For a while effective TT and reach have been getting longer and longer, with loads of guff marketing journo speak words talking about more room to move around the bike and greater stability etc. The Mojo Nicolai abortitron thing being the ultimate example I guess. Just looking at Remi Therion’s bike check on pinkbike http://www.pinkbike.com/news/remi-thirion-commencal-bike-check-world-cup-dh-lenzerheide.html I was struck how short the reach looks, and looking up the geometry his medium frame has a reach of 392mm and the large has a reach of 407mm.
A medium bird aeris has a reach of 444mm, even the xs has a reach of 410mm.
So to ask an obvious question if a long reach gives more stability then what gives with these numbers for the DH bike vs the all mountain/ endoooro bike? Is the longer reach mainly about climbing?

no-one? c’mon it’s Friday – I’m bored

Still wondering this, c’mon if help educate me – and if not me, possibly Hora of the too small bikes as well.

just personal preference isn’t it. There isn’t “one rule”

Why does the chain do that?! 😯

DH bikes are weird…

Have you read the Chris Porter MBR articles on geometry?

I don’t really understand this stuff, but Porter certainly doesn’t think length is just about climbing. He probably reckons that Commie is too short.

He probably does but then Remi doesn’t seem to be slowed down by it. The frame even has a set of adjustable cups to allow the rider to lengthen the TT by 10mm but Remi runs the 0mm ones.

Thirion seems to do best on really steep, twisty tracks doesn’t he? Wonder if the bike plays any part in that.

For contrast the GT Fury has reach of 438mm for a medium and 464mm for a large. Which makes it a big bike by any standard.

But Gee seemed to be just as fast when he was on a Commencal.

Personally I find it really difficult to go back to any bike with a short reach, feels a bit like having narrow bars again. All twitchy.

personal preference, there was a review of one of the Kona’s a while back that was long for it’s time. A right pain in the UK style twisty stuff but out in the big WC stage with fast flat out big style courses it was in it’s own.

If you judge a bike with a tape measure then you missed the point, ride it see what happens.

I’m trying to get a better understanding of what the benefits of a longer frame are, and if those benefits would suit me. I might be in the market for a new FS frame in the near future and am not convinced that the trend for super long reach is going to make a good frame for what I like to ride.

The point being different better is better for different things. It depends on what you like to ride, how and where.

I remember a article I read where one of the things Gee said was that the commencal was a very short bike. I think his current bike is a slighter larger large.

So if the GT is at one end and the Commencal at the other then maybe it’s riding style rather than where you ride that dictate whether a long TT is useful?

I remember a article I read where one of the things Gee said was that the commencal was a very short bike. I think his current bike is a slighter larger large.

I read (same article?) that Gee ran super long chainstays on his Commencal – his mechanic said that most people wouldn’t be able to corner on it, it would just go straight on..

I’ve got one and regardless of what the custom version was the standard is a very long bike anyway.

In general is not the idea that your bars stay in the same position but you run a shorter stem?

The frame is getting longer but the bike stays the same length.

Wot /\ said.It’s basically just running the front wheel further forwards.

In general is not the idea that your bars stay in the same position but you run a shorter stem?

Yes, but only assuming the rider wasn’t on a short bike to begin with.

For many I expect it’s a bit of both.

thepodge – Member

In general is not the idea that your bars stay in the same position but you run a shorter stem?

Not really in DH, no. DH stems tend to vary between 35-45mm so not enough to offset massive reach variations. There are bikes build around using a shorter stem (Mondraker) but it’s not a popular option

chakaping – Yes, but only assuming the rider wasn’t on a short bike to begin with.

For many I expect it’s a bit of both.

Even if you’re on a short bike the bars still stay the same place. having a bike that fits you properly and having a long frame are two separate things.

legend – Not really in DH, no. DH stems tend to vary between 35-45mm so not enough to offset massive reach variations. There are bikes build around using a shorter stem (Mondraker) but it’s not a popular option

No but in reply to the guy further up who seemed to just be asking about longer frames in general, not DH specifically…

having a bike that fits you properly and having a long frame are two separate things.

Absolutely, and I think a lot of riders are cottoning on to both at the same time at the moment.

Watching with interest here. My current frame is 10 years old. 23.4″ top tube with a pretty conventional seat angle. Stem started out at 70mm which was great but now running a 55mm which makes it a bit more focused on the downs. Now, the new bike, I’m looking at a medium 23.4″ or a large 24.4″ and considering a 35mm stem. To ale matters worse, not really any around to test ride.

I am in pretty much the same position as you onzadog – looking to replace an older frame and wondering whether to look for a much longer TT frame, or stick with something closer to what I have now but a bit longer to account for a reduced stem length to what was originally fitted.

So if a person is in between a medium and a large what would be the pros / cons of sizing up or sizing down?

Or to bring it back to the original question why do some WC DH bikes have an unfashionable short reach, whilst some are considerably longer – they’re all designed to do the same job – get down a steep, techie hill in the fastest time so why the differences? Please don’t say personal preference …

Or to bring it back to the original question why do some WC DH bikes have an unfashionable short reach, whilst some are considerably longer – they’re all designed to do the same job – get down a steep, techie hill in the fastest time so why the differences? Please don’t say personal preference …

Between sizes? try, look at set up, unless you are basing sizing on sitting on it then the height guide is only good for averages.

My take is some things work for some people other things work for others – if you want to believe there is a magic bullet to sizing then I’d be looking at something that gets this into it somehow.

In the end getting the sizing right is the biggest thing. Lower standovers mean more people can get onto what were once larger sized bikes so more people are trying different. Small and chuckable used to be the term for putting up with smashing your knees on the bars, so longer and lower TT’s helped.

<rephrases question more tightly>
Okay so if I was Mr Average, exactly split between a manufacturers 2 sizes. What are the pros and cons of sizing up or sizing down.
Can no one tell me? Do I have to try and test ride a load of bikes myself? Problem with this is I won’t get a long enough test ride to get used to a longer TT so will obviously be biased towards something close to what I have now.

tighter answer, which size are you on the line of height or reach, if you are right on the line of both which ever feels better, bigger bike shorter stem smaller bike longer stem.

I’m thinking about reach here.
same length stem.
So its entirely subjective?

Im in a similar situation, im looking for a second hand DH bike but struggling with finding any with sizing a like. Im riding a 2014 Orange Alpine, ETT is 620 and reach is about 480 and a 65 degree head angle, im 6ft 1in. Finding something without feeling im over the front wheel due to the shorter reach in second hand is pretty tough. And my wheelbase is 1200.

He probably does but then Remi doesn’t seem to be slowed down by it. The frame even has a set of adjustable cups to allow the rider to lengthen the TT by 10mm but Remi runs the 0mm ones.

Maybe he just likes a small bike?

The other end of the scale, you have Greg Minnaar, who’s running an XXL SC V10, with a standard reach of 475mm (i.e. massive!) who has made it longer still with those CK Buzzworks offset cups & a custom lower link to make the wheelbase even longer.

And apparently he knows a thing or two about winning races…

So its entirely subjective?

My opinion yes, if you can’t get a proper test or at least a sit on it and you are that close between sizes I’d probably pass – again personal preference.

The flip side is if you are not going for the podium at WC’s does the few mm either way impact or slow you down?

In the case of some of the top WC guys if I spent that long on a bike, rode that many and worked with the designers/builders/factory I’d get something that was perfect for me partly just because I could.

Okay so if I was Mr Average, exactly split between a manufacturers 2 sizes. What are the pros and cons of sizing up or sizing down.

IMO – the shorter frame will be more nimble, the longer frame more stable.

I had a long trail bike with a particularly low BB for a while and it just felt like it was on rails. So easy to drift and pull back from the brink.

I wish I’d gone a size bigger on my current big bike TBH.

I’ve said this countless times- only use the manufacturers size charts and other riders size/model replies on specific bikes as a guide. Its all personal taste. On my 650b/feel abit underwhelmed experience there was a couple of comments that you get used to a bike. I always want to see a spark of something there from the moment I jump on a bike.

Plus for different applications I think a longer reach/top tube is spot on- XC/long rides but for a fun/lightish 2-3hour ride bike why not go slightly smaller? Jump on my medium V4 and you’d be surprised how long it feels still. Jump on a medium V3 and its waaaay too short. Both from the same manufacturer. Also on my frame – if I’d have gone for the large, I’d have to factor in the inch or so for the dropper on top of the seat tube length which would have given me a seat tube of 20+inches- too long for fun etc. ATM its circa 18.5inch which is spot on.

All totally IMO and its all fun.

I’ve said this countless times

Yeah, but no one listens to you Hora.

I guess if I sold you a magazine for £4.99 full of adverts you’d listen.

This topic did a good job of trying to get to the bottom of the reach thing:

http://singletrackworld.com/forum/topic/getting-my-head-round-reach-stack-after-years-of-effective-top-tube

As far as I can fathom, for pretty much any riding apart from Dirt Jumps/ Slopestyle/Skatepark there are more benefits to a longer reach than a shorter reach, especially in terms of

~stability both in a straight line and cornering

~riding steeps

~rolling over obstacles

This review of the GT Fury on Pinkbike conveys it well

Most people are running shorter stems now, even DH bikes often had 50-60mm stems in the past, now people are moving to 35mm stems so the frames need to be 15-20mm longer to compensate. Also a lot of DH riders and people who favoured gravity rode smaller frames to get lower stand over and make it more “chuckable” whereas now you can get bikes that git better that have lower stand over and we’re all realising we don’t want short bikes because we’re not spinning and tail whipping (at least I’m not). Also longer wheelbases and slacker head angles will make them more forgiving at high speeds.

Please don’t say personal preference …

trouble is…Without standard sizing I honestly think it’s entirely this. I rode a large Privee Shan for a bit and for a hard tail it was proper mahoosive, but it was entirely nimble chuckable, and fast, because I felt I could throw it into things (built like a brick shithouse) it WAS. then got a large Bfe , essentially the same size bike, didn’t feel anything like as good.

Once you’re found a comfy bike it doesn’t matter (within limits) what size it is. How you get to that point is irrelevant, if it fits, it’ll be ace

Please don’t say personal preference …

Ok riding preference then.Some people hang off the back of the bike and a shorter reach suits this.Some people ride over the front and a longer reach suits them.
It’s great to have a choice innit?

Yes but apparently some people state that you adapt your riding style or as I see it ‘take what you are told is good for you’.

In a way Im referring to wheelsize but Im also eluding to all sizing.

Okay, I can see how a longer reach/top tube might work for k going down hill. What impact would that likely have on seated (most of the time) climbing?

I find that if you go long reach short stem you can shift your body weight forward to give more front grip without the feeling you are about to be ejected out the front at any moment.