Results 1 to 23 of 23
  1. #1
    mtbr member
    Reputation: frankzetank's Avatar
    Join Date
    Feb 2013
    Posts
    57

    Frame numéro trois - Fat enough for Iditarod Trail Invitational

    So I've had the great opportunity to get a (late) ticket for the Iditarod Trail Invitational coming up in February; a 350 mile race through Alaska. My current fat bike is a 2009 907 frame that can *barely* fit Big Fat Larry on 80mm rims. SO this is where this frame building project starts! The task was clear: build a frame for this race.

    So after much considerations, I decided to go as big as it gets (for now!); 190mm rear end, Moonlander OD crank and rear end capable of fitting Bud/Lou on 100mm rims.

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p1030039.jpg

    Geometry ended up as followed. It is a copy of my current 907 with some tweaks (shorter CS, slacker ST angle, larger front triangle for frame bag):

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-frame-num%E9ro-trois-fat-geometry.jpg

    Design specs are:
    190mm rear spacing no offset
    Built around Carver carbon fork with 135mm front spacing
    Designed with clearance for Bud/Lou on 100mm rims
    2x10 drive train with direct mount front derailler (using problem solver band mount adaptor)
    Surly OD crank Moonlander axle

    Tube set is as followed:
    NOVA 29er Tubeset S-Bend Seatstay and Chainstays
    HT: 37mm 1.6
    DT: 38mm .8/.5/.8
    TT: 31.8mm .8/.5/.8
    ST: 28.6mm .9/.6/1.2^
    CS: 30x16mm tapered and pre bent (but I add to rebend them)
    SS: 19mm tapered and pre bent (but I add to rebend them)

    Learning from my frame numéro 2 experience, I used the same method to bend my stays. Filled with iced on a modified pipe bender. The Nova 19mm seat stays were again a piece of cake to bring into shape

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p1040046.jpg

    The CS needed some dimpling this time as opposed to simply bending it. I did get a little bit of wrinkles in the process. Nothing that I am concerned with from a structural point of view.

    The front triangle is tacked up and waiting for the final brass fillet to be laid.

    More soon, I want to finish this up ASAP to test ride it thoroughly before the race!

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p1040041.jpg

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p1040044.jpg

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p1040045.jpg

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p1060054.jpg

  2. #2
    Living the thug life.
    Reputation: Logantri's Avatar
    Join Date
    Mar 2004
    Posts
    714
    I always wished I had the talent to do this. Looks cool, I'll look for it in AK.
    I proudly ride for these guys.

    My blog.

  3. #3
    is buachail foighneach me
    Reputation: sean salach's Avatar
    Join Date
    Sep 2007
    Posts
    5,840
    Awesome!

  4. #4
    Harrumph
    Reputation: G-reg's Avatar
    Join Date
    Jan 2004
    Posts
    1,564
    Awesome, I haven't gathered the stones to really even think about that one.

    Just saving time with the DM FD adapter? If you fabricate one theres some precious daylight to be gained between the tire and derailleur cage.

    I recently added a Bud to my Clownshoed/Carver Forked Fatty. It's a huge step up in performance as a front tire than the worn out first gen Larry I was using, but it's barely crammed in there. Only ~1/4in clearance, enough that a busted spoke/nipple etc. would be trouble.

    Slowly slipping to retrogrouchyness

  5. #5
    mtbr member
    Reputation: frankzetank's Avatar
    Join Date
    Feb 2013
    Posts
    57
    Progress happenned today! I tacked up the CS and checked clearances. The tire to CS have 15mm (Big Fat Larry on Clown Shoe). The Moonlander OD crank 36t ring has about 5mm (I plan to run a 32t) and the crank arm also clears. Front derailleur also clear everything. With everything clearing and were it is supposed to be, I started laying the final fillets.

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p1110056.jpg

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p1110057.jpg

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p1110058.jpg

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p1110065.jpg

  6. #6
    mtbr member
    Reputation: frankzetank's Avatar
    Join Date
    Feb 2013
    Posts
    57
    Quote Originally Posted by G-reg View Post
    Just saving time with the DM FD adapter? If you fabricate one theres some precious daylight to be gained between the tire and derailleur cage.

    I recently added a Bud to my Clownshoed/Carver Forked Fatty. It's a huge step up in performance as a front tire than the worn out first gen Larry I was using, but it's barely crammed in there. Only ~1/4in clearance, enough that a busted spoke/nipple etc. would be trouble.
    Yeah pretty much saving time. I have the moonlander version with an XT 2x10 FD and everything seems to clear.

  7. #7
    mtbr member
    Reputation: bikecycology's Avatar
    Join Date
    Apr 2010
    Posts
    83
    Good on you and good luck with the whole experience. It is one of my ambitions to build a frame and successfully race it. Keep the updates coming.

  8. #8
    mtbr member
    Reputation: Meriwether's Avatar
    Join Date
    Jul 2007
    Posts
    340

    Frame numéro trois - Fat enough for Iditarod Trail Invitational

    Very nice! Hope the race goes well, I'm jealous. Looking forward to more pics and the race report!

  9. #9
    mtbr member
    Reputation: frankzetank's Avatar
    Join Date
    Feb 2013
    Posts
    57

    It's alive!

    So last week was pretty busy! I spent more time doing than documenting... sorry! But major progress did happen. The bike is complete and assembled as of yesterday!

    Seat stays went on OK but the SS/ST junction is one of the toughest (I find) to miter. I just have a hard time getting everything to line up with minimal gaps between tubes. I noticed while assembling the components that the SS bents did not rest in one single plane. This doesn't create any structural problem but shows I'm a noob!

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-dsc_0014.jpg

    Braze ons went OK. I choose under the DT cable routing for 3 reasons:
    1- I like how it looks
    2- I will have a "handle bar roll" (similar to the pic above) to carry my sleep system and this is the routing I find works best around the "roll".
    3- It leaves the TT uncluttered for the occasional lifting the bike over stuff.

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-dsc_0012.jpg

    I went to my LBS and he was very nice and let me use his tools for cleaning threads, facing and reaming all necessary surfaces and checked alignment of the drop outs. I also installed the head set crown and fork race.

    I assembled the bike and found no major surprises. I did notice very small clearance between the front derailleur cage and CS. I'm running a 32 as my biggest ring so this contributed to keeping the derailleur low on the ST.

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-dsc_0015.jpg

    Drive train has decent clearance with my BFL/CS even on the granny gear (full 2x9 gearing) thanks to the Moonlander OD crank axle and 190mm rear hub

    Took it out for an "in the driveway test ride", everything "feels" OK. It rides in a straight line, component don't interfere under load. It feels like a "normal" bike! I had *some* concerns about heel strike with the 190 rear hub but this turn out to be a non issue. I wear size US12 and my Lake winter boots are size 48 and I don't get any heel strike on both CS and SS. Even trying to hit my heel on purpose is hard

    I just rode my first hand made bike; I'm happy!

    Longer ride report and more pics to come. I'm gearing up for a shakedown ride this week end to test everything. I still have a frame bag to make and drop bags to ship!

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-dsc_0002.jpg

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-dsc_0006.jpg

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-dsc_0007.jpg

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-dsc_0008.jpg

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-dsc_0010.jpg

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-dsc_0004.jpg

  10. #10
    Nemophilist
    Reputation: TrailMaker's Avatar
    Join Date
    Sep 2007
    Posts
    1,697
    Congrats, Frank!

    SS are indeed tricky. I use my stay fixture to set my SS in place, tack in the bridge, and then miter them on the vert mill. Having the tubes unitized and those miters perfectly in phase really does help a lot. Doing them separately would be far more time consuming. I guess it's a matter of how much time, effort, and expense you can/want/need to dedicate to fixturing.

    I'm forgetting a lot of what I went through getting there. Time to build another bike, I guess. Looking forward to seeing how it rides for you!
    Most people ply the Well Trodden Path. A few seek a different way, and leave a Trail behind.
    - John Hajny, a.k.a. TrailMaker

  11. #11
    mtbr member
    Reputation:
    Join Date
    Dec 2012
    Posts
    52
    Friggin' awesome. Nice build.

  12. #12
    Harrumph
    Reputation: G-reg's Avatar
    Join Date
    Jan 2004
    Posts
    1,564
    Seatstays are a real pain, and there's no way around it without big machines and tooling....even then. Easily the easiest frame component to scrutinize, at the same time the least important structurally.
    Slowly slipping to retrogrouchyness

  13. #13
    J_K
    J_K is online now
    mtbr member
    Reputation:
    Join Date
    Jan 2010
    Posts
    124
    Very nice! Although I'm not a fan of those carbon forks on a steel fatbikes, they look a little bit too bulky.
    The seatstays are my worst enemy on a frame building, it takes me way too much time to get them right.
    Now I can't wait to get my frame back from the powder coating.

  14. #14
    mtbr member
    Reputation: frankzetank's Avatar
    Join Date
    Feb 2013
    Posts
    57

    Shake down ride

    So in the last 2 weeks, I got a few rides on my bike and in the week end, I got it fully loaded up with all my planned gear and went for a long shake down ride. Rode/hike-a-biked for 7h on a frozen lake and adjacent snowmobile trail to try and ride in as representative conditions as possible to upcoming ITI.

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p2010085.jpg

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p2010087.jpg

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p2010089.jpg

    Ride went great. From a framebuilding point of view, the bike handdles great. Its stable in soft conditions yet not slogish in fast twisty single tracks. Position feel spot on for me.

    I sow a custom frame bag to fill the front triangle; I made it wide and tapering towards the front to get more capacity out of it. I'm satisfied that I made the triangle bigger as the capacity is noticeably larger that my previous 907.

    One thing I did NOT track while designing the geometry is the "front roll" diameter and how it was going to fit under my handdlebar and over the tire. Turns out, it *barely* fits with ~1/2" between the tire and bottom of the "roll". Everything else fits but I got to admit that the handdle bar/cockpit is pretty crammed up!

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p2010088.jpg

    With this test ride completed, I'm hoping that I will have time to have it properly painted/coated before the race but this are going to be hard as things are going by SO fast. Plan B is to rattle can it.

    Other then that, the rest if non framebuilding related. Drop bag are shipped. Gear is getting sorted out in piles. Now I have to make myself a bike boxe big enough to fit the bike and partial gear into an airplane. My plan is to make it out of corrugated plastic sheets in two halves (similar to the crateworks).

    I'll report back after the race! If anyone has any questions; frame related or not and want details about; feel free!

  15. #15
    mtbr member
    Reputation: frankzetank's Avatar
    Join Date
    Feb 2013
    Posts
    57
    Pics painted and fully assembled. Sorry for the crappy end of day flat light! I'll try to do better but the bike is going in its bike box in just a few days!!

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p2150103.jpg

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p2150104.jpg

    Frame numéro trois - Fat enough for Iditarod Trail Invitational-p2150105.jpg

  16. #16
    WIGGLER
    Reputation: todwil's Avatar
    Join Date
    Feb 2007
    Posts
    753
    Your bike turned out great and good luck on your race.
    PAYASO 36er.....Live the Circus

  17. #17
    mtbr member
    Reputation: frankzetank's Avatar
    Join Date
    Feb 2013
    Posts
    57

    Made it!

    So, my frame made it along he 350 miles from Knik Lake to McGrath at the Iditarod Trail Invitational... and so did I! Condition this year were totally exceptionnal with rideable hard trail the whole way. Records were shattered.

    From a framebuilding stand point, I have very few problems to report. Frame performed well with no break down, interference of other problems. The geometry was confortable and stable. Steel frame were rare on the sharp end of the race. Shinny Carbon was more common (Fatback, Borealis, Salsa and 907). But there was a Moonlander and another hand made bike in the top 10.

    I finished 7th in 2day11h50min which I am totally satisfied with. Race went well. Slept 4 (err...overslept 5h45!) in Rohn which is about the half way point on a nice spruce bed! Meet a bunch of great people, racers, logde owner and volunteers without which, this race would not exist.

    Here is a video I made with the footage I took during the race. Any questions, feel free!


  18. #18
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    197
    Nice job on the whole project! Great build, great race, nice video
    cheers
    andy walker

  19. #19
    Harrumph
    Reputation: G-reg's Avatar
    Join Date
    Jan 2004
    Posts
    1,564
    Good work,
    How was your fit? That much time on a bike unsupported is a really good measure of how you've personally fitted yourself to a bike.
    Slowly slipping to retrogrouchyness

  20. #20
    mtbr member
    Reputation: frankzetank's Avatar
    Join Date
    Feb 2013
    Posts
    57
    Fit was, as far as I can tell, "adequate". I felt good on the bike with a good compromise between confort and performance for my position and bike handling feel that was a good balance between stability and fast handling. Overall, very satisfied and I wouldn't change anything if I was doing another one for this race.

    My one ache after 350 miles were my hands... they are still numb 10 days after finishing. I do have ergon type grips over taped with foam but it wasn't enough. I'll be looking into alternate bars (Jones Hbar, Luv handles and the likes). I've been lurking at them for years now and I feel like a wider more sweep back handle bar could provide a more natural position to my wrist and ease the pressure on my hands for ultra long rides. I'll be testing that in the near future.

  21. #21
    Nemophilist
    Reputation: TrailMaker's Avatar
    Join Date
    Sep 2007
    Posts
    1,697
    Hey;

    Congratulations Frank. That is quite a fine performance. Doing it on a bike you built is even better! You might try the legendary On One Mary bar as an inexpensive means of testing your theory. I ride with nothing else these days. All my bikes have them. SOLD!
    Most people ply the Well Trodden Path. A few seek a different way, and leave a Trail behind.
    - John Hajny, a.k.a. TrailMaker

  22. #22
    mtbr member
    Reputation:
    Join Date
    Sep 2011
    Posts
    39
    Hey, I can't believe I didn't see this thread before I left! I'm still impressed by the bike, and told the story to everyone I talked to. I wish I had the skills and time to do something like this as it is a really cool story. Great meeting you up there, and I'm sure our fat tire paths are going to cross again.

  23. #23
    mtbr member
    Reputation: Meriwether's Avatar
    Join Date
    Jul 2007
    Posts
    340
    Congratulations frankzetank, so damn cool! Super jealous, what an awesome adventure start to finish from making the bike to placing 7th. Hope the hands get some feeling back in them soon, that's creepy! I really like the Salsa Bend 2's for a budge "M" bar, i like better than the Mary's and most other alt bars and I've tried a ton. I'll sell you a 10-ish year old Jones H-bar for cheap, PM me if you're interested.

Similar Threads

  1. 2013 Iditarod Trail Invitational
    By sean salach in forum Fat Bikes
    Replies: 78
    Last Post: 03-22-2013, 03:35 PM
  2. Iditarod Trail Invitational
    By mtbxplorer in forum Women's Lounge
    Replies: 4
    Last Post: 02-24-2013, 04:26 PM
  3. Iditarod Trail Invitational 2011
    By FrankM in forum Alaska
    Replies: 86
    Last Post: 03-26-2011, 11:06 PM
  4. Iditarod Trail Invitational
    By sryanak in forum Endurance XC Racing
    Replies: 0
    Last Post: 03-02-2011, 10:16 AM
  5. Iditarod Trail Invitational 2011
    By juxtaposition in forum Fat Bikes
    Replies: 4
    Last Post: 03-01-2011, 11:56 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •