Bike porn

And I can't get my head around that gearing at all

They're the new SRAM XX1 designed as a 1x11 mainly aimed at 29ers.

10-42t rear cassette give you a good amount of range without needing a double or triple;

^where would you need 240" or more?

Les Gets, Chamonix and Whistler all have downhill trails that last for about 30/40 mins. I think keeping a 35lb MTB going a reasonable speed constitutes more energy loss than scrubbing off speed of a 15lb road bike.

It'd be an interesting comparison if someone actually worked out the kinetic energy being turned into heat for an MTB going down (say) a ski-slope in the summer, and a road bike going down the same mountain via the roads.

As a percentage of the total system weight a 15lb road bike isn't so different from a 35lb MTB.

I'm 171 pounds, so with roadbike and kit probably 190? Me on an MTB would be (say) 215.

The MTB would (assumption!) see fairly frequent braking whereas the road bike would see repeated, heavy but relatively infrequent decelerations from ~50mph down to 15mph or lower (hairpins).

I cannot help but think that there is a reason they fit rally cars with much bigger brakes for asphalt courses.

designed as a 1x10 mainly aimed at 29ers.

1x11, and aimed at all XC wheel sizes, not just 29"

What was it you were saying about rational and informative?

^where would you need 240" or more?

240" development, not 240 GI. Rarely expressed like that, as it's only Forrins who do development, and they measure in metres.

Is that the final TightAss? Looks great.

240" development, not 240 GI. Rarely expressed like that, as it's only Forrins who do development, and they measure in metres.

aah, gotcha. Thanks

Force of habit, I've only just heard about this whole 10 speed lark.

This look awesome;

Touring bike;

The Skull Bike clubs visit to EAI's warehouse...

More here:flickr

so good!
thanks for that.

29er is teh sex.

Strange stem choice on the Gaulzetti - I haven't seen a flawless build up from them yet - but Im a massive fan of the frames.

It match the handlebar, but it does look strange with the painted seat mast.

Touring bike;

Really? Despite the S&S coupling and wide range of gears, I would hesitate to call it anything more than a credit card tourer for smmoth terrain and dry climates

Nice bike though

I would, nothing stopping you from going touring on it.

saddlebag ID??

Viscacha by revelate.

The newer design is a lots better and addressed some of the fault I've found with it.

It'd be an interesting comparison if someone actually worked out the kinetic energy being turned into heat for an MTB going down (say) a ski-slope in the summer, and a road bike going down the same mountain via the roads.

As a percentage of the total system weight a 15lb road bike isn't so different from a 35lb MTB.

I'm 171 pounds, so with roadbike and kit probably 190? Me on an MTB would be (say) 215.

The MTB would (assumption!) see fairly frequent braking whereas the road bike would see repeated, heavy but relatively infrequent decelerations from ~50mph down to 15mph or lower (hairpins).

I cannot help but think that there is a reason they fit rally cars with much bigger brakes for asphalt courses.

If we assume that neither rider is pedalling much, the amount of energy in play is just the gravitational potential energy, i.e.
mass of bike & rider x hight descended x strength of gravity

That energy goes three ways as they descend: into rolling resistance, air resistance, and brake heat. The MTB will have slightly higher rolling resistance, but by moving faster and further the road bike will have much higher air resistance, leaving less for the brakes. So on average, the slower bike's brakes work harder.

This look awesome;

[IMG]gaulzetti.jpg[IMG]

That is glorious. Even better that is breaks with the convention (tape, classic wheels, non-matching stem/post). And it comes with a great groupset that has problems getting love.

Any more pics?

No idea, found on Tumblr, think that would be my idea road bike.

Repost? nicest Pegoretti I've seen so far;

So on average, the slower bike's brakes work harder.

Really? After a road bike has already slowed to the MTB speed, it still has as much kinetic energy as the MTB, along with it's lower rolling resistance and less drag. Once the speeds are equalised, the road bike's brakes still have more to do than the MTB's

In other words, if you rode an MTB down a typical Alpine road descent, its brakes would have an easier time than a road bike's on the same descent.

What about rolling inertia of heavy mtb tyres/wheels/frame?

I feel a little dirrty making porn...

with parts.

What about rolling inertia of heavy mtb tyres/wheels/frame?

Pretty trivial when there's 80kg of meat along for the ride. Feel free to include it in your analysis, but don't expect it to make much difference.