Mountain Bike Reviews Forum banner

1 - 20 of 25 Posts

·
Live 2 Ride
Joined
·
6,083 Posts
Discussion Starter · #1 ·
I asked a few of the OC members here, and I respect what they said. Now I would like a bit more input.

I recently traded up to a 2001 GT I-Drive. I was reading through the GT sub-forum and wanted to ask about the seat mask cracking. I don't mess with my seat height. I weight around 277 pounds and ride on the streets in my town along with light XC riding, some moderate downhill, nothing I would consider too extreme. They say this frame is prone to cracking. I'm afraid to ride it.

So what should I do?
 

·
Registered
Joined
·
15 Posts
I have an 96 GT I-drive and haven't had any issues. Ride and keep an eye on the area you know is a problem. Inspect it before and after. Ride it dude!
 

·
Live 2 Ride
Joined
·
6,083 Posts
Discussion Starter · #4 ·
The seat post is fully inserted. See the picture I am posting.

2014-03-31 16.10.11.jpg
 

·
Moderator
Joined
·
2,015 Posts
I had one, I'm a little lighter than you and rode xc with it. It cracked. They are just known for it. I've seen a few that other people cracked as well. Best thing you can do is keep some seatpost sticking out the bottom of the mast and cross your fingers.
 

·
Live 2 Ride
Joined
·
6,083 Posts
Discussion Starter · #6 ·
Or I could find someone trade frames with. Last thing I want is to be riding and hear a crack.
 

·
> /dev/null 2&>1
Joined
·
3,824 Posts
The seat post is fully inserted. See the picture I am posting.

View attachment 883298
Ok so this is good. To minimize the likelihood of a frame crack on this frame, you do want the bottom of your post to go as far add possible into the seat tube. And, luckily if this is your normal riding position it doesn't look like you ride very high, minimizing the leverage that the seat has on the frame. This will help minimize risk of frame failure.


But, side note, extending the post below the seat tube as you have it won't give you any extra strength benefits. In fact, yours actually looks too long and the shock might even bump up against it on full compression, so you might even consider cutting some of that off. Moreover you're going to want to drop your post a little on downhills right? Doesn't look like you could right now.

However, all that aside, I think the vulnerable point is where the seat tube 'triangle' meets the main triangle, and, stress there is a function of your seat height (which you have no control over), how hard you ride, fatigue, your weight, etc.

Personally I wouldn't worry about it because if you Google gt idrive crack and gt idrive failure, you find threads with a variety of failures in different places on the frame, but not a concentration of seat tube failures. Failures on an old AL frame like this can happen anywhere and I wouldn't lose sleep over it.
 

·
Live 2 Ride
Joined
·
6,083 Posts
Discussion Starter · #8 ·
Actually I don't lower the seat post at all for anything. When at full compression the shock goes down a bit, never been an issue.
 

·
Live 2 Ride
Joined
·
6,083 Posts
Discussion Starter · #10 ·
Kinda scared to ride it. What do I do if it cracks? :(
 

·
Registered
Joined
·
89 Posts
Aluminum frames do not last forever. We are talking about a 13 year old from here, there is a fatigue factor with aluminum. With your weight, I would not be tempting fate and having a issue where you could potentially get hurt. At least in my eyes I would be looking for a cro mo hardtail.
 

·
Moderator
Joined
·
2,015 Posts
Kinda scared to ride it. What do I do if it cracks? :(
It becomes a nice piece to hang on the wall.

When they crack they don't fail catastrophically, they just crack at the top and start to creak more then the I-Drives usually do. The crack grows each ride after that.

If it was mine and it was the only bike I had I would ride the hell out of it. Bikes don't last forever (usually).
 

·
gobsmacked
Joined
·
8,757 Posts
When they crack they don't fail catastrophically, they just crack at the top and start to creak more then the I-Drives usually do. The crack grows each ride after that.

If it was mine and it was the only bike I had I would ride the hell out of it. Bikes don't last forever (usually).
Kona, they generally don't suddenly blow apart in a billion pieces. You'll see a crack forming. You can ride it as long as you can and then replace it when it does fail. In the meantime, relax and get some exercise and lose some weight and all will be good. Stop fretting and get moving.
 

·
Banned
Joined
·
2,320 Posts
If so, you'll hear it start to creak, and have a good tale to tell.

Now, ride Sally ride...............>
 

·
Ride More, Work Less
Joined
·
7,774 Posts
Or I could find someone trade frames with. Last thing I want is to be riding and hear a crack.
Hearing the crack is fine. Not hearing the crack could be exciting. You've successfully traded bikes several times. Why not just trade this one as is? That way you don't have to break it down and rebuild on the new frame.
 

·
Content from my avatar
Joined
·
4,355 Posts
Dude, just ride it. It's not going to explode catastrophically. My old road bike (~2001 aluminum S-works) broke at the chainstay while I was riding one day. On a fast, sweeping, downhill (40 MPH), I noticed that the rear end was feeling kinda loose. So I got off the bike and checked it out. This is what I found.



I probably could have ridden home on it, but I decided not to risk it because there were some even faster, longer descents on the way home. So I hitchhiked instead.
 

·
Live 2 Ride
Joined
·
6,083 Posts
Discussion Starter · #20 · (Edited)
Quick question: how would I go about removing a rounded brake boss? Lock jaws?

EDIT: Nevermind. I got it out. :)
 
1 - 20 of 25 Posts
Top