Reducing a bike's weigh by removing material?

xCatch22x

By material I mean by machining, cutting off or removing what was originally there rather than buying leightweight components.

What lengths have people gone to?

For me I have always reduced the bars to suit my riding, shortened the seat post, machined material from pedals, removed reflectors and bells, removed a spocket or 2, drilled brake levers etc etc.

I only ask as I am interested. I could reduce weight in many other areas including my lardy censored , but these methods dont interest me.

Anonymous

surely you'd save more weight by having a mighty dump before going on a ride?

Dick Scruttock

I agree i always try and have a massive catering offload before a ride.

paul.skibum

I'm not in a race I dont care if my bike weighs 50g more than it might. I'd buy lighter wheels and tyres if I was bothered before I started shaving bits off my pedals and seat post.

Buckled_Rims

paul.skibum wrote:

I'm not in a race I dont care if my bike weighs 50g more than it might. I'd buy lighter wheels and tyres if I was bothered before I started shaving bits off my pedals and seat post.

+1

Just take your wheels off the bike and lift the frame, see how light it is. Now, put the wheels back on and lift it up....wow I bet it's quite a bit heavier.

Wheels and tyres = most weight savings for immediate results.

supersonic

Reducing weight has it's benefits - but if shaving material, have to be careful not to go too far. In the 90s the trend was to drill holes in the frame, cranks and so on. Now that is just a bit daft lol. But reflectors and so on, why not - and many chop bars and seat posts. As long as the latter has still enough in the frame all will be well.

nicklouse

Mmm Drillium that exotic material that come pre-drilled.

not much metal that can be removed from most frames which would not then require something to cover the holes to stop heavier material getting in.

unixnerd

If you want to get rid of some weight start with the tyres, you'd be amazed at the differences in similar looking products.

desmosedici

Back in the 60's and early 70's it was quite trendy to ride a motorcycle with drilled out parts. This was due to a bankruptcy in engineering thought and innovation at the time. We couldn't get more power out of the engines, so the other option was to lighten the bike. And since carbon fiber was only available in Area 51 and no exotic materials were available except for Duralumin, we made do with drilling out brake discs and fender mounts. Net result for 5 hours work with a drill press? Sweet f**k all :P

A modern quality bicycle would have probably been designed with CAD and using finite element analysis. I would be loathe to remove material if the designer/engineer had seen fit to include it in the frame or part. Drilling parts out introduces stresses that the part may not have been designed to take.

Saying that, feel free to do what you wish.

lesz42

fill your tyres with helium.

glauciaregina9

I reckon you'd be mad to attempt to lighten your bike by removing material... the only parts that are appropriate for cutting are seatposts, fork steerers and handlebars...

These days, any good quality bike part will have been designed to use as little material as possible in the first place, so making your own 'enhancements' may remove weight but will also remove structural integrity and durability...

Buy some lightweight wheels, tyres and forks to get the most weight-saving benefit... other than that, unless you're a super-lean 10-stone athlete saving a few grams here and there on the bike aint gonna matter :-)

njee20

There was a bloke on Weight Weenies who 'drilled' an XT front mech, he sand blasted it and properly refinished it, it looked amazing, really well done.

Beyond getting hose and cable lengths right I can't be arsed, which is odd as I'm among the more weight conscious out there! Tend to leave seatposts within reason, easier to sell the bike at the end of the year!

xCatch22x

Guys and gals,

Thanks for all the comments, but please be aware that I am not asking for ideas for me to try as I have already done this on my old bikes, just to see what I could get away with without compromising safety and performance.

I'm simply curious to see what other people have tried that's all.

I suppose that rotaional mass is probably the best place to start.

PS Machining material from the pedals refers to the lugs that hold the reflectors on.

njee20

Drill holes in your tyres.

xCatch22x

njee20 wrote:

Drill holes in your tyres.

Not as good as the helium in my book!! LOL!

I'm thinking of cross drilling my carbon fibre rims to see if that helps. What about shotening the brake levers to make them a one finger operation? Quick release levers shortened too, or even a removeable lever that does seat post and wheels?

I may even make my pedals into those special BMX types that I saw kids riding during my youth, you know, the ones that are only have the spindle sticking out.

I also think my bread bag tags on my spokes my be adding weight too, do you think they should go.

Just wanted to get across that I'm not totally serious about this topic. It is of interest only.

.blitz

mba dismantled a GF Procaliber a while back and weighed all the parts:


The mounting hardware (nuts, bolts etc) accounted for more than 25% of the weight on some components.

njee20

That's why aluminium bolts are your friend! Headset top cap, mechs, shifter and brake lever bolts they're fine, I'd certainly run 3 alu/3 ti bolts in rotors too (enough people only running 3 ti bolts that I'm sure it'd be fine!), and shouldn't be a problem in post mount front brakes either.

Ti elsewhere.

diy

Could drill holes in the rider too - how about some liposuction.

ride_whenever

just go to poshbikes and buy everything from there... the biggest saving will be your wallet!

Saddles are another good place to remove material, no padding and drill out the shell.

I mean you can go silly light, but it does get outrageously expensive.

njee20

Most stuff on Posh Bikes is so out of date there's lighter alternatives anyway, don't think they've updated the site in about 5 years!

You can mill out brake adapters quite successfully, saves hardly any weight though! Like this, IIRC it saved about 1.3g!:



Or this:



Which saves more.[/img]

ride_whenever

If you want the bleeding edge stuff you phone poshbikes up, they never update the website, but do stock all sorts of interesting things.

Radioactiveman

Dont mean to be a party pooper but I don't think I would fancy drilling out or machining any component.it.

I dont think it is possible to weight weeny without spending money on lighter more expensive parts made of exotic materials without compromising safety/durability/performance

Surely machining a brake mount is going to allow flex in some direction and a loss of performance albeit small. My aim in lightening my bike is to reduce the weight without compromising durability and performance.

only my opinion but I am sure designers consider a lot more things than purely wieght.

bamba

Is the second picture after the first atempt snaped ?,
dont think i'd trust that, especaily being as you spent a fair bit on the brakes there.
Have you done the same on the front ?

njee20

If you want the bleeding edge stuff you phone poshbikes up, they never update the website, but do stock all sorts of interesting things

Just make sure you have a few weeks spare to talk to Andy.

I just can't believe a company like that manages to succeed with a rubbish website, I'd buy more stuff off them if I could just order it online.

only my opinion but I am sure designers consider a lot more things than purely wieght.

Of course they do, but there's a degree of inbuilt 'security' with components, understandably. I've not modified my brake mounts personally, but I would. I'm a 66kg XC racer, with 160/140 brakes. Avid design exactly the same mount to do a 203mm front brake on a DH bike, under a 120kg rider. There's a fair margin for error in there!

Things like mechs can also be 'tuned' without any real ill effects IMO, I just don't have the time/patience/skill to bother to do it properly! We're not exactly talking about drilling stems and cranks, that's a bit too 90s!

supersonic

If you remove the bar linking the brak mount bolts don't you risk them moving?

antikythera

xCatch22x wrote:

By material I mean by machining, cutting off or removing what was originally there rather than buying leightweight components.

When I get off I get rid of a sh*t-load of weight from the bike :P

Sorry, had to be said

njee20

If you remove the bar linking the brak mount bolts don't you risk them moving?

You'd think so wouldn't you! It's not my bike I linked to I should add, so I can't actually say. I'd be worried about the leverage you put on the bolts too, strikes me as askin to running 8" of spacers under a stem!

supersonic

I have to admit I am a 'moderate' weight weenie. I like parts - but sensibly light parts to suit an all round type of bike. And my wallet lol.

Anonymous

yeah, that second brake adapter looks like it's just asking for trouble. With Avid's twin round washer setup, there's really nothing to prevent the brake adapter from rotating, and throwing the calliper out of alignment.

njee20

Several of the pros were doing it, I know they get their bikes checked after 2 hours riding, but even so, there must be a degree of confidence that it won't shift the second you brake.

Thinking about it, in a completely non-scientific way though, it would struggle to actually rotate. The XX brakes use a different adapter, which I imagine is more expensive, so I'm not gonna try hacking mine about! May try and get a standard one to play with, find out for sure!

Edit: 4 times the price of a standard one, ouch! Not gonna be hacking that around, I'll weigh it when I remember, probably find it's lighter than a standard one cut in half anyway!

Anonymous

pros? you mean pro XC riders?
I thought (honestly) that most of them ran discs so small they didn;t need adapters at all anwyay.