Building an Old GT Karakoram… I might be crazy

Forums Mountain Bike Forum Building an Old GT Karakoram… I might be crazy

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    • #126615

      Let me start by saying hi. New to the forum but I have been lurking through the site for a few months now. I recently picked up what some might call a lost cause. It is a 90’s GT Karakoram. $20 off of CL complete. Let me say, I am not a pro MTBer and I know most people would tell me to just get a new frame instead of dumping money into this old bucket… However I love the look and feel of old ChroMo frames. I had a Trek 930 that was stolen after I painted and upgraded it. Ever since then I have been looking for another old project to pick up. I’ve heard the Karakoram frame is bullet proof. This is more about the fun of doing this myself.

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      What’s done so far:

      I’ve brought the frame home and stripped it of all the components. I then sent the frame off to be blasted and powder coated. Should be ready in a couple of days. Pics to come later tonight. This consisted of buying all the tools needed to remove the Crank, BB and Headset Cups, then doing the work. I am going to keep all of the Shimano Deore LX components for the bike and basically change everything else.

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      So that is the current state of things. Now for the fun stuff, the planned upgrades!

      Here’s the list:
      New chain
      New BB
      WTB Speed V Saddle
      Cane Creek 40 Series Headset
      Vuelta Zerolite Wheelset
      RockShox XC30TK fork
      Avid BB7 Front disc set
      Avid Single Digit V brake for the rear
      Kool Stop Dual Compound Mountain Pads
      LVWA Carbon fiber riser bar
      RaceFace 70mm 6 degree stem
      Maxxis High Roller II 2.3 for the front
      WTB Weirwolf 2.3 for the rear

      Please feel free to jump in and give me advice or suggestions. I really want to have this as a chronicle of the build from start to finish and the problems I run into if any!

    • #126616

      If you like the bike, then build it, naysayers be damned. That being said, you couldn’t pay me to move back to era of bike 😀

      Share some pics of the progress!

    • #126617

      Update: Frame is back from the shop and parts have started to roll in!

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    • #126618

      Haha, I came within a gnat’s whisker of ordering that bar off of Amazon, but in the end went with the Chinese knockoff Race Face carbon bar on eBay for $12.

    • #126619

      I probably should have done that. For $50 this one sure feels solid though. I guess the real test will be after the bike is complete!

      One thing I noticed on the powder coat is that they coated the posts for the rear brakes. I’ll need to sand these down right?

    • #126620

      I’m pretty sure you’ll need to to have the proper fit on the posts. It looks like your BB and headset is all nice and clean, so that’s good to go.

    • #126621
      "schwim" wrote

      I’m pretty sure you’ll need to to have the proper fit on the posts. It looks like your BB and headset is all nice and clean, so that’s good to go.

      Yeah, I made sure that the shop new not to coat the BB and headset but forgot to mention the brake posts. Guess I’ll give it a go tonight and see how the brakes fit on there.

    • #126622

      So I was able to clean the brake posts last night with a knife and some light sanding. Rear brakes are now on, and I’m excited about how the black on red is going to look on this one. Also got some more parts in today! Stem and Cane Creek 40 headset, also NOS decals in black. (I’ll be putting those on tonight!)

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    • #126623

      Very nice! Happy to see you didn’t go with the lower end CC headset. I was shocked when I opened up the CC 10 series headset to find a plastic crown race 😏 .

    • #126624
      "schwim" wrote

      Very nice! Happy to see you didn’t go with the lower end CC headset. I was shocked when I opened up the CC 10 series headset to find a plastic crown race 😏 .

      That’s exactly why I got this one. I read a comment somewhere that mentioned the plastic race.

    • #126625

      Well, decals came in and I decided it would be easiest to put them on now. I still haven’t bee able to track down the Karakoram decal for the top tube if anyone knows were I might find it let me know. Sorry for the low quality pics in advance.

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      I’m pressing the headset in today, and all the other parts except wheels and tires should be here by Wednesday. I am adding a new cassette for the back, should I or can I even change the front sprockets on the crank arm? Or does that require a new crank?

      • #181060

        Hi, I know this thread is a few months old, hut I’m beginning my own rebuild project as I have a ’94 Karakoram that’s only seen light use and is in pretty good shape. My frame decals are in bad shape after years of drying out and cracking/flaking. I can’t seem to find replacements anywhere. Can I ask where.you sourced your new decals from?

        Great build by the way. I’m inspired by what you’ve done!

    • #126626

      First of all, it’s looking great! Keep sharing the progress!

      Secondly, there are 5 bolt chainrings available for purchase. I can’t see any details of the crankset in the picture, but it looks like a square taper crankset with a larger 5 bolt pattern, maybe a 110 BCD.

      You can pick up a takeoff 4 bolt 104 BCD Shimano Hollowtech crankset on eBay for super cheap. I think your BB is a 68mm, so it shouldn’t be an issue in regards to fitment and you could probably get a whole setup for less than the cost of the chainrings on the vintage set.

      The last crankset/BB I bought on eBay cost me $25.

    • #126627
      "schwim" wrote

      First of all, it’s looking great! Keep sharing the progress!

      Secondly, there are 5 bolt chainrings available for purchase. I can’t see any details of the crankset in the picture, but it looks like a square taper crankset with a larger 5 bolt pattern, maybe a 110 BCD.

      You can pick up a takeoff 4 bolt 104 BCD Shimano Hollowtech crankset on eBay for super cheap. I think your BB is a 68mm, so it shouldn’t be an issue in regards to fitment and you could probably get a whole setup for less than the cost of the chainrings on the vintage set.

      The last crankset/BB I bought on eBay cost me $25.

      It is definitely 5 bolt with square taper. After inspecting it more closely it looks like some of the teeth are worn down a bit so I will start the search on ebay. I had ordered a Shimano UN55 BB to replace the current BB. Will I need a different one for the Hollow Tech? I’m starting to get the hang of how bikes are put together but still a noob. I’m used to pulling apart cars.

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      You can see the difference in the wear on the teeth below:

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    • #126628

      It’s generally suggested to replace the chainrings when replacing the chain/cassette. the three items wear together and often replacing only one or two in the group will cause the new non-stretched chain to hop or skip when the teeth no longer perfectly fit the chain. That being said, if the wear is minor, you can sometimes get away with replacing only part of the group.

      My main reason for suggesting a new crankset is this: That looks like a 48 tooth large ring which will never get used by a casual mountain biker on a 20ish year old bike unless you find you have made a wrong turn on the trail and accidentally entered the Tour de France. As for the other rings, you’re limited as to how small you can go by the BCD(bolt center diameter). Finally, prices for vintage-era specs are usually much higher than for current tech stuff.

      If you already have a new BB, you can find square taper arms on eBay as well. I would look for something with a 4 bolt 104 BCD, which allows you to find replacement chainrings on the cheap.

      The 68mm threaded BB allows you some wiggle room for the cranks, as it’s a hugely popular standard and a lot of things fit it. That leaves you a lot of options when purchasing secondhand or new take-offs. I’ve put SRAM GXP, Shimano Hollowtech, Raceface and Truvativ square taper cranks in it.

    • #126629

      I’ll start looking around for a newer crank. Looks like my chainrings are 46-26 on the front.

      Also, got the headset pressed in today. Now time to sit back and wait for more parts…

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    • #126630

      Question. I am trying to wrap my head around the whole, 7 8 9 speed thing. I have 7 speed cassette in the rear, the crank I found that I like is a 9 speed crank. This just refers to the spacing and size of chain right? Can i use the 9 speed chainring and crank with my 7 speed cassette?

      Here what I was going to get: http://www.amazon.com/dp/B005YP4WAA/ref … 4YU3&psc=1

      I liked the idea of an external BB too.

    • #126631

      Check out this great article on chain and gear compatibility. Basically, you can usually mix within reason, but might lose some crispness in operation.

      Quote of importance from his page:

      Up through 9-speeds, all cassettes use very nearly the same wdith of sprocket teeth, and will work with 7/8 or 9-speed chains.

      It being a 7 speed, it’s very unlikely you can upgrade the cassette to a higher number of gears due to the freewheel type and dropout width. You’re best bet for cost effectiveness is to go with a 9 speed crank and chain.

    • #126632

      So I ended up getting an SRAM 9 speed crank. It was only about $45 new and I figure I will upgrade it pretty fast to something else. Maybe external BB, but I’ll start here. I also received the seat, chain, Jagwire shift kit, headset spacers, and front forks. I decided to go with one 10mm spacer on the headtube and got everything mounted up and ready. Holy crap! the Cane Creek Forty is smooth as butter, I can’t wait to get this on the trail. I have some new pedals coming in tomorrow along with the BB, and maybe my Jagwire brake cable kit. Last things to order are tires, rims, and the freewheel. Getting close!

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    • #126633

      Fix those pics so we can see the fun stuff 😀

      I’m living vicariously through your build. You’re doing a bang-up job 😃

    • #126634

      Got some more goodies in today, I received my UN55 BB, along with a set of Shimano Saint pedals that I am supper pumped about! Got a set of WTB grips but in person they are a lot bigger than they looked in the picture. So i might be sending them back and just picking up a good set of standard grips for the bars. Any recommendations on this? Also got a parktool spanner for my pedals just to realize that they have allen key bolts on the back and no need for the spanner. 😕

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    • #126635

      Wow, it’s looking fantastic, man.

      RE: your grips, I use ODI grips on all my bikes and they are pretty fantastic. They’re also pretty inexpensive on Amazon. Just make sure you get the clamps with them as some vendors are selling just the replacement grips. The clamp system on them happens to work fantastically with the carbon bars, as well.

    • #126636

      So my BB came in yesterday and I was able to get a lot done last night. BB, Crank, Pedals, cleaned and re-installed derailleurs, cleaned and re-installed shifters and levers, decided to give the WTB grips a shot. Also ran the Jagwire shift cables. Last thing I need is wheels and tires, along with the Jagwire brake kit. Both should arrive next week. I’m so close I can almost taste it! Eventually I might swap out the shifters as well for something a bit newer but I am going to stick with what I have from the original bike now.

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      Shimano UN55 BB installed.

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      Pedals and crank bolted down and ready!

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      Rear derailleur cleaned and installed

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      Grips and shifters locked down! Jagwires installed but not tight yet.

    • #126637

      Almost there! I was going to order a set of Vuelta rims but ended up finding a brand new set of Alex DH22 rims with Shimano hubs. They ran $120 for the set and I can always upgrade later. I ordered a WTB Weirwolf 2.3 for the back and a Continental Mountain King Protection 2.4 for the front(2.4 because reviews on this said the tire was undersized so I opted for a larger tire up front.) Mounted them with tubes for now but might update them later and convert to tubeless. Locked on a new HG-50 13-28 rear cassette. Everything is mounted up and looking pretty sick! I ran into an issue running the rear brake lines that has made me look at going back with a nice set of canti’s on the back instead of the V-Brakes. I’ll post more on this later tonight. All that is left is run the chain and install the front disc when it arrives. Getting excited about running this thing down the trail a bit! One thing I found is that the bike is huge! The frame is 24" and I’m 6’1" and can barely straddle it.

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    • #126638

      It looks fantastic man!

      Bummer about the frame size. Who knows though, you may find a more appropriately sized frame some day for another 20 spot. You can take your time and clean it all up at your leisure while you ride this one.

      Seriously great job, so far. You’re super close!

    • #126639

      It’s been a lot of work and a learning experience but I have finally finished the bike! Here’s a quick update from my last post.

      Rear brakes: I ended up going with cantilever brakes, due to the original brake cable route, as well as the compatibility with the levers that came on my bike. Which brings me to my next issue. The righthand shifter that came with the bike ended up being broke. So I had to order new shifter assemblies. It ended up being good though because the lever on the new shifter is compatible with the Avid BB7 I put on the front. All said and done, I left the original shifter assembly on the left and the new assembly on the right. Everything runs smooth! Got the chain installed, ran the rest of the Jagwires and got the derailleur dialed in so it shifts nice and smooth. I have decided that I will eventually run an 8 speed cassette in the rear and maybe a single or double chain ring on the front. So without further ado, here she is!

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      And after her first ride through Marshall Canyon in the San Gabriel Mountains!

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    • #126640

      Man, you did a fantastic job on that bike. You’re going to have a blast on it!

    • #126641

      That is a nice looking bike. Thanks for posting all the information.

    • #126642

      I love the old gt’s. they just hit the mark in the 90’s. I also just finished building my GT about a month ago. Your bike is going to blow the competition away.

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