First fixed gear (KRZBERG v5), trying for under 6.8kg

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huffington
Posts: 17
Joined: Sun Nov 29, 2015 3:29 pm

by huffington

Hi guys, I finally have the resources to build a new bike, and I need a little help and more opinions with what I want to do. I want a slick, lightweight fixed gear for all-purpose training and commuting. It also has to look cool! :D

I found a frame I like and bought it, as well as a SRAM Omnium crankset with BB (found a good deal) and a Dura Ace front brake (best looking rim brake I found). I need a front brake for safety, and the rear hub will be single side (or double) fixed.

Here are some pics of the parts I have:

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Here's what parts I had in mind so far (* purchased):

Frame: 8Bar Krzberg V5 / 1670g * - I like the minimal look of it, smooth welds and slightly downward top tube. Size M
Fork: 8Bar Carbon fork * / 410g uncut - came with the frame, it's still uncut. Probably have to cut around 15cm of it, weight might go down to 355g as advertised.
Headset: 8bar Tapered Integrated * / 122g - Not sure if it' worth spending 80 or more euro to get a better headset...I did find some that shave around 40g.

seatpost clamp: generic 8bar clamp / 15g
Seatpost: Deda Zero 100 / 230g - 27.2x350mm
Seat: TT seat / 250g - I used to have numbness in long rides on my road bike, so I wanted something more comfortable in that aspect, I also want to mount a bottle cage in the rear of the seat. So I was looking at either a Specialized Sitero (270g) or a Fizik Tritone (250g), both coming with a rear mount for bottle cage, and in the case of the Tritone, a double cage mount and room for spare tube.

Stem: Deda Zero100 Pista / 126g for 110mm
Bar: Deda Pista bars / 280g, 420mm width
Bartape: Deda Perforated / 28g
Brakes: Dura ace BR-9000 * / 145g
Levers: Cane creek crosstop / 48g - for a single top mounted lever

Crankset: Sram Omnium * / 825g for crankset and chainring, 48T
Bottom Bracket: Sram GXP * / 100g
Chain: Izumi 1/8 / 330g I was looking at Izumi chains, they seem pretty tough, haven't found a reliable source for the weight online, but I think the standard 1/8 chain might be around 330g with all links
Sprocket: Miche 18 teeth sprocket / 30g, maybe, not sure of weight

4,554g so far.

Wheels - wheels I found ready build are either too heavy (over 2kg) or too expensive, I think the best bet is to custom build them, or at least only the rear one. I'm also not sure on the spoke count, maybe 36 rear, 32 front?
hubs: Shimano Dura Ace 7600 Large flange rear / 313g, Dura ace HB-9000 front hub / 120g Mack Track Rear Low Flange / 190g, Mack Road front / 66g
Spokes: Sapim CX-Ray,/ 273g for 64 pieces
Rims: H plus Son Archetype / 470g x 2 or Mavic Open Pro's, that come at 435g a piece
Innertubes: Generic tube / 80g x 2
Tires: Continental Gatorskin Folding, 700x25c / 240g x 2


6,663g with wheels

Pedals: Token tk456 / 360g I was looking at either some classic track pedals with toe straps, the lightest I could find are the Tokens. Another options are MTB pedals with wide toe straps (like Cinelli Kink Straps, or Restraps). I found the Xpedo Spry flat pedals that come at 260g per pair and toe straps might come at 100g or more.

7,023g total.

On what parts could I shave some weight from? Ideally, Id want to stay under 7kg with pedals included. Any suggestion of lighter parts to swap? I have maybe around 1000 euro budget for the remaining components.
Last edited by huffington on Mon Nov 30, 2015 6:15 pm, edited 4 times in total.

martinko
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Location: Slovakia

by martinko

That crankset is heavy for a single chainring. But I don't know what other 1x options are and you don't seem willing to change it. :)

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prendrefeu
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by prendrefeu

Some general notes on this, if you truly want to save weight intelligently. Hopefully you'll find them helpful:

1. You can use 3/32" instead of 1/8" for the chain. 3/32" chains are just as strong as 1/8" (they really are), and there are lighter varieties. You don't need to get a "single speed" or "track" specific chain, the chain's plates won't determine it jumping off a cog or not, that's on the cog or chainring's tooth shape. a 3/32 chain with hollowed out plates and pins will be significantly lighter than the 1/8" chain.
2. Added bonus with going 3/32 is the matching cogs and chainrings will be lower in weight as well. They exist, find them.
3. You don't need a track crankset. Just get the lightest crankset you can afford/find and add a single speed or track chainring to it at the tooth count you want. Place it either on the inside or outside to get your appropriate chainline. Preferably the outside.
4. There are lighter hubs. Those DA ones are nice, but really even your basic generic Formula track hub runs ridiculously smooth... I mean really ridiculously smooth and nice. In short, DA is nice and bling, but in reality and in this specific instance a bit overkill/overrated for your purposes. You want really light hubs? MACK. There is no equal (afaik)
http://www.mackhubs.com/
5. DA brakes are nice, but heavy. On a budget? Consider the Planet-X CNC brakes... Plenty of stopping power, modulation, and plenty light on a budget.

There are lighter BB options for SRAM. Look into those from Mortop... you'll be at around 65g.
Get a lighter seatpost *after you've been fitted* - even a generic carbon on ebay will save you 100g. You'll also have a better ride.
Headset? Mortop will get you at 65g again, and not expensive at all.
Stem? Lighter and better options out there. Take a look at FWB's stem review, also look into the Uno stem (search WW for discussions). For most purposes, particularly commuting, it will be plenty stiff enough and significantly lighter.

Pedals... Wellgo R226. You don't need toestraps and cages if you're running clips, and if you're not you might as well have a platform instead of a cage which will get banged up when you actually use the bike instead of walking it around all the time :lol:
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jekyll man
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by jekyll man

If you're only planning on using it on the road, then i reckon you'll need to gear down a bit if you dont want to risk blowing your knees out on any serious gradient. 70 inch is a bit butch :wink:
I'm on 65" (42/17) and that can hurt on some of the grindy hills around here. 20-22mph is fairly comfortable on the flat with that gear, but anything above 25 becomes hard work for any duration.

I dont know what size chainring you can go down to on 144bcd- im on 130.
1/8" chains and sprockets are easier to get hold of than 3/32", going with the larger chain will enable you to run on either if you decide to swap gearing etc. Obviously cant go onto wider sprockets with a narrower chain.
Half links are also available for 1/8", never seen them for 3/32".

I'm not sure how comfortable a sitero is going to be on a fixed bike- need something that you can move around and bounce on. I've got 1 on my tt bike, but not thinking about putting it on my fixed anytime soon.. Cheap slr or similar would fit the bill, and buy an out the back type bottle holder. Profile used to make a 2 bottle version.

Halo aerorage is a reasonable rear wheel. Hub is smooth and not too heavy. Dont buy the fix-g version though. Also cheap 8)
Dont forget a lockring too :wink:
For a front, you may as well pick a standard front hub with qr. No need for a bolt on wheel if you arent racing track. I'm on a Plant sex superlight 20h (or 24h) hub mated to a matching halo rim. Plenty stiff enough, and also lighter.

Junk the tatorskins and get some proper tyres. Conti 4 seasons or GP's in 25 are far better.

Standard clipless pedals will be fine. Unless someone is going to strap you in at every junction, and you're planning on putting out 1300w between said junctions, theres no need for going overboard.


Are your Deda weights measured or manufacturers? I've never seen any deda within 10% of claimed.

For the other stuff, as prend says look at Uno stuff for cheap weight savings.

I reckon specced smartly you will get close to 6.8kg.
My Dolan precursa in winter road guise is 8.0 but that only cost me £150 complete :thumbup:
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Devon
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Joined: Fri Apr 12, 2013 1:19 pm
Location: Sydney, Australia

by Devon

jekyll man wrote:If you're only planning on using it on the road, then i reckon you'll need to gear down a bit if you dont want to risk blowing your knees out on any serious gradient. 70 inch is a bit butch :wink:
I'm on 65" (42/17) and that can hurt on some of the grindy hills around here.


Wow, really? I commute on 46/16 and get fed up of spinning. It depends on length of ride though, for sure. I definitely wouldn't want to gear down more than an 18t for anything that I use it for - you'd never get anywhere.



That aside, looks like a good build. I'd be shocked if you couldn't get a fixed bike below 6.8kg. Glad to see you using decent brakes :thumbup:

huffington
Posts: 17
Joined: Sun Nov 29, 2015 3:29 pm

by huffington

Thanks a lot for the answers, guys, have to do some more research on parts!

martinko wrote:That crankset is heavy for a single chainring. But I don't know what other 1x options are and you don't seem willing to change it. :)

Hmm, I haven't found anything cool, there is a Miche Crankset with a similar weight, that uses a super heavy square tapered bottom bracket, and the Rotor 3D Track crankset, at 574g, without chainrings (140g) and without BB...and also at more than double the price of the Omnium.

I might switch it if I find a good alternative. There are some good-looking one-chainring cranks from Sram, like the Force 1 (at 572g), but they're made for 1x11 setup, and I have no idea what chain/sprocket combination might work. Maybe use that crankset with a road chainring? Then I'm not sure on the chainline...

prendrefeu wrote:4. There are lighter hubs. Those DA ones are nice, but really even your basic generic Formula track hub runs ridiculously smooth... I mean really ridiculously smooth and nice. In short, DA is nice and bling, but in reality and in this specific instance a bit overkill/overrated for your purposes. You want really light hubs? MACK. There is no equal (afaik)
http://www.mackhubs.com/
5. DA brakes are nice, but heavy. On a budget? Consider the Planet-X CNC brakes... Plenty of stopping power, modulation, and plenty light on a budget.
Pedals... Wellgo R226. You don't need toestraps and cages if you're running clips, and if you're not you might as well have a platform instead of a cage which will get banged up when you actually use the bike instead of walking it around all the time :lol:

Good points...I'm not sure what to do with the crankset, apart from I already bought it :D , I don't want to have any difference in chainline, and I'm not so experienced to mix and match parts, I'd rather have something that is good and proven. But switching the chainring sound like a good idea, I can get a 3/32 specific one, I found a 44T (the lowest for 144BCD).

Those Mack hubs are cool, and they're even cheaper than the Dura Ace ones, also I save around 175 grams, I'll switch with Macks :D I already bought the DA brake..the Planet-X one looks good but I think I'll stick to the Dura ace for now, maybe in the future I'll find a cool upgrade. I'll have to do some research on the headset and bottom bracket, if I could save 100grams it might be worth it. :) It's a little harder as I can't order anything from outside of Europe (the shipping costs and import taxes are huge).

jekyll man wrote:Standard clipless pedals will be fine. Unless someone is going to strap you in at every junction, and you're planning on putting out 1300w between said junctions, theres no need for going overboard.


I prefer not to use clipless pedals, as I had some bad experiences with them, and I commute/fun ride with casual shoes most of the time. Using toe straps (something from Restrap maybe) looks like a more day-to-day solution and seems safer.

I also want to take this bike for some hard sprints at the local velodrome, and I want to be sure my shoes won't slip. I have the Shimano A600 on my MTB (which are one side clipless, one side flat), they're very light at 286g for a pair, but the flat part is super slippery and non-grippy..it doesn't seem safe if I use casual shoes with it.

jekyll man wrote:I'm not sure how comfortable a sitero is going to be on a fixed bike- need something that you can move around and bounce on. I've got 1 on my tt bike, but not thinking about putting it on my fixed anytime soon.. Cheap slr or similar would fit the bill, and buy an out the back type bottle holder. Profile used to make a 2 bottle version.

Are your Deda weights measured or manufacturers? I've never seen any deda within 10% of claimed.

Junk the tatorskins and get some proper tyres. Conti 4 seasons or GP's in 25 are far better.

I reckon specced smartly you will get close to 6.8kg.
My Dolan precursa in winter road guise is 8.0 but that only cost me £150 complete :thumbup:


I don't know about the Sitero..I imagine with drop bars I'll be leaning forward a bit, but I'm not sure (my commuter had bullhorns and sometimes I got numbness). I found some standard saddles (at around 145g), with padding and everything. But a separate bike holder that mounts on the saddle from Profile Design is 190g (dual cage), and a single one (with room for spare tyre and bag), the Elite Sekane, is 135g. So in the end, it might be the same thing..the Fizik Tritone is 250g including the dual bottle holder and I might get it for cheaper then a saddle + holder.

Deda weights are from the bike shop descriptions...not good if they're actually heavier :( I can't find Uno parts for cheap in Europe. I also couldn't find another light stem for track (at 68-70 degrees), I think it looks better if the stem is perfectly straight after mounted, and I want this bike to look cool! :D

On tyres, I had GP 4000 S2's, but after under 500km I had a 1cm side gash in the rear (making it unusable), and the front got all cut up. I'd rather have something that lasts (also the streets here are pretty rough, and the only velodrome has crumbling asphalt). The 4-Seasons look like a good option, but I'm undecided for now :P


Devon wrote:That aside, looks like a good build. I'd be shocked if you couldn't get a fixed bike below 6.8kg. Glad to see you using decent brakes :thumbup:


Thanks, I couldn't imagine riding without brakes! :P If i switch to Mack hubs, get a lighter saddle, headset and BB, I'll definitely be under 6,9 kg, with pedals included! :D

Devon
Posts: 782
Joined: Fri Apr 12, 2013 1:19 pm
Location: Sydney, Australia

by Devon

In regards to pedals - you don't like clippless, which is understandable, but then say you consider toe straps to be safer?

This suggests to me that your bad experience with clippless was due to being stuck in the pedals and falling over. Well with toe straps, this is FAR more likely. I would suggest trying clippless with the tensions set correctly. Toe straps are terrifying!

huffington
Posts: 17
Joined: Sun Nov 29, 2015 3:29 pm

by huffington

It was quite the opposite, my shoe came out during a sprint, and not only once (it also happened when jumping over obstacles with my MTB, and then I was pulling straight up). The spring tension was adjusted correctly and the cleats were almost new...maybe I didn't set up something correctly, but I just don't feel safe pushing 100 percent if I know that by the accidental flick of the heel my shoe can come off.

I never used pedals with toe bands or metal cages and straps, but they look like a safer options when pushing the hardest - for sure my shoes will not slip out. I don't know how much of a good idea they are when commuting though, but the strap tightness is adjustable, maybe some fiddling will make it ok. I'd rather fall on one side standing still than losing balance at 50kmh :P

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Devon
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by Devon

Yeah, I'd say there was a problem with your pedals/shoes/cleats. That never happens. If you get a chance I'd recommend giving them another chance!

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