Aluminum frame weight differences between models

bikert

Hi, so first, is 6061 aluminum alloy considered 'lightweight' at all, or heavy? I had one made of it, and although it was a bigger size than the walmart steel frame I had before it, can't say it was 'that' much lighter in weight (had expected aluminum to be very light by comparison). More namely however, what my question boils down to is, what minimum price is there for a mountainbike that's at least noticeably lighter than a walmart steel one? I hope I don't have to go carbon or titanium, not looking for 'the' lightest, just something that's noticeably lighter than walmart steel. Is 6061 alu a good start, as far as not being 'cheap & heavy'?

larkim

The frame is only one part of the contribution to light weight bikes though. No point in getting a lightweight frame without other weight saving components, especially wheels and tyres.

steve_sordy

"Cheap, light, strong - pick any two!" Those were the words of one of the founding guru's of mtb (name escapes me).

Unless you are going from cheap and nasty to only slightly less cheap and nasty, saving weight can be expensive!
With one or two notable exceptions (like tyres), but mostly true for whole bikes and important components, weight saving costs about £1 per gram (£1000/kg).

larkim is correct, frame differences are but one contributor to weight. But remembering the "cheap, light, strong" formula, I would rather have a good alloy frame than a cheap carbon fibre one! And I'm writing as someone who has a CF frame now and has had two before that. To have a really light CF frame that won't disintegrate after the first fall, you are talking megabucks!

billycool

As has been said - the frame makes up part of the bike and is not the only contributor to bike weight. My 140mm FS enduro frame is 6061 alloy and that's on a $5000 bike.

I have very light wheels and carbon bars etc. The bike is also 1x.

The other components make is nearly as light as a my HT @ c.13kg. It climbs very well and descends as you'd expect.

So - cheaper bikes use cheaper/heavier components and can skew the figures.

Loads of decent spec MTB's are made using 6061. I think you'd be looking at c.£750/$1200 for something sensible.

mattyfez

Frame design can play a part too, a well thought out frame will have thicker material at stress points and thinner material where the strength isn't needed so much, whereas a 'cheap' 6061 frame will just be standard size alloy tubes welded together, so heavier.

bikert

Thanks a lot, I think the replies answered my question.

The Rookie

steve_sordy wrote:

"Cheap, light, strong - pick any two!" Those were the words of one of the founding guru's of mtb (name escapes me).

Keith Bontrager

As for your original question, where you comparing bike weights or frame weights?

A typical cheap frame is 2.2-3.0kg (alloy to steel) but the bike itself will weigh circa 15kg so the different frame makes very little difference.

A good quality steel frame is lighter than a poorer quality alloy one.

steve_sordy

"Keith Bontrager!" Thanks for the memory prod. Didn't he found Trek?

robertpb

steve_sordy wrote:

"Keith Bontrager!" Thanks for the memory prod. Didn't he found Trek?

Nope that was Dick Burke and Bevil Hogg. Keith was Bontrager which was taken over by Trek.

Keith is a nice guy, I had a few email conversations with him over tyre pressure in his Mud tyre, he was running 28-34psi when I was 22-25psi, he'd never tried pressures that low. The 28psi he reckond he only used when he went to Yorkshire as it was the worst stickyest mud he had ever ridden.

steve_sordy

robertpb wrote:

steve_sordy wrote:

"Keith Bontrager!" Thanks for the memory prod. Didn't he found Trek?

Nope that was Dick Burke and Bevil Hogg. Keith was Bontrager which was taken over by Trek.

..............

Thanks!

Every day is a learning day!