If your running an 100mm right now then it will make a difference and if your running an 80mm it will make a big difference in the way the bike handles (ie Steering). A big change like from 80mm to 120mm could almost reach a point where you bike can be unsafe due to added stress being put on the frame (ie steer tube) On the other hand if your doing big drops then it may be desired to stretch out to 120mm of travel. If the Marathon S has an adjustment that allows you to set the amount of sag in the fork then you could increase the amount of sag and thus reduce the ride height slightly. Just a thought. I think I would go that far, but thats just me.ibleedblackandgold said:Hi guys, I am looking at a Marzzo Marathon S that has a real good price,but the travel is 120mm. Can my frame's geometry comfortably handle this beast? Any thoughts will be appreciated. Thanks
I think it is the other way around. a longer fork will give a slacker angle rather than steeper. you will probably bring it into the 60's.ibleedblackandgold said:my head angle is 70.5. If I increase my suspension by 40 mm, wouldn't that give me an angle of 72.5 which is optimum?
FreeRangeChicken said:You need to be really careful or you're going to end up with a really expensive wall ornament.
If your current bike has a 50mm fork and was designed for that fork, you could run into some big problems if you just slap a long travel fork on it. A few things are going to happen when you stick a longer fork on your bike:
1) loss of standover height - if you have a lot of standover right now this may not be a big issue, but if you only have an inch or two now, it cold be a problem
2) slackening head tube angle - This will slow down steering and if the change is dramatic, can cause the steering to feel like it flops from side to side. this also tends to unweight the front tire which can cause the front tire to wash out in corners[/edit]
3) slackening the seat tube - this shifts your weight backwards and may make it difficult or impossible to climb without lifting your front wheel off the ground.
I had a bike that I changed from a 64mm fork to a 80mm fork and found the setup to be completely unacceptable for me. You're talking about going from 50mm to 75-100mm. That's huge. If at all possible try a longer fork on your bike before you buy something.
I'm not trying to discourage or dissuade you. Just trying to make you aware of the possible pitfalls.
I have an '05 Trek 4300 and I put a Marz 105 EXR Pro on it. It rides great. It feels great and solid. The bike's slope does appear steeper but I don't feel any negative ride characteristics. I actually feel safer decending. I put a RaceFace stem with a lower angle on it and now it climbs better than before.ibleedblackandgold said:THANKS to everyones comments. I contacted Trek today, and they agreed with you guys that 100mm is the max for travel on this frame. They said since Marzo 105 forks crown length was about the same as Rock Shox 100, that would work too. So, I just ordered a 04' MX Comp Air 85mm from Pricepoint. I am still learning obviously, and thanks to you guys and to Trek, I didnt have to learn the hardway this time.