ciclista_pazza

Do people here recommend pedal adapters? I want to use Lambda MKS pedals but they are 9/16" and my Schwinn Le Tour requires 1/2" pedals. When I talked to the bike shop guy, I told him how disappointed I was when he said I couldn't use the Lambda pedals on the Schwinn. So I"m not sure why he didn't just recommend pedal adapters. Are pedal adapters not a good idea for some reason? I found these on Amazon - https://www.amazon.com/Alta-Bicycle-...ct_top?ie=UTF8 - and it looks like they would work.

This would totally solve my problem and allow me to use the pedals I want, but I wonder if there is some reason pedal adapters would not be advisable? And how do you know if you need a 21mm or a 27mm adapter (like in the Amazon listing)?

FBOATSB

They are also called pedal extenders or "knee savers". I use them on all my bikes because of my wonky knees, not just because of thread mismatch. They come in 9/16 X 9/16 as well. They work fine for me.
If you just need them for pedal adapters get the shorter ones.

frogman

They look like a good solution to me. I would go with the shorter 21mm adapters. The adapters extend the distance from the cranks to the pedal, no sense in making this distance
any more than necessary.

JanMM

Surprised that a 1980 LeTour would have a crank requiring 1/2" pedals. Must have been replaced a time or two since new.

jaxgtr

A lot people don't like them because they create a larger q factor. When I started riding, I was much heavier and they helped me have a much smoother pedal stroke, but as I lost weight, I found I did not need them. But like FBOATSB mentions, they are fantastic for peeps with bad knees. I also believe some of the bent bikes use them as well.

FBOATSB

I was somewhat puzzled by this as well. I'd like to see a pic of that.

ciclista_pazza

Below is a picture of the crank. I'm not sure if you can see enough here to tell. By the way, the serial # is SA996596. Is there any way to look this up? I saw one forum thread said the last number is the last digit of the year so now I"m curious if this is really not a 1980 model.

ciclista_pazza

Thanks! This is good to know!

ciclista_pazza

I figured out that with my serial # being SA996596, that this looks like it was made in 1979 rather than 1980, at least per what I found here https://www.schwinnbikeforum.com/SLDB/serial.htm

CrimsonEclipse

So adapters are fine, but why not replace the crank arms?

Or drill out the holes and tap in new threads?

ciclista_pazza

I don't know much about this. Are those the wrong cranks for the 1979 model? Is it better to have new crank arms than to just use adapters? And is something like this - https://www.amazon.com/CRANKARM-CRAN.../dp/B079YB8RQW - what you're referring to?

ofajen

Personally, I prefer a narrow Q-factor, so I would replace the cranks if there are no good pedals with 1/2” threads. But a wider Q-factor is better for some, so YMMV!

Otto

SkinGriz

I thought only Ashtabula (1 piece) had 1/2” pedals?

CrimsonEclipse

Kind of.

Depending on bike model, the threads of the crank and pedals are opposite on each side.
So facing the bike, you will need to turn the pedal shaft (to loosen) clockwise on the right side and counter clock wise on the left side.
So you would need two different taps.

There are rare exceptions to this rule so definitely check.

so:
https://www.amazon.com/20-Right-Left...75N48H1S&psc=1

rumrunn6

over the years & w/ several pedals, I've experimented w/ pedal extenders to accommodate my big winter boots. keeps them from hanging off the outside edge of the pedals



but I take them off for the summer. I've used them w. summer shoes & they're OK, but it's a little weird because I sometimes find myself looking for the best foot placement

I just don't need them w/ regular shoes

I think you will be happier w/o them
sounds like a better fix is changing the crank arm. btw I rode lots of old bikes & the pedals also fit my more modern bikes. so sounds like a crank arm swap is a possibility?
cpl more pics from a seasonal pedal swap (w/ some Rock Bros. MTB pedals)



always helpful to have a narrow pedal wrench

for winter, I would rather use wider pedals left>right but when cos. advertise wide pedals they boast about front>rear width, which in my mind isn't width, it's length

FBOATSB

That's a Sugino Super Maxy just like on my '81 LeTour. There is also an Asian serial number decoder here: https://www.bikeforums.net/classic-v...ber-guide.html in the C&V forum.

dedhed

Again, remove the existing pedals and check the threading. A 3 pc crank is normally 9/16" threaded.
​​​​​​https://velobase.com/ViewComponent.a...0-517af51c2817

Chuck M 

Did the bike shop guy actually look at your bike or did he assume that because it was an old Schwinn it had a one piece crank with 1/2 threads? Because IMHO the replies here suggesting you remove the existing pedals and check the threads are better than what the shop guy gave you.

JohnDThompson 

That appears to be an aluminum crank arm. I'm not aware of any aluminum cranks that use 1/2" pedal thread, but it's a big world out there. If it is actually 1/2" pedal thread, check for a bushing in the pedal eye. If there is no bushing, the arm could be reamed and tapped for a standard thread pedal.

The problem with pedal adapters, besides the increased "Q-factor" mentioned by others above, is that it creates a longer lever arm for the pedal, which can increase risk of crank failure at the pedal eye. This is particularly a problem if your pedaling style tends toward "mashing" rather than spinning. That said, my wife has been using pedal extenders on her bike for years, to increase the Q-factor, and has yet to see a problem. But she's not a "masher."

alcjphil

I agree with this. The chances that this crank needs a 1/2" pedal are vanishingly small

ciclista_pazza

Thanks for the replies! I'll see what I can find out. If this will allow 1/2" pedals as it is, that would be great. If not, I'll probably get replacement crank arms as suggested rather than the adapters.

ciclista_pazza

I was really hoping my bike was made in Japan, but I read this page yesterday - https://www.schwinnbikeforum.com/SLDB/serial.htm - where it implies that if it was built in 1979 and made in Japan, there would only be one letter at the beginning of the serial #, being in either the 1st or 2nd position, but since mine has two letters at the beginning (SA996596), I'm guessing it was made in Chicago. Mine is on the left rear axle hanger.

That site says:
"The 1979 Chicago built Le Tour and Super Le Tour models had their Serial Numbers on the left rear axle hanger and began with an 'S', followed by the standard letter/number scheme. Bicycles from Japan will have Serial Numbers located on the left, rear axle hanger, on the bottom bracket shell or on the lower section of the headlug. The number will have a production month letter in either the first or second position and a production year number in the other (first or second) position. Examples: J677123 = September, 1976.

The Chicago Serial Numbers consist of a letter representing the month of manufacture, a number indicating the last digit of the year (1960 - 1964; 0=1960, 1=1961, etc.) or a letter indicating the year(1965 - 1979; A=1965, B=1966, etc.), followed by a sequential series of five or six digits (e.g. A367584 or CB77584)."

alcjphil

I thought that your OP indicated that you wanted to use 9/16" pedals

ciclista_pazza

Actually, after reading my reply above I became confused again on the serial # issue. I wish I could just type it into a database and find out more details. It's such a puzzle to figure out.

ciclista_pazza

Yes, but I was told by the bike shop that my bike could only handle 1/2" pedals. That was the reason for my confusion. Based on replies here, I'll take it in to see if they can check to be sure what it really is.