# Old 1998 Avalanche Upgrade



## skunkgrunt (Mar 8, 2013)

Good morning folks!

I have an old 1998 (I believe) GT Avalanche that I'm upgrading, but it's been so long since I was involved in the MTB community, I have no idea what components would work with/fit this old beauty.

New forks would be nice, disc brakes (mechanical are fine), but a new drivetrain is a MUST.

Any/all help or suggestions would be appreciated!

P.S. - Here's the link the specs: BicycleBlueBook


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## Crankyone (Dec 8, 2014)

In short, my experience is you will be better served by buying a new bike.


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## skunkgrunt (Mar 8, 2013)

I guess I should've been more clear in my original post. I'm doing this because I love this bike, it fits me like a custom frame, and I love riding it, so I'm doing the upgrades because I want to, not because I just want a working bike.


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## MNSparky (Sep 27, 2020)

I started a project like this with my beloved 1998 Schwinn Mesa GSX that had been hanging in the garage for 15 years. It's difficult to upgrade a bike that is 23 years old using todays parts. I started with the simple stuff like getting rid of the long stem, short bars and ditching the "antlers". Replaced the tires and did a total tear down, clean and relube. Forks are going to be difficult as you have a straight tube and most higher end forks are for tapered tubes now. I ended up rebuilding mine vs replacing. If you want to upgrade the drivetrain to a 1x system you will probably have to get a different rear wheel with a narrow hub to allow for the wider cassette, unless you are lucky enough to have a spacer and can squeeze a 9 speed in there. I was not so fortunate and kept the 3x7. I also kept the rim brakes, just put nicer pads on, they worked well. In the end, I added up the costs I would have to pay to "upgrade" this bike and it just wasn't worth it. Really the only thing that would have been original was the frame and saddle. I bought a new bike instead and have my Schwinn still operational, just not to today's standards. It's still fun to ride and makes a great loaner when someone wants to go ride with me, but it's nothing like my Trek.















.


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## kmartfullsquish (Mar 10, 2021)

skunkgrunt said:


> Good morning folks!
> 
> I have an old 1998 (I believe) GT Avalanche that I'm upgrading, but it's been so long since I was involved in the MTB community, I have no idea what components would work with/fit this old beauty.
> 
> ...


look into box component drivetrains. im putting a box three prime nine drivetrain kit on my old trek fuel.


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## paramount3 (Jul 13, 2014)

You can't put reasonably put disk brakes on a rim brake frame. There are YouTube videos of people brazing on brake mounts, but this is idiocy. You could put a disk-capable fork on it and run a mutt system, front disk/rear rim, but not much point in doing that. I have a 1991 Schwinn Paramount that I still ride--as a rigid 3x8 commuter. It's great for that, or as a flat-bar gravel bike, but it will never be considered a mountain bike again. If you are willing to ride your GT in that spirit, then you could get a ca-2015 2x10 drivetrain, e.g. FC-M617 SLX 36/22 cranks, 11-34 or 11-36 cassette, clutch derailleur, etc. Consider a rigid Kona P2 or Surly fork. 26 x 1.9 tires. Such a bike is a great gravel bike alternative.


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## skunkgrunt (Mar 8, 2013)

kmartfullsquish said:


> look into box component drivetrains. im putting a box three prime nine drivetrain kit on my old trek fuel.


I hadn't heard of this until now. This might be a game changer...


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## skunkgrunt (Mar 8, 2013)

paramount3 said:


> You can't put reasonably put disk brakes on a rim brake frame. There are YouTube videos of people brazing on brake mounts, but this is idiocy. You could put a disk-capable fork on it and run a mutt system, front disk/rear rim, but not much point in doing that. I have a 1991 Schwinn Paramount that I still ride--as a rigid 3x8 commuter. It's great for that, or as a flat-bar gravel bike, but it will never be considered a mountain bike again. If you are willing to ride your GT in that spirit, then you could get a ca-2015 2x10 drivetrain, e.g. FC-M617 SLX 36/22 cranks, 11-34 or 11-36 cassette, clutch derailleur, etc. Consider a rigid Kona P2 or Surly fork. 26 x 1.9 tires. Such a bike is a great gravel bike alternative.


Luckily, the frame and forks are set up for disc brakes. I did buy new wheels a while back because the stock Mavics weren't set up for discs, so I'm good on that front. Just never got around to actually buying them. I tried fitting some old Juicy brakes my brother gave me, but the never wanted to work correctly, so I passed on them.


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## skunkgrunt (Mar 8, 2013)

kmartfullsquish said:


> look into box component drivetrains. im putting a box three prime nine drivetrain kit on my old trek fuel.


Looks like the Box 3 Prime is sold out damn near everywhere, but a couple places have Box Two Primes available for around $300...I'd be willing to bite the bullet on it...


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## kmartfullsquish (Mar 10, 2021)

skunkgrunt said:


> Looks like the Box 3 Prime is sold out damn near everywhere, but a couple places have Box Two Primes available for around $300...I'd be willing to bite the bullet on it...


yeah if its compatible go for it, they're good components.


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## paramount3 (Jul 13, 2014)

skunkgrunt said:


> Luckily, the frame and forks are set up for disc brakes. I did buy new wheels a while back because the stock Mavics weren't set up for discs, so I'm good on that front. Just never got around to actually buying them. I tried fitting some old Juicy brakes my brother gave me, but the never wanted to work correctly, so I passed on them.


My guess is your bike is not a 1998 if you have disk brake mounts.


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## skunkgrunt (Mar 8, 2013)

kmartfullsquish said:


> yeah if its compatible go for it, they're good components.


Ordered the box 2 groupset today!


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## skunkgrunt (Mar 8, 2013)

paramount3 said:


> My guess is your bike is not a 1998 if you have disk brake mounts.


'98 was the closest I could come to matching up components on bicycle blue book. My brother, who has an infinitely better memory than I, says it's a 2000. He bought it when GT was liquidating assets during their bankruptcy proceedings.


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## kmartfullsquish (Mar 10, 2021)

skunkgrunt said:


> Ordered the box 2 groupset today!


nice, post some pics of it when you get it installed on the bike and let us know how it goes. good luck


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## skunkgrunt (Mar 8, 2013)

kmartfullsquish said:


> nice, post some pics of it when you get it installed on the bike and let us know how it goes. good luck


Thanks! Did the full break down today. Man that bottom bracket was a PAIN!


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## kmartfullsquish (Mar 10, 2021)

skunkgrunt said:


> Thanks! Did the full break down today. Man that bottom bracket was a PAIN!
> View attachment 1922403


haha i can imagine


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## kmartfullsquish (Mar 10, 2021)

skunkgrunt said:


> Thanks! Did the full break down today. Man that bottom bracket was a PAIN!
> View attachment 1922403


also I think i forgot to mention but you're probably going to need a one by front chainring. like a narrow wide 104 bcd one. thats the one i need for my bike


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## skunkgrunt (Mar 8, 2013)

kmartfullsquish said:


> also I think i forgot to mention but you're probably going to need a one by front chainring. like a narrow wide 104 bcd one. thats the one i need for my bike


Thanks! I did find that out when I was reading the page on the Box website so I have one picked out. Good info though. It's not obvious unless you do a little reading.


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