Big Wheels blowing out corners?
- Thread starter GeurieMTB
- Start date
mittagongmtb
Likes Dirt
Maybe it's because there are more XL riders taking up the sport and so even a XL 26" bike will have a longer turning circle than a S or XS 26"........
Last weekend I rode 2 tight courses - one on a Trance, one on a A29er. There was no difference in the lines taken - both were well within the course lines and both courses were attacked with race speeds. At Mt Annan I noticed that there were sections where people had cut across corners and this was degrading the track and I suspect it may have been due to a recent enduro out there. Large number of people of varying abilities - new lines are inevitable. Only way to reduce their impact is to place logs, rocks etc along the boundaries. (I also have ridden stonefly at Buller on an A29er and closely followed a 26" rider the whole track - no problems with lines.....) Reckon its the rider not the bike.
Last weekend I rode 2 tight courses - one on a Trance, one on a A29er. There was no difference in the lines taken - both were well within the course lines and both courses were attacked with race speeds. At Mt Annan I noticed that there were sections where people had cut across corners and this was degrading the track and I suspect it may have been due to a recent enduro out there. Large number of people of varying abilities - new lines are inevitable. Only way to reduce their impact is to place logs, rocks etc along the boundaries. (I also have ridden stonefly at Buller on an A29er and closely followed a 26" rider the whole track - no problems with lines.....) Reckon its the rider not the bike.
Timmy!!!
Likes Dirt
What drivel. I dare you to point me to the theory of mechanics that validates your assertion. (And, before you attack my knowledge base, I have taken the trouble to study the physics involved in some depth).
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Anti_Trainer
Likes Dirt
I blame my kids on their 20" wheels for making the corners tighter.
redbruce
Eats Squid
Ok so you have both studied the physics and disagree on the interpretation, welcome to the world of science (mind you no need to use the disparaging term "drivel", not an engineer by chance are you).
Suspect mittagongmtb has hit the nail on the head, its the rider more so than the bike. Based on my experiences returning to mtb after a significant layoff (kids!!) my initial trepidation (older = more risk adverse) resulted in hunting through corners I now confidently rail on a tighter line.
cramhobart
Likes Dirt
I'm not much for science but in the latest amb Jenny Fay (2nd short course 4th cross country at nats) is quoted "next year I will probably switch to a 26" bike to get around the turns a little easier" , I suspect she's a better rider than me, maybe physics has a bit to do with it, bmx v's 26" pump track times suggest to me that there are two ways to get around a corner faster: shorter wheelbases (requiring smaller wheels) or MAKE THE CORNER WIDER...
Timmy!!!
Likes Dirt
What interpretation? The original assertion had no basis in physics. Ergo, no interpretation required.
Yes, it's not so much the wheel size but along with bigger wheels, most 29er's have a longer wheelbase than their 26" equivalent.
Take the popular Anthem, the 29er has a wheelbase that is 25mm longer than the 26er. 2.5cm is a pretty significant difference in wheelbase and 'turning circle'.
Antsonline
Likes Dirt
Dude - got some sand in your va-jay-jay?
Calm down.
I am not about to attack anything, because i am obviously no-where near as stressed as you.
My 'name' doesnt even have an exclamation mark for goodness sake.
Anyway, I'm wrong, despite riding both types of bike, regularly, at a fair level.
Enjoy the rest of your period.
thecat
NSWMTB, Central Tableland MBC
Gyro effect making it harder to lean the big wheels over....
As I said before I don't think its a wheel size thing just a rider thing. While corners are blowing out I'm finding less braking stutters.
Timmy!!!
Likes Dirt
While that's possible, it's unlikely.
It is useful to compare our situation with that of, say, the modern sports motorcycle. Although their wheels are slightly smaller diameter than ours they spin very much faster and are considerably heavier. Their gyroscopic forces are probably an order of magnitude greater than ours (perhaps more!). Even so, they can go from upright to a lean angle of 45 degrees in a second or so. That's a very high "flick rate" indeed! It allows for a very rapid turn-in to the corner.
Our wheels are lighter, spinning slower, and our lean angle is far less. It's unlikely, therefore, that the difference between 26" and 29er wheels will result in a significantly decreased rate of turn-in.
Now THAT's interesting. I wonder what could be behind it?
GeurieMTB
Likes Dirt
The situation here is that we are getting more new riders, including roadies now on xc machines, and we are going from a pretty relaxed crew of mainly social riders to a more competitive feel, races are becoming more regular here, riders are recording "hot laps", more riders are heading away to race (hence training at greater intensities) and rider and lap numbers are way up.
The issue here isnt cutting corners, its people running wide and widening those corners. If corners start getting cut I simply drag logs accross to block them
So, based on the above discussion, riders are maybe trying to carry too much speed through corners, inexperienced riders are using the relatively flat obstacle free corners and blowing them out with too much speed and this would be happening with or without the bigger hoops.
Is this whats happened at older/more popular trails? Esp interested in what happened elsewhere in the days before 29ers
In answer to previous posts, the country out here is undulating, mostly grassy woodlands (with Callitris in dense swathes in places) great for open flowy fast trails, the corners in question have been fine for the last 8 years but blowing out over the past 6 months, and thats coinciding with the influx of newbies on 29's and roadies getting into xc.
Intersestingly the riders who are blowing the corners are the most active and interested in building berms in those places so as to maintain their speed
The issue here isnt cutting corners, its people running wide and widening those corners. If corners start getting cut I simply drag logs accross to block them
So, based on the above discussion, riders are maybe trying to carry too much speed through corners, inexperienced riders are using the relatively flat obstacle free corners and blowing them out with too much speed and this would be happening with or without the bigger hoops.
Is this whats happened at older/more popular trails? Esp interested in what happened elsewhere in the days before 29ers
In answer to previous posts, the country out here is undulating, mostly grassy woodlands (with Callitris in dense swathes in places) great for open flowy fast trails, the corners in question have been fine for the last 8 years but blowing out over the past 6 months, and thats coinciding with the influx of newbies on 29's and roadies getting into xc.
Intersestingly the riders who are blowing the corners are the most active and interested in building berms in those places so as to maintain their speed
mittagongmtb
Likes Dirt
You've answered your own question..... same thing happens on all tracks. Take for example Appin or Yellowmundah - high use, high speed - people will blow the exits, especially if flat or off camber.
I know your poking fun but what a foolish boy!
Everyone in the know, knows 26 is the best. HA!
thecat
NSWMTB, Central Tableland MBC
could it be that over the years trails have adapted to the more clunky 26er, then along comes the quicker rolling 29er and hence we are seeing an evolution in trails to the superior mtb.
Na it's just the UCI trying to merge MTB with cyclocross and 29er riders failing to realise a 29er is just a Cyclocross bike for riders to scared to run drop bars and too inept to use rim brakes.
The evolution is thus:
* Change MTB rules to allow 29" wheels
* Blow out corners to open them up more.
* Groom trails to within an inch of their life (help there are loose rocks on the trail someone get the broom!) and put a berm on every corner
* Add some silly barriers so riders need to get off and jump over, pretending they are jumping fences as they escape the wrath of their lovers boy friend.
* Convince the Guberment that riding through muddy bogs is perfectly fine
* Goal! MTB becomes Cyclocross.
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