tcaraway1

I bought a Colnago that has a billet aluminum crankset (no markings that I can see). The seller tells me it's very high end and rare (I will take pictures tonight.)

Here's what's weird.... he tells me the left side crank arm does not have the standard reverse threading for the pedal. He then proceeded to unscrew the pedal on the left side, and it was in fact a standard right hand thread. It was as though this bike utilized 2 drive side pedals instead of 1 being right hand threaded and one being reverse threaded.

Has anyone ever heard of this? I'm having a very difficult time searching for anything quite like this. I'm also unsure how I'll get pedals for it. I might have to order 2 drive side pedals. But I'm hoping someone here will say "ohhh that's a such and such type of crank, use this search term...."

Thanks for any help!!!

tiger1964 

Tandem?

tcaraway1

It's not a tandem bike. Here's a pic of my dad holding the bike.

fietsbob

Yup. Front crossover drive, the captain's right crank arm has no spider...

Made from the same part as the left single bike crank arm , but for the threading.

the crank is not the original one,

but since a lot of Italian frames Shipped bare, every buyer had to add their own component choices.

Someone chose that crankset and mixed up various parts
from wherever they got them..

Style reminds me of Cook Brothers.. A US CNC machine owning company.
Seat post looks like 'American Classic.'.
Both are closed by now


OK want to change what you have , (Ask a pro Bike shop)
use a pedal thread Repair kit.

Reams out the existing thread cuts a new one larger, then ,

a double threaded sleeve is inserted in this case LH thread..

Helicoil is a similar idea , but a coil, rather than sleeve..

Or just buy whatever new crankset floats your Italophile boat..

Colnago had some Pantographed logo ones if you go on the auction
quest..


FWIW, another user of a same arm with RH & LH thread... single bike..

My Swiss made planet geared crankset, neither crank-arm is directly attached
to the chain ring , because it is made to have the chainring rotate at a different rate from the cranks ..

if arm faster than chain ring that is a reduction gear
as if the chain ring were smaller..

If the Chain Ring rotates faster than the crank , an Overdrive..





..

rhm

Right, the crank for the captain position on a tandem is backwards; the spider is on the left, tapped with a left handed thread, and a plain non-drive side crank on the right side, tapped right handed. The stoker has two cranks with spiders, the one on the left has a left hand thread, the other is normal.

The non-drive side crank on your bike was made for the drive side of a tandem.

You can usually change the axle of a pedal pretty easily, but you'll need right side axles for both sides.

fietsbob

or, in short, just buy a Shimano crank with an Italian thread BB,,

sell the 'rare, valuable' one on eBay.

Salamandrine 

That is a Topline crankset. From the early 90s CNC craze. They were exotic and expensive. He ain't lyin'. They were also crazy light. Not sure I'd recommend riding one if you weigh more than Simon Yates. Cool though. I'd keep them if it's just an occasional rider.

I don't remember anything about right threads on both arms, and I doubt they ever made a tandem set. It may be a prototype crank or something. As mentioned, you'd need to find pedals with swap-able axles. I think if you install the left with some loctite it should be OK. It's also possible the left crank started off as a right crank, and someone removed the spider.

VeloBase.com - Component: Topline Road

unworthy1

even more (probably all there is) on the Topline cranks: Topline Bike Cranks - the Buyer's Guide, 2015
No mention that there was ever a tandem version so I guess it's either a faulty factory mistake (and should have been caught by QC) or as mentioned it could be that somebody re-purposed a RH arm (a misguided idea) but if so you should be able to see the remains of the threading the spider screwed onto and of the "pin" that once locked the spider in place. See anything like this?

Hoopdriver

Nice looking crank.