GT Timberline - Street Beater

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  • So, I've finally found a GT frame, to satisfy that need for some triple triangle goodness.

    The plan is to build it up as a singlespeed beater bike with fat 26" slicks.

    This build is probably going to be slow, as I have little money on hand at the moment, and my parts bin isn't that full.

    First buy will be wheels. I'd like something 26", wide, for rimbrakes. Shouldn't be that hard, eh? Anyway, any recommendation for 25mm+ internal width wheels?

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  • Cool!!
    You'll have no problem finding the wheels. Either for single speed or fixed gear (disc hub with bolt on cog).
    Just be aware that this frame takes u-brake in the rear. But on the front you can run v-brake or canti.
    If you'll need any info or ideas, check out my gt thread. Cheers!!

  • Thanks for tuning in! Your thread really was the inspiration for this.
    I have looked up on U-brakes and think they'll work okay. I have an Avid SD7 in my parts bin, which I'll use at the front. That should stop me nicely.

  • I use sd7 on both my GTs, they work great.
    you'll need 26.6 seatpost for this one, if i'm not mistaken...

    Looking forward to seeing this finished!

  • According to the seller it's 26.2 I'll measure when it's here.

  • The Frame arrived!
    It was pretty dirty, so I cleaned it up a little. Apart from some paint scratches around the chainstays with a little rust it seems solid. No rust inside the seattube and BB-shell which is nice.

    I still have to measure out the seatpost. the clamp area seems a little crimped inwards, which would speak for 26.6 and someone who used a 26.2 post.

    I have some plans on wheels. There are some cheap 26" wheelsets to be had with Exal XL 25 rims laced to cheap shimano hubs. I think one of these will do. Heavy as fuck, but the 25mm internal width and 36 spokes make it bombproof and better for wider tires.

    The tires are probably going to be 26*2,3" Kenda Kiniption semislicks. That's going to be fun.

    @kifla what gear ratio do you use with yours? I have a nice 18t cog for casette hubs, but don't quite know what to pair with it...

  • Check your clearence in the rear triangle. My tequesta can take 1.95 tires both fron and back and it's pretty tight. I used 45x17 and now use 44x19, and 39x17 on the other gt (magic gear). Both fixed gear, 6 bolt disc cogs from velosolo. Easy, but i find it ideal for city cruising, wider tires and riding up on steeper hills.
    I have mavic xm319 disc wheel on the rear, i think it's either 17 or 19mm internal width. No need for wider than that. It can take tires up to 2.3. So Bombproof that they are straight like the first day. And i have some super shitty roads here and ride higher pressure too. Check your clearences! It seems to me that your fork can take 2.3 but not sure about the back. My fork is a bit different and 1.95 is the limit. Almost rizla :D the other one has loads of space and can take 2.5 and more as well.

  • I'll check that.

    I noticed, that the rear dropouts are spaced 130mm. So maybe a 135mm hub is not the best choice. I'm playing with the idea of lacing something to Sturmey Archer Track hubs (they come with a 130mm conversion kit), which would give me the fix/free choice.

    Spacing in the rear triangle:
    Seatstays: At the height of the brake bridge: 60mm. between the U-Brake studs: 70mm
    Chainstays: 60-ish mms at the same distance from the dropout as the u-brake studs are on the seatstays.

    Could get a little tight with 62mm tires...

    Well, 50mm then. Or I'll just wait and see how big they come out?

  • I also have 130mm rear spacing too on tequesta. I just took one or two washers and have no problems running it like that. + it's steel so no worries.
    Don't use track hubs! There is no way you can get 42-45mm chainline with those chainstays.
    Get yourself a 6bolt disc wheel, find an old cassette, pick a cog and drill 6 holes. Or buy some from velosolo.
    On my ricochet i have a rear 6bolt disc wheel with braking surface and i can ride it both fixed or single speed. That is probably the best combo.
    Using a disc wheel will make your life easier!! I use road cranks on both gts. . Sugino messenger and shimano 105 1050. 113mm spindle. You can find 105 cranksets for cheap and the shimano bb 113 is available and cheap too. Perfect chainlines, enough chainring and crank clearance.

  • Chainline is an issue, right. Okay, so that's the Track Hub plan out the window.
    Also I found out, that with the front V-brake, a rim width of 30mm external is just too much. 27-28mm is pushing it.
    So maybe I'll just give in and go to a 19mm internal width rim.

  • Progress!

    I has wheels now and finally managed to undo the headset. Cleaned all the gunk out.
    The tubes are in really good nick internally, couldn't spot any substantial rust. It's just really dirty from the outside.

    A lot of stuff including a new headset is on it's way to me. Going to be built up soon.

    I'm not quite sure what to do with the fork though. It's obviously not original and it's a little ugly too.
    Let's see what I can find.

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  • my similar GT eats 26.2 seatposts. Very nice build by the way!

  • Damnit. just ordered a 26.4. Well if it doesn't fit I still can go and have my lbs ream out the missing .2mm?

  • No, unfortunately you can not do that. Reaming isn't about removing material form the tube. It is more a matter of 'rounding the inside' after heat has de-shaped the tube and removing burrs.
    0.2 mm doesn't sound like a lot, but it is in a tube. Get the right seat post.

  • If it doesn't fit I will hang my head in shame and buy the right one.

    Although the catalogues I found say 26.4mm usually, so it's a bit of a gamble.

    Anyway: there's not much room in the dropouts and I'm good at pulling rear wheels out of alignment.. Is there any recommended chain tensioner for this setup?
    The Surly Hurdy Gurdy should work, but it's expensive...

  • Shame??
    I have 26.8, 26.6 and 26.4 laying around, so don't talk to me about shame..

  • Yeah. No shame in having bought the wrong seatpost. The shame is not to learn from it. Buy a vernier caliper (they can be had for cheap) and learn how to measure using it. It is essential if you want to order parts online and DIY.
    A strong cam qr will keep wheel in place... Forward facing dropouts and chain tensioner can be a bit tedious...

  • I owned a caliper once. Then I lost it. Or my dad lost it. Or my dad just took it and assimilated it into his workshop and then lost it.
    While working with a caliper, there is the problem, that the upper part of the seattube looks a tiny bit crimped, as if someone mounted a seatpost a size to small and compensated by clamping up harder.

    Well we'll see tomorrow. Seatpost, rear brake, handlebars, new headset, and lot's of other small stuff will arrive tomorrow. Today the tires arrived. 50mm Kojaks. I also sprayed the inside of the frame with some kind of anti rust stuff.
    Now the frame stinks and leaks sticky brown fluid everywhere. Will clean up again tomorrow and start throwing parts at it.

    @kifla I have a cheap crankset with a 46t ring lying around, as well as a 18t cog, which should give me a nice and usable ~66GI. Question is: Will the 46t fit? I have a pretty long BB axle handy, but some testing is in order...

  • Then you need to get it reamed. If you fit a too small seat post it will move back and forth in the seat tube and eventually cause cracking.

    Or just not care as it is a beater...

  • @Murphys_Law depends on the crankset/BB combo. What kind of crankset is it?

  • It's a 46t single speed crankset. I got it to work with a rather long BB-spindle. It clears the chainstays by a few mm. Fair enough. Chainline is about 48mm which I could replicate on the rear.
    Parts have arrived. Wrong seapost size though. *hangs head in shame* gotta hit up a bikeshop today and hope they stock 26.2...

  • It's alive!

    Runs well. I think I'll switch fork and seatpost out for something blacker sometime though.
    Stopping power of the U-Brake is meh, but the Single Digit up front takes care of any stopping needs.

    Also that stem, while original, is HUGE. something shorter and maybe a little lower could be in order.

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  • Very nice! I'd just change the cockpit for something less upright and with a bit of sweep back, with some chunky oury grips

  • Yes, maybe another stem. Chunky Ourys would be awesome. That's actually 15° sweep already. Not sure about more.

  • I like it all apart from the seatpost. Stem is super rad.

    Could you not just rattle can the forks grey or Matte black? Or some funky neon colour? Pink? You could then get neon pink ourys to match...

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GT Timberline - Street Beater

Posted by Avatar for Murphy's_Law @Murphy's_Law