Sunday, March 26, 2017

Passage refit part III Crank set


I really should have spent today working on the Passage frame - there are some rust spots to deal with  - but I didn't.  Instead I worked on the crank since I had received all the new rings, the Passage was spec'd with 50/46/30 rings which I wanted to change to 46/36/26.

old up top and new on the bottom
I won't have the top-end speed but I don't need that, I need low end and mid-range that the spec did not have in order to haul my fat-a$$ up the hills.  I did make a mistake on the disassembly of the crank-set.  I didn't take careful notes of how it all went together!

I gave all the parts a bath in the sonic cleaner and although I had a general idea of how it should go together I wasn't sure.  I did some web searching but couldn't find the exploded view I wanted.  I have a shot of the crank which I then magnified and was able to confirm some things about the crank assembly.  Thank you digital photos!

spacer positioning
I did have a few things to do before reassembling the crank, cleaning of course and some polish.


In the photo above the non-drive crank arm has been polished and the spider-arm has only been cleaned.  I was hoping for a more dramatic result but this is where having a garage workshop with a bench mounted grinder/polisher would come in handy.   One of the things I love about the older cranks is the model is engraved in the crank arm, its not a sticker or laser etched.  I also had a part to replace, while taking the crank apart a thin washer escaped and has yet to be apprehended.  You will notice in the photo of the layout of crank parts above there are four groups of 5 parts and one of only 4.  Since this washer is a spacer I needed to replace it, fortunately a washer is pretty easy to find at the local hardware, the other parts wouldn't be.

new on the left
 The replacement is a plumbing washer, not as much flange but I was more concerned with the inner diameter and the thickness.  So to start putting the crank back together we begin with the middle ring and fitting the threaded nuts into the side with the bevel around the bolt holes.


Threaded nut is in place ready to be positioned on the underside of the spider arm.


And this is where the washer is comes in where it will be a spacer between the outside of the spider arm and the outer 46t chain-ring.


And now we are ready to put on the outer ring with beveled bolt holes facing to the outside.


Finally we are ready for bolts to connect the 36t middle and 46t outer chain-rings together.


My special Park tool CNW-1 comes in handy to hold the threaded nut on the underside of the middle ring steady while I tighten the Allen bolts, comes in handy for disassembly too.



Two down and one to go, the granny ring gets the rest of the hardware.  Spacers between the spider arm and 26t chain-ring first.

Then I could position the the small ring on top of the spacers with the beveled side of the bolt holes facing inward (toward the frame).


 And now its all together with the new rings and the crank is ready for the bike to be reassembled.


These Sugino chain-rings are old school with no fancy ramps or pins but I did notice that the 46t and 36t rings have small tabs on the inner part of the ring, since with a more modern chain-ring there is  a pin  you line it up with the crank arm I lined up the tab with the crank arm as well.



I am about 95% sure I have put it back together correctly and now have a record of how it was supposed to all connect.  I won't know for sure if its right until I get the Passage back together and start riding it, if my chain starts falling off or the front shifting doesn't work then I will be back to square one.

I should have another post soon on the other new stuff that I have for this bike and how it compares to the items that came on the bike.  Until next time; Ride. Smile.Repeat.

2 comments:

  1. I am caught up! Good for you to stay with it, I hope it is right!!

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  2. More to come Jim and we'll see how the crank-set works out

    ReplyDelete