Old dura-ace crank
#1
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Old dura-ace crank
Hello
In the mid 1990's I bought a univega road bike for $200 andd have since ridden the wheels of the bike. I would like to continue riding it.
When I bought the bike I noticed that a threaded insert had been screwed into the pedal holes in the cranks that apparently reduced the hole size from about 9/16 to about 3/8. I'm guessing this is so a more modern pedal could be installed.
The other day I was riding and noticed the left pedal was loose. When I attempted to tighten it back into place I noticed the threads on the insert had been damaged and would no longer allow the pedal back into place. The bike shop told me there was nothing they could do with this and told me I would need to either buy an older crank with the smaller hole in it or find a new insert.
I have 2 questions. The first one is, what are these threaded inserts called? The 2nd question is, are these inserts threaded with the lefty tighty right loosey deal like left pedals?,,,,,,any suggestions are welcome,,,thanks in advance
In the mid 1990's I bought a univega road bike for $200 andd have since ridden the wheels of the bike. I would like to continue riding it.
When I bought the bike I noticed that a threaded insert had been screwed into the pedal holes in the cranks that apparently reduced the hole size from about 9/16 to about 3/8. I'm guessing this is so a more modern pedal could be installed.
The other day I was riding and noticed the left pedal was loose. When I attempted to tighten it back into place I noticed the threads on the insert had been damaged and would no longer allow the pedal back into place. The bike shop told me there was nothing they could do with this and told me I would need to either buy an older crank with the smaller hole in it or find a new insert.
I have 2 questions. The first one is, what are these threaded inserts called? The 2nd question is, are these inserts threaded with the lefty tighty right loosey deal like left pedals?,,,,,,any suggestions are welcome,,,thanks in advance
#2
Insane Bicycle Mechanic
A picture would be nice, but I'm guessing that you have Dura-Ace "Dyna Drive" cranks. These had an extra-large hole for a special pedal. Shimano also sold a reducer so standard size pedals could fit, and your best bet would be to hunt down another set. Here's what they look like: https://www.worthpoint.com/worthopedi...pedal-76174296
On the other hand, if the crank took a standard pedal and someone previously fixed it with a Helicoil insert, you'll have to find someone with the special left-hand-thread Helicoils. It sounds like the original one is toast.
Does your crank look like this?
On the other hand, if the crank took a standard pedal and someone previously fixed it with a Helicoil insert, you'll have to find someone with the special left-hand-thread Helicoils. It sounds like the original one is toast.
Does your crank look like this?

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The goofy Dyna-Drive "system" was also used on the regular (non-AX) 7200 series cranks. I was lucky enough to get the weird pedals with my weird crank and finding some of those may be your best bet. Here are some I found on ebay and here appear to be some on a site I know nothing about, though they may be sold out. Good luck.
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Dura-Ace reducer
Hi, Thanks for the input.
I think your dead on with the shimano reducer. I don't have a real critical eye but the picture looks right and yes I'm pretty sure those are the cranks.
So I'm gonna try and buy a set of reducers, got ya. Another obvious question,does that reducer screw in like a left pedal with the "lefty tighty righty loosey" deal? I would think that it does but I ask because I'm having trouble getting it loose so I want to be sure before I put any real force on it.
I'd like your opinion on one other thing. Givin that I'm more of a commuter, I've been looking at getting a cyclo cross or some other commuter type bike. I'm wondering if there's a market for the univega or the parts on it that would help me pay for the new bike? I'm not really dialed into the old bike officonado circles so I'm not sure what's hot and what's not.
Thanks in advance. Happy pedaling
Bradley
I think your dead on with the shimano reducer. I don't have a real critical eye but the picture looks right and yes I'm pretty sure those are the cranks.
So I'm gonna try and buy a set of reducers, got ya. Another obvious question,does that reducer screw in like a left pedal with the "lefty tighty righty loosey" deal? I would think that it does but I ask because I'm having trouble getting it loose so I want to be sure before I put any real force on it.
I'd like your opinion on one other thing. Givin that I'm more of a commuter, I've been looking at getting a cyclo cross or some other commuter type bike. I'm wondering if there's a market for the univega or the parts on it that would help me pay for the new bike? I'm not really dialed into the old bike officonado circles so I'm not sure what's hot and what's not.
Thanks in advance. Happy pedaling
Bradley
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Drive side pedals have right handed threads. Non drive side pedals are left hand threaded - every time. At least, so far and so far, for me, includes thousands of old bicycles...

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^Its Super Randyjawa^
Able to leap stacks of bicycles.
I think we need to all pitch in and get you a cape or a mask or something. Maybe a shop apron with a giant "R" on it.
Thats a great picture. Along with the great work that you do, I think you are a superhero.
You're not one of the crazy bagpipers from Thunder Bay that goes to Applefest in Bayfield Wisconsin are you?
Able to leap stacks of bicycles.
I think we need to all pitch in and get you a cape or a mask or something. Maybe a shop apron with a giant "R" on it.
Thats a great picture. Along with the great work that you do, I think you are a superhero.
You're not one of the crazy bagpipers from Thunder Bay that goes to Applefest in Bayfield Wisconsin are you?
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Nice Pic Randyjawa !!!!any keepers in the bunch ????
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What else would fit?
Well obviously I'm asking my questions in the right place. If I cant find another reducer and I don't want to use the Dyna-drive pedals, what kind of crank will fit in this old bike and get me pedaling again?
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alternative to dyna-drive
Well I've pretty much struck out on dyna-drive pedal adapters. Do any of you vintage bike buffs know what arms i can use in place of these dyna-drive ones?
#12
Insane Bicycle Mechanic
You need new crank arms that take standard pedals. You may need a new bottom bracket, as well. I'm guessing that your BB is 107mm in length, and had JIS tapers. Since you never supplied pictures or told us a model number, this is just a guess.
Your best bet is to buy a new crankset and the proper bottom bracket for it.
Your best bet is to buy a new crankset and the proper bottom bracket for it.
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