Vintage Crankset Restoration Quandary

[Caj Remtiw]

I have a few pair of VERY rare vintage (like from the earliest days of the first mt. bikes) cranksets that I am refurbishing to sell. They are all in really good shape, most never assembled much less ridden. With some buffing "love" they will look like NOS.

So here is my quandary... They are tandem arms! You know right crank arms with left hand pedal thread & left arm with right thread! I have a very good local machine shop that can drill out the pedal threads and re-tap them for the correct thread Heli-Coils. I have no doubt they will turn out perfect!

So if in my ads, if I explain in detail and show close-up pictures of the cranks... Do you collectors think they will be well received or will I get "monkey-dung" slung at me?????

 

[klunkrider]

You have front and rear seats or only the front?

If you have front and rear then surely selling as a complete tandem set is going to get you the biggest return.

My guess is that you’d realise about as much for a front set modified for ‘normal’ use as you would for the front half of a tandem set without the rear. Ie, not very much.

If you have front and rear and modify the fronts, what do you do with the rear set that has two ‘driveside’ cranks? Nobody’s going to buy them by themselves.

 

[Dr Dremel]

There will be some deduction pricewise, no matter what you do. The question is if you´ll get the machine shop costs back if you sell them rethreaded. That´s a difficult question, as there are simply not many examples.
Personally I wouldn´t bother to Helicoil them. With symmetrical pedals (for instance XT 731) they´re perfectly usable as they are.

 

[Caj Remtiw]

Thanks for the replies guys.

I have several pair of tandem sets and some regular arms of the particular era (40+ years old). My goal is to restore as many "ride able" sets as possible. Along with that, tandem bike collecting does not have anywhere near the following that single bikes do.

As for machining, my buddy will gladly trade me the work for a couple of bit and pieces of vintage parts I'll be releasing soon. Regarding price reduction, I doubt that will be an issue because the stuff is so rare that collectors just can't find this age of parts anymore.

Thanks again for the input!

 

[hamster]

Personally I wouldn´t bother to Helicoil them. With symmetrical pedals (for instance XT 731) they´re perfectly usable as they are.

Except that the pedals will generally unscrew themselves and then mangle the crank.

 

[Dr Dremel]

Except that the pedals will generally unscrew themselves and then mangle the crank.

Yeah I know the mechanic principles, but has that actually ever happened? Also: Loctite is yor friend.
That being said: If there is no concern regarding profit and he can get the work done properly, there is no reason not to rethread them, is there?

 

[Ren Rawbor]

There will be some deduction pricewise, no matter what you do. The question is if you´ll get the machine shop costs back if you sell them rethreaded. That´s a difficult question, as there are simply not many examples.
Personally I wouldn´t bother to Helicoil them. With symmetrical pedals (for instance XT 731) they´re perfectly usable as they are.

And in the case of asymmetrical pedals, not a huge deal to swap L and R axles between bodies. Most pedals contemporary to the cranks likely need regreasing anyway that said, if helicoiling them is economical then no reason not to.

 

[Caj Remtiw]

I got the arms retapped and hopefully over the weekend will polish them, then they will up for sale!

Thanks again all of you for your input!

 

[Walterscot]

Correct me if I’m wrong but they look like they’re simply Specialities TA Cyclotouriste cranks. Used on early mountain bikes including the original Stumpjumpers because there was nothing else available to provide the low gearing required. A quality crankset undoubtedly but not that rare as they were a go-to for touring bikes (and tandems) from the early 1960. Still plenty of them around even now. Probably not that many unused sets knocking about to be fair.

https://velobase.com/ViewComponent.aspx?id=19692c31-4452-4c95-aa38-f7da41cdbafa

 

[Caj Remtiw]

You are 100% correct!

I just posted a picture of one of the vintage "Klunkers"in my collection. The American made crank arms that I was/ am speaking of were originally for BMX and the company that made them produced a spyder to take the TA rings (VERY RARE). Honestly the first Mt. Bike specific cranksets ever made.
I am sorry for the confusion!