Wednesday, January 29, 2014

2014-01-29 - Bike mechanics 101 - Part III

I spent some time trying to get the front derailleur of the mountain bike to shift to the big ring. I had no luck until I noticed that I had not pulled the drive side crank arm all the way on. I thought I was finished with the old style square tapered cranks but here we are. They are a pain to work with. They have to be pulled off with a special tool and it is hard to get them seated when installing and if they are not all the way on the resulting free play can ruin the crank hole. After I tightened the crank I was able to adjust the shifting with no problem. I gave it a couple of test rides today and it shifts well and is ready to go:

I re-cabled the road bike brakes several days ago and removed the crank and old bearings. The crank bearing set came this afternoon. I removed the bearing cups from the bottom bracket shell which was much easier than expected and took the drive side bearing race off the crank which also was much easier than expected thanks to copious Liquid Wrench. I washed the pound of dirt out of the bottom bracket shell and cleaned up the crank and rings and am ready to install the new bearing set and crank:

Old and new cups and bearings (just a touch of rust):

Crank installed:

Chain cut to length and installed (note the reflective sidewalls on my touring bike tires in the background):

Derailleurs cabled and first test ride completed:

I will spend some time tomorrow attempting to adjust the shifting. I expect it to be difficult as there are no adjusters on the shifters or derailleurs (I think). Modern bikes have screw adjusters at both ends. Since this bike has no cable stops the cable housings run end to end and are secured to the frame with zip ties. I saw this on a similar bike on a web site. The crank feels good and if I can make it shift well it will be an adequate bike. This bike would probably be a better single speed but I decided not to do that because the kids live in a hilly area and a selection of gears will be useful.

A new project bike pulled from the trash enclosure today. This may become my knock around bike. The one I can leave out without fear of it being stolen. Thanks to my neighbor JJ for telling me it was there. It needs quite a bit of work and is very heavy but will be fine for putting around the park, going to the mail box, etc. :

No comments:

Post a Comment