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It seems like long bikes are becoming the norm in World Cup racing. The tall guys have been on XXL bikes for a while now, but now average-height riders are getting on long bikes.
A certain someone raced Bootleg on an XL bike instead of the Large he was originally planning on and I did a bike check with Bruce Klein (it will post soon) who's on an XL with a long-reach headset cup...XL and a half. He's not very tall. Bernard Kerr went from a medium to a large.
I understand World Cuppers are going ludicrous speeds on wide-open tracks. Riding style, terrain, body types etc can all factor in, but for the sake of discussion, would you go up a size from your "standard" DH choice? Do you think the same size ideas make sense for the average downhiller?
A certain someone raced Bootleg on an XL bike instead of the Large he was originally planning on and I did a bike check with Bruce Klein (it will post soon) who's on an XL with a long-reach headset cup...XL and a half. He's not very tall. Bernard Kerr went from a medium to a large.
I understand World Cuppers are going ludicrous speeds on wide-open tracks. Riding style, terrain, body types etc can all factor in, but for the sake of discussion, would you go up a size from your "standard" DH choice? Do you think the same size ideas make sense for the average downhiller?
I think where people would struggle is if they are new to riding or if they are of the smaller build. Cornering feels a bit different - but to me faster. I feel more in the bike and able to control it, riding through rough terrain and straightening corners more.
There was an interview with Greg Minaar, when he was talking about the new V10. He said that they built up test mules to determine sizing before making the molds. In the interview, he said that the largest/longest bike they built was the best they tested for him, and they put that into production. To me, this really suggests that they should have tried even longer bikes, to test the results. I think we'll continue to see bikes getting longer and longer for the foreseeable future.
I know I annoy a lot of Vital's faithful when I cite what skiing has done, being they are very different sports.
Still, in the ski world, you'll see smaller dudes pushing big/long/stiff sticks when the situation warrants. Say, a big mountain competition (which is akin to DH mtn bike racing).
Outside of that super specialized use however, its rare to see a small dude on giant skis. Or even a big dude on a set of giant sticks. They become unpractical outside mach loony or crazy deep snow. You'll still see good riders on slightly longer sticks day to day, but nothing as crazy as a 51" wheelbase for trail riding. What I'm saying is there is a point of diminishing returns.
I know I ride better on longer bikes, to a point, so long as everything is kept in proportion. I've also found there are limits to this, though again, the whole idea of proportion is usually where the equation crumbles for me. Not to make this into a chainstay length thing again, but if you are going to make XXXL bikes, you have to have the rear end grow too.
Fun fact, Blenki went to a smaller bike at the EWS in NZ with a 65 (gasp) stem. He felt faster.
In the end I think we'll have found that uber long bikes do have their place at the top levels of DH racing and for Reggie Miller. Outside of this however, especially with respect to trail bikes, I think we're close to sizing that "makes sense".
The real gripe I've got is "why are we still putting 21" seat tubes on any bike" (you know who you are...) - There are 170mm droppers for a reason.
Maybe some riders are just trying to reach beyond their current sponsors thoughts of 'good enough' and are picking the 'best length' bike for them? If it helps the pros, I would assume it would help the average rider, although the magnitude of that difference may change.
The advent of ultra-long bikes is beneficial at high speeds, but requires a lot more work to get through a tight corner. When you think about the sorts of tracks that are commonplace on the World Cup circuit now, riders don't have to deal with repeatedly tight, awkward corners. It's all about hitting gnarly lines at warp speed, and a bike with a longer wheelbase will provide better stability. It's not as comfortable, won't jump as well and certainly won't corner as well (at slower speeds, at least), but a bike that long will maintain composure at high speed limits. However, a XXL V10 is truly a massive bike - it has a 50.4" wheelbase in the low setting, for reference. The regular sizes (M, L, XL) have grown longer and longer over time already, so the XXL is not just a longer version of an XL from a few years ago.
I do believe that a lot of this does have to do with personal preference, and also what's suitable to a given location. Pros will switch frame sizes depending on the track, a luxury that mere mortals don't have. When you consider that bike parks are increasingly becoming the domain of burly "enduro" bikes, where downhill bikes once were considered the only real option, it shows just how radical modern DH bike geometry has become, and how other, shorter travel rigs are become more capable and filling that gap.
I'm personally all for longer bikes. IMO they're just more fun to ride being that you can open it up a bit more.
Either way, I feel more comfortable descending on a 460mm reach bike versus a similar bike with a reach of 430.
From there, the head angle and bb height need to be in sync.
Once those four numbers are established, the merit of bumping up a size can be discussed.
If the sizing e.g. S, M, L, XL are all too small or too large (Example Santa Cruz v.s. Commencal in 2016), then it is going to make sense to size up or down to achieve the desired fit. At which point it should be noted that riding style and terrain of choice ought to be the top considerations. For consumers, the "go bigger" trend is often to their detriment, as it gives them large, unwieldy bikes which they can't control. But, too small a bike, and it will be too easy to override.
Again, it's a balance. I decided to size up in '15 to a Large trail bike and DH bike because I was developing back issues from being too cramped. The trade-off at the time was the seat tube was too long/tall on the trail bike, which was difficult to work with in the steeps. But, in the case of both bikes, I had more room to move around, and my riding improved, some of it likely from general confidence. Now, I'm only 5'10" on a good day, but my reach is more like 6'+, a little extra Ape factor, and my inseam is maybe 30...so I'm all torso. Moving to a larger bike was beneficial for this reason.
Depending on the brand of DH bike, I'd even consider an XL - particularly if I was riding big, fast terrain.
So where does this leave me in this conversation? I'd say: look at the numbers, and consider where you ride most. Don't just buy into what the Pros are doing and go for it, because you're not one of them - their circumstances are considerably different than anything even a local Pro tends to encounter.
Something something else is that a company like Kona will messure their XL trail bikes at 485mm reach yet fit similar to an SCB XL (470mm reach). So what measurments are accurate I can't really say. It's all a bit silly.
Got a current gen V10 in XXL and it fits pretty bang on. I wouldnt like any longer. On both bikes I have been running a Race Face stem that can be flipped between 30/50mm which has served its use fairly well, some tracks the shorther and higher bar position helps and on some others the longer lower is better.
On trail bikes I usually opt for a slightly shorter bike and until last summer always been on a 50 stem but went 30 now. Having a shorter setup feels alot more practical and fun on the trail bike since it never sees the same speeds and I actually have to pedal the bike.
Overall I think for dh people have been on slightly to short bikes in the past and now the industry as a whole is getting to a more perfect spot with sizings across the board. But the main point is looking at the actual numbers not the label.
Back in the 90's when everyone was on short bikes with 3" rise bars, the dominant style was an elbows down, crouched style. Tracks got steep and gnarly so this evolved into a more elbows out, aggresssive moto style. Allowing the rider to be on the front wheel with his weight in the center of the bike became an important factor so bikes got longer.
I would say that the super long bikes are a result of the current world cup track selections. The faster more open style courses of recent years are shaping the sport and equipment, with riders and companies going more extreme to gain an advantage. The long front, short chainstay thing is becoming obsolete too, as carrying speed and predicatabilty on the very limit become the most important characteristics of a WC bike.
I touched on this in the 29er in DH thread, but there will come a point when the equipment is so specialised that it is irrelevant to the average privateer and recreational rider.
Two things I think worth mentioning: A lot of brands didn't change their sizing, or didn't change it significantly, when we all moved from 70-90mm stems to 50mm or shorter. So at some level, the more moderate upsizing is just catching up with that. The brands that are going "extreme" with reach measurements are really the only brands actually lengthening their bikes.
Second, Minnaar actually isn't a fan of ultra short stems: his rule of thumb is that they should always be right at the fork offset number.
One thing I've found with modern bikes, is that I have to think much more about keeping weight over the front wheel than I did on old school, steeper HA bikes. Certainly some of that is trying to counteract old habits from the days of needing to hang off the back of the bike to keep the COG between the wheels on the steeps, but I find myself trying out slightly longer stems & a lower stack height in order try make the front wheel feel less like it's floating out in front of me.
The issue for me is that when the riding gets steep and I need to move weight back on longer bikes I have to bend so much at the hips. This leads to me not having as much range of motion for available in my arms (they are too extended) to push/weight the front tire and my legs feel more cramped and make it hard for me to pump with them. I've found the shorter bike (or i should say being at the upper range of the size for my height) allows me to have a more neutral and what feels to be a more athletic stance on the bike which allows me to work the bike more.
The sizing thing is interesting, but I am shocked that bike companies, especially the internet ones, haven't opted better sizing tech to help people fit a bike. If you look at business wear sites (proper cloth, knot standard) they employ some really cool tech to help you get a tailored fit via your computer. Why doesn't a bike company do that? You could look at body dimensions and then discuss riding styles to really help people get the feel they want.
Retraction! I was tripping. Up to 27". Perhaps 28"?
It's a long bike 452mm chainstays, and running a longer fork I think the wheelbase is pushing 49"... But the added length out back keeps it balanced.
The strange part is that this is the most reactive and playful feeling full suspension bike I've owned. I had to go into XC bike travel and demo the Gucci builds to get a livelier feel, so the size alone isn't the limitation that - I finally have a bike that fits me. On just the shakedown ride, I was setting personal bests, and even a random KOM on a downhill segment.
I am about 5'9", and while many bikes ive owned and ridden were around a 425mm reach, both bikes ive been looking at have recommended around 450mm reach for my size.
What does everybody think of sizing up for this kind of application?
Either a med/long chromag surface at 453mm reach, or a medium kona honzo at 450mm reaxh?
For what its worth, I did size up for my dh bike, getting a large trek session, which is just around 425mm. I think it was definitely a good choice in the end... which is partially why i am sweating about the trail bike size haha.
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