I have a freewheel and I keep bending the axle, however the rim, spokes and tire are all fine, does anyone think it would be possible to unscrew the spokes, buy a new hub that has a freehub, install that with maybe new spokes and my previous rim? (And also buy a cassette) because I don't see the point in buying a whole new wheel just for the hub.
Simple answer: yes, but it’s not worth doing.
Cost of hub, spokes, nipples and having wheel rebuilt will exceed the cost of a new wheel. Even if you re-use the spokes a new wheel will still be cheaper.
Wheel building requires special equipment, expertise and time to do correctly.
Yes - I have personally done this, by installing an 8 speed cassette freehub into a wheel that had a 6 speed freewheel. The donor was a 26" MTB wheel, and the recipient was a 20" wheel for my folding bike
It was only worth doing because I had a donor wheel and I was able to reuse the 20" spokes well enough. I even reused the 8 speed cassette and chain.
My purpose was to get access to smaller and larger gears, because the freewheel was a 14-28 and I now have an 11-32.
The downsides were
- Assembling used parts can be a bit fiddly, might need some finangling to get things lined up.
- Used parts are dirty and less fun to assemble
- Used parts will be worn and slightly closer to breakage than new parts.
It took several hours to assemble, and I messed up the location of the valve hole.
Upside, I have a perfectly working, true, QR-based, 8 speed 20" rear wheel and that bike has 2000 km on it now.
You'll need parts and some normal bike repair tools:
- Spoke nipple tool and probably some spare nipples
- Cassette removal tools - chain whip and lockring tool
- Freewheel removal tools - a bench vise and a freewheel tool, OR a grinder with a cutting wheel (mine was a non-removable chinese thing hence power tools)
- Chain tool
- Either a truing stand, or some way to use your bike frame/fork to true the wheel.
Feel free to ask further clarification questions.
As the others have already stated: Yes, it is possible, but ...
However, I feel that the really important message has not been transported yet: Building a wheel is not easy for the uninitiated. Yes, it can be done. Yes, you will likely get something that looks like a true wheel. But you may easily end up with many broken spokes the weeks after.
The critical part about building a wheel is, that you need to apply even tension to the spokes. Fail to do so, and they may break very quickly. And with even tension, I really mean very even. It won't suffice that they feel evenly tensioned to the touch, the tolerances are surprisingly small. If you have a musical ear, that helps a lot, as you can just tune your spokes (that's what I do, at least). However, doing so takes time. Time that may be better spent on other pursuits. After all, when you adjust the tension of one spoke, 35 other spokes have their tensions changed slightly as well...
That said, building a rear-wheel with a cassette is an additional challenge, as you need to build it asymmetrically. Consequently, the spokes on one side need a much higher tension than on the other side. With the tuning approach, that's two different tones, the exact pitch of which depends on the geometry that you aim for.
So, if your goal is to get to know how your bike is built, go for it. You can learn it. But expect to pay for these skills with a significant amount of time, and likely broken spokes. If your goal is just to save a penny, think twice: buying a new wheel saves more in terms of time than you can save in money by building yourself, and the bought wheel has less risk of failing quickly.
Of course it is possible, you're simply building a new wheel with some used and some new parts. Unless we are talking about carbon rims where the spokes are glued and the wheel is trued in the factory already.
When doing that take the following into consideration:
- is the new hub as high as the old one (you have high flange hubs) - if not, new spokes will be needed
- new hub (the one accepting a cassette) will be asymmetrical - spokes on the non-drive side will reach to the very outside of the whole assembly while the spokes on the drive side will reach to like 2/3 of the complete assembly width as there needs to be some room for the cassette. Most likely the spokes you have will be too long and will protrude through the nipples. Either you need to buy a new set of spokes or trim the existing ones
- is your rim in good condition - when using rim brakes the rim should be replaced once it is worn out
- if all the spokes and nipples can be reused - I hope you won't break any of those while disassembling
- if you are using the nipple washers, you most likely need a new set
- once the wheel is laced, it needs to be trued and dished - either you outsource it to someone with proper tools and expertise or you do it yourself (a truing stand is almost a must)
Yes, one can do this. But you ask "Can I...?" (my emphasis) and the answer is "probably not, at least not right now." Please don't take this the wrong way, but building a wheel requires a lot of skill and equipment and the fact that you're asking the question suggests that you don't have those.
Unless you're dealing with a particularly high-end wheel, rebuilding it will be more expensive than just buying a complete wheel, especially once you factor in the value of your time. However, if you want to learn how to build wheels as a hobby project, then go for it.