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Messages - handlebar

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Rad Modifications / Re: 2 x 24" rims on a Radrunner?
« on: July 31, 2022, 06:48:52 PM »
You may need to drill out the spoke nipple holes in the 24" rims. The stock holes for 14g spokes are probably to small.

I hadn't thought of that. The company says they're good for ebikes.
You're right, they don't mention spoke gauge.

I was more concerned about length. Figuring it out for a new rim is supposed to be a problem. After the mistake I made in measuring the OEM spokes, I think I can deal with it.

Online I read that you measure from the threaded tip to the head. I measured 130mm. The ones I got measure 130mm from the threaded tip to the bottom of the bend. They were hard to install because they're too long. The corresponding distance is 125mm on the OEM spokes. I measured 130mm to the head because the 90 degree bends had straightened a bit.

If I knew the thread size, I could get a die, grind the spokes to 125mm, and extend the threads. I guess 130mm will do.

With 30 psi in the OEM tire, bumps can be brutal on my hands. Now I know why motorcycles, and some bicycles, had springs on the front long before they had them on the back. I may replace the font rim first.

Rad Modifications / 2 x 24" rims on a Radrunner?
« on: July 28, 2022, 11:04:56 AM »
My OEM tubes lost air. Months ago, I I bought a pair of tubes the same size. When I mounted one on the back, I got a pair of pinch holes on one side. I thought I'd pinched it with a pry bar. I'd changed a lot of bicycle and motorcycle tires and never done that before. To avoid doing that again, I've been mounting tires without tools. These Radrunner tires fit loosely enough to do that.

I left the OEM tube in the front and continued to add air. When it began losing air faster, I found that the valve core was loose. I know I'd torqued it. I mounted the tire with an aftermarket tube to get a better valve. At 5 psi, I saw that the bead wasn't quite seated at one spot. I deflated the tire and pumped it slightly. I bounced it around.  Finally, I had to use pry bars to get the tube out from under the bead.

One reason for the problem is that the rim is undersized: that is, a 4.00 tube is the nearest size that's big enough. Now it also seems that the tire bead doesn't fit the rim very well; otherwise, with two  layers of tube between the bead and the rim, it would have been much more obvious that the bead wasn't seated.

Lately, I've ridden a bike with 2 x 26" tires at 50 psi. I was amazed at how much more comfortable they were on the rough pavement around here and how quiet they were. They were also easier to pedal at 15 mph, for example.

I think the efficiency difference may be aerodynamic, like the hydrodynamic comparison between a wide ship and a narrow one. The wide ship has to fight high pressure in front and low pressure in back. With a narrow ship, these areas won't be as wide, and the water can more easily move aside in front and close in behind. Similarly, as a wheel speeds up, it may be fighting more pressure as it squishes air in front and more vacuum as it rises behind. A narrower tire may have an advantage.

In inches, bicycle tires are measured by the outside diameter, which makes my Radrunner tires 23". I've got more than an inch of clearance. A 2x24" tire would be half an inch closer to the fenders. I can get a rim for $25 and a set of spokes for about the same. Why not go for it? In that size, I'd have a choice of tires and tubes.

Service & Repair / Re: How do your spokes look?
« on: July 24, 2022, 11:47:16 AM »
Looks like the heads broke off due to defective spokes, or metal fatigue from them being loose and moving. Have the spokes replaced, the wheel trued, and the tension set by a shop. No lube. I have 6000 miles on my RadMini with no spoke problems, but I do check and adjust tension as a part of maintenance.

The spokes arrived. The half-pound package took 12 days to leave China, 3 days to cross the Pacific, and 6 days to cross the US.

I'd measured the old spokes, but the new ones seemed much too long. You have to bow them to fit between hub and rim, to get to the hole in the rim. With such short pieces of 12-gauge steel, that took a lot of force.

Rather than ruin the rim liner, I cut a little hole for each nipple I had to access. Replacing the two broken spokes brought the other 34 pretty well into tune. The broken ones were on the chain side. One on the disk side didn't sound tight enough, and I discovered that it was already adjusted as tight as possible. The head was a bit sunken, so I replaced it.

I covered the nipple holes with little squares of 1mm polypropylene. I put duck tape over the squares to keep them in place and give the tube a slick surface. I put the tire back on, but the wheel on the bike, and gave it a spin. It was out of true. With a stick braced against the chain stay, I found a 6" section that was out by 1 or 2 mm.

After I'd tuned the first two replacements, they had relaxed enough for the spokes on the other side of the hub to pull the rim out of line. Retuning the replacements brought the rim into line. The end of the stick dragged evenly against the rim all the way around.

On the head of the third spoke I'd replaced, not even the enamel was damaged. The diameter is 4.6mm. The diameter of the new ones is 4.9mm. That explained why it had sunk somewhat into the countersunk hole in the hub. The problem spokes were defective in head diameter. All three had J bends that had stretched to more than 90 degrees. It makes sense. If the head sinks too deep, the bend is no longer against the other side of the hub. As the angle increases, the pressure on the head focuses on one side. The explains why the heads had popped off on the first two.

If I hadn't periodically tightened loose spokes, they might simple have loosened and let the others carry the load.

I wish Radpower had taken the trouble to answer my inquiry about replacement spokes.

General Chat / Re: How Many Bikes You Own
« on: July 24, 2022, 10:03:24 AM »
With the drop handlebars, the Sagres riding position was already in a pretty low position. I never used it for sprinting, but the position was good for marathons and long distance. For causal rides I'd use the brake levers for a hand rest, which they were designed for and made it easy to use the brakes with your middle and ring fingers. It's an easy bike to cruise on at 20 to 25mph, and I personally know it was stable at 50mph going downhill, though hitting a bump or pothole at that speed probably would have been fatal.

I've found more than one article about bike fitting. You want the seat as high as possible without straightening your leg so far that you rock your pelvis forward. That's usually the height from which you can just reach the bottom pedal with your heel. Then you check the fore-and-aft position by assuming your riding position with the ball of your foot on the forward level pedal (3 or 9 o'clock, depending on how you view it). A plumb line should show that the end of your knee is above the spindle.

With a laser plumb line, that's exactly what I got with a layback seat on my Radrunner. The Evryjourney also gives me that position. I imagine that's true of your Sagres.

I was in first grade when I began putting in miles on a Jackson. Later, I rode a similar Huffy Sportsman what was also in the family. I was 14 by the time I had $20 to buy my own decrepit looking Jackson, which had cost $10 new. When I got home, my homicidal brother deliberately hit the back of my front wheel with a basketball. I was probably going 10 mph, in high gear. One might have expected the wheel to veer out from under me, and I would be thrown headlong. My riding position was so stable that the wheel didn't deviate noticeably. However, the decrepit fender crumpled, locking the wheel and causing the bike to go end over end. Because of my stable relationship to the bars, as they went down, I could somersault over them, landing neatly on my feet. I like a bike that handles that way!

I guess I leaned forward about 25 degrees, similar to the position on British and German motorcycles in those days. It didn't reduce air drag much. Nowadays there are flat bars with prongs out front so the rider can choose between stability-comfort and low drag.

General Chat / Re: How Many Bikes You Own
« on: July 08, 2022, 04:01:47 PM »
I bought a Radrover 5 in 2020. Still going but I did get Error 25 but after unplugging the brake light is fine. I bout a $1,000 Trek bike a couple months a go as a backup but I'm getting the itch for another bike.

How many and what type you own? How many is to many?


I expect to own two next Tuesday. I bought my Radrunner in December, 2020. It was available, and I needed transportation while I figured out what was wrong with my antique car. I've kept up auto insurance and registration, but biking is so much better that I haven't paid much attention to fixing it.

A few days ago I found that the heads on two rear spokes had broken, allowing them to come out of the hub. Other spoke heads had sunk into the holes, meaning they were on the way to popping loose. I've read that it's fairly common for rear spokes on an ebike to break because the big hub means they're shorter than the front, and that means they pull at greater angles from a radius. This would be especially acute for a Radrunner due to its small rim diameter. However, spokes almost always break at the elbow or the threads. When they fail at the head, it usually means defective spokes or a bad hub design. I'll go with hub design. The Bfang hub probably wasn't intended for the small rims that Radpower chose.

Like the tires, the spokes are an oddball size. I couldn't find any except in China, with a lead time of several weeks. I contacted Customer Service three days ago, and they have ignored me. Radpower is not a good company. I'm reduced to walking so maybe my bike will still work when I absolutely need it.

So I ordered a Six Three Zero. More than one expert has said that if you want a good ebike, start with a good bike. Would anyone want a Radrunner without the motor? The company started in 2007 when the CEO, at 15, built an ebike in his garage. When a kid does that, I call the result a toy. Six Three Zero started in 2005 when several enthusiasts began building bicycles in a garage.

The CEO says theirs aren't fast like road bikes or tough like mountain bikes, but his cost less while meeting the needs of a typical rider very well. That sounds like Henry Ford; as he developed his designs, others were marketing impractical toys for the rich. It wasn't until 1913 that he could begin bringing the price down drastically. By then, his car was known to meet consumer needs especially well. For bicycles, Six Three Zero accepts returns for 365 days. I guess that shows confidence in customer satisfaction.

The CEO says he never even rode an ebike until 4 years ago. That's like the Wright Brothers, developing a good glider before building an airplane.

Their advertising is largely for women. That's good. Women don't want bikes that are toys. Considering the amount I have spent trying to make my Radrunner suit my needs, I'd say I've had an expensive adventure with a toy. Two bikes is too many for me. Ebikes have little resale value. I think I'll give my Radrunner to a neighbor. For some time, he and his wife have been getting by on one car. Before then, he used to say he envied me because my Radrunner looked like so much fun. He drove a Stryker in Afghanistan, and I haven't met many combat veterans in the last 50 years. A few weeks ago he got laid off and landed a great job 2 miles away. I guess a Radrunner can go that far.

General Chat / Re: How Many Bikes You Own
« on: July 08, 2022, 01:04:13 PM »
At the moment, just three. A RadMini GT, a vintage Fuji Sagres 12 speed I used to use for tours and marathons, and an old folding bike called the Roll and Go which I've been mulling over discarding. The RadMini gives me either the most exercise or the least exercise, my choice 😉

I found photos of Fugi Sagres 12 speeds. In one, the seat looks remarkably far aft for a racer. Lately I've read that a racer's seat is forward so the rider's pelvis will be tipped forward. That way, when he's leaned way over to reduce his profile, he can produce more power because he won't be so sharply bent at the waist.

April 12, 1980, the delegates to the USOC met in Colorado Springs and voted 1604 to 797 to boycott the Olympics. My brother was there training with the bicycle team. I was saved from the lifelong humiliation of being reminded that he'd raced in the Olympics and I hadn't. I visited him five months later. He challenged me to a race to a restaurant 10 miles away. I knew the roads. It was almost a straight shot on 4-lane highways where the limit was 45. The few traffic lights were timed so traffic on main roads wouldn't have to stop much. Traffic was light. It was a breeze on my 57 hp motorcycle. He beat me.

Before motorcycles, I'd ridden A B Jacksons. Under the law, a bicycle wasn't a bicycle unless the dealer assembled it. An A B Jackson was a Raleigh imported as a box of motorcycle parts to avoid the prohibitive tariff. I used to average 15 mph whether or not it was hilly, unless there was a headwind. On level ground I could do about 30 in a burst. I could coast downhill at 45 with rock steady handling.

On the racer it amazed me that we kept up with traffic on 4-lane roads marked at 35 mph. Part of it was lower air drag, and rolling resistance was incredibly low. (Fixing a puncture required sewing and cementing.) The riding position was new to me. It steered and pedaled OK, but I didn't like it. It was hard to monitor the road behind me. With my weight so far forward, I could be unstable in an emergency.

That had happened to him as he rode 300 miles home from visiting somebody. He could do that in a day, but this time an oncoming car crossed the centerline to force him off the road. He went down on the shoulder and got cut up. On my Jackson I would have stayed in control.

Service & Repair / Re: Brand New Bike- 3 Burst Tubes in 24 Hours!
« on: July 06, 2022, 09:37:53 AM »
One other thing to check is if there is a loose piece of polyester in the tire itself.  I had a road bike get random punctures for about 3 months I finally took the tire off and lightly rubbed a cotton ball over the inside of the tire and found a very very slight loose fiber (Kevlar in this case) that caused punctures after about 6 miles on hot roads.  Put a Slime Glue patch on it and the tired lasted the rest of its life.

Whenever I get a flat with a tube set up (most of my bikes are tubeless) I always do this test.

With my Radrunner, I would get punctures so small that I might not see bubbles if I submerged the inflated tube. I finally found the culprit by marking the drive side of the tire at the valve and marking the drive side of the tube so that when I found the leak in the tube I'd know exactly where to look in the tire. I saw a little discolored spot. I thought I felt something but couldn't grab it with tweezers until I pushed it by inserting a wire behind it. It was a wire as fine as window screening or a human whisker. When I reached for calipers to measure the diameter, it fell off my finger and disappeared. Something that fine would have bent or broken rather than go through my tire lug, so I don't know how it got there.

I got my first real flat after 2500 miles. I was surprised that something with so little head hadn't simply been knocked down. For the first time, I noticed how thin and flimsy are the OEM tires on my Radrunner. A combination of low pressure and thin construction can allow an object to push a dimple in a tire, and then it can penetrate instead of being knocked down. In my days with 1-3/8 x 26 tires, they weren't this flimsy until they were worn bald, and then I was vulnerable to flats. The only tires available for the Radrunner's oddball rim size have 30 threads per inch. I've read that this can make them vulnerable because there's more space between threads for an object to make a dimple.

General Chat / Re: Getting old
« on: July 06, 2022, 08:50:19 AM »
Your body forms a tripod on the bike, but the bike still only has two points of contact with the ground. I've never had a low speed stability problem with mine, but maybe it's the combination of the geometry and the individual?

The Radrunner has two entirely different geometries. In almost all the youtube videos, riders demonstrating Radrunners, including the CEO, ride them as scooters, with the seat about 30" high. A man's shoulder would be about 10" higher than the bars, making a stable tripod. My seat is at 40", typical of a man's bicycle, so I can pedal. That tripod was horribly unstable.

About 1970, I met a biker whose friend had lengthened the frame of a BMW R-60 to accommodate a VW engine. Dressed in leather, he'd accelerated to 100 mph when violent wobbling threw him off. I don't think he was hospitalized, but he broke at least one bone in tumbling. Left with two points of contact and no destabilizing load, the bike straightened out and coasted down the road almost to a stop before tipping onto its cylinder heads, undamaged.

Ideally, hand grips should be even with the steering axis. When one hand moves forward, the other moves back, and your upper body stays in position relative to the bike. His bars swept back to accommodate the long frame. Steering left entailed moving both handgrips right. With two points swinging together from side to side, the tripod supporting his upper body was no longer stable.

By the time he hit 100 mph, a slight correction to the left would cause inertia to throw his shoulders right, turning the bars farther left until the bike corrected itself, throwing his shoulders right and building up to violent oscillations. On a poorly set-up bicycle, that kind of thing can occur coasting down a hill. Rider instability is a particular problem at slow speeds because steering corrections are bigger.

RadRunner / Re: Radrunner rake / trail / fork dimensions?
« on: July 05, 2022, 06:31:46 PM »
Thanks, Handlebar! Really appreciate the response.

3cm sounds possible for sure. Is yours the original radrunner with 71* head angle or new "Radrunner 2" with 68* head tube? Wondering if it's the same fork on both...

Mine's the original. Measuring on a photo, the Radrunner 2 looks about the same.

RadRunner / Re: Radrunner rake / trail / fork dimensions?
« on: July 05, 2022, 07:28:44 AM »
The forks appeared to line up with the steering axis, so I would have said 2 cm.

My laser says they don't quite line up. It looks like 3 cm.

I once had an Earles fork where that was adjustable. On motorcycles, we called it trail.

Service & Repair / How do your spokes look?
« on: July 05, 2022, 06:48:03 AM »
On a routine check at 2500 miles, all my rear spokes sounded a little loose, and two had come out. That's the least common kind of failure, and it often results from a defective spoke. Checking the hub, I've found several that are sinking. The photo shows what I mean. The top spoke looks good. The second and fourth are gone. The third looks like it's about to go.

Will lubing the holes and tensioning the spokes help? Do yours show signs of wear?

I don't expect the replacements to arrive for several weeks. That bike is my only transportation. Is a new bike my best bet?

General Chat / Re: Getting old
« on: July 03, 2022, 08:10:11 PM »
I have a Mini 4 , a little over 600 hundred miles since I got it in the fall of last year, Michigan weather shut me down for awhile.
 I have never felt safe on it, balancing is hard at low speeds.  So I took my 25 year old Trek out today,  no problems with balancing, is it larger tires and a gyroscope effect that helps.

I do like my Mini, any low speed turns are not good.

A bull rider has to balance. You shouldn't have to balance on a bicycle with a saddle and hand grips. If they're spaced right,  your upper body is stable on a tripod of your arms and spine. All you have to do is steer.

I believe my Radrunner 1 had a seating position like your Mini 4. My "balance" was so poor that I was an accident looking for a place to happen. I got a bad case of tennis elbow trying to control the bike with my right hand when I took my left hand off the bar to signal.

It was iffy to make a u-turn on an 18-foot street. The problem was instability, not balance. The hand grips weren't far ahead of my belt. My "tripod" was too short for stability. I moved my saddle 7" aft with a layback seat post. With a more stable seating position, I could make u-turns on a 10-foot driveway.

General Chat / Re: Hit and almost run
« on: July 03, 2022, 07:30:37 PM »
Wear a vest like the cop's. Works for me!

Service & Repair / Re: Spokes wearing out after 2500 miles.
« on: July 03, 2022, 07:19:16 PM »

Metal fatigue makes spokes fail, but I've ridden bicycles and motorcycles for decades without a spoke failure. I keep most of my weight on the pedals most of the time, which means the front wheel is loaded almost as heavily as the rear. Maybe the front has stood up better because the spokes are longer.

I've found the difference between my front and rear spokes. The heads of the front spokes stick out of the hub like roundhead rivets. On the rear hub, they're like countersunk rivets. Some are more sunk than others, so I'm afraid a catastrophic failure is looming.

I used to wonder why so many WWII aircraft had their metal skins attached by rows of roundhead rivets, not countersunk. Now I see. With its thin edges, countersunk rivets are more subject to metal fatigue. I don't recall seeing spokes with countersunk heads before. What was Radpower thinking!

They don't sell replacement spokes. I hope my wheel holds together until the boat arrives from China.

Service & Repair / Re: Spokes wearing out after 2500 miles.
« on: July 03, 2022, 07:46:06 AM »
I got mine from eBay here in the U.K. arrived real fast . I didn?t need to remove the tire, just screwed straight in. What bike ? 20 inch wheel. I will try to find the size I boaught.

It looks as if it has the same rims. Was your problem on the front or rear? My rear spokes are especially short because of the motor hub.

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