Author Topic: Spokes wearing out after 2500 miles.  (Read 2095 times)

handlebar

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Spokes wearing out after 2500 miles.
« on: July 02, 2022, 06:42:11 PM »
About dusk I took a screwdriver and spoke wrench out to the garage in case my spokes needed tuning. The front ones sounded fine, but the back ones sounded a little loose. One sounded especially dull, and it curved where it crossed another spoke. Another spoke was the same way. Tightening the nipple didn't increase tension, and I saw the problem.

At the J end, the flare had worn or broken off, allowing it the slip through the hole in the hub. It was getting dark, so I didn't check them all. There may be more than two that have popped through. The sound of the others makes me wonder if they're all on their way to popping out.

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 seem to need 130mm 12 gauge J spokes. The ones I've seen are shipped from China. Not knowing how soon I could have a catastrophic failure, I'd like to replace bad spokes in the coming week. Where can I get replacements?

Tony

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Re: Spokes wearing out after 2500 miles.
« Reply #1 on: July 03, 2022, 12:55:37 AM »
I had the same problem with one spoke on the rear of my mini 4 that I replaced awhile ago. Thanks for the reminder, I will check the others.

handlebar

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Re: Spokes wearing out after 2500 miles.
« Reply #2 on: July 03, 2022, 04:36:47 AM »
I had the same problem with one spoke on the rear of my mini 4 that I replaced awhile ago. Thanks for the reminder, I will check the others.

Does yours use hard-to-find spokes? I ordered 36 from China: lead time 3-5 weeks.

I checked this morning. Only two have pulled out. They are alternate spokes on the right, meaning they pull the rim aft and toward the right. Replacing them may bring up the tension on the rest. That may help them because I understand that inadequate tension increases metal fatigue because of greater changes between relaxation (at the bottom) and tension (at the top). I understand that it's after you break a third spoke that catastrophic failure looms.

I guess I'll have to remove the tire to replace such short, stiff spokes. Maybe I'll replace all 36 while I'm at it.

Tony

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Re: Spokes wearing out after 2500 miles.
« Reply #3 on: July 03, 2022, 05:25:51 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.

handlebar

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Re: Spokes wearing out after 2500 miles.
« Reply #4 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.

handlebar

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Re: Spokes wearing out after 2500 miles.
« Reply #5 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.

Rad Power Bikes Owners Forum

Re: Spokes wearing out after 2500 miles.
« Reply #5 on: July 03, 2022, 07:19:16 PM »