BIKEPGH MESSAGE BOARD ARCHIVE

You can, you just need an adapter.

However, once you buy an adapter, a new bb, and a new crank, is it really worth it for an old low-end frame?

you can get a BMX bottom bracket to fit the big unthreaded BB shell, they come in standard square taper so you can put on whatever crank you want.

Worth it as far as the bike goes, Maybe not. Worth it on what I can learn about building bike, possibly.

Im not sure. I was more concerned about if it was possible. I am really hard on bikes, just riding them I stress them out. im just thinking that a newer bottom bracket may be moredurable than the single piece one that is on there now.

I imagine you would learn nearly as much replacing the bearings and using the one you've got, as long as there isn't anything wrong with it.

That frame isn't worth spending any real money on bottom bracket adapters and the like to use.

If you're worried about the durability I would definitely go with the BMX setup I suggested. Less parts to mess up, and the bearings are a lot bigger so I think they would hold up better to a lot of stress. Here is one. http://www.bikewagon.com/Eastern-Bikes-19mm-American/Drivetrain/BMX/BMX-Bottom-Brackets-p7465632.html I cant seem to find one that comes with a spindle after a quick search, though. I have one made by a company called Primo on my old BMX bike that I wouldn't have a problem parting with if you're interested.

the above bottom bracket can only be used with a three piece bmx crankset, like profiles, etc. it's not a square taper bb spindle, it's a splined system that will only work with a single chainring.

also, that frame is not worth putting any money into.

On second inspection, you're right. I know for a fact that the Primo one is square though, i just cant find it online. Agree on the fact that its not really worth it, but then again does it really need to be? A cheapo frame can be just as fun to ride as a thousand dollar frame.

if you really want to learn about working on bikes you should sign up for the classes at freeride. you are much better off learning how to do things the right way the first time. there are a lot of mistakes you might easily make that can either a)ruin the bike and make it unrepairable by any reasonable means, b)not be noticed by you until you are riding and the bike catastrophically fails, or c)both.

The design goal for three-piece cranks was not increased durability. For now, I think you should stick with the setup that came with the bike. I'll bet you put an awful lot of force on a crank.

a 350# biker trying to crank up a hill has to stress out a bike.

I figure unless I buy something heavy duty then it is a given I will break it.

The weak part of that entire equation is and always will be the Magna frame no matter what parts are hung from it. Fine to learn basic mechanics on, but beyond that it's a toy. You're talking about a bike that was $100 when it was new.

If you're serious about wanting to spend money on heavier duty stuff you're going to spend a few hundred dollars no matter what way you slice it, and you're far better off purchasing a new complete bike. There is some good stuff out there for $400-500.

Brad, I have a great bike. Orange diamondback response that has stood up to all the beating I have put on it.

This bike is something I am doing to

1. learn the different parts of the bike.

2. give me something to tinker with when im not riding

3. just to have fun

Pretty much the end of the list. I want to use good quality parts since I want to learn how to work with the good quality parts. (granted I want to be able to ride and enjoy a bike once I get it put together and built from the ground up.) And for most normal sized people I have to believe that they can put together a decent bike that will give them miles and miles of use without it costing an arm and leg.

If your goal is to experiment and build an everyday budget pavement pounder, you might reconsider just keeping and working with the original one piece crank, unless there is something wrong with it. There are 50 year old bikes with cranks like that still running fine. There are plenty of other components you can change with much less complication and cost.

@edmonds59

I think you are right, I will replace the bearings and go from there.

if you get yourself a pipe cutter, you can make a few pretty sweet "cheater bars" for use when working on actual bikes... but seriously, there aren't really many "upgrades" for any bike that has a single piece crank setup for a good reason.

if you put a nice set of stiff cranks on that frame, you'll probably more easily notice the bike bending in half with each pedal stroke.

i was reading a thread once where a mechanic was calling them "magna bike shaped objects".

we have a pile of BSOs at thick. they go to the scrap yard to get recycled because they aren't worth the effort to attempt to make them safe practical or reliable enough to ride.

As part of a business I can see where bikes like this are total pain, as a hobby however, I have to say that I am enjoying the work and learning something everyday.

So aside from the people who answer my question with "Buy a real bike" which would be fine if I had asked a question about buying a bike. aside from that I'm having a great time with this BSO

Then after you've gotten the experience out of it, you can give it to Free Ride, or put it in a crate to Africa, or just give it to someone who has no bike, who would be happy to have a running BSO. Whatever that is.

...so long as you don't have two girls getting on a BSO and crashing into a tree at the bottom of a hill and killing/maiming themselves.

Edmond

that is pretty much the idea, I spent a fun evening last night at free-ride volunteering (it was my first time) and I really enjoyed myself. will have to go back again and help out.

Stu

That would be bad but I think BSO's get a bad wrap, for what they are for (garage decoration, a kid who rides his bike for the summer) I think they have their place. When I first started riding and was unsure if I would even enjoy it I bought a schwinn from wal-mart since I could justify 130$ for that bike where as there was no way I was going to spend 400-500$ bucks on a bike when I didnt even know if I was going to like riding.

So in those kinds of cases I would rather a person buy a cheaper bike and find out if they are going to ride as opposed to them not buying any bike at all since they arent going to buy an expensive bike at that point.

To many people look at it as the choice between a cheap bike and a good bike when they have to realize that for many people the choice is between a cheap bike and NO bike.

Argh, yeah, I knew I should have included a link to the story. I forget how many new people are on this board.

When kids die because they ride a bike that isn't up to the task that they're put to, it does the whole cycling movement more harm than good. Maybe if each girl had had her own bike, even a BSO, they'd both be alive and whole today.

i was more replying to unixdork than you dback. i think that once you have played around on this bike you would really like the whole freeride idea. you get to fix bikes, learn more about bikes, hang out with other cyclists, and donate the results of your labor to a good cause.

That accident probably had less to do with the quality of the bike than with the dangerous circumstances involved: two riders, no helmets, going downhill.

cburch, please consider donating your scrap bikes to free ride if they're not rusted out. I realize that oftentimes the time it would take to repair it would cost more than the value of the bike, but most of the people working at free ride work for free, and the bikes they repair frequently go to people in the community that can't afford a bike from a shop. These people, especially if they're kids, will then develop an addiction to cycling that will last a lifetime.

Cburch

I went to free-ride last night, it was fantastic!! I wish I could of gotten to know the people there more but I was busy, there was about 20 of us there working last night.

asobi. not my call, but i will mention it to chris.

dback. i keep trying to get time to go there and volunteer, but life has a funny way of kicking my ass.

I hadn't noticed a shortage of bso frames at free ride.

dbacklover,

I will probably be volunteering at freeride next week. Be sure to come say hello, I'll probably be sorting tiny sharp hunks of metal

noah

I know what you mean, they just pointed me at the racks of wheels and said "sort-em" almost threw my OCD into waves of joy and fear

for real. i was steered towards a bucket of all kinds of tiny pieces of bike guts. most of which i had NO IDEA what it was...or where it went. it was a real crash course in bike anatomy.

yeah I saw two guys sorting nuts and bolts. Made me feel happy I had the wheels. It also turns out im sort of a savant(or idiot at least) when it comes to removing the tire and tube from the wheel.

Best way to go: take a class in something at free ride, then every time you go to a volunteer night, you will be the leading authority on whatever you took the class on. Then find a bike that needs work and do that thing you learned how to do. Repeat until self-actualization.