The Downhill Thread

[darnijl]

I'm 6ft tall and I just ride a small frame (15"). Works for me! i like the idea of it being small. Don't like it too big - can't manoeuvre it... But then again, I have a 6kg fork..... 

darnijl2009-08-30 11:45:27

[DownhillingKing]

It doesn't matter how much rear travel you got as long as it more than 140/150mm and you are not doing 20m drops! just get a huge fork as when you bottom out your fork at speed and hiting it hard well it doesn't end well.

[Airborne]

Here is my 2008 Morewood Izimu (Build still in progress)

[Brad@TheRiot]

It doesn't matter how much rear travel you got as long as it more than 140/150mm and you are not doing 20m drops! just get a huge fork as when you bottom out your fork at speed and hiting it hard well it doesn't end well.

 

I disagree. For DH racing, you actually want the bike to be balanced. For the record, suspension is not there to sort out your lack of talent when jumping off things. It's there to soak up bumps and rocks etc.

 

It's a common misconception, people seem to believe that full suspension bikes are for jumping. Wrong. Think about BMX'ers, trials riders and MTB jumpers... the MTB jumpers only run front suspension (if they're not running a h/tail), that suspension is to soak up small bumps at the trails (dirt jumps). BMX riders do 360's down 20 stairs and land smoothly. It's in technique, not suspension. A suspension bike would break, because it woud no doubt bottom out.

 

Free riders use 160+mm bikes because they're riding rough terrain, not because of the size of the drop offs that they're doing.

 

If you run a fork that is too long for the rear end then you'll be slacking up the head tube angle. Two problems there: firstly, the geometry changes and the bike will not handle as it is supposed to. Secondly, you run the risk of snapping the head tube off - as you slacken the head tube, so more stress is at the head tube/down tube junction. If the bike is not meant to run so slack, the chance are that the frame will not hold up.

[jrussell]

Cool thanks for all the help guys, Brad do you think 170mm in the rear is alright then for FR/DH? and just btw discussing the buying of those cranks tonight, so will let you know by this evening whats going on.

and how much front travel would you recocmend for a 170 out back? a 180 fork?

[Brad@TheRiot]

Cool thanks for all the help guys' date=' Brad do you think 170mm in the rear is alright then for FR/DH? and just btw discussing the buying of those cranks tonight, so will let you know by this evening whats going on[img']https://assets.bikehub.co.za/legacy_images/smilies/smiley1.gif[/img].

and how much front travel would you recocmend for a 170 out back? a 180 fork?

 

Firstly, free riding and DH are very different. DH bikes have lots of travel but are built as light as possible. Free ride bikes are built to last and take big hits. In some cases they're also quite pedalable (in terms of a small amount of climbing).

 

I know that in parts of the UK guys run 7" bikes for a DH, even with single crown forks. It's because there tracks are less steep and/or less technical. But all the world cup guys are running 8" plus bikes with triple clamp forks, because they're riding on tracks that require a bike that can soak up insane rock gardens and deep braking bumps etc.

 

I chatted to one guy who believed that 7" was enough "for most SA tracks". But he was 40sec's of the winning time at Mankele (on a 7" fork)... so I'm not sure about that.

 

I think 170mm in the rear is ok for free riding and certain DH course. But remember, that it depends what you're trying yo get out of the bike. Also, the mm measurement is not the be all and end all of what makes a frame... the rest of the geometry is really important as is the actual build strength. Consider that an Ibis Mojo is 6" bike, but it's far from being a free ride or DH bike. Even a Santa Cruz Nomad has 160mm of rear wheel travel, but it too is far from a DH bike or serious free ride bike.

[Capricorn]

brad's on the money in two instances of note (not saying the other points are invalid )

balance and frame.

take the giant Ac for example. You could get away with a lot with that frame, as long you respect the limits of the frame. I mention the AC cos i had one, but it's the same for other frames as well. In fact, Giant states warrantee void if going over 150mm travel, as the head angle becomes too slack for how the frame was designed, but you could still slap on a Boxxer and go crazy. for a bit.

The other part about balance is so important. once heard one of the world cup commentors sayin how the rear shock is the heart of a DH rig. When I got my fox, I was a believer. It just felt better, more balanced.

So now that i've moved over to a more DH specific frame, and an RS Vivid, the riding dynamic feels so much better. Lower BB height, slacker head angle, shorter effective top tube length. Subtle changes, but quite noticable. Overally a better experience.

But dont let the best out there be a barrier to entry for you. The more fortunate are the more fortunate. Struggle within your budget. As Brad said: there is no substitute for skill. SO no matter what you use: use it as best you can.

[jrussell]

freeride? im wanting a 180 fork not this 150, what you think?

[DownhillingKing]

You got a point so really you just need a strong frame and a good mind to pick out the smoothest lines!?

[Capricorn]

again, as one of hte commentators was stating during the World Cup run at Fort William (SCO): it's sometimes the less dramatic riders who are going the fastest.?

Case in point: Greg. He is my captain supersmooth. The counterpoint to Greg is my other super favorite for the future: Sam Blenkinsop: that boy always looks like he is just ripping it up, yet the clock shows he is often well off the pace, good enough for top 10, but hardly top 5.

But i bet, the minute blenki calms down, that boy's gonna rip it up.

[jrussell]

What do you guys think of the Shimano SLX derailer's and shifters and possibly even crank for DH? I have been looking and asking around and slx sounds like the best value for money option, any advice would be appreciated

[Brad@TheRiot]

What do you guys think of the Shimano SLX derailer's and shifters and possibly even crank for DH? I have been looking and asking around and slx sounds like the best value for money option' date=' any advice would be appreciated [img']https://assets.bikehub.co.za/legacy_images/smilies/smiley1.gif[/img]

 

SLX is designed for all mountain/trail riding. It is hard wearing, more so than Deore. But it's by no means a DH groupo. As far as I know, the SLX CWS does not come in a 83mm bb shell option, so it wont even fit on most DH frames.

 

I also doubt that you can get it in a short cage option. If medium cage was available, it would be sort of ok... if you were running an easy ratio cassette, like a 11-32 or similar. But if you were to run a close ratio cassette like say a 11-23, then you'd need a short cage derailleur. Road derailleur's are available in close ratios, but they not as hard wearing as MTB derailleur's. More importantly, they don't feature "shadow" technology... so the derailleur bounces forward and slaps against the frame and slackens the chain tension. These are things that you do not want to happen

 

The SLX shifter will work with a Saint derailleur, but the shifting is not as crisp as Saint with Saint is.

 

In a nutshell... NO! SLX is not for DH.

[DownhillingKing]

for us people that don't have the bucks sram x9 or x7 works well as a dh groubo

[Brad@TheRiot]

for us people that don't have the bucks sram x9 or x7 works well as a dh groubo

 

X7 and X9 will ok.

 

But, it's not just about the money. It's about what your riding style requires. If something does not work, save for something better. I work as bike mechanic/salesman. Far from loaded. But I spend what I need to on my bike, even if it means waiting a bit longer for better stuff. I'm running a 105 rear der, but it slaps around too much. Saving for Saint.

 

Life's too short to ride sh*t!

[Brad@TheRiot]

Got some new toys:

 

http://i111.photobucket.com/albums/n130/hellchops/DSC08839Small.jpg

 

http://i111.photobucket.com/albums/n130/hellchops/DSC08849Small-1.jpg

 

http://i111.photobucket.com/albums/n130/hellchops/DSC08848Small.jpg

Boxxer World Cup, NOS. '07 I think. I'm loving this work. I weigh so little, so the air fork works well for me. I don't miss the sound of the coils rattling in my old Boxxer

 

http://i111.photobucket.com/albums/n130/hellchops/DSC08844Small.jpg

Sunline direct mount stem. Direct mounts are the answer. Lighter, stiffer, can't slip, lower stack height!

 

http://i111.photobucket.com/albums/n130/hellchops/DSC08845Small.jpg

WTB Devo saddle. Ti rail (light ), but most importantly it's nice and short. Long saddles make XS bikes look weird.

 

http://i111.photobucket.com/albums/n130/hellchops/DSC08840Small.jpg

Saint (old) cranks, 165mm.

 

I still need a few things before I'm satisfied. The chain device is not mine. I borrowed it for the race on Sunday. I have a E13 LG1 but the taco touches the frame. So I've ordered a MRP G2, that should work. I still want the Sunline bars to match my stem. But Rush don't have the V1 flat bar, so I'll have to wait. Lastly, I want a short cage Saint rear derailleur. The 105 is just too sloppy.

[Bakkies]

I Had to put in my newest steed.

Brand new frame. This is my build 

X0 shifters +rear derailer

Avid juisy 7 discs

MTX rims laced to swiss dt 440 hubs

Boxxer WC

Saint cranks

Easton carbon monkey bar

Easton vice stem

oja- fox dhx5.0 rear shock