Fork upgrade on threaded headset

[Punx0r]

Hi guys,

I'm looking at ways to fit some proper forks to my bike. I'd found some marzocchi forks on ebay with a 1" steerer and thought they'd fit, but after reading this:

http://sheldonbrown.com/headsets.html

It seems I was quite wrong.

My bike has a 7/8" wedge/type stem and a 1" threaded headset/steerer.

My knowlege of bicycle mechanics is limited and I'm learning as I go, so I'd apprectiate any suggestions or corrections to what I'm thinking.

As far as I can see, I have two options to fit "proper" forks:

1) Find some forks with a threadless, 1" steerer and fit a threadless headset and stem (or could I even use my old stem inside the threadless steerer?)

2) Find any forks, and replace the steerer with a 1" threaded item

The internet suggests that steerers can be swapped, but is vague on how exactly, and I've been unable to spot any steerers themselves for sale.

I'd be grateful for any suggestions on how difficult each of these options would be and any sources/guide prices for parts. I'm mechanically competent, just not experienced with bikes...

Thanks,
Ant

[Drunkskunk]

Likely you will only need to change the bearing race from the threaded to a threadless headset on the top bearing, but there can be some size differences between brands, so you may have to change over the whole headset to a threadless.

Here's a breakdown of a threadless headset. the parts that are different are on the right hand side. The Adjustment race, and the centering sleeve are what you need to change.

[dogman]

Not hard to do really. I'm surprised sheldon brown say's it's hard. Maybe they just mean that you cant, or at least shouldn't use the same bearing races. New ones that come with the headset will fit the seals, and your old races may not.

But really, the bottom bearing race should not matter all that much, provided the race on the new fork fits it. If not, tapping gently with a screwdriver and hammer can usually remove the race from your old fork to be installed on your new one. New one might even come with no bearing race.

Buy a 1" headset and you are good to go. You will also need a new stem in 1". The old stem won't work, the threadless headset needs the stem to hold the bearings tight in the headset.

Bear in mind, your new fork better have a stem on it at least 1.5" longer than your old one. The extra length is what the threadless stem clamps to. Some of that ebay stuff is dirt cheap because the stem has been cut short, perhaps too short for the headset tube on your bike.

Replacing the steer tube on a set of forks is not really an option, unless you have a machine shop with the right adapters for a press. Even bike shops rarely have that tool.

[cal3thousand]

I am building a project bike from frame up so I have some experience with conversion. Here's what I've found you need to know:

Not all headsets are they same, even if the steerer dimension is right 1", 1.125", etc... you will need to measure the diameter of the headtube flange

Make sure the steerer is long enough if buying used. Buying new, they are extra long so you will have to know how to cut it

You will need a new headset, stem, spacers, fork

[Punx0r]

Thanks for the replies guys - very helpful.

One question I omitted from my first post was whether my frame's headtube limits me to a 1" steerer, or with the correct headset can I fit a 1 1/8" steerer? The later would give me more choice when buying forks.

Good point on the steerer length - I will be sure to check this before buying any used forks.

Am I correct in assuming that I will need to change the pressed frame races?

Cal, what is the headtube flange?

If I buy a headset, is it *everything* I need to take a bare frame and a bare fork/steerer and fit them together? I'm a little confused because I'm getting the impression that some of the old bits can be reused?

Obviously I don't want to waste money buying new parts I don't need, but I'd also like to have everything I need to hand when I start the job, save the bike being out of service while I wait for those few extra bits it turned out I needed

[dogman]

It's very unlikely that your 1" frame will accept a 1 1/8 headset and tube. Chances are, it's inside diameter is just too small for it to work.

I've tried it on several bikes, and it never has worked for me. It might be possible to get a heaset race that did go the other way, 1 1/8 to 1"

Since you will be going from 1" threaded to 1" threadless, it's possible some stuff can be reused, like the bearing race on the fork itself, and maybe the bottom headest bearing cup.

A full headset kit should have everything in it, so it may not matter. The headset will not contain the stem, or any spacers you might need though.

[cal3thousand]

Thanks for the replies guys - very helpful.

One question I omitted from my first post was whether my frame's headtube limits me to a 1" steerer, or with the correct headset can I fit a 1 1/8" steerer? The later would give me more choice when buying forks.

Good point on the steerer length - I will be sure to check this before buying any used forks.

Am I correct in assuming that I will need to change the pressed frame races?

Cal, what is the headtube flange?

If I buy a headset, is it *everything* I need to take a bare frame and a bare fork/steerer and fit them together? I'm a little confused because I'm getting the impression that some of the old bits can be reused?

Obviously I don't want to waste money buying new parts I don't need, but I'd also like to have everything I need to hand when I start the job, save the bike being out of service while I wait for those few extra bits it turned out I needed

You will need to press the new races from the new headset in. And that's where the flange comes in. This diameter can vary based on the frame. I found this out the hard way by purchasing a threadless headset that was the incorrect diameter to sit in a 44mm diameter flange.

Btw, you don't need to buy any special tools to press them in. A threaded rod with nuts and a couple flat washer like plates will allow you to crank the plates down to press the races in.

I saw an ingenious method that used a threaded dumbbell and a couple 5 lb plates. It's on youtube if you need a better visual.

[chisixer6]

want steerer tube? here are some

http://www.niagaracycle.com/index.php?c ... 01_4601010

to change 1" to 1 1/8" headtube, you need one of these;

http://www.gaerlan.com/bikeparts/frame/ ... ubing.html

cut off your old headtube, weld on new headtube....presto done....sounds easy
provide you got a steel frame, for alloy frame you'll need a tig welder

this job requires a lot of eyeing..lol

[Gregor]

Remember, a lot depends on that connection between fork and frame. It might be best to ask someone perhaps in a used bike shop in your area about any final assembly of the parts you end up with. The bearing race that is sometimes left on a used fork is called the "crown race". It possibly is compatible with your new headset kit, but again , asking someone to look it over before wasting any time on assembly is well worth it IMHO.

[d8veh]

You can get a used frame on Ebay for not a lot of money, which to me seems to be a much better option. They normally come with headsets and often with forks too. Look at this Marin - probably less that what you'll pay for forks, headsets and adapters.:
http://www.ebay.co.uk/itm/MARIN-DOWNHIL ... 3a78c8c80b
I got my Giant NRS with Marzocci Bomers, rear suspension unit, headset, seat pin, and some other bits for about £110. There was a whole Giant NRS minus wheels and brakes on there a couple of weeks ago that I was offered at about £300.
Take your pick:
http://www.ebay.co.uk/sch/Bike-Parts-/5 ... ames&rt=nc

[Punx0r]

I'm pretty well commited to frame I currently have now. There isn't much wrong with it to my eye (steel, heavy, decent welds), just the laughable suspension letting things down

I'll shop for some 1" forks, head set and stem. Replacing the steerer can be plan B and welding in a different headtube a distant plan C

Cal, sorry to labour this point, but I'm still unclear what the flange is when it comes to the head tube? I'd like to heed your warning and measure it before buying a headset.

Thanks,
Ant

[dogman]

The flange would be the part that is inserted into the head tube on the frame, then the race is the wider part that remains visible.

That hadn't occured to me, I guess I got lucky when I bought a headset, and the flanges were the same size. Meaning the tube stock used for my headtube was identical to the other. there is a possiblilty that more variation in the headtube size exists in 1" stuff. The 1 1/8 stuff in my pile of old frames appears all the same. All fairly cheap frames though.

It is possible, but not so likely that you can fit the new headset parts into the old bearing races. I have found though, that often the bearing seals don't fit right when switching from threaded to threadless. Slightly different cup sizes, even if the flanges are same. So I'd swap the bearing races from one frame to the other, turning the threadless frame into a threaded frame.

Oh, and slacker that I am, I just tap in the races with a cushioning block of wood and a hammer.

[cal3thousand]

I'm pretty well commited to frame I currently have now. There isn't much wrong with it to my eye (steel, heavy, decent welds), just the laughable suspension letting things down

I'll shop for some 1" forks, head set and stem. Replacing the steerer can be plan B and welding in a different headtube a distant plan C

Cal, sorry to labour this point, but I'm still unclear what the flange is when it comes to the head tube? I'd like to heed your warning and measure it before buying a headset.

Thanks,
Ant

There are a couple standards in the same measurement. If you use the following link and choose not Integrated, you will see different headtube measurements for both 1" and 1.125" steerers:

http://www.canecreek.com/headset-fit-fi ... lastStep=3

[amberwolf]

FWIW, I ran into issues converting CrazyBike2 from threaded to threadless. I still have some looseness problems because I am not using the right "cups" for the headset, though I am using bearings/races (modular units) for threadless on it; I had to shim things to get it to fit right. Pics and details are in various pages of CB2's build thread, starting march-ish of 2011, just before the DeathRace, and then further work months later after my ankle healed and other problems worked out.

But it can be done, and if you use the correct parts, it should be relatively easy and "painless".

[Punx0r]

I'm hoping my frame is "standard (ISO)" 1". I think I'm going to keep and eye out for some forks, then wait until winter to pull the bike apart, measure up and then order the headset, stem etc.

[cal3thousand]

I'm hoping my frame is "standard (ISO)" 1". I think I'm going to keep and eye out for some forks, then wait until winter to pull the bike apart, measure up and then order the headset, stem etc.

Sounds like a solid plan. But, if you measure it up now... you can keep your eye out for those items in the interim and possibly score a deal during a sale period.

In the US, Labor Day and Black Friday are pretty good shopping days. Not sure about on your side of the pond.

[Punx0r]

Don't I have to disassemble the head to measure the important dimensions?

[cal3thousand]

Don't I have to disassemble the head to measure the important dimensions?

Yes, you would have to. But it's silly easy. One allen key and the stem is out with handlebars. One large adjustable wrench (spanner) at least 35mm open. A mallet and a long rod (I use a 9" long 3/8" bit extension) to tap out the races from the inside.

[Punx0r]

I'll give it a go sometime soon