juan162

To make a long story short, the Commie R20 thread got me wanting to do more modifications on my Crescent Separable. At the point that my Crescent is at right now, I believe the greatest improvement to the ride would be to replace the one piece crank and bottom bracket, or at least open her up, get new bearings, and repack it all with grease. What do you guys think?

If I decide to try to convert the Crank, I have these two posibilities:
https://www.choppersus.com/store/prod...onversion-Set/
https://www.choppersus.com/store/prod...onversion-Kit/
While I would like to use the more modern of the two, I don't even know if it will fit on my bike. The second one with the cones is probably the safer choice. Any thoughts? Here's the pic of the bike as it stands now:

click for full size

After that, I would finish the upgrade process by:
1. Adding MKS detachable pedals
2. Switching to 451 rims/tires: Single speed flipflop
3. Adding a dual caliper road style break to the front.
4. Use Jur's stem fix on his R20 to get more stretched out
5. Adding drop bars
6. New Paint

Any suggestions are welcome!

caotropheus

First of all, consider just the first option to convert the BB from american to european threaded. Only this possibility will allow you to use cartridge BB. I made a conversion of a "Made in USSR" bicycle, very similar to your Crescent. I also had a BB issue and I am very glad that I made a conversion to BSA threaded.

1. Pedals is a question of personal preference. I use Coda SPDs and so far so good. Of course I have to remove the pedals if I want to pack my bicycle and here the advantage of the MKS detachable pedals is relevant.

2. Good choice

3. Good choice, don't forget the rear wheel as well, if you go single speed.

4. Good choice

5. Again is a question of personal preference. I use time trial bars (actually cut drop bars with Cane Creek 200 TT brake levers) and I am very happy with them.

Enjoy

badmother

Are you sure your BB housing is american standard? Think that is 5o+mm. Going to do the same myself soon, thinking of buying the first option, to be able to use regular BB.

Also thinking of maybe doing it the "el cheapo way" like I did with my cottered crank bike (BB shell 40 x 70) since I found no other solution for that one:

This time I would start with an alu "donor frame", alu becouse of low weight. Cut out the whole BB thing (angle grinder), meaning cutting of seattube, both chainstays and the downtube close to the BB housing. Grind it down to fit innside your "upgrade project`s" BB house. Make sure it is the right way around, and epoxy in place. Wait for it to dry and keep on working.

Cheap and different..

caotropheus

That's exactly what I have done to my bicycle since the original BB diameter was smaller than the american BB but large enough to accommodate a scrap bicycle's BB european size.

juan162

I doubt it is american standard, which was why I was thinking of going with the 2nd choice. I think I'm going to have to think about your "el cheapo way" because I'd really like to use a modern BB.

Thanks for all your thoughts, folks,

Juan

alecw35

can you post pics of the bike frame with no components.

Maybe measure the frame.

For BB size.
For head tube length
For fork steerer length

badmother

Just to ensure.. The "el cheapo" way let you do this. When you decide on what donor bike to use you decide what BB to use in the future. You make sure you use a modern standard bike to take a a standard modern BB.

I relly like some of the perfectly upgraded folders you can see her. Real eye candy, and I am sure a pleasure to own and ride.

BUT. Sometimes you are not sure if you are going to ride the bike alot or not, and some times solutions is hard to find, you end up with "my way or no way". Also sometimes there is a limit to what you are willing to pay. My present folder project (standard American, one piece crank) I want to be able to use it, and to lock it up with no worry. Maybe the next one is going to be the pefect looking one. Tell us more laterabout what you do!