Author Topic: Diamondback bike - forks are seized - can I DIY this?  (Read 1524 times)

meghan88

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Diamondback bike - forks are seized - can I DIY this?
« on: July 20, 2017, 01:43:50 PM »
While I've mucked around on chains and derailleurs and tires etc., I've never tackled forks.  I poked around online and found some stuff about how to replace the forks, but nothing on how to fix them.  Do I need any special tools - e.g., something to get off the caps at the top of the stanchions.  I was hoping for a quick fix to loosen them up somehow without taking the whole thing apart, but I might be out of luck. 

Maybe trying to get some oil around the inner stanchions to seep down into the works, and then a few hard hits with a rubber mallet?

I figure I might just keep riding it as-is if it's too difficult.  A pic is attached.

roastbeefbandit

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Re: Diamondback bike - forks are seized - can I DIY this?
« Reply #1 on: July 20, 2017, 05:09:56 PM »
You probably won't have a whole lot of luck oiling and beating the thing. I can't tell what brand the fork is there, but it looks to be pretty cheap. I would recommend replacing the whole fork, as the replacement parts, if you can find them, will likely cost as much as the whole fork. I just replaced a set on a bike a few months ago for $100 off of ebay. A few notes on that:

1. make sure you get the right size steering tube (looks like 1 1/8" threadless, but please measure!)
2. don't forget to get a star nut to put in the top of the steering tube to thread the bolt for the headset into, should be a couple of buck at your local bike shop, or 5-7 on Amazon
3. make sure you get a fork with mounts for cantilever brakes. Many come only with disc brake mounts these days.
4. don't get a wildly different shock length. It will change how the bike rides. You should stay at or under 100mm on that one.
5. looks like 26" wheels. Don't get a fork for 29" wheels!

Checkout the link for some that might work for you, again PLEASE DOUBLE CHECK MY GUESSES AT YOUR BIKES SIZES. I don't want you to get the wrong part!

https://www.ebay.com/sch/Forks/177815/i.html?Brake%2520Type=Cantilever&_udhi=100&_mPrRngCbx=1&Steerer%2520Tube%2520Diameter=1%252D1%252F8%2520inch%2520Threadless&_from=R40&_nkw&For%2520Wheel%2520Size=26%2522&_dcat=177815&rt=nc&_udlo
« Last Edit: July 20, 2017, 05:12:48 PM by roastbeefbandit »

meghan88

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Re: Diamondback bike - forks are seized - can I DIY this?
« Reply #2 on: July 21, 2017, 08:27:11 AM »
Thanks for the info.  It's a Diamondback Ozark bike - probably the original shocks.  Diamondbacks are supposed to be decent bikes for the price.  I paid 80 for it so I'd probably rather ride it as-is than spend more than what I paid for the bike on new shocks.  It'll only be used for commuting in any case, though I am a bit spoiled because my other bike has working shocks.

We have a bike co-op in town and I might end up taking it there to see if they, and borrowed tools, might help.  Sometimes they have a reasonable selection of used parts.

rothwem

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Re: Diamondback bike - forks are seized - can I DIY this?
« Reply #3 on: July 21, 2017, 09:43:58 AM »
I wouldn't bother messing with the fork.  From the looks of the bike, its a commuter, and honestly, a suspension fork only slows you down on the road.  If the locked up fork really bothers you, then get a rigid fork to replace it like this:

http://www.nashbar.com/webapp/wcs/stores/servlet/Product_10053_10052_174928_-1___


meghan88

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Re: Diamondback bike - forks are seized - can I DIY this?
« Reply #4 on: July 21, 2017, 01:57:35 PM »
Thanks.  I'm wondering if a seized-up fork is the same as a rigid fork, so I might as well just leave the seized-up one on there anyway, unless it's a safety issue to be riding around on a seized-up fork?

sandmaninator

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Re: Diamondback bike - forks are seized - can I DIY this?
« Reply #5 on: July 25, 2017, 04:32:47 PM »
I have a Nashbar rigid carbon fiber 26" fork with 1&1/8th straight steerer which I just took off my hard-tail bike in order to put a shock back on.
I did it because the rigid fork did not have suspension-adjusted geometry and it caused the front end of the bike to be too low.
New shock fork corrected that problem.
Anyway, I am willing to part with the rigid fork if anyone is interested. Say, $50 + shipping?
It has about 8&1/4" of steerer tube left. I am happy to measure and provide pictures.
It has both disc and cantilever brake mounts.

rothwem

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Re: Diamondback bike - forks are seized - can I DIY this?
« Reply #6 on: July 26, 2017, 10:03:03 AM »
I have a Nashbar rigid carbon fiber 26" fork with 1&1/8th straight steerer which I just took off my hard-tail bike in order to put a shock back on.
I did it because the rigid fork did not have suspension-adjusted geometry and it caused the front end of the bike to be too low.
New shock fork corrected that problem.
Anyway, I am willing to part with the rigid fork if anyone is interested. Say, $50 + shipping?
It has about 8&1/4" of steerer tube left. I am happy to measure and provide pictures.
It has both disc and cantilever brake mounts.

I don't want to kill your sale, but the OP is going to have the same problem you did, since she currently has a suspension fork on the bike. 

The one I linked to, btw, IS suspension corrected, you could get one of those too.

sandmaninator

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Re: Diamondback bike - forks are seized - can I DIY this?
« Reply #7 on: July 26, 2017, 04:33:34 PM »
Yeah, that's why I said "anyone ".  Ideal customer would be someone with a bike that originally came with a rigid CroMo fork and wanted something lighter and an upgrade to disc brakes. Shimano hydraulic disc brakes are getting very reasonably priced these days!
Anyway, I am off topic from the OP.

meghan88

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Re: Diamondback bike - forks are seized - can I DIY this?
« Reply #8 on: July 27, 2017, 10:29:49 AM »
That's OK.  I'm sure you'll find a buyer.  My main concern at this point is whether the seized fork is a safety issue, but I don't see how it could be?  I might take it to the bike co-op here to see what can be done.  On Tuesday I took my other bike (an old Trek) to the co-op and I re-packed the bearings in the front wheel hub by myself - cost for the new parts was $2 and they have all the proper tools onsite.  Sometimes they have suitable old parts such as seats, forks, chains etc. that they sell for a song.  Love that place.

rothwem

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Re: Diamondback bike - forks are seized - can I DIY this?
« Reply #9 on: July 28, 2017, 06:06:24 AM »
That's OK.  I'm sure you'll find a buyer.  My main concern at this point is whether the seized fork is a safety issue, but I don't see how it could be?  I might take it to the bike co-op here to see what can be done.  On Tuesday I took my other bike (an old Trek) to the co-op and I re-packed the bearings in the front wheel hub by myself - cost for the new parts was $2 and they have all the proper tools onsite.  Sometimes they have suitable old parts such as seats, forks, chains etc. that they sell for a song.  Love that place.

I wouldn't think that it would be an issue.  Seized is better than broken internally and bobbing around.  At the risk of sounding like a bike snob, you're not going to be able to do much with that fork, its a really low end fork.  The way you fix a fork is you buy a rebuild kit that has new bushings and seals, but I sincerely doubt you'll find a rebuild kit for that fork. I wouldn't be surprised if the bushings are molded into the lowers somehow and non-removable. 

Enjoy your new rigid fork and its increased efficiency!

BlueMR2

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Re: Diamondback bike - forks are seized - can I DIY this?
« Reply #10 on: July 29, 2017, 10:08:43 AM »
Thanks.  I'm wondering if a seized-up fork is the same as a rigid fork, so I might as well just leave the seized-up one on there anyway, unless it's a safety issue to be riding around on a seized-up fork?

Could be a really interesting surprise if it ever were to unseize on you at in inopportune time...  Might be uneventful, but *could* put you face first on the pavement with expensive dental bills (or even death if it happens in a busy intersection).  Safe route would be to just replace, and as mentioned, with something rigid due to your uses anyways.  That said, I personally would probably ride it as-is as long as there were no warning signs.  I leave lots of safety margin in my riding as equipment failures *can* happen unexpectedly no matter how well you maintain your equipment!  You'll have to decide on your own risk tolerance...

skeeder

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Re: Diamondback bike - forks are seized - can I DIY this?
« Reply #11 on: August 02, 2017, 06:27:52 AM »
Almost everyone I know that does mountain biking will tell you the same thing...a good overhaul on a fork would cost you over $100 at a LBS.  Don't bother doing it on something cheap.

I recommend just swapping it out for a non-suspension fork if you're not into trails.

Never cry for money because it never cries for you. -Mr. Wonderful

meghan88

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Re: Diamondback bike - forks are seized - can I DIY this?
« Reply #12 on: August 03, 2017, 01:14:54 PM »
Almost everyone I know that does mountain biking will tell you the same thing...a good overhaul on a fork would cost you over $100 at a LBS.  Don't bother doing it on something cheap.

I recommend just swapping it out for a non-suspension fork if you're not into trails.

Thanks - I'm still curious as to why I would need to do that, unless it's a safety issue, as I am just assuming that a seized fork = a non-suspension fork anyway?  I just use the bike to commute.  It will never see an unpaved trail.

FiftyIsTheNewTwenty

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Re: Diamondback bike - forks are seized - can I DIY this?
« Reply #13 on: August 18, 2017, 08:52:34 PM »

Thanks - I'm still curious as to why I would need to do that, unless it's a safety issue, as I am just assuming that a seized fork = a non-suspension fork anyway?  I just use the bike to commute.  It will never see an unpaved trail.

I wouldn't worry about it.  Seized forks tend to stay that way.  Worst case, it frees itself over a bump and starts compressing again.  In that case you can take it apart and lube it, or make it rigid again by inserting solid spacers made from PVC pipe or a wooden dowel.

I had one like this -- searched for replacement elastomers on eBay, but finally gave up.  Wound up giving the bike to someone who needed it for transportation.

ChpBstrd

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Re: Diamondback bike - forks are seized - can I DIY this?
« Reply #14 on: September 13, 2017, 04:07:09 PM »
There are probably 2 allen bolts on the bottom of each leg, near where the wheel attaches. Remove these bolts and pull the lower portion apart from the upper portion. My first bet is a bunch of water or muck made its way inside the fork and caused a hydraulic lock or rust situation. My second bet is that an object has blocked the hole where air/oil squishes between the upper and lower air chambers.

If you cannot get the fork apart after removing the two lower bolts, a bigger hammer or compressed air may work.

GuloGulo

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Re: Diamondback bike - forks are seized - can I DIY this?
« Reply #15 on: September 16, 2017, 11:28:27 AM »
The bike looks pretty solid, but at this price level suspension is good for marketing/looks only--as you found out when it seized up.  The seized fork is not dangerous, you just have a rigid fork that's a little heavier! You could keep an eye out for a cheap used fork, but if you do I'd recommend staying within 20mm of the original fork travel (or "suspension-corrected" to within 20mm in the case of a rigid fork.) Your original fork is probably either 80 or 100mm travel.