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My new project...

Posted: Thu Jul 01, 2004 4:13 am
by BAC5.2
Well, I've had a Specialized S-Works frame laying around my room for the past 9 months, and I decided to do something with it.

So, I'm building a bike with all of my spare parts that I've gathered over the years.

Here's the specs:

-17" Stumpjumper S-works (2003 Pro frame, 3lbs)

- Surly Instigator Rigid Fork (actually got this off of a buddy of mine for $20 bucks)

- Shimano XT cranks with an XT bottom bracket

- Alex TD-17 wheelset with a ghetto-rigged, broken cassette single speed (break apart the cassette, space out the hub and put the desired ring on there, flank it with 2 larger rings to act as a chain guide).

- Nokian NBX 2.3" tires (not installed yet)

- STS headset (I was going to use my PIG, but I don't have a crown race for either of the two that I have, so I'm getting the STS for free off of my buddy).

- KOSKI stem, bars, and seat

- Avid SD-3 Levers (customer donated them to me :))

- SALSA Pro-ring 32T unramped front chainring.

- Un-ramped, 16t rear cog.

- Promax Mechanical Disc brakes

- Hingulator (a chain tensioner made from a door hinge and a derailuer pulley. Pretty ghetto).

I think that's about it. SUPER simple, durable, and light.

Sans the fork/front wheel, the whole setup as you see it weighs 11 pounds, that's about the same as my whole rear wheel from my downhill bike. Target weight is 20 pounds or less, for as little money as possible.

So far, I've spent $31 on the whole bike, and I don't see myself spending any more (other than a new chain).

WOOO! FREEBIES!

Image

Posted: Thu Jul 01, 2004 4:17 am
by QuickDrive
Awesome, Full Rigid bike that will weigh in under 26lbs when you're done hopefully.

I get teased anytime I'm on a trail with my 11 year old ghetto rigged full rigid xt/lx 25lb xc racer.

Posted: Thu Jul 01, 2004 4:30 am
by BAC5.2
There is a big singlespeed crowd out here. I've done the 27-speed, 24lb XC bike. I've done the 50lb, 18 speed downhill bike. Now it's time to do the 1 speed, 20lb, full rigid bike.

It's not just an XC bike though. I plan on doing a lot of technical urban riding on it. The bike should hold up OK to my riding. I had an 02 Stumpjumper Comp (which I DID break, but unrelated to the riding I was doing. I did all my hardcore riding on it after it was broken while waiting for the S-Works warranty frame) that I regularly did 6-foot to flat drops on.

It's going to be an all-around deal. If I can finish putting it together tomorrow, I might go dirt jumping on it on Friday to get used to it again.

I gotta get used to clipless pedals again, and I need a set of flat pedals now since I gave up my favorite pair of pedals EVER when I sold my downhill bike :(

Posted: Fri Jul 02, 2004 6:42 am
by BAC5.2
21 pounds before chain and brakes :(

I want to build a cheap, but light, wheelset to replace the setup I've got. Maybe shave a pound or two.

Posted: Fri Jul 02, 2004 6:52 am
by evolutionmovement
I would have been surprised if you got under 20 for that cheap. I don't think my Allez is that light. 21's still nice, though. My tank MTB weighs about 35. Can you despoke a standard rim without losing too much strength?

Steve

Posted: Fri Jul 02, 2004 7:40 am
by BAC5.2
Meh, I was honestly expecting around 18 sans chain and brakes. The fork turned out to be a lot heavier than I was expecting (it's steel, not aluminum).

No, you can't despoke a rim and not lose strength. What happens is the tension is split evenly (should be anyway) across the spokes (mine are 32). You remove spokes, you lose spoke crosses (the more times the spokes cross, the stronger the wheel. Your average wheel is 3 crossed. Each spoke will cross 3 spokes). You lose spoke crosses, you have to remove 2 spokes that are next to eachother and remove enough to keep the wheel balanced.

Now you are down to 16 spokes on a regular 32 spoke rim. 16 spokes, means double the tension on each spoke. The rim, which was designed for 32 spokes, now has to suffer more tension on fewer contact points. You risk rim breakage at the empty holes, and even worse the increased tension has a VERY high potential to pull the nipple out of the eyelet.

You'd save a LOT of weight, but the wheel would only be 1/4th as strong.

My old downhill bike was 47.5 pounds. My Old stumpjumper, at it's lightest, was around 24 with a full 27 speed setup. Then the Stumpjumper turned into 31lbs in free-ride mode. Now, single speed setup is 21 pounds. I'm excited because it rides kind of like a trials bike. Really stable and I have to work to get the front end up (which is good because it'll help balance :)). It'll be all together tomorrow for a total and final cost of $32.

Posted: Fri Jul 02, 2004 5:44 pm
by evolutionmovement
Could they be reoriented, though? I know they're usually race bikes, but I see a lot of high end wheels with far fewer spokes that are usually somewhat bladed to reduce turbulence. I didn't know if it would be feasable to install a set of those spokes to a standard rim. I doubt it, but don't really know.

Either way, that's a damn light bike for short cash. There's nothing like a lack of weight for response and feel. I barely ride my MTB because it feels exactly like driving a tank - just crashing through shit. The road bike is like a race car. If I move to NH or someplace with better longer trails close by I'll have to get a light MTB. I'll also want to ditch the full suspension and go back to a hardtail as it's much more fun.

Steve

Posted: Fri Jul 02, 2004 7:30 pm
by BAC5.2
I could reorient them, but my rear wheel is the troublesome weight devil. I could 2-cross the drive side and radial lace the non-drive, but that's still 32 spokes, and I'd lose a significant amount of strength for like 20 grams in weight savings. I could radially lace the front wheel, but running disc's, that's WAY to much strain on the wheel, espically since the bike isn't just solely an XC ride.

My next expensive wheelset, I'm going to build a 32 hole setup with SAPIM bladed mountain spokes. All the strength of a double butted spoke, at almost half the weight. Not to mention the increased rigidity (which is good for power transfer). I'd LOVE to build a wheel with those spokes, but at almost 60 bucks for 32 spokes (at my discounted prices too) that's just not a feasable option.

But with those spokes, I'd have to get a dope set of light disc brakes and a set of slick light rims (probable something like a Sun SUB-4) and some AC (American Classic) Ultralite Mountain hubs (for weight reference, an AC front ultralite hub weighed less than the AXLE of my downhill fork).

There's really no such thing as a standard rim, as all are designed differently. I'm running some disc specific, trail rims (515g's each, fairly heavy by todays standards, my downhill rims were 565 grams, and that was light for DH rims), which are nice and strong and can take about anything my 150lb frame can dishout.

I'm going riding tonight to break it in! I hope it rides as nicely as I am hoping. No front brake though, as I don't really feel like setting it up today.

Posted: Sun Jul 04, 2004 7:29 am
by BAC5.2
23 pounds flat, and rides like shit :(

WAY to stiff, it bounces all over the trail and holds a turn like a shopping cart.

Got some work to do

Posted: Sun Jul 04, 2004 7:36 am
by evolutionmovement
Wasn't that frame intended to be used with a suspension front fork? Maybe they made the thing too damn stiff thinking that would take some of the pain.

Steve

Posted: Sun Jul 04, 2004 8:21 am
by BAC5.2
The Stumpjumper is a SUPER stiff frame. Coupled with a SUPER stiff fork (Surly Instigator, 4130 chromoly steel fork), and 40psi (to prevent pinchflats). It was a bit rough.

I'll probably keep it as-is for when I go urban/dirtjumping and see how she does. Otherwise, I'll probably just swap the fork with something crappy.

I wish I had the money to build another beef hardtail. I want a frame with identical geometry to my Stumpy, and put a 6 to 7" dual crown on it. I had a 6" dual crown on the stumpy back in the day, and it rode PERFECTLY. About the only thing this bike does well is climb, and I don't have the legs to keep it spinning fast (geared to low, gotta spin your ass off to get it up hill). Lack of front brake also doesn't help confidence. I have ZERO confidence in the bike around turns or over bumps, so in turn, I'm not fast :(. I'm not used to being slow.

I need to check the books and see what has the same geometry as my stumpy and try to score one of those frames, then save a ton and try to snag a 6" fork. Probably build it single speed for a while, just so I can save some money for a good setup. I'd rather have a nice set of discs than a 9-speed setup.