Mountain Bike Reviews Forum banner
1 - 15 of 15 Posts

·
Registered
Joined
·
31 Posts
Discussion Starter · #1 ·
I raised my seat on my hard tail(17.5 trek - and i'm 5.10")because it feels alot more comfortable like that(my knees are still slightly bent so it's all good). But when riding trails my weight doesn't feel right. Meaning, when riding trails with alot of rocks if my front tire hits a side of a rock it it makes my bike feel like it want to wash out(flip sideways...like if a quarter is rolling and falls sideways). This feeling is decreased and I have more control over the bike(in this manner) if the seat is lower, but then I have to peddle harder and is less comfortable. Any suggestions?
 
G

·
how much pressure are you running in your tires?

if they're too hard you'll have washout problems.
 

·
Registered
Joined
·
2,310 Posts
remedy: don't ride trails with alot of rocks. Just kidding.

Higher seat equals slightly higher center of gravity, slightly less control. Lower the seat for technical sections. It's about the tradeoffs for power/comfort to control and how often you are willing to adjust your seat.
 

·
Big Boned
Joined
·
1,535 Posts
The issue has little to do with where your seat is. It has everything to do with where your weight is.

If you're coming into a turn hot, or if you're about to hit a rock garden, shift your weight back (you may have to slide your butt back off the saddle a little) and unweight your front wheel by applying a smooth, steady backward pressure to the bars. Don't jerk your bars back, just lean back and hold onto the bars firmly and let your weight do the work. With your front wheel unweighted, it will float more easily over rough terrain, and it will hold traction in turns better.

The more weight you have over that front wheel, the more pressure you're putting on that tire tread, and it will drift sooner than if it's not weighted. Weighting the front end also causes your fork to pack up, and that limits its effectiveness. Unweighted, your wheel should bounce right over most average-sized rocks, and your rear wheel will follow.

Also, I could be wrong but your bike might be a little small for you. I'm also 5-10" (give or take 0.5") and I have a 31 inch inseam, and I know a 17.5" frame would require me to raise my seat way too high, and would also be too short in the top-tube. If you ran a bigger frame you could keep your seat lower and run a shorter stem, which would also help keep that front end under control.

FWIW, for XC I ride an 18.5 or 19, depending on the bike.
 

·
Registered
Joined
·
249 Posts
I'm 5'11" and ride a 17.5 but I have a 30" inseem. Technically I probably would have fit better on a 19.5 but I like the smaller frame in the more technical sections. Without knowing how your bike is set up or what kind of riding position you are in it's tough to say for sure why the rear is washing out on you. You could try moving the seat back on the rails, a laid back seat post, dropping tire pressure in the rear or maybe you jus need to get up out of the saddle in the rocks.
 

·
mbtr member
Joined
·
6,503 Posts
Manmountain Dense said:
The more weight you have over that front wheel, the more pressure you're putting on that tire tread, and it will drift sooner than if it's not weighted. Weighting the front end also causes your fork to pack up, and that limits its effectiveness. Unweighted, your wheel should bounce right over most average-sized rocks, and your rear wheel will follow.
this is bass ackwards. You weight the front end to get the tire to hook up. A tire that is bouncing around with no weight on it isn't gonna hook up too well. Sure, if it needs to go over some chunky rock or brake, you have to unweight it. Similarly, if you get your weight back and get on the rear brake, it sure stops a lot better than if you have your weight on the front.

when you're riding with your seat up pretty high, it makes the front end feel more dive-y. If you have low speed compression control, turn it up a little bit and the bike will feel a lot better.
 

·
Big Boned
Joined
·
1,535 Posts
scottzg said:
this is bass ackwards. You weight the front end to get the tire to hook up. A tire that is bouncing around with no weight on it isn't gonna hook up too well. Sure, if it needs to go over some chunky rock or brake, you have to unweight it. Similarly, if you get your weight back and get on the rear brake, it sure stops a lot better than if you have your weight on the front.
Yes, this is what happens when you unweight your front wheel **too** much. And there is such a thing.

But as is typical with responses on this forum, you didn't carefully read what I actually wrote. Which was "If you're coming into a turn hot, or if you're about to hit a rock garden..."

Go ahead and fly into a loose hard turn at speed and deliberately put your weight over the front wheel **on the approach** and stay that way as you enter the turn. See if you don't wash out or auger in.

When I used the words "Coming into..." and "About to hit..." I was talking about preparing for the terrain ahead by shifting your weight back, not trying to wheelie through the turn. That's just MTB 101. You can then lean forward or push the bars as needed to adjust and clear the obstacle or turn. In the case of a turn, that would be **after** the apex. But even then, you shouldn't have to consciously weight the front wheel to get traction. If you do, there's something very wrong with your tires, because it really doesn't take much to keep adequate weight over that front wheel.

Think about it like this. You're on a road bike on wet pavement riding fast, approaching a sharp turn. Do you want to lean forward and push that front wheel as you enter the turn, or lean back gently and let the front wheel pass the apex before shifting your weight forward? Answer carefully. Second prize is a set of steak knives. Third prize is a skin graft on your hip and forearm.

As with almost all bike handling skills, you have to start from a rearward-to-neutral position or else you have no bail out -- it's much easier to correct for being too far back than it is to correct for being too far forward, because often, too far forward = sudden meeting between face and dirt before you have time to react.

The OP's problem sounds like his seat is up above his bars, and that position is forcing him to lean forward onto his arms, like a time-trial bike does. The OP's issue was washing out, e.g. skidding sideways and having the bike tip out from under him.

Washing out indicates that you have reached the limits of the lateral traction your front tire can provide. It means you're leaning really hard, like a hockey stop on skates. Skipping or manualing would be the opposite of that -- your front wheel comes off the ground too easily.

There is clearly a balance between the two, and that balance shifts depending on where you are in relation to the obstacle.

But if your front wheel is washing out in turns, you're weighting it too much going in. No question.
 

·
Registered
Joined
·
251 Posts
coolmoed said:
I raised my seat on my hard tail(17.5 trek - and i'm 5.10")because it feels alot more comfortable like that(my knees are still slightly bent so it's all good). But when riding trails my weight doesn't feel right. Meaning, when riding trails with alot of rocks if my front tire hits a side of a rock it it makes my bike feel like it want to wash out(flip sideways...like if a quarter is rolling and falls sideways). This feeling is decreased and I have more control over the bike(in this manner) if the seat is lower, but then I have to peddle harder and is less comfortable. Any suggestions?
FWIW. ( I have just posted and discussed about how I bent my saddle rails. <G> However, I watch my riding style always with interest, and listen to others' tales. )

Raising saddle height is a great way to get better pedalling power, but as you are finding, offroad it has a price.

I reckon there are various things involved. You have altered the whole dynamic of the bike/rider unit.

How much did you raise the saddle? If it was significant (1" or more) then you will take some time to get used to it. This is not to say you just have to take it, but factor that in.

When you hit rocks are you off the saddle or on it? It helps a lot if you get up off the saddle a bit, for better comfort (for a start) and also to allow faster movement and responsiveness of the bike.

Is this uphill, downhill, on turns or just generally?

Generally: The simpler stuff.

Firstly, you are putting more weight on the front wheel by raising the saddle height. This could cause what you are talking about, although it will tend to actually give better traction on gravel etc. It can cause the wheel to fall harder off a larger object, where it may have bounced over, or not fallen as hard, with your body lower down. The front wheel has suddenly been given more control of the bike and rider.

Secondly, you are putting more weight on your arms as well, so you will feel the bump more.

Thirdly, because you're sitting more forward and down, you will feel more insecure about the front wheel. Have you tried riding exactly the same places with the lower saddle and seeing if your wheel does actually behave the same way (jumps the same distance) although it feels better?

I would try raising the bars a little, to see if that makes you feel more secure. It will also help to restore the balance you are used to on the bike. Do all of this bits (1/4" - 1/2") at a time and remember where you had it before. Every change you make will cause other differences and problems. If you can, do it in a controlled area with obstacles, rather than simply on a track.

Also try to get back a little when you are going to hit a rock. Downhill or flat that is. Do it uphill and the results can be interesting <G>.

Nick
 

·
Registered
Joined
·
31 Posts
Discussion Starter · #12 · (Edited)
ya, i was afraid my bike is a little to small for me because of this issue(i have a 32 inseam if that matters). i already have a extension on my bar so i don't feel so crowded. it kind of sux because the lbs guy told me(this was about 4 years ago) that i should go with the 17.5 for sure. but he was a shorter than me and i don't think he realized the feeling of being tall and the bike not fitting. that is just a guess.

the seat is level with the bars, but i have an extender that put's my bars up higher. if i didn't have the extender and stayed with the stock stem, the seat would probably be about 1-2" above the bars.

the ground is level with rocks. it's not super rocky. it's just got some rocks. and a rock about the half size of a baseball will want to make my bike flip sideways(more so in the front).

i can counteract the feeling by putting alot of weight back...pretty much so to where my but is hanging over the rear tire. or i can lower the seat back down (i think i raised it about 1 1/2"). but i'd like to be comfortable so i can achieve max. speed and endurance and doing these work arounds contradicts it.

if i wanted to ride at a decent seat position that is comfortable to me and still keep a good handle of gravity, am i stuck going to a large frame?
 

·
mbtr member
Joined
·
6,503 Posts
Manmountain Dense said:
But as is typical with responses on this forum, you didn't carefully read what I actually wrote. Which was "If you're coming into a turn hot, or if you're about to hit a rock garden..."

Go ahead and fly into a loose hard turn at speed and deliberately put your weight over the front wheel **on the approach** and stay that way as you enter the turn. See if you don't wash out or auger in.
or, i didn't quote that part because it was irrelevant. I've never had much trouble with my front end washing out in rock gardens, have you?

In your road bike example, i weight the front, its even more important that my tire conforms to the irregularity of the road since surface contact is compromised. My old XC bike didn't need me to weight the front much since my weight was always there, but my trailbike hooks up much better in loose rocks when i lean forward through turns. Hopefully this is a lost in translation thing, cuz this is a pretty basic concept.

Cool, be sure to stay as loose with your seat up as you were with it lower. It's easy to stiffen up when you are effectively losing leg-suspension.
 

·
local trails rider
Joined
·
12,300 Posts
Even with the seat high, you can still move your weight forward and back, up or down.

When the terrain gets interesting, I usually get best results with my center of gravity low. That means elbows bent and chest low. It might also mean moving my backside more or less behind the seat, to prevent having too much weight in the front.
 

·
Registered
Joined
·
251 Posts
Ok. Set level with bars is about right. 17.5" _might_ be on the small side, but should not be a disaster at 5'10", especially as it sounds as if you have longish legs for that height. So the rest of you is not so long! <G>

1.5" at one go is a lot to raise the seat IMO. If you were continually changing it for up and down hill work, it's different, but as a once-off, it will throw off for sure. Drop it down 1/2-3/4". Ride like that and get used to it. Then try again.

Rocks can be a real biznitch, especially if loose.

However, there are some techniques.
(1) miss it! <G>....seriously, try to pick a line. But if you go around the rock with the front, be prepared for the little sucker to catch your rear and remind you it's there! <G>
(2) because you have a lot more weight on your front, to retain control you are going to need to be more active. Riding around with your bum back all the time is not the only way, and gets a bit tiresome. If you enter a patch of rocks that you know are going to be trouble, _then_ get the weight back and down (not too extremely on the flat), and as someone said, bend the elbows and "frog' a bit to get the weight low and spread evenly along the bike. Also to absorb shocks. This will try your triceps at first.
(3) But if you see an isolated rock coming, by all means move your bum back (bit only just in time), and as you get to the rock, lift the bars a bit, to get over the rock, and not simply crash into it. This allows you to not have to move so far back all the time and lets you have control rather than just falling away from the rock.
(4) Don't do all of this really extreme at first, and know that every situation is going to be a bit different. There is no "stance" that will get you there. The idea is to start easy, and get used to the feel. Don't just expect the same action to suit all occasions. I think I said that before, but I feel that it's terribly important. You need to practice, make mistakes and get a feel for situations that are _like_ the one you are approaching. Also, be ready to fail later. I have this particular rock that I climb over. For the last week it has me psyched. Just can't get it. Hate it.....sorry I digress.
(5) Learn to not lean on the bars. Use your torso to help you sit the bike. I like to call this "riding light". You keep weight on the pedals, not on the seat, even when pedalling (this is NOT standing up to pedal but just making sure that your weight is on the pedals and )and use your legs and body to get the weight off the bars. At first it will tire you, but in the end it will reward you.

Have you done any other sports? MTB is a tough sport. It requires a very active response to every situation and puts your body through quite a bit, both by pounding and because you need to really work at it. You and the bike are a naturally-unbalanced, tightly knit thing. A lot of people do not realise that, especially if their only experience is road cruising (although I would rather fall off a rock than get tangled with some ignorant twerp in the $4WD <G>)

So if you have done any other hardish activity, apply the mindset to MTB. Adapt actively to every situation. We're talking football and basketball and kayaking rapids here, rather than baseball.

Apart from that, some of this is simply getting used to the new feel.

Enough gibber.

Nick
 
1 - 15 of 15 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top