over the pedals, but if the bars are perhaps  ten inches higher than the seat, you can lean forward without putting much weight on your hands.

A lot of English bikes were designed that way before 1900. In 1930, Raleigh made a documentary proving it also worked for children. A man with a 28" Raleigh bought his 10-year-old daughter a 26" model. In those days, English children didn't ride, so she spent a couple of days learning. Then they pedaled over some high hills to a town a hundred miles away. She was interviewed in her nineties. She said that instead of getting a ride back, they pedaled a hundred miles home the next day.

My Radmission had similar geometry to a Radcity. I bought a layback seat post and heated it with a propane torch to bend it more, to get my seat back far enough for my legs. Cantilevered so far back, the post needed support. I cut a plywood triangle of the desired height. I put a notch at the top for the post and two at the bottom for the rack. I raised the post, put the support in place, lowered the post, and clamped the post. The rack and the post lock the support in position. I used not one but two risers to raise the bars enough for stable, comfortable riding with the seat back.

This greatly improves my hill climbing, and it's much more efficient than standing up. Standing on the pedals entails moving a lot of body weight up and down.

2
I didn't like the stock tires on my Rad City 5.  When I would take one hand off the handlebars I would feel a light front end shake/wobble.  I changed to the schwabe marathon e-plus and they cured te problem.

I guess I lucked out. My OE Radmision tire is a CST 50-584 with no model number on the sidewall. It's the same ERTRO size as the Schwalbe Marathon E-Plus, but Schwalbe rounded it up to 2.00 inches, and CST rounded it down to 1.95.

My Radrunner was so unstable that I got tennis elbow keeping it straight with my right hand when I took my left hand off the bar to signal. In this case, it wasn't the fault of the tires but of the seating geometry. After I changed that, I could ride without touching the bars. In case the unexpected happened, I'd keep a thumb and forefinger looped around each hand grip, without contact.

3
I didn't like the 20 x 3.3 tires that came on my Radrunner. There wasn't much else available for those rims.

I've run 1200 miles on the 27.5 x 1.95 tires that came on my Radmission. I replaced the tubes with ones less porous. The tires have been okay. If I need new ones, I'll go to Modern Bike for their online listing of what's available in that diameter and approximately that width.

"Stretching" is usually how chains wear out. It's really a loosening of pin joints. A gauge to check is pretty cheap, but I use a digital caliper. I just checked one. First I checked roller diameters: .300 inch. Then I rolled the pedals to put one straight out in front and laid a board on it to put a bit of tension on the chain. Then, on the top run of chain, I measured across as many rollers as possible with my 6 inch caliper: 5.786. Links are nominally 1/2 inch, so that was 11 links plus an extra roller. So I subtracted 0.3 inch to get the length of 11 links with 11 rollers: 5.486.

A link is nominally 1/2 inch, so 11 links would be 5.500 inches, but chains are often manufactured undersized to have more allowance for wear. Many say 0.5% too long is okay. That would be would be 5.528 inches for 11 links. Most say a chain should be replaced if it's 1% too long. That would be 5.556 for 11 links.

When my bike "skips," it's not the chain but the derailleur. The lower wheel on a derailleur is the tensioner. The upper wheel is the guide. It should be adjusted so that the guide wheel lines up perfectly with the cog wheel for the gear you select. Adjustment instructions depend on what derailleur you have. They're online.

4
General Chat / Re: Rad Power Bikes New Model Discussion 2024
« on: March 07, 2024, 06:40:32 PM »
I like the changes to the Radwagon. 20" tires, front suspension, hydraulic disk brakes. Also it does not come with the semi integrated batteries. Maybe in a few years a used RW5 could be a viable replacement for my trusty RW3. I just hope they have improved on their welds and their wheels have proper spoke tension out of the factory.
Let's see how the quality holds up over the next years. I never buy new and particularly never by new model releases until any teething problems have been addressed.

From the frying pan into the fire! Those tires were why I offered to give my Radrunner away. (The guy wouldn't accept that, so he offered what amounted to 15% of what I'd put into it. Glad to get rid of it!)

I think maybe it's not possible to make a 3.3 inch bicycle tire with a diameter that small that will be strong and quiet and handle well and smooth bumps and have low rolling resistance. There's not much available for those rims.

I bought an Aventon Abound with 20 x 2.4 tires. In comfort, handling, and rolling resistance, they performed much better than the 3.3 tires but they were no better in puncture resistance. Lots of tires are available for the narrower rims, so I quickly switched.

You can vary the RadWagon seat height by 11 inches but the handlebars not at all. What were they thinking? The Abound handlebars can be moved about 6 inches without tools.

5
General Chat / Re: Rad Power Bikes New Model Discussion 2024
« on: March 06, 2024, 07:26:56 PM »
I honestly haven't taken a deep look at the new models as I just found out about them the day before release. Here they are though: https://bit.ly/3InDL2E


In the video, every rider has the saddle set too low for proper leg extension. It's as if Radpower doesn't take bicycling seriously. That may explain why no model has adjustable handlebars.

6
General Chat / Re: Rad Power Bikes New Model Discussion 2024
« on: March 06, 2024, 11:24:54 AM »
Oh, hey - RadWagon now with 20" x 3.3" tires, instead of the oddball 22".

The smaller diameter gets the passengers or cargo a little lower to be easier to manage and safer. Using fattish tires somewhat defeats the purpose.

I hated those 3.3 inch tires on my Radrunner. The manual said less than 30 PSI would be unsafe. A tire that wide at that pressure rode hard on bumps, and less pressure meant significantly more resistance and poorer handling.

Besides, there aren't many 20" tires for rims that wide. I would have had to lace on new rims to use better tires.

7
I am looking to buy a new rim for my rad ebike. Where can I find same rim or one I can use

I've never bought a rim. Three criteria are the number of spokes, the diameter, and the width. Most wheels seem to use 36 spokes. The diameter needs to fit the bead of the tire will use. The width of the rim has to be suitable of the tire you will use; I've seen a chart of what rim widths work with what tire widths.


8
Service & Repair / Re: Radcity 5 plus bike - lights don't turn on
« on: March 04, 2024, 06:39:20 PM »
I have the same issue with a RadCity 5.  The bike comes on, but the lights will not come on.  The brake light does light up when using the brakes and the lights flash for .5 seconds when the bike turns off.  Has anyone been able to determine what part is going out on all these bikes?  Mine is out of warranty and I can't afford to buy a bunch of parts.  Thank you!

The best thing for the back is a 3" reflector,  just below the seat, for $1 or so. You can't count on a rear light, but reflector will work if the overtaking vehicle has headlights. For the front, I mounted a $35 rechargeable handlebar light. It's bright. The display shows what percent is left.

9

Did you find that graph somewhere, or is it from your own set of measurements?

I'll bet it's from his own measurements. I don't have equipment to record charts, but I can estimate current by monitoring watts. In an unbalanced battery, some cells are less charged than others. Imbalance will lengthen the tapering as the lower cells catch up. Today I charged my Radmission battery for the first time in 16 weeks, in which I've ridden it only 30 miles. The charged tapered pretty steeply to about 1 watt ( a few milliamps ), showing that it had stayed pretty balanced.

10
Wife?s Mini has started to fail to turn on unless the key is inserted, turned all the way to battery lock release, then back to on. Once it is turned off at the handle bar switch or timed out due to inactivity, it will not turn on unless you cycle the key again.
Any ideas?

I believe your bikes use the same kind of battery. I'd swap batteries to see what happens. That's cheaper than buying a new controller and being wrong!

11
Service & Repair / Re: Bottle thrown at me + wheel issue
« on: March 04, 2024, 05:38:49 PM »
Maybe the bottle knocked the caliper out of line. If it seems to be the caliper, it can be removed with two screws to see if the wheel spins freely. If it's the caliper, I'd screw it back on, loosen the screws half a turn or so to allow movement, reach through the spokes with a 5mm hex bit on a shaft 6" long or more, and tighten the brake adjuster just enough to lock the wheel.

IIRC backing off less than a quarter turn should let the wheel spin freely. If it drags, the caliper may be bent out of line.

If it spins freely, I like to apply the brake by tying the lever to the handlebar, then tighten the mounting screws. If you then untie the brake and the wheel drags, that, too, could mean the caliper is bent. If it's bent, maybe it can  be straightened. Otherwise, Amazon has replacements. The mounting screws on the replacement have to go in the same direction as on the original caliper. (My front and rear calipers are not interchangeable because they aren't mounted the same.)

12
Pride & Joy / Re: Folding Rad Family Fotos - Sackville, NB
« on: February 27, 2024, 03:40:21 PM »

I was disappointed to see that the LCD dims when you look at it through polarized sunglasses, but cranking up the backlight level helped. They should be able to make one that has the polarization angle 90o from how it is now, since sunglasses are all polarized to the same angle.

How does your smartphone screen look through your sunglasses?

13
RadMini / Re: Replacement wire harness, controller for 2018 Mini
« on: February 21, 2024, 10:55:18 AM »
I don't remember how to turn the headlight on with an OEM Rad controller. With my 25 amp controller, I hold the UP button 4 seconds. An indicator appears on the display, and the headlight comes on.

14
RadExpand / Re: RadExpand 5 bike repair stand?
« on: February 20, 2024, 07:31:45 AM »

Quote
Another is to put the center stand on a cement block.
I thought about that too, but it seemed precarious.



I know. I tried it to change my back tire on my Abound. The axle resisted being shoved back into the dropouts, and I pushed the bike off the stand. Lashing the front brake would have prevented that, but I learned it's better to invert the bike. When it's upright, you can't see both dropouts at once, and you're fighting gravity.

I like to check tire pressure with the valve at 6 o'clock, where I get the most clearance and pushing the valve open won't roll the bike. This entails getting down on my knees and getting back up. So far I don't have an elevated surface for pressure checks

15
RadExpand / Re: RadExpand 5 bike repair stand?
« on: February 19, 2024, 05:29:37 AM »
I have three approaches. One is to get the stuff on the handlebar out of the way and turn a bike over. Another is to put the center stand on a cement block.

The third is a quarter-ton chain hoist, which I bought 6 months ago to put a riding mower on blocks for under-deck maintenance. I put a massive eye bolt through a 4 x 4, which I rested across rungs of a Little Giant ladder set up as an 11-foot a-frame. I weighed an ebike that way. For maintenance, it might work better to hang the hoist from a rafter or a board across rafters. Ropes could prevent unwanted swinging.

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