Bicycle Mechanics - The pedals fell off my bike - not how you think; please help

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.




cliffbar
11-15-10, 07:28 PM
Earlier tonight I got on my bike (moderately crappy old road bike that I got at a bike show a few years ago; I mostly just use it to get to and from class) and started pedaling to find that my right pedal was sliding off. I stopped, and the platform part of the pedal had somehow become separated from the shaft that it rotated around, which was still firmly attached to the crankarm. After riding for another minute or two, the same thing happened to the other pedal. I tried to keep pedaling but it was a nuisance, so I removed both pedals and was able to pedal with just the "shafts" and no platforms. It doesn't seem like there's any way that the pedals can be reattached.

Here are a few pictures I took with my phone. The balls for the pedals' bearings are sort of falling out, too.
http://img263.imageshack.us/img263/7776/20101115202249.jpg
http://img264.imageshack.us/img264/4501/20101115202206.jpg
http://img264.imageshack.us/img264/3582/20101115202220.jpg
http://img269.imageshack.us/img269/7400/20101115202242.jpg

When I first got the bike I took it to a store to see if I could get new pedals, but the guy said that I had a nonstandard size and that he couldn't do it. Should I try taking it to a different shop? Should I just suck it up and ride it as it is? Is there some way to get these back on?

Thanks


fietsbob
11-15-10, 07:35 PM
Go and get another pair of 1/2 inch pedals, that is the size you need with your one piece crank .
Put the others in the metal recycling bin, they are scrap.

remember pedals are threaded in opposites , if you put the pedal arm pointed ahead, the wrench pointed back towards the rear
you will loosen them ... 1 right hand and the other left hand threaded.

cliffbar
11-16-10, 05:21 PM
Which dimension on the pedals does the 1/2 inch specify? I want to measure it to make sure to get the right size.

Thanks


fietsbob
11-16-10, 05:50 PM
It's the thread that holds the pedal into the crank itself . 1/2" x 20 tpi

there are 2 standards for bicycles 9/16" .. and 1/2"


One piece Cranks as you show in the picture is requiring the the 1/2 inch type pedal.

a pair of pedals has 1 right hand threaded pedal and one left hand threaded pedal

CACycling
11-16-10, 05:51 PM
The threads on the pedal spindle that mate with the crank arm. Three piece cranksets typically use 9/16" and one piece cranksets typically use 1/2". Remove the pedal axles from the crank arms (remember that one side is left hand thread) and measure those threads. Replacement pedals should not be difficult to find you just need to make sure you get the right size.

JanMM
11-16-10, 05:53 PM
1/2" is the diameter of the hole in the crank arm. Also the diameter of the pedal axle.
You have a choice of 1/2" or 9/16".
Your style of crank takes 1/2".

cliffbar
11-16-10, 08:55 PM
Should I order the pedals online (where would be good for that?) and install them myself or take it into a bike shop?

Dan Burkhart
11-16-10, 09:01 PM
Should I order the pedals online (where would be good for that?) and install them myself or take it into a bike shop?
Pedals of that nature are cheap. Why not just go to the LBS, buy the pedals and have them install them?
Lots of bikes get dragged into bike shops with stripped threads in the cranks from botched attempts at pedal installation. Then, the job gets a bit costlier.

wrk101
11-16-10, 09:06 PM
You can buy that size pedal at Walmart cheap. Should take a couple of minutes to replace.

BikeWise1
11-16-10, 10:28 PM
You can buy that size pedal at Walmart cheap. Should take a couple of minutes to replace.

The Walmart ones are cheap plastic crap. I'm pretty sure they don't even actually have bearings on both ends. Spend a little more for metal ones at the LBS. They'll last way longer and not be just more landfill fodder.

DannoXYZ
11-17-10, 01:00 AM
Should I order the pedals online (where would be good for that?) and install them myself or take it into a bike shop?Well, you can get some decent pedals (much better than the original ones that broke) from numerous sources. Here's two online sources for the same Sunlite BMX pedal in 1/2" thread (also sold as M-wave brand):

Niagra Cycle Works $12.99 (http://www.niagaracycle.com/product_info.php?products_id=20134)
Walmart $8.00 (http://www.walmart.com/ip/Alloy-BMX-Pedal-1-2/13012249)

Both are the exact same pedal with alloy body, chromoly axle and adjustable ball-bearings. I don't see a need to spend more than that for replacement pedals as costs starts accumulating and can easily end up more than what it would take to buy a complete used bike.

Then follow this Park Tool guide on replacing pedals (http://www.parktool.com/blog/repair-help/pedal-installation-and-removal-pw-3-pw-4-pw-5-hcw-16).

http://www.niagaracycle.com/images/jbimages/41557.jpg

dabac
11-17-10, 03:12 AM
1/2" is the diameter of the hole in the crank arm. Also the diameter of the pedal axle.

'Scuse the nit-picking, but - no. That'd make for a crude axle-and-bearing, but not for a threaded interface. There won't be any material overlap for the threads to grasp on to between a 1/2" hole and a thread with a 1/2" outer diameter . The hole in which you can cut a 1/2 thread will be a tad smaller, as will the easiest measurable diameter be even after the thread is cut.

truman
11-17-10, 08:02 AM
Man, I wish I had a nickle for every summer-vacation mile I put on my brother's yellow 10-speed with one pedal and one spindle. Especially the miles I rode with Anna, the Swedish foreign-exchange student... [/reverie]

Doohickie
11-17-10, 08:56 AM
I would go to the LBS, buy the cheapest 1/2" spindle pedals they have, and a pedal wrench. That way you'll be able to change pedals out whenever you need to.

fietsbob
11-17-10, 08:57 AM
RE Plastic It could be called a self bushing pedal, just like common shimano derailleur pulleys, which have no bearings,
and rotate hundreds of times for each pedal rotation.

for just getting the job done a nylon on steel bushing is not the end of the world. ..

Doohickie
11-17-10, 09:59 AM
I have plastic pedals on my commuter, not sure what's inside them, and I've been riding it for over two years and they're fine.

hotbike
11-17-10, 10:14 AM
I haven't seen those kind of pedals in YEARS! We called them "Rat Trap" pedals.

You should get the alloy kind, that Dannoxyz showed in his reply.

As for *both* pedals falling off within minutes of each other, somehow I suspect vandalism.
Maybe precise "planned obsolesence"? These pedals were made in like, 1978, and the engineers designed them to both break at the same time...

You didn't spray WD40 on them by any chance , did you? Sometimes the WD40 melts the gummy grease that is holding things together.

ColonelJLloyd
11-17-10, 10:59 AM
If you're not interested in upgrading to alloy pedals just go to an older LBS. I suspect they have boxes of old "take-off" parts and will likely give you a pair of pedals if you buy a tube or two.

Please support your LBS rather than going to X-Mart to buy your bicycle related items.

cliffbar
11-17-10, 12:01 PM
You didn't spray WD40 on them by any chance , did you? Sometimes the WD40 melts the gummy grease that is holding things together.
Hah, they'd been getting pretty squeaky so I sprayed on some WD40 about a week ago. I think I'm better off without the pedals than with them and the amount of noise they were making...

Anyway, if I want to upgrade to pedals with some sort of toe cage what'd be my best bet? Still the LBS?

CACycling
11-17-10, 12:27 PM
You'll typically buy the pedals, cages and straps as seperate items. Going to your LBS will ensure you get everything compatible.

JanMM
11-17-10, 06:24 PM
'Scuse the nit-picking, but - no. That'd make for a crude axle-and-bearing, but not for a threaded interface. There won't be any material overlap for the threads to grasp on to between a 1/2" hole and a thread with a 1/2" outer diameter . The hole in which you can cut a 1/2 thread will be a tad smaller, as will the easiest measurable diameter be even after the thread is cut.

Let me re-phrase that as "approx. 1/2" hole in the crank arm". As opposed to "approx. 9/16" hole"