# Cracked seat tube. Fix, or replace frame??



## JHensley (May 11, 2020)

Hi everyone. 
I bought this bike (diamondback overdrive) last spring. I've ridden it all last spring/summer/fall. Almost every weekend. A couple of weeks ago the seat tube cracked on me. I don't have a tig welder, so I tried using some aluminum brazing to fix the crack. It didn't hold. I'm becoming rather frustrated as this is the third week I have been unable to ride due to a broken bike!
I also noticed that my seat post took a little bend from the leverage on it.

I am 6' tall 265lbs. The only riding I do is my local mtb trails, bumpy with a lot of roots and climbs.

If you would suggest replacing the frame, can you suggest a better frame?


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## JHensley (May 11, 2020)

No input from anyone?
New frame suggestions? Something hopefully under $1k


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## mlx john (Mar 22, 2010)

Steel is real. Look for a Kona Honzo frame, new or used.
Availability might be an issue.






KONA BIKES | MTB | HONZO | Honzo ST Frame


The cult favorite continues. The Honzo ST frame is the bike you’ll find under a messenger, under that old-school soul ripper, or under the rider who really wants to build something beautiful and custom. A 66-degree headtube is ideal for all kinds of tricky, steep terrain, and the short seat tube...



konaworld.com


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## bjcccat (Jul 28, 2009)

Salsa Timberjack Alloy Frameset, well under $1k.


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## bjcccat (Jul 28, 2009)

Also, just be aware that with your slight setback seatpost and your saddle clamped at the most forward rail position a rider at your weight can be putting serious leverage on that seat tube, likely contributing to the crack.

However, alloy bikes with long seat tube segments that extend above top tube can be more likely to have these failure.


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## JHensley (May 11, 2020)

Thank you for your input guys. I was also thinking that steel would probably be a better option.
I guess the difficult task now will be finding an available frame.


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## brawlo (Mar 13, 2012)

Pay some attention to what has caused the issue, otherwise you could just be looking at a repeat on your next bike. Maybe a longer seatpost so that there's more overlap within the frame. Maybe look at a thudbuster style seatpost to absorb a big chunk of the impact if you stay with a hardtail frame.

Also, repairing an alloy frame can be beyond the abilities of most backyard hacks. Some alloys require specific treatment at welding.

**Looking at the pic again, is it possible that the cracking originated at the top of the weld of the small gusset? Could be a warranty fix if it did, but your braze effort could hinder that process


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## Dawgprimo (Mar 7, 2004)

I would take it to a qualified frame builder and see if they can fix it.
if anyone could it would be them.
You might have to call a couple till you find one willing to fix it.
Otherwise you are shopping for a new frame.
Unfortunately this is not the best time to be shopping for a new frame or used frame.......as you know it is pricey and lack of inventory.
Just my 2 cents!


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## justin70 (Sep 17, 2007)

pole taival


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## TooTallUK (Jul 5, 2005)

Your frame is dead. Not worth the effort to try and repair as it will fail again.
That's not a great design for that area of the frame. too many small pieces of metal and too many welds. Don't worry about whether the next frame is alu or steel - I'm your weight and have ridden alu for decades with only 1 frame breaking after 10 years of abuse.


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## sixate (Feb 27, 2008)

Time for a new frame, but how far down does that seatpost go? And it looks like your saddle rails are bent too. Warranty on the frame?

Not much available for replacement. Best to check your local shops and see if they even have anything.


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## JHensley (May 11, 2020)

Good news! I found a frame!

I have a lead on a kona hanzo that I'll grab to replace my diamondback. An upgrade for sure.

As far as the Diamondback, I may take it to a fab shop and have the seat tube repaired. We'll see.


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## TooTallUK (Jul 5, 2005)

Congrats on the Kona frame find! 
You'll be throwing good money after bad if you try and repair that frame. Given the welds there and the need for hear treatment it will never work. I've seen similar breaks and never seen a repair that lasted more than a couple of rides.


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## NYrr496 (Sep 10, 2008)

I had a frame repaired after that exact same crack. This is the only guy in the whole world I would have trusted with the fix. This was four or five years ago. Still good. Frame is actually re powder coated and going to a new home. The new owner is fully aware.


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## bjcccat (Jul 28, 2009)

Sorry, didn’t mention this before. Your frame should have anywhere from 5 years to a lifetime warranty. Have you filed a claim with Diamondbac?

Even if you get a new frame from another manufacture, it is still worth seeing if DB will replace this one.

If not caused by a crash, they should replace.


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## JHensley (May 11, 2020)

bjcccat said:


> Sorry, didn't mention this before. Your frame should have anywhere from 5 years to a lifetime warranty. Have you filed a claim with Diamondbac?
> 
> Even if you get a new frame from another manufacture, it is still worth seeing if DB will replace this one.
> 
> If not caused by a crash, they should replace.


I will try to contact Diamondback. I bought this bike secondhand through ebay. It is a 2018, so I think I should be okay?


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## JHensley (May 11, 2020)

I just checked Diamondback's website. The warranty is a dead end in my case. 

I am not the original retail purchaser, I have modified the bike, I tried to repair it, and I painted my repair.

Next time I'll look at warranty info before I try anything. For this purpose, I also made sure to buy my new frame new from a retailer. This way I can register it and hold the lifetime warranty that Kona provides.


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## justriddinalog (Sep 8, 2020)

6000 series aluminum is considered non weldable without post weld heat treating. 7000 series is weld repairable and strong enough as welded provided the proper filler metal is used. IF you find someone that will repair it keep in mind its more luck than welder skill that will determine its lifespan


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## JHensley (May 11, 2020)

Kona Honzo St frame showed up today. Just lucky enough to find one available from a small bike shop in Bath Maine!


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## Jayem (Jul 16, 2005)

One big key is to use a frame big enough for you. If you have a lot of exposed seatpost, it doesn't matter how much insertion you have, you have created a giant lever and will eventually break the frame. Unfortunately, lots of shops and people in the 90s created this idea in people's heads that you always need to "downsize" and there was some truth to that back in the day before dropper posts, short stems, short head-tubes and dropped top-tubes, but these days it's a bad idea for structural reasons and because it'll cramp your position most of the time.


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## NYrr496 (Sep 10, 2008)

That’s a cool shop. I’ve been in there.


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## mlx john (Mar 22, 2010)

Sweet frame


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## JHensley (May 11, 2020)

NYrr496 said:


> That's a cool shop. I've been in there.


Bath cycle and ski?

I came across bikeman.com while looking for frames. They had a small, in stock on their site that I somehow mistook for a large. I called to check their inventory and they had one large left, hidden away in their attic! Great price, really fast shipping. I wish I had a bike shop like that local to me.


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## NYrr496 (Sep 10, 2008)

Yep. I have family in Maine 15 minutes away from that shop.


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## JHensley (May 11, 2020)

I just wanted to share a couple of photos. I've been riding this guy for the last 3 weeks now. Awesome replacement!


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## Bob-o-matic (Jun 25, 2021)

Bike looks great. Maybe a blessing DB frame broke? I look for bikeman alot when I shop... great selection, fast shipping to VT.

I'm also a clyde and worry about breaking stuff. Luckily I've only bent seat post and rails ...until trying a suspension seatpost... Like a Thudbuster that was metioned earlier. It's not true suspension but it makes ride a little smoother and reduces some of the ''leverage'' also mentioned in an earlier post. Since using Thudbuster [ long travel ] I've had same seat for 4 seasons now... Was getting new seat and post every Xmas.


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## JHensley (May 11, 2020)

This was definitely a blessing in disguise! This Honzo is a much better bike than my DB was. I think I may try one of the thudbuster seatposts. I've just kind of exhausted my bike budget for this year!

I will also need to replace my Sid Fork with the correct travel. I should have a 140mm fork, this is 120mm. I have had a lot more pedal strikes than I should.

I love the Honzo. It's great!


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## D. Inoobinati (Aug 28, 2020)

I've gone through a couple of thudbusters, but have used them primarily on my commuter bike where the tires are rock hard. I'd go with a dropper post and softer, bulletproof tires.


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