Mountain Biking - Where's the weight?

Hi folks,

I'm in the process of converting a mountain bike--Kona Blast--into a commuter. The main thing I want to do is drop some weight.

I was surprised to find (on Kona's Web site) that the frame is really light, at 2.7 pounds, unless that's a typo. But the bike weights a little over 30 pounds. I see bikes with frames that weigh about the same (Like Kona's PhD) that weigh 21 pounds. So somewhere on my bike there's nine pounds I ought to be able to shed.

The first step, obviously, is the fork: If I replace the Marzocchi MZ3 with a fixed steel fork I'll save pounds (how many I'm not sure; can anyone tell me how much a fixed fork for a mountain-style frame weighs?). If I go with carbon I'd save a few more ounces.

So I'm going to do that: take off the shock and put on a fixed. So what should I do next? Tires, wheels?

Can somebody make me a list of the most efficient/cheapest weighs to reduce the weight of a mountain bike while turning it into a commuter?

Thanks,
Jim

Make sure and get a travel corrected fork. If it's not tall enough for your frame geometry, it may be twitchy and just plain weird to ride.

Tires, tubes, and wheels first. Any rotating weight saved will make the biggest difference.

The listed frame weight can't be right. 2.7 lbs is lighter than some of the nicest carbon and ti road frames. I'd figure your frame alone weighs somewhere around 4.5 lbs.

I got that frame weight from the Kona Web site--there's an Excel spread sheet you can download--but I'm sure you're right; I don't know much about the weight of bike frames, but that seemed awfully light to me.

Thanks,
Jim

Make sure and get a travel corrected fork. If it's not tall enough for your frame geometry, it may be twitchy and just plain weird to ride.

Thanks for the advice. I'm working with the folks at Kona to pick out a suitable replacement.

Jim

Here's the fork (http://www.speedgoat.com/product.asp?part=114105&cat=160&brand=182) I would go with, not cheap but it sure is sweet!!!!!

cranks could account for some weight

Here's the fork (http://www.speedgoat.com/product.asp?part=114105&cat=160&brand=182) I would go with, not cheap but it sure is sweet!!!!!
Call me old-fashioned, but I like steel. I just like the way it feels. Steel fork is $240 cheaper ($80) and 100 grams heavier. When I get within 100 grams (0.2 pounds) of my ideal weight, THEN we'll talk about carbon-fiber forks!

'Tis sweet though.

Jim

The Kona Excel sheet doesn't list the weight of the Blast as frame only. You're looking at the Kula Supreme weight which is a lightweight Scandium race frame while the Blast is a 7005 Aluminum all mountain frame (i.e., heavier and beefier). Not the same frame material and different tubing diameters/shapes and maybe even thicknesses.

If you want to lose weight for commuting, do the rigid fork, lighter wheels and tires, and go to a lightweight crankset (maybe even a double road crank).

yeah after wheels, tires and fork the next heaviest thing is the crank. like never said you may consider a double ... a compact road crank may work pretty well. not sure how different the road/mtn chains are. i think they're the same

Ever think of a singlespeed for the commute? As you do it more, you are going to find the simplicity of fewer parts nice, and you get to drop the weight that you were talking about. There are plenty of articles on how to convert to a single speed, and it is pretty easy. My bike went from 32 pounds to about 23-24 by converting to a full rigid singlespeed. The only part you would need to buy you are planning on anyway (rigid fork), and maybe a Surly Singleator or related device. Go with a Surly 1x1, it weighs 2 pounds and is rock solid, and only 55 bucks, and the singleator is about 50 bucks. Therefore, you will get a simple, reliable, light bike for maybe 100 bucks.

aside from cranks... all the small parts, bars, stem, grips, levers, shifters, cables, derailleurs, pedals, brakes... everything can add up and up

Here's the fork (http://www.speedgoat.com/product.asp?part=114105&cat=160&brand=182) I would go with, not cheap but it sure is sweet!!!!!

That is a nice fork but expensive, here's one that is half the price and only 50 grams more. I've got one on a Access XCL frame and it works great.

http://www.speedgoat.com/product.asp?part=40983&cat=160&brand=130

The Kona Excel sheet doesn't list the weight of the Blast as frame only. You're looking at the Kula Supreme weight which is a lightweight Scandium race frame while the Blast is a 7005 Aluminum all mountain frame (i.e., heavier and beefier). Not the same frame material and different tubing diameters/shapes and maybe even thicknesses.

If you want to lose weight for commuting, do the rigid fork, lighter wheels and tires, and go to a lightweight crankset (maybe even a double road crank).

Thanks, never, for setting me straight. You're right about the frame weight; I looked at it wrong. My apologies.

Jim