120mm forks too much for hartail?

[marcopolo]

I'm not a member of any cycling :tinfoil:forums but reckon there are a few cyclists here so I have a question.

Will 120mm be too much travel for my 16in hardtail? 100mm more suitable?I'm wanting to do more technical rocky trails but am worried about screwing up the geometry of my bike (I currently put 75mm forks on my frame). I'm comfy with the rear of the bike running big 2.35's so am not too worried about moving to full sus.

Tried Glentress (Scotland) red route and my v-brakes and 75mm forks were way out of their depth today. My wrists/arms are damn sore from pulling brake and hitting big stones!! Hit the trails hard and fast but there is just so much fast rubbly downhill my whole front end was shaking apart!

Help!.

Marco.

 

[Coop]

120mm is too much for any hardtail unless you're going to do some serious dirt jump or freeride stuff. 100mm should be plenty for most forms of trail riding. If your fork bottoms out, you might want to look into stiffer springs or dampening adjustments. For me this made a world of difference. I used to run a 80mm fork, upgraded to 100mm and still had the same problems. I was ready to buy yet another fork but instead I switched some of the forks greasy bits, and after that the fork was perfect. The price difference between the upgrade kit and the fork the LBS recommended was over $500!

 

[orbital]

+

First thought is 120mm would be too much.

Some questions:

1. What is the fork you have now?
2. Is your fork adjustable?
3. How hard are you grabbing your bars??
4. Is your upper body tense when you ride?
5. Do you feel relaxed when downhilling?
6. How much off road riding do you do per year & where?

I mean no disrespect by any these questions, they are all factors.

 

[mechBgon]

Also, long forks exert more leverage on the frame. If the bike's frame is a lightweight cross-country-racing type that's built for forks in the 80-100mm range, then you might be wise to switch to something in the all-mountain category if you want to just bolt on a 120mm+ fork and blitz the nasty stuff.

 

[marcopolo]

Thanks for replies everyone.
Orbital:

1.RST 381R (very rubbish old fork)
2.No, not adjustable
3. Very hard but only because i've got v-brakes! (will get disc with my new fork.)
4. Maybe a bit. When I was doing the downhill bits yesterday I tried to "let got a bit" and relax my arms when I spotted myself tensing up.
5. Generally, yes Except when I don't know whats over the next dropoff! Honestly i'm still figuring out how to effectively ride downhill although i've been riding timid xc terain for years.
6. 2 rides offroad per month in and around Scotland (muddy, damp, rocky)

thanks,

Marco.

 

[270winchester]

the frame is the big variable. If the frame was made with a specific Axle to Crown height in mind then changing the travel, or even changing between forks of same travel can cause a change in the handling. Most newer hartails can handle forks in the 100-120mm range, the head angle only changes by a degree or so going from 100 to 120, but some forks have longer A-to-C length than others. ALso a good 100mm fork will be better than a 120 mm fork with poor damping.

 

[Coop]

Maybe it would help if you told us what frame you're running.

Don't be ashamed if it's old & uncool... My hardtail will be 10 years old next year (and still going strong)


And a little heads up, Wiggle.co.uk has a sale on forks this month. I saw some pretty good deals on their site

 

[marcopolo]

The frame is a "Handsome Dog" 16in double butted, 7005.

Virtually identical to this (except no rear brake mount. Got the frame in 2005.)

 

[orbital]

Thanks for replies everyone.
Orbital:

1.RST 381R (very rubbish old fork)
2.No, not adjustable
3. Very hard but only because i've got v-brakes! (will get disc with my new fork.)
4. Maybe a bit. When I was doing the downhill bits yesterday I tried to "let got a bit" and relax my arms when I spotted myself tensing up.
5. Generally, yes Except when I don't know whats over the next dropoff! Honestly i'm still figuring out how to effectively ride downhill although i've been riding timid xc terain for years.
6. 2 rides offroad per month in and around Scotland (muddy, damp, rocky)

thanks,

Marco.

+

Marco, really try to relax your upper body and hands when you ride.

Grab on to your grips only hard enough to stay in control,...no more.
Picking a smooth line while downhilling while staying relaxed, will do more for you than you'll ever know.

Get a fork with stiffness adjustability @ 80~100mm.
I can't speak for disk brakes because my XT V-brakes are plenty powerful enough (Kool-Stop pads)

~ Personally, I have a hard tail and cross country ride. (I like to climb )
Lived and mtn. biked in Oregon, California, Wisconsin, Colorado,..currently in Wisconsin with some of the best riding anywhere,....really!!!

 

[Gimpy00Wang]

Another thing to consider is how the steering response will change. Increasing the fork length will slacken the head tube angle -- which in turn will make the bike respond more slowly. On the positive side...more slack gives more confidence when descending. It can also make climbing more difficult.

So you need to strike a balance. You don't want the head tube angle to be too slack or too steep. What is "just right" depends on your riding style, terrtain, etc, etc...

- Chris