Suggestions on making my kona lighter

[suburbanreuben]

EDIT: Cut off the excess seatpost in your frame. I had a 450mm thomson that weighed about 350g. Cut off what I didn't need and now its 190g (I also modified the clamp)

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:shock:
I find that extremely hard to believe. You halved the weight of your seatpost by cutting off the excess? Given that most of the weight is in the head, how short was it once you'd butchered it?

 

[Sithlord]

you know that your on that weight weanie slope. No return

GUILTY as charged..

 

[mikesnowdon]

EDIT: Cut off the excess seatpost in your frame. I had a 450mm thomson that weighed about 350g. Cut off what I didn't need and now its 190g (I also modified the clamp)

.

:shock:
I find that extremely hard to believe. You halved the weight of your seatpost by cutting off the excess? Given that most of the weight is in the head, how short was it once you'd butchered it?

Now I admit, I didnt weigh it before but according to http://weightweenies.starbike.com/listings/components.php?type=seatposts the stock weight is around 293g (sorry I was wrong above). I'm using the post on a 19" (c2t) Kona frame which has an extended seat tube. So nearly half the post was basically not needed. I left the same amount of post in the frame that Thomson recommends with the markings on the bottom of the post, so its safe. I just cut it to allow about the post to be at my ideal height. Its only 250mm long now. I also modified the upper clamp, pics below. When fitted you cant tell the post hs been messed with at all. I'll be changing the bolts and barrels to Ti ones soon (lose another 10g). As it is I have saved about 100g off this post.

I also butchered my Kona seatpost clamp...

 

[mikesnowdon]

These are the Ti bolts/barrels:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... K:MEWAX:IT

And a pic of the post in the frame....

 

[andrewl]

chainset and pedals are the killer IMO, I'd run the fork at 80mm too but it should be plenty light. After that your fine tuning, new frame would probably be next and then super pimp wheels.

Hone cranks aren't that heavy (and they are exactly the same as LX just black)

As eveyone else has said just lookat wheels and tyres, and get rid on the heavy pedals. Its a heavy frame (relatively speaking) so it will never be that light.

Machining every small part on the bike is only worth doing if the rider goes to a similar effort themselves too

 

[Anthony]

I also butchered my Kona seatpost clamp...

What is the fine line emanating from the machined angle at the bottom right of the picture?

On the seat post, I think it's always good practice to have your post long enough to end an inch or more below the top tube/seat stay welds. Welding permanently damages and weakens a tube, so having a tight-fitting post both above and below the weakened area places significantly less strain on it than having the post only immediately above the weak area, as you have. Not that you ever fall off of course and I'm sure you're as light as a feather, but there is the potential for severe lateral forces to be applied to that weakened area and that can cause problems.

 

[mikesnowdon]

I also butchered my Kona seatpost clamp...

What is the fine line emanating from the machined angle at the bottom right of the picture?

On the seat post, I think it's always good practice to have your post long enough to end an inch or more below the top tube/seat stay welds. Welding permanently damages and weakens a tube, so having a tight-fitting post both above and below the weakened area places significantly less strain on it than having the post only immediately above the weak area, as you have. Not that you ever fall off of course and I'm sure you're as light as a feather, but there is the potential for severe lateral forces to be applied to that weakened area and that can cause problems.

Machined angle?

I get your point on the seatpost. I dont think its a major issue though.

 

[suburbanreuben]

:shock: It seems silly to risk buggering up a perfectly good frame for the sake of 50grammes though- I've always assumed the seatpost MUST extend below the top tube.

 

[SeeingisBelievingGTMuseum]

These are the Ti bolts/barrels:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... K:MEWAX:IT

And a pic of the post in the frame....

That is a picture of a cracked frame waiting to happen. If your line is correct it will crack just above the weld with some riding on rougher terrain. It's not a matter of if but when. Seat post should always go in far enough to get past the weld at the top of the top tube at the seat tube. How many of us have seen this before? Numbers of us.

 

[Anthony]

Machined angle?

I assume you have cut/machined the slot between the upper and lower bands, and I just thought I could see a line there (below)