doingthis

Hello Anyone (first post),

I've just purchased a Giant Rainier 2001 frame. I get a lot more enjoyment out of building things than I do out of just buying them new, so I'm used to problems coming up and solving them. Also, I'm an engineer with a good amount of mechanical background so I don't shy away from challenging problems, but I much prefer to research things before I dive in, except maybe in that very rare situation where it just requires "quick and dirty--get it done" mentality.
So my question is: (and please give me links with further information if available so I can get up to speed) I need to know where the measurement is taken (in the head tube) which determines the size requirement for the headset. (e.g. Measure the I.D. of the existing bearing, measure the I.D. of the head tube itself). I don't have any fork with the frame and my limited understanding is that the Giant Frame has an "integrated" (I'm assuming it can still be replaced) headset. Measuring the smallest I.D. of the existing bearing installed in the head tube gives 1.178" (29.92mm). I've never looked at any of the headset measurements because this is my first bike in about 10 years (mostly into BMWs lately...no I'm not an old preppy, just like to work on them). The Marzocchi fork that I ordered is 1 1/8" which I'm assumming is the O.D. of the steerer tube. And I just thought there would be an interference fit of the fork steerer tube and the bearing races in the head tube. (Obviously, just taking one apart would probably answer all my verbage, but I don't have a complete bike lying around).
Please explain how the Giant frame is "different", what I need to do to install a standard headset (looking at an FSA pig DH 1 1/8"), reducers, etc., and where can I get these parts.
Thanks in advance for the help. The next thing I'm doing with the frame is magnafluxing it to check for stress fractures and then I need a real expert with a TIG welder to weld the V-brake standoffs on the rear of the frame. (Also, I need a contact with a frame manufacturer to get some suppliers lined up for some odd ball materials I'll be needing. Preferably in the manufacture of aluminum tubing, etc.). And finally, has anyone got a good LBS near or around Scottsdale where I can rent some tools occasionally. I've got a number of these bikes to build up with varying frame makers (mostly all aluminum or carbon at this stage), and I need to start buying/renting some tools, but borrowing would be helpful in the beginning. Specifically, I need a thread chaser and facing tool for the BBs.
Lastly, who's got some experience with X-type installations? I'm hoping to get some "throw-away" bearings for failure analysis and sizing purposes.
Sorry for the long post. :-)

-Jeff

hypersnazz

https://www.giantbicycle.com/us/030.0...01&model=10354

IIRC Giant uses the Cane Creek IS standard, not Campagnolo. These headsets are readily available at a bike shop near you.

I don't have any information about Scottsdale, so I can't help you there. Bottom bracket thread chasing and milling tools are kinda pricey, so unless you're doing it a bunch not really worth the investment.

By 'X-type' I'm assuming you mean bottom brackets. The dimension specs are all the same, Shimano, FSA, Truvativ (and other cranksets made by Truvativ) and I believe Race Face as well, so pretty much whatever cups you can get your hands on should work with any given matched set of crank arms and applicable spacers.

sheba

Headset measurements are done on the inside diameter of the headtube itself. The usual standard on mountain bikes is 1 1/8 inch. Giant headsets are 41.3 mm. If you really wanted to measure the ID of the headtube yourself, you will need to punch one of the cups out. Punching out a headset can be done the ghetto way (with a punch and hammer) or with a special tool (see this).

Also when installing a headset cup, it can be done the ghetto way (block of wood and hammer) or with this.

A little on Integrated Headsets: I tend to side on Chris King with their view of IT headsets. You can check out their press release here. Although, Giant headsets are not technically IT headsets in that the bearings don't rest directly on the frame. Giant uses zero stack headsets in which there are actual replaceable cups. However, zero stack headsets only press into the frame about a millimeter. In my opinion, this lack of contact surface does compromise the structural integrity of the frame. True, on their downhill and freeride models they use the standard 1 1/8 inch, allowing a wider selection of quality headsets, but I think 1 1/8 is the way to go for everything.
Oh yeah, on their STP model, intended for dirt jumping/urban, Giant unfortunatly uses a zero stack headset. I can just picture an ovalized headtube waiting to happen.

for what it's worth

doingthis

Sheba,
Thanks for the information. Unfortunately, I'm still confused. You say the inside diameter of the head tube is what you measure, and "standard" mountain bikes are 1 1/8th inches. But I thought the O.D. of the steerer tube was 1 1/8th inches. Basically, that would leave zero space for the bearings. Also, if the Giant headtube I.D. measurement is 41.3mm then that is 1 5/8th inches, which is 1/2" larger than other headsets. I would think these bigger bearings would be sturdier??
Also, looking at the bearings that are pressed into the headtube, I see they are definitely pressed in more than one millimeter. A millimeter would be less than 1 25th of an inch?? Are we talking about a 2001 Giant Rainier? I popped one out and the race shoulder depth is approx. .275 inches which is just less than 7mm.
-jeff

sheba

shucks shoulda proofread better
your right, the OD of the fork is 1 1/8 not the ID of the head tube
did I write millimeter, I meant to say centimeter

veteran_youth

The aluminum Ranier frame will need to be re-heat-treated after any welding is done to it. This will likely require repainting too. As far as the brake bosses go, you may be able to order an aluminum female end through QBP, the threaded steel part that the brake actually mounts to are fairly common but come in several different thread pitches.

As for the headset, just get to your nearest Giant dealer and tell them what you need. Depending on the bearing quality 35-55 installed is reasonable.

Andrew

www.cycle-solutions.com

veteran_youth

Sorry to repost, but reducers are available from Giant too, should be about 15 for the pair, I am in Canada so I am not sure exactly what US pricing is like. The integrated Giant headsets do work well though, and will probably cost the same as Pig w/reducers.

Andrew