Headsets, Frame & Fork

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Headset Installation
Fork replacement
Steel frame internal rust
Water buildup prevention
Frames

 

HEADSET installation without expensive tools.

Home headset installation with inexpensive too is easy. Follow these tips -

The tools needed for "Poor Man's Headset Installation" are:

Hammer (not too big or too small).
Plastic tipped or rubber hammer.
Two eight inch (or so) pieces of 2x4 lumber.
One workbench or other stable, raised surface.
One trusted helper who knows the meaning of the words "steady, level, left, right, up, down, turn over".
One long (about 8" or so) tapered drift-punch or large flat bladed screwdriver.
Grease.

Preliminary comment - Your frame's head tube and fork crown race seat may need "reaming and facing" before installing a new headset. Some frames are prepared by the maker and some are not.  This goes for whether you use my method or a $200 fancy press. I've had many new frames, both store bought and custom made, and have never had to get one faced and reamed yet. This may not apply to you though. 

Let's read what the Park Tool Co.  has to say about headset fit -

Many headset cups are held in place by a "press fit". The headset cup has a slightly larger diameter than the head tube inside diameter. Generally, differences of 0.1-0.25mm are considered adequate for a press fit. If the pressed cup is more than 0.3mm larger than the frame inside diameter, it may be very difficult to install, and frame damage may result.

If the press fit difference is from 0mm to 0.05mm, the press fit may be weak, and may result in movement during use. It may be possible to find a different headset cup that is slightly larger to improve the press fit. Otherwise, a strong grade of bearing retaining compound is recommended. If the headset cup is actually smaller than the inside diameter of the head tube, a new headset with a larger diameter is recommended.

You can measure headtube and headset dimensions with a fairly inexpensive Vernier Caliper. 
You can see this tool and this process on the Park Tool site.

One more comment - nowhere here do I say that this method is better than, or should be used instead of, any factory recommended method for installation of the headset in question.  I'm just giving a tried and tested alternative method for those who can't or don't want to use expensive tools or get the job done by a bike shop "mechanic". 
Any method used - this method or the method used by the bike shop "professional mechanic", is only as good as the person performing the job. 
Neither fancy tools nor a sign over the door are a guarantee of quality work or qualifications of the person doing the job.

There are no mysteries or black magic surrounding headsets and their installation.  They are a simple interference fit.

Assuming the head tube and crown race seat are ready to accept the headset, proceed as follows.

Remove as many of the bike's parts as practical. You will have to invert the frame, so remove at least the wheels and maybe the bar/stem combo so they won't be flopping around attached to the cables.

Headset removal - we're going to tap the old cups out with the tapered drift punch or the large screwdriver.  Some folks use wooden dowel, plastic pipe or an old handlebar but I use the punch.  Look down inside the frame's head tube and you will see the edges of the headset sleeve inside the frame.  Hold the frame with the bottom cup over a rag on the floor (so the cup won't fall too far) and gently, with care and passion, tap the cup out.  Don't be silly and tap all in one spot!  Go around the edges of the cup in a cross pattern to get it coming out evenly.  Flip the frame over for the other cup.  Lots of people freak at the above process but my goodness..........what could be much simpler?  :o\

Headset installation - have trusted helper hold onto back end of frame with bottom end of head tube sitting SQUARELY on one of the 2x4's which is sitting at the edge of the bench.

Place the top cup (make sure it IS the top cup) and gently tap it to just get it started into the frame using a plastic tipped hammer. Grease it lightly before installing. Make sure it is LEVEL by eye. Squat right down next to it and make sure

Place the other 2x4 on top of the cup and tap gently but firmly to start the cup going into the frame. This is where judgment comes in. Before you freak and rush off to the LBS remember....the constant checking and re-adjusting strategy from here on in is NO different if a fancy press is used. One must check constantly for the cup going in straight with ANY method used.

If all is level at this point then carry on tapping firmly and checking constantly. Depending on the quality of the interference fit, your taps may need to be little ones or bigger ones - whatever it takes. If the cup becomes un-level then tap on the wood on the high side until the cup is level. Use care, good judgment and passion here.

Keep tapping until the cup is completely seated squarely on the head tube.

You have done NOTHING so far that you would not have done using a fancy press other that the hammer blows are intermittent pressing motions. You can get a cup going in cock-eyed using a press if you are not observant and careful.

Have the helper turn the frame over and repeat for the other cup.

Crown Race
For the fork crown race, get a 2x4 that is a couple of inches longer than the distance from the fork tips to the UNDERSIDE of the fork crown. Place the 2x4 standing on end on the floor and sit the underside of the fork crown on the end of the 2x4. The fork ends will not be touching the floor. Have the trusted helper hold the fork firmly and level by the legs.

Place the crown race (correct side up!) on the seat. Gently, with much care and compassion, tap the race down onto its seat with the drift punch. Go alternate sides (4 of them) to keep it level and square. Keep going until it's firmly seated. Some people use a good fitting pipe - either metal or ABS plumbing pipe here. The store-bought tool is just a fancy pipe. I've used a hammer and punch for 38 years with no problems YET.   Maybe I should buy the correct tool.. Yeah, right.

The job is done. It should take about 10 minutes tops and if you keep everything going down level then you will have no problems.

Warning: If you are not observant, do not make adjustments or otherwise are ham-fisted you could wreck the headset or the bike frame.

This advice goes for if you use my method or the world's most expensive press.

el-cheapo headset press.

Buy a length of (about) 3/4" threaded rod from a hardware store and cut a  9-12" piece from it.  Get two nuts and washers while you're at the store.  You'll probably have to buy a three foot piece of the rod so make tools for your buddies out of it too.


 

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How to remove an old fork and install a new one.

This answer is by John Burtner (Shiva) with comments by Mike T.

Check also at www.parktool.com for instructions, needed tools and pictures.  It's a great site.

Warning - if you're replacing an older fork, be aware of the type of brakes you presently have.  If you have an older bike with "cantilever" brakes (center pull cable with a hanger on the fork) be aware that just about no forkmakers make a fork with a cable hanger anymore.  If you have this type of brakes you are going to have to get a v-brake and a v-brake lever too.  If your shifters are part of the old brake lever you're going to have to invest in shifters too.

This article will assume you have a threadless headset and an unthreaded steerer on your forks. These are today’s industry standards and the instructions to follow will apply to almost all bikes made in the past 12 years or so. I’m also assuming you are planning on re-using your present headset and stem.

Step one: Remove the front wheel.

Remove the front brakes. No need to remove the cable, just unbolt them from the fork and let them dangle.

Remove the stem top cap bolt.

Loosen the stem clamp bolts. Hold on to the fork, or it’ll hit the floor!

Mike here – sometimes the fork steerer will be quite tight inside the headset and will not simply pull (or fall) out. Remove the stem and then tap on the end of the protruding steerer with something softer than the steerer (a 2x4 or a rubber mallet).

Set the headset parts and any spacers aside in the order they came off the fork.

Remove the crown race. The crown race is the part of the headset that sits atop the fork crown and around the steerer tube. Removal can be a bit difficult, as the race is pressed onto the steerer tube very tightly. Also, most suspension fork crowns are so bulky that it’s almost impossible to get at the bottom of the crown race to pry or drive it off. A small cold chisel or punch and a light hammer will usually work though. An old flat-bladed screwdriver will work in a pinch. Have a helper hold the fork upside down on a solid surface. Do not clamp the fork in a vise. Slip the chisel between the race and the fork crown angled down. Give the chisel a couple of light taps with the hammer, then move the chisel to the other side and give a few more taps. Keep working around, trying to hit the high spots so the race can be driven off without binding. Patience is a virtue. Tap, tap, move. Tap, tap, move.

If you're sure that you liked the height of your stem previously then measure, mark, and cut the steerer tube of the new fork so it’s exactly the same length as the steerer on the old fork. As Norm Abram says "Measure twice, cut once."

Mike T. here – if you have to cut the steerer with no old fork to measure the new steerer against, do this –

Install the crown race on the new fork. Do not allow the tool to mar the race surface itself. Drive it on by carefully holding the tool on the innermost flat surface of the race, not the conical bearing surface.  Mike uses about an 8" drift punch with a " dia flat end on it for this operation.

**At this point consider adding spacers to the steerer.  Spacers can lift the stem up if it's going to be too low.  They are a good idea even if you don't need the height as they can always go on top of the stem.  Spacers allow just a bit of a Fudge Factor when cutting the steerer.  They should not be used to cure sloppy measuring and cutting but hey a bad measurement can mean a new fork!

As said before, you can add spacers under and over the stem.  The ones on top of the stem are just spacers "in storage" as they provide no practical purpose there.  If and when you're happy with your stem height, you can remove any upper spacers, re-measure the steerer length (next step below) and re-cut.  You can use any amount of spacers but about 20mm is thought practical.  They can be got in a variety of thicknesses so buy a selection and mix 'em up.  You can use any number of spacers to give you the height you need.

Install the fork with the full length steerer, install all the headset parts and any spacers (below, above or a combo). Install the stem and push everything down by hand as tight as possible with the wheel on the floor.  Do not install the stem top cap (you can’t anyway!). Scribe a line around the steerer around the top edge of the stem (or top spacer!). Remove fork. Scribe another line 3mm BELOW the first one, all around the steerer. Cut the steerer at this 2nd line line. I cut with a hacksaw but then I’m not a mechani-clutz. You can use a big pipe cutter if you wish. Tip – clamp a hose clamp around the steerer and cut down the side of it using it as a guide. Make it all nice and smooth with a file. File a slight chamfer (bevel) around the top of the steerer.

Install a new Starfangled nut. These are available at any bike shop and should be set in the steerer tube about 15 mm deep. Make sure the nut goes in straight and square. Drive it in with something like a 1" diameter wooden dowel.  This nut cannot be removed upwards once in place without severe damage to it.  You can drive it out the bottom of the steerer though. It might still be damaged.  Again this is shown on the www.parktool.com site.

Slide the new fork into the bike’s headtube with the headset bearings and spacers in the proper order and orientation.

Place the stem on the steerer, but do not tighten the clamp bolts.

Install the top cap and top cap bolt and tighten just until there is no play or slop in the headset bearings. Do not overtighten.

Align the stem, and tighten the stem clamp bolts.

Install the front brakes and the front wheel. Since the new fork’s brake bosses are most likely not in exactly the same spot as the bosses on the old fork you’ll probably have to adjust the pads.

Take a test ride. Make sure the brakes work properly and the headset is not loose.

Enjoy your new fork, and enjoy knowing that you installed it yourself!

 John Burtner June 26, 2000

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            Steel frame internal rusting and how to prevent it.

Steel frames can rust through and it is totally preventable. Water can enter a frame from a few sources and if it's allowed to accumulate it can ruin your frame.

Good products for frame protection are from automobile rust protection applications. The newer breed of these are very thin, penetrating water-displacement oils - quite unlike the thick, tar-like treatments of several years ago.

There are two products that I'm familiar with - Krown and Rust-Chek, and they are available from the franchise rust protection dealers or some auto supply dealers. Look in your local Yellow Pages under "Rust Protection (or Prevention)" to see what's available locally. There is a product called "Frame Saver" but like fancy bike lubes it's probably a re-packaged product at a premium price.

I'd get a spray can of Krown and a small bottle of bulk fluid to do a frame. My dealer gave it to me for free when I got my car done by him.

The frame should be stripped completely to begin. You will need an area where you can spill oil without getting into too much trouble and some minor supplies.

I use a very small funnel with a drinking straw as a extension to get into the frame tubes. You may also use a turkey baster (not Mom's good one!). You'll need a margarine tub to drain the tubes into. A helper is handy too.

Look inside the BB shell - are there two holes leading to the chainstays? Then use these to fill those tubes - half fill with the oil, swish around to coat ALL the surfaces and drain. If there are no BB holes into the chainstays then there will be two very small holes at the dropout ends - use the spray cans and thin nozzles here.

Do the same with the seat-stays.

For the downtube, seat stays and top tube,  put one finger over the hole at one end and 1/4 fill the tube from the other end. Plug this end with a finger and tumble the frame. Make sure you get all the surfaces inside the tubes. Drain well.

There - the job's done! Why not repeat annually? Your frame will never rust away.

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How you can prevent water building up inside your frame.

Water probably enters at the seat post slot even though you take extreme measures to keep it out. It was not possible to stop it getting into my old Bonty frame even though I tried.  I'd rather put my efforts into helping it to easily escape.

Water will obviously collect at the lowest spot in the frame so I drill a 3/32" hole under the BB shell. To stop this plugging up with muck I spent years and thousands of dollars developing "Mike's Patented Jiggle Valve". I'll tell you how it operates but don't make one or I'll sue the bike from under you.

Take an old spoke and snip1/2" off the end with the bend.  Then straighten the bend with pliers. From inside the BB shell, drop the spoke down through the drilled hole and re-insert the BB unit. That's it !! Don't try this at home as serious injury could occur and I AM a professional!

As you merrily pedal along the valve jiggles and keeps your hole unplugged (no the bike's, stupid). 

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Frames - Dented headtube.  Reaming and facing.

I recently read a web posting from a frustrated fellow whose frame had been shipped to him in a box.  The box had been dropped and the bottom lip of the headtube had been dented so that the headset cup could not be installed.

The first course of action here would be to collect damages from the shipper.  Failing this, here is the easy fix - obtain a metal bar about 1" diameter and 1' long.  Place the bar into the frame's head tube (from the dented end) about 1/2 or 3/4 the way up the headtube.  Now pull on the bar against the dent and massage the dent back into shape.
It would now be a good idea to have the frame's head tube faced and reamed to return it to its ideal dimensions.
Reaming - done with a special cutter to make sure that the internal diameter of the headtube is of the correct size to accept a headset cup.
Facing - done with a special cutter to make sure that the end of the headtube is square to the frame's axis and flat.
All good bike shops should be able to offer this service.