BoBo

Thinking about going rigid but, Im not sure if there are any restraints with my frame or anything.

I ride an '03 Giant Iguana Disc can Front Suspension Hardtails use a rigid fork? and if so the fork comes in two sizes 400mm and 425mm what would I get? or how would i measure to find out

yes

I recently got the nashbar rigid, b/c it was on sale for $35. It had a longer measurement (I think 460mm), and matched up better w/ my 05 Trek w/ an 80-100mm fork. Check the measurement on your current fork b/t the axle and crown race for your headset. Look up how they do the measurement for the fork you want to buy.

BoBo

whats b/t? is it by the? and did you mean crown face?

anonymouse99

I use b/t as shorthand notation for between. Although he very well may have meant something else, I think he meant that.

AnthonyG

When you fit a standard length rigid fork you will change the frame geometry compared to a suspension fork, effectively steepening the geometry. You can buy forks that are extra long that maintain the origional geometry however you may prefer to go with a shorter fork for improved aerodynamics and performance anyway. Since typical Mtn bikes have very slack head angles you will probably benifit from a steeper head tube angle although with seat tube angle it might be more complicated and it depends on whether you are after improved performance or you still want a relaxed riding position. If your setup allows you to move your saddle back further this would be a good starting point to try when you fit a shorter/standard rigid fork.

I did a quick measurement of my bike and the 400 mm fork is more standard and the 425 mm is a little elevated.

Regards, Anthony

BoBo

now what should i be measuring, i measured he leg (not sure if thats what its called) and it came out to exactly 420mm so its the same length as the other one, which i messed up on and it isnt 425 it is 420mm. So would it be the same fit? Im getting into Trials riding and need a rigid fork for that so would it be the proper fit for my bike?

AnthonyG

Well I don't know anything about trails but I assume that you want the longer ones inorder to maintain your rearward balance and riding position. The shorter one's would be better for road use. Have a look at what other trails bike's have and I would assume that they have a lot of front wheel clearance with the front forks jacked up.

As to what to measure I assume its from the dropout to the bolt hole in the middle of the fork crown (that would be traditional) but since modern forks don't always have that bolt hole its anybody's guess.

Regards, Anthony

Peek the Geek

This section on rigid fork sizing comes from Vicious Cycles' web site:

How to select a mountain fork to fit a particular frame:
The best way is to measure! Using a tape measure, find the distance between the top of the front portion of the race ring (where the headset mounts) and the center line of the front axle...No tape measure? These are some general, but not foolproof guidelines to help achieve the correct fit. If your bike is a 1996 model or older use the 413mm model. If your bike is a 1997 model or newer use the 425 mm model. If your bike is a 1990 or earlier you will probably be needing a Vicious Cycles short length mountain fork which is available by special order. Please be aware that some manufacturers pay no attention to industry standards in which case only a direct measurement will be accurate.
[from https://www.viciouscycles.com/forks.php3]

Your fork, according to the Giant web site, is an 80mm travel fork, so you'd most likely want to go with the 425mm rigid. Measure according to the advice above to be sure.