jet jennings

I'm a commutor and recently I've started to get pain in my wrists. I beleieve this is because my position is wrong due to a high seat and low handlebars with no suspension on my bike at all. I have off my old bike a flexstem which attaches to the headset the old way but my newish bike works on a ahead system. Is it possible to change as this will cure my problem?

MichaelW

You cant put a quill stem on a threadless system
You can get adjustable stems which you can position higher and closer.
On some bikes the steerer tube of the fork is quite long and there are some spacer rings above and below the stem. You can reposition the height of the stem by switching the order of rings from over the stem to below the stem.
If your stem is set at an angle, you can flip it to get a different angle which may raise or lower the bars.

Retro Grouch 

If you want to raise your handlebar the most cost effective solution will probably be to get a stem that has more rise angle. The art is in getting the length right. As you raise your handlebar it also comes closer to you due to the angle of the head tube. Most people, however, like a high handlebr a little closer so a little bit of that is good.

If you plan to raise your handlebars very much you might as well plan on buying all new control cables and housings too because your current ones are likely to come up too short.

TallRider

The first two suggestions are good, but if you want to actually swith your bike over to a threaded headset, it's easy enough. As long as your fork has a steel steerer tube. Have a shop cut it and thread it for you (hopefully they still have tools to thread the fork - they did when I worked in bike shopes 9-10 years ago). And put a threaded headset in. But only do this if you really want to use the suspension stem. And even then, you can rig things up to use the quill stem in a threadless system - you'll just need a seat-clamp type of lockring to tighten around the steerer tube once you've got the headset adjusted, so then you can take the top cap off of the steerer tube and stick a quill stem in there.

bellweatherman

Yep, this is totally correct. I've done this before. To the OP, all you gotta do to convert your threadless fork steerer to a threaded fork steerer (so that you can use your old quill stem), is to:
1) Using a hacksaw, carefully cut some steerer tube off so that your steerer is closer to the top headset cup.
2) Using a threaded cutting dies for a fork steerer, Park and Hozan makes some. Cut some threads into the top of the fork steerer.
3) Buy a new headset for the old threaded system.
4) Thread the fork into the new headset top threaded thingy
5) Adjust headset
6) Ride

If you are totally clueless about what and how much to cut, then you should take your bike over to a bikeshop. Potentially though, they might not want to do that operation. It might surprise you, but some bike shops don't have the thread cutting dies to do this. In that case, just find a local framebuilder. That's probably a better alternative anyway.

Grand Bois

Rivendel is big on getting the bars up higher to take weight off of the hands. You may be able to find some info at rivbike.com. I've noticed that on some of their bikes they have left the steerer tube long and used a tall spacer, presumeably to give extra support to long quill stems. I don't know what they're using for a spacer. I have the same problem with pain in my hands and wrists and I solved it on a couple of my bikes with a Nitto Dirtdrop stem from Rivendel. I like it so much that I made it my screen name. You can use a Technomic stem if you prefer stems that are shaped like a "7".

I'm a vintage guy, so I don't know anything about converting from threadless to threaded. I've never worked on a bike with a threadless fork. I don't even fully understand how threadless works.