Ok, geometry questions 🙂 Yay!

I have bought a Full Suss Giant Ac1 frame off a friend, in a hope to build up a project, learning about the way bikes work etc in the process.
Now i have done some research on this bike, and as standard i believe it was sold with a 130mm travel front fork.

Now, although i am building up this frame as my first project, i’m trying to spend a fair amount on components, so after it’s built, i can push everything over onto a new built lightish freeride frame in the future. I understand the geometry of the bikes plays a big part in everything, so this is my question.

How do i know what the maximum length fork my frame can take? What disadvantages everything will have, what pros it will have, does the angle being changed mean it can be countered with the stem you buy?

I believe the Head Tube Angle – 69 Degrees

I’m hoping this isn’t too much trouble for somebody to answer, if it is i apologise for the inconvenience 🙂

Thanks
TomO

http://www.sheldonbrown.com/rinard/forklengths.htm

69 degrees is, these days, considered pretty steep for this sort of bike. While they did, yes, come with 130mm forks, many people have upgraded to 150mm ones. I even rode one once with 170mm dual crown forks on it. A lot of people ran these as light weight DH bikes. The majority of cracks and breaks in this frame were around the seattube.

You should be OK fitting a longer fork, but perhaps consider an adjustable travel one such as a Rock Shox Lyric or Manitou Travis- drop the travel for your Giant, then when you get a new frame up the travel.

mrmichaelwright – Thank you

rolfharris – i was looking around 150 to 160mm so you seem to have out my mind at rest slightly. In regards to the cracks and breaks, i like to ride fast, but generally pretty close to the ground so nothing break worthy hopefully 🙂

Thanks to you both

I'm not saying breaks were a common thing, just that when they did happen it tended not to be fork stress related.

Stick some totems on it – the axle to crown height will be less than some of the triples people used to run on them and you'll have an excellent fork for your next build.

You sure about that MrGnar?

most dual crown forks will allow you to raise the stanchions so for the same amount of travel A-C length can be run much shorter than a single crown fork.

GW

You sure about that MrGnar?

Well now that you ask no, not 100%. If I recall correctly though the axle to crown height on totems is roughly similar to the old boxxers. At any rate the totem is just about the only decent fr specific fork on the market (excepting 2010 66s if they aren't tripe).

most dual crown forks will allow you to raise the stanchions so for the same amount of travel A-C length can be run much shorter than a single crown fork.

If you ignore min and max adjustments yeah.

mate has a AC2 and used to run double crown Marz. 170mm. now runs a U-turn Lyrik (115-160) and swears that 145mm is 'where-it's-at' both front and rear. soon i'll get him to ride a HT.

bit of a bitch when it comes to riding uphill due to the seat angle. not my type of bike but he's 'begeistert' (thrilled)