Hello everyone. This is my first post so take it easy on me.

I recently bought a Firenze GL5000 at a rummage in decent shape as a fixer upper as I am not sure how much I want to spend on a good bike until I know how much I will use it.

I was looking at replacing the cranks which are the older cottered type. I am assuming to replace the cranks I would most likely need to replace the BB as well.

So my question is, Can I convert it over to a new modern style bottom bracket? and if so how would I find out what size I would need?

Thanks in advance for any help. I am totally new to biking.

Rob

Yes, you can but it will depend on your threading in the bottom bracket. Sometimes you can replace the axle and reuse the cups - although going with a sealed unit is better.

How old is the bike - if it's vintage - 80's and older try posting in the C&V forum. You'll find a lot of help there.

Scozim,

Thanks for the reply. I'm sure the bike is either 70's or 80's

I am not sure the threading of the bike. I would be looking at use a sealed unit.

I know the model: it's a cheap Taiwanese made road bike -- "Italian-styled" in knock-off fashion.

It will have an English 1.37 x 24 tpi BB. Width will likely be 68 or 70 mm.

I'm not familiar with the brand but unless it's Italian or French made, the bottom bracket threading is most likely English. Look at your bb cups and see if anything is engraved on them. English will say something like "BSC" or "1.37" x 24 tpi".

"Firenze" was a low-end department store type Taiwan brand from before the days when Taiwan was building decent bikes. "Crazy TV Lenny" in Madison used to give them away for free with every television purchase, so you can draw your own conclusions. But they are English thread, which makes things easier for the OP.

Perhaps the worst bike ever made; I don't say this casually, I've worked on them and ridden them. There were a lot of them in my area because they came free with purchase of a stereo or TV. Bike shop Yellow Page ads frequently had the phrase "We will not service Firenzes" (really!)

Anyway, no matter how easy it is to put on a new bb and crank, it'll always be a pig. I understand not wanting to spend a lot of money on a bike when you're not yet a cyclist... but this will not be a good introduction.

We frequently get guys like you in here who buy the bike first and then come looking for advice. That's too bad because we have a lot of good advice for what kind of bike to buy.

So... I would advise against spending any more money on a new crank and BB, but if you can find another old bike with an English BB you might enjoy getting your hands dirty with a swap.

Thanks for the background. I once tried to work on this level of bike for my neighbor and it was the most frustrating afternoon I ever spent.

I agree on the inadvisability of putting any significant money into it but it could be a cheap way to learn the basics. At least mistakes won't hurt something valuable.

I love this thread!!
Here's mine, it is actually one of my favorite bikes.
I just did the Shiner century ride on it FG (passed a lot of carbon).
The chain popped 15 ft before the finish line (mechanics fault, not the bikes).

To the OP yes a standard sealed bb will work.
By replacing all the steel components with Al you will take 8lbs off the bike.

Enjoy