View Full Version : Dirt Rag discussion on "96ers" / Silk Ti


Guitar Ted
02-26-2006, 04:02 AM
Check out this interview on Dirt Rag's web page http://www.dirtragmag.com/web/brainfart.php?ID=202

Brownie interviews John Castellano who has a bit of a different take on these half breed bikes. I like the terminology he has come up with for them, calling them 50/50's, which makes way more sense to me than "69er", or "96er" or whatever.

I gotta admit that Brownie has somewhat of a point when it comes to fitting smaller riders, and Castellano seems to think so too. At least this discussion makes some sense to me. You guys check it out and see what you think.

steelbike
02-26-2006, 05:55 AM
One of the problems with retrofitting a bike for shorter inseams is that the top tubes on smaller bikes are shorter which tend to lead to toe overlap depending on the ht angle, rake, etc. I 50/50'd several bikes and some worked better than others.
Some of the specs on small 29ers cause me to wonder if they have toe overlap also.
Anyway, I'm running a Kelly fork on my 15" Gunnar (22" TT) and my size 40 Sidis just clear the Ignitor. A beefier shoe doesn't clear. It's a good ride for me and the only costs were spokes, rim and tire since I build my own wheels .
As far as height, I'm 5-5 and I really don't see a problem with sizing a 29er as long as it's set up right for me. I was going to have a frame made but decided to order a small Soma Juice instead as the geom looks right for me. Guess what? They're out of stock for now. Short riders want frames too!

Cloxxki
02-26-2006, 07:08 AM
I strongly disagree woith most that both have to say. False arguments and ones that are half-true. Main facts and factors seem to be left out of the discussion.

And I PLEAD someone explain me why a 26" rear does SO much better at short steep climbs? I dismiss the weight reason, some tires already have well over a 150g difference between a steel and kevlar version. So cheap tires are useless for short steep climbs? The weight difference gets totally lots in that of bike and rider.
If you stand in front of that short steep hill, armed with 2 front wheels (obvious reasons), one 29", or 26". Propelled with only one arm/hand (rather than two trained legs and clipless pedals), does the 26" one shoot to the summit while the 29" one stalls halfway? Seriously, Brown and Catellano, try it. You're making your living out of writing about or building bikes, back up claims with facts please.
I may be odd, but for steep climbs I tend to appreciate my traction. It's an established fact that larger wheels offer better traction. So my 29"er gets me up steeps more easily. And the rolling resistance advantage of a larger rear wheel already more than compensates for the increase in weight. On steep climbs, 90% of the weight is on the rear wheel. If that then rolls a bit easier, that's worth more than it's increase in weight. If it didn't work that way, we'd never out-grow out BMX bikes.

If the industry would just get it's act together already, any rider 5' and up would fit a 29"er fine, (s)he would not require a corrected head tube angle on it, and still get nice and quick handling. Custom rigid forks+frames can already be had for ~$900, only very few tried it, probably considering it impossible.

Q: What did the industry come up with when 26" bikes ended up with handlebars lower than the riders preferred?
-Answer : riser stems that reach higher.
Q: And when that didn't suffice?
-Answer: riser handlebars that reach higher.
Q: Now when a 29"er fit on the tall side up front, what do we do?
- Uhmmmm. That's a tough one man. I think 29" just won't work then, you see it, too damn tall! Nothing will help for that.
......

With those mentionned 29/26 conversions, going from an 80mm suspension fork to a rigid one, they don't NEED a 1º steeper head tube angle to get the same handling quickness!! They probably went from 38mm (typical suspension fork offset, for some reason) to 45mm with the 1x1 fork. This already overcomes the effect on trail that a 29" front wheel holds over 26". As long as the headtube ends up at around the same height as before, handling will be a-ok. Now if the 1x1 is around an inch shorter than the 26" suspension unit (it is), all is be fine.
Oh, and the extra offset already takes away a bit from the toe overlap issue by putting the front wheel a bit more forward.

Now if 29" suspension fork had a bit more offset, and people would figure out that handlebars only have an "up" and "down" because of the way the logo's are attached...

Please discuss and educate me, I still don't understand.

Cloxxki
-Planning to have a flipped Mary setup in a matter of days.

Guitar Ted
02-26-2006, 12:19 PM
Cloxxki: I hear you on your points and I agree with them. I thought that Castellano and Browne hit upon something here for the exact same reasons you are upset with the suspension fork manufacturers for. That being the rake that is a fixed number right now with suspension forks. I do disagree with Castellano's assesment of who these 50/50 bikes are for. I think the upper limit of the range should be set at 5'5". Anyone that tall or taller should be on a full on 29"er. But until the fork trail conundrum is solved for those wanting a suspension fork, I can see where this 50/50 idea might be a solution.

Now I know that Bigwheel, mikesee and a couple of others have shown their significant others/ friends on very small 29"ers, so I know it can be done, but I think the problem is the suspension fork geometry, which causes some problems for frame designers.

White chimed in here at one time and said that different fork crowns for different sizes,( which would be the ideal, no?) would be very expensive and therefore not practical. I can see that point, and I agree. So, what we are left with is what we have. Perhaps someday we will see someone produce a more 29"er friendly, small person friendly fork crown/ trail figure that will render the mere idea of a 50/50 bike a joke. Until then, I gotta say they have a point there.

Cloxxki
02-26-2006, 12:53 PM
50/50 is not a solution for short people, the same toe overlap issues persist. Rigid bikes are the solution for everyone 4'11" and up.

mainemud
02-26-2006, 01:21 PM
Welcome to my private hell..... I've been struggling with toe overlap issues on our 13" 96er frames for months. There's only so much distance between the BB and the front hub. When you start whittling away at that distance with 170 mm. cranks, an eccentric BB in a rear position, an assumption that a 13" frame size rider has small feet (not always true), and a reasonable tire width, it can be done, but there's not much room left over. Sure, we could lengthen the top tube, but what's the point? We've redesigned our frame three times, and come to the conclusion that there will always be a "limiting factor". Our three choices were to...

1. Build a 13" frame with the top tube of a 15". Not so bad for a short inseamed rider, but sluggish and uncomfortable for a normally proportioned shorter rider.

2. Stick with a short top tube and slacken the head angle. Lots of low speed wheel flop when climbing and generally funky handling characteristics.

3. Go for the shortest top tube possible, a normal head angle, and the limitations of 2.1" tires or less, 170 cranks, and a shoe size of 41 or smaller.

Just curious what you all think???

Cloxxki
02-26-2006, 01:57 PM
Just don't offer the 13", or do so with a rigid fork built especially for it and the 15". Throw in 50mm offset of more (Jones makes them 63mm). And as you're going rigid anyway, make it non-suspension corrected to get the bars at desired height. Now THAT would be a great ahndling bike!
On Eurobike I saw some modern flex stem ideas. JUst might not suck, especially for 13" and 15" riders. Just might be the way forward if you MUST have front squish on a quick ahndling small 29"er.

I can only imagine how it must be to stand 5' tall, and ride a 29"er with short top tube that fits like a glove, with some decent stem length even, and only 70mm or so trail. HOW to endo such a bike? And worse for me : how to ever keep up with such a rocket midget?

What I forgot to mention ealier : the 29" rear wheel is hardly a factor for small riders, unless they insist on hanging way over the back of their seats. Being so short and with such a long 29" wheeled front center, I can barely imagine that to be required more than once in a while.

Guitar Ted
02-26-2006, 04:56 PM
What I forgot to mention earlier : the 29" rear wheel is hardly a factor for small riders, unless they insist on hanging way over the back of their seats. Being so short and with such a long 29" wheeled front center, I can barely imagine that to be required more than once in a while.
You guys have discussed the front/ center problem, but no one has touched on the stand over issue that was brought up in the Dirt Rag piece. I gathered from the interview that the reason Castellano uses the 50/50 is to gain a bit more standover height in smaller sizes. This reason that you bring up here, Cloxxki, might also be another influencing factor.

My opinion about the standover issue is that it's a bogus reason to go to a 50/50. I thought that perhaps someone would pick up on that. :p

Judging from what I'm seeing here, it might be easy to draw the conclusion that short folks should just stick to 26 inchers, since there would be far less hurdles to overcome to get on a bike and ride. Correct?

Cloxxki
02-27-2006, 02:49 AM
30 years since the first mountainbikes, probably 100+ years of mixte frames, and we would not be able to get standover right on smaller frames?
The 13" bikes should anyway be equipped with 165-170mm cranks, allowing for a lower BB already. 75-80mm BB drop shouldn't be a problem at all. The cross-brace solution is very common on Softtails and FSs already.
Maybe some day we'll see special 29"er rear fender that allow a short rider to safely hang behind theirs seats and even lean on the fender. Perhaps *gaps* use it even as purposely designed ass-brake.

big & single
02-27-2006, 04:27 AM
You can also minimize the negative effects of the retrofit with longer handlebars to compensate for the extra trail.

I really don't get this statement - how do longer bars which slow down steering response 'compensate' for slower steering from a larger trail figure? I'm not doubting Castellano, just would like to hear his reasoning behind this statement - anyone got any ideas?

Cloxxki
02-27-2006, 04:58 AM
I can see how a SUPER HEAVY front wheel will make a wider handlebar useful, but for 26" vs. 29"...I'd like to know too. I do know that if you have a long-for-you toptube, a stort stem and wide handlebar work just fine. If downhillers like their <40mm stems, why not short 29" riders? Keep toptube long, head tube angle steep, and end up with quick handling anyway. Normal width bars might be fine for short riders though.

motoman711
02-27-2006, 08:08 AM
You guys have discussed the front/ center problem, but no one has touched on the stand over issue that was brought up in the Dirt Rag piece. I gathered from the interview that the reason Castellano uses the 50/50 is to gain a bit more standover height in smaller sizes. This reason that you bring up here, Cloxxki, might also be another influencing factor.

My opinion about the standover issue is that it's a bogus reason to go to a 50/50. I thought that perhaps someone would pick up on that. :p

Judging from what I'm seeing here, it might be easy to draw the conclusion that short folks should just stick to 26 inchers, since there would be far less hurdles to overcome to get on a bike and ride. Correct?

tons of Stand-over, 22.5" top-tube and lots of toe clearence:

Rivet
02-27-2006, 09:22 AM
I strongly disagree woith most that both have to say. False arguments and ones that are half-true. Main facts and factors seem to be left out of the discussion.


Ya, Castellano doesn't know sh*t about bike frames, you should give him an education. How many frames have you built by the way?

Cloxxki
02-27-2006, 10:43 AM
I don't have to be a master builder to disagree. I can be clueless and still disagree.
I've got two left ands and can't ride worth ****, but I do have an opinion on this topic.

Guitar Ted
02-27-2006, 01:35 PM
I think what was trying to be said was that in order for the smaller frame size to work out with the fixed trail number/ head tube angle (to preserve handling traits) the top tube could only be made short to a point, which for the really small sizes, wasn't short enough. To compensate, Castellano was saying a short stem/ wide handlebar combo could offset this problem.

I think a really interesting comment was made by mikesee about his Black Sheep single speed, (a darn fine looking machine, by the way!) when he said that his trail/ head angle was a quick handling combination, and I seem to remember that head angle was something like 69 degrees, no? That sort of set up would eliminate the use of a suspension fork, but it would help with toe overlap and top tube length. Cloxxki, you already said this, I think, so I'm sorry if I'm repeating here!

The use of the smaller rear wheel, which really is the defining nature of this whole 50/ 50 thing, is absolutely bogus. It doesn't help you make a smaller frame, and it doesn't increase performance over a 29" wheel. I agree that most of the benefits of 29"ers are to be found at the rear wheel. If "rolling over stuff" better is the reason you stick a bigger front wheel on the front of your bike, than why in the world wouldn't you want your rear wheel to do the same? Heck, that's what suspension forks were designed for 26 inch wheels for, to get them to roll over stuff better. Then they found out that it really made a huge difference when you helped the rear end roll over stuff better with rear suspension. Now with 29"ers, people go back to riding rigid and hardtails because the wheels are doing what suspension did on 26"ers. It's also the reason that alot of folks say that 4" rear travel on a 29"er feels like more.

So, if you are too small for a 29"er, you can go 26"er, but please, let's leave this 50/ 50 stuff behind. It just doesn't make any sense on any level, to me. At least not anymore since I've read through this thread. I did have a glimmer of hope for it, though I knew it was probably in vain. Thanks guys!

Cloxxki
02-27-2006, 02:47 PM
Bikes like MikeC wasn't hat I meant to refer to, rahter the opposite in a Genesis kind of way : huge toptube, steep head angle still, supershort stem.
Why MikeC enjoys his unique bike as "quick" handling may be thanks to his skillz, or a unique weight distribution. For mere mortals it may not work well on box-stock frames.

Please let carver use his (way cool) family name to make 29/29 bikes! Apart from the small rear wheels, it's a fine concept in many way.
What I still don't understand about the Carvers, is that the "Mini" accepts 26" and 24" both front and rear, while even the hugest XXL 96'er doesn't accept a 29" rear wheel. In percentage of rider height (6'2"+ vs sub-5') even over a 24/24 bike the XXL should be AT LEAST 29/29.


Who'll build a 69'er? Simply your 29" hardtail or FS, mated to a typical 26" front wheel (who hasn't got one to use or borrow) and an appopriate length fork. Note that the fork would have to be ~60mm longer than a typical 26" fork to keep geoemtry level. Ideal is a Kona 2-9, with it's 71º HTA, like seen on most non-Kona 26" bikes. A long-ass fork with travel reduced to 80 or 100mm.

See how it handles. Cornering of a good 26" front end, and the smooth rolling, steep climbing of a 29" rear wheel. By concept (when purposely built) identical to, or lower total weigth than the 96'er. No geometry restrictions, just a tad longer rear end. All the meaty front tires in the world to chose from for real bite. Higher straightline speeds due to lower rollingresistance regardless. Choice of Fox and Manitou forks. Lots of front rims. More brakepower from the same front rotor saize, oh man, the advantages of a front wheel are endless!

Guitar Ted
02-27-2006, 04:16 PM
GlowBoy, who often posts here used to put a Gazzalodi 3.0 on the front of his Karate Monkey. He claimed it was very nearly the same ride height as a standard 29" wheel and tire combo. I remember that it didn't perform too badly, but he didn't care for the weight or something as I recall.

Cloxxki
02-27-2006, 04:56 PM
I know he did, but maily for ridig cush.traction reason I think. 3.0 is hardly a typical XC tire now, is it? :-)

Li'l Bastard
02-27-2006, 05:38 PM
On steep climbs, 90% of the weight is on the rear wheel..


On steep climbs, I'm standing up and my weight is mostly over the bars. Explain the 90% figure, please?

Cloxxki
02-27-2006, 06:41 PM
Your climb is not steep enough for my taste ;-) The kind I mean by steep, you can't keep your front wheel on the trail (or wall). You may have weight on the bars, but when the bars are vertically above the rear wheel, what goes does that do for the front wheel? Try endo on a steep hill.
But you're right, singlespeeders may be less of an example to support my case.

Guitar Ted
02-28-2006, 03:51 AM
Your climb is not steep enough for my taste ;-) The kind I mean by steep, you can't keep your front wheel on the trail (or wall). You may have weight on the bars, but when the bars are vertically above the rear wheel, what goes does that do for the front wheel? Try endo on a steep hill.
But you're right, singlespeeders may be less of an example to support my case.
Cloxxki: My KM is a single speed and even if it wasn't, the nature of technical, steep climbing is really about the same. One must balance their body weight to a point that the front tire is in contact with the ground, but that doesn't necessarily mean you have a lot of weight over that wheel. Consider what happens if you un-weight the rear wheel a little too much during a climb. Spin out! So, even though you may be out of the saddle climbing, and it might appear that you have your front tire weighted evenly with the rear, this is not the case. Your rear tire needs more weight on it during climbing to make it bite into the terrain. Any hint of un-weighting, and your climb is over.

This is probably obvious to some, so please pardon me. I am only trying to show that Cloxxki is at least partially correct in his statement about rear tire weighting. It may not be 90%, but that'd be a great number to achieve as long as you could keep the front end down on a climb!

b1umb0y
02-28-2006, 05:12 AM
Cloxxki: My KM is a single speed and even if it wasn't, the nature of technical, steep climbing is really about the same. One must balance their body weight to a point that the front tire is in contact with the ground, but that doesn't necessarily mean you have a lot of weight over that wheel. Consider what happens if you un-weight the rear wheel a little too much during a climb. Spin out! So, even though you may be out of the saddle climbing, and it might appear that you have your front tire weighted evenly with the rear, this is not the case. Your rear tire needs more weight on it during climbing to make it bite into the terrain. Any hint of un-weighting, and your climb is over.

This is probably obvious to some, so please pardon me. I am only trying to show that Cloxxki is at least partially correct in his statement about rear tire weighting. It may not be 90%, but that'd be a great number to achieve as long as you could keep the front end down on a climb!

Absolutely! It is a dynamic balancing act...

bb

GlowBoy
02-28-2006, 01:10 PM
GlowBoy, who often posts here used to put a Gazzalodi 3.0 on the front of his Karate Monkey. He claimed it was very nearly the same ride height as a standard 29" wheel and tire combo. I remember that it didn't perform too badly, but he didn't care for the weight or something as I recall.

Good memory! That was 18 months ago. Yes, I ran an Arrow Prime Wide 26x3.0 on the front of my KM for a few weeks. It definitely made the bike feel a bit more sluggish accelerating and climbing, but not outrageously so.

Although it made the ride more comfortable and I could bash huge rocks with ease, I was surprised to find that the bike still didn't have that same feeling of "rolling over" stuff that it did with the 29" wheel up front, probably because a lot of the extra diameter got eaten up as the tire compressed.

Also, I was surprised to find that the bike lost a lot of its magical 29" stability with the 3.0 on the front. It felt like a 26"er again in that respect. I didn't have the same ability to keep the bike balanced at low speeds through rock gardens and around switchbacks as I'd gotten used to. The 26" fattie only dropped the front end half an inch or so -- at least when the tire was unweighted. Maybe that's enough geometry change to throw off the handling, or maybe it's just that real-world biking compresses the tire enough to steepen the geometry a lot more than half a degree. In any event, I couldn't believe how much better the bike handled when I put the 29" front wheel back in.

- Dan

Cloxxki
02-28-2006, 02:23 PM
Perhaps a fat 26" tire just has a really wide and short contact patch, vs. the long and narrow for the typical 29" tire. I can imagine that to offer a totally different feel even if the geoemtry is more or less the same.

shapirob
04-15-2006, 05:51 PM
I stumbled across this thread recently and thought a few elements had been lost in the analysis of the 50/50 for the Silk Ti. Ive spoke to John about this model and he argues that the front 29" retains 75% or so of the 29" advantage. And from what I understand ta nl 29" is a disadvantage in tight, twisty turns, and for some reason it is greater if one is shorter, perhaps due to weight/momentum issues of the rider vs. bike. The greater issue in the silk ti is that the design has limitations so that the tob tube has to converge near the the top of the rear triangle. Im sure it could be further tweeked, but it is by far the best design for a soft tail yet prodcued and a YYB or anything else does not compare. And as we know John is a particularly creative individual in working with the dynamics of metals and thinking out of the box.

Just my two cents

vaya cond dios

ben

Guitar Ted
04-15-2006, 06:07 PM
I stumbled across this thread recently and thought a few elements had been lost in the analysis of the 50/50 for the Silk Ti. Ive spoke to John about this model and he argues that the front 29" retains 75% or so of the 29" advantage.

Once again I ask: Why settle for "75%" of something good when you can have it all?

And from what I understand ta nl 29" is a disadvantage in tight, twisty turns,.....

ben

Not true at all. It's a matter of rider skill, proper fit on the bike, and set up. Several examples of video and testimony on this board exist that dispell that notion.

shapirob
04-15-2006, 06:59 PM
There are times I feel even tight on a 26" .... so I do stonrgly believe there is a disadvantage in trying to turn a 29" wheel over a 26" in a tight space in many (certainly not all) contexts - I have heard shorter people state that a 29er can be harder to manuever in tight twisty single track and I bet it is proportionally greater for a smaller version for given they are trying to manage proportionally more weight and size of person versus bike. There are obvious reasons why different styles of bikes focus on shorter wheelbases and TT's.

Anyway, the point of mentioning the 75% advantage, is that he argues it is in front, not in the rear, and that the castellano softtail design makes the bike more than 25% better overall - just read the comparison of the silk ti versus an equivalent ti hardtail and all the lust it engendered. While some of the soft tail design might be compensated by a 29" rear - I bet you just the opposite is true as well, as a silk ti and a ripley have no bob and the most efficient climbing machines due to soaking up bumps that lose traction (and a smaller person is much more likely to not absorb a small bump, due to less inertia, than a larger person).

Any thoughts on this?

ben

POG
04-15-2006, 09:47 PM
but I sure am enjoying my Silk Ti 29er with big wheels on both ends. My 26" Silk Ti is just hanging on the wall now.

GlowBoy
04-15-2006, 10:13 PM
And from what I understand ta nl 29" is a disadvantage in tight, twisty turns ...
All the comments I have ever heard (with absolutely zero exception) about 29" being a disadvantage in tight turns come from two sources:

Those who have "heard" that they are disadvantage but have not actually ridden a 29"er.
Those who have demo'ed Gary Fishers. GF 29"ers are notorious for longish wheelbases -- the GF that fits me best is 1.7" longer in wheelbase than either my KM or my Vulture. And whaddaya know, the one time I demo'ed a Fisher I thought its handling was a bit slow in tight twisty stuff. However, the two 29"ers I own do not behave this way, and they are just as quick in the turns as my prior 26"ers.


and for some reason it is greater if one is shorter
On this point I must go beyond amiable disagreement to calling outright bullsh1t. I'm 5'7". If that were true, I'd know about it.

Ive spoke to John about this model and he argues that the front 29" retains 75% or so of the 29" advantage. I agree that 75% of the roll-over-stuff benefits are at the front wheel. So does John seriously think that 75% of the traction, rolling resistance and stability benefits are due to the front wheel too -- or does he deny the existence of those benefits?

---

On another note, could someone explain to me how a 50-50 bike would have better standover than a 29"er built for the same rider? Seat tubes can be made pretty short, and as already mentioned the top tube can be joined to them at any point. I think it's mostly just a function of the front wheelsize.

shapirob
04-15-2006, 10:52 PM
so the claims about manueverability could be ******** - but there are definite points if Im coming slow over a sharp rise and have to make a sudden sharp turn, a 26" wheel can be hard to flick - I would assume it would be greater for a 29" wheel - I think we are talking solely at slow speed.

As for the standover issue with the JC Silk Ti - I am 5'6" with a short inseam of 30" and he feels pretty strongly that he can only fit me in a 50/50 (once I save up gobs of money) - I think it has to do with the geometry required for the suspension - some of his 29er's are built with a curved seat tube that the rear wheel sets into for smaller sizes. Here's a picture of the famed 50/50, for a 30" inseam and a 5'3 - looks like it would be hard t ofurther optomize it:

Rainman
04-15-2006, 11:59 PM
I really can't understand what this fuss is all about...honestly.

50/50, 96'ers, toe overlap, standover, slow handling, etc etc etc..blah blah blah... !

My experience on 29'ers has so far shown me that : If you choose the right frame, and this does NOT have to be custom...

....With the right geometry, with 29'er wheels on both ends of it, then ride it for a few weeks, the average rider will probably find that they love it.

I currently ride a medium size SIR 9. This is my second frame from Niner Bikes. It's fast, very manoueverable, stable, fast, 'flicky', fast, easy to ride, fast, climbs like a mountain goat, fast, handles really well, fast, corners like it's on rails.....and did I say it's fast?

Now................get this: I stand 5'4" tall. I have no problems with the medium size frame...none, nix, zero...

It fits me like a glove. Two of my sons [16 and 10] can ride it, no problem. My wife can ride it, no problem. My whole family is short. We can all ride the 29'ers, no problems.

Why anyone would need a 96'er or a 50/50 is beyond me. Everyone who rides my SIR 9 loves it. There has not been a single rider who has tried my bike that has had any problems at all, from 5'-0 upwards.

I don't argue about this with anyone any more. I just simply hand them my bike and watch what happens.

It's like watching a light come on in a dark building...*click*... whoa! wow! ...this thing is great ! !.

So simple, really. :)

Just ride one...that's all it takes.

R.

shapirob
04-16-2006, 12:27 AM
Wow - tell us more - how does a 29er ride with as a softtai??? Especially versus the original Ibis.

From my discussions with John, I could only go with a 50/50 due to my 30" inseam .... or look elsewere and move to a hardtail 29er of which there are many options - hard to tell if the 26" rear and the silk ti rear end is an advantage over a 29" hardtail rear (assuming he truly can't build something with adequate clearance)

thanks

ben

brant@on-one.co.uk
04-16-2006, 12:34 AM
I think it has to do with the geometry required for the suspension - some of his 29er's are built with a curved seat tube that the rear wheel sets into for smaller sizes. Here's a picture of the famed 50/50, for a 30" inseam and a 5'3 - looks like it would be hard t ofurther optomize it:

I think it's cos of the position of the shock - smaller frames would end up with a seat tube extension like salsa do on the Dos.

Cloxxki
04-16-2006, 02:47 AM
JC seems to be dead-set on using a shock, and can't get it to fit nicely to a 29" rear. His design restraint, but it's really a sales restaint. If you can't make a 29" rear wheel to work with a shock (or find it too ugly hwen solved), don't use the shock! A 29" rear wheel without shock in my expectation is not so much worse, if at all, in the weight/plushness department. Oh, and it's a couple hundred dollars cheaper, in JC's case maybe a grand even?

I'll agree with naysayer that a 29" front end takes more force at the handlebar to turn. That's our lusty longer contact patch (and often slightly lower psi) at work. Like the larger bladed knife in the same butter cup. But don't confuse this increased effort with time lost. I've never missed a corner because my wheel wasn't ready for the turn in time. The muscle used for that initial turning is immediately gained back with the first steering correction the 29" wheel doesn't require, as it just takes it's line.
Unlike the BA Baracus A-Team Van, bikes are not propelled from the handlebar/steering wheel.

Guitar Ted
04-16-2006, 03:16 AM
JC seems to be dead-set on using a shock, and can't get it to fit nicely to a 29" rear. His design restraint, but it's really a sales restaint.

This is true! That design has always had a compromised rear triangle/ seat tube arrangement and is hard to make in a smaller size, even in a 26 inch wheeled format. Check out Specilaized's old Ground Control full suspension bikes as a reference point.

'll agree with naysayer that a 29" front end takes more force at the handlebar to turn. That's our lusty longer contact patch (and often slightly lower psi) at work. Like the larger bladed knife in the same butter cup. But don't confuse this increased effort with time lost. I've never missed a corner because my wheel wasn't ready for the turn in time. The muscle used for that initial turning is immediately gained back with the first steering correction the 29" wheel doesn't require, as it just takes it's line.

And let's not forget that rear wheel contact patch! In 29 inch sizes it conspires to bring more traction and the aforementioned comfort that a 26 inch rear wheel doesn't have. And if the 50/50 bike has "75%" of the roll over benefits of a 29"er because of the front wheel, again: Why not have 100% of the roll over benefits with a full on 29"er? :rolleyes:


Unlike the BA Baracus A-Team Van, bikes are not propelled from the handlebar/steering wheel.

Cloxxki! Rolling out the "A Team" reference! I am impressed. :p :p

MtotheF
04-16-2006, 08:58 AM
why the evangelism guys? if someone wants a 50/50 bike, mentioning it on here seems like a sure way to get flamed into a smoking pile of ashes. you should be stoked that they are at least getting one wheel bigger.

for every one of you with such solid opinions of "it won't work. it's a half measure" i have to ask - have you ridden one? why are you so keen to bag on castellano, on travis brown, on carver? do you really think that the people riding and building these bikes have NOT tried all the options? or do you just like to bang the big wheel drum to hear yourselves make noise?

people in here act as if 26" wheels are some sort of plague (not surprising given the forum, but seriously, the level of negativity on this forum toward any idea aside from "bigger is ALWAYS better is really pretty depressing. very closeminded and groupthink-y). they are not. neither are 29" wheels going to revolutionize anything. they're just wheels. a bike still needs two of them, and it doesn't really make a hell of a difference one way or another without a rider what size those wheels are. slow riders will still eb slow riders. poor bike handlers will still be poor bike handlers. good riders will still beat you to the top of the hill regardless what they ride.

This is true! That design has always had a compromised rear triangle/ seat tube arrangement and is hard to make in a smaller size, even in a 26 inch wheeled format. Check out Specilaized's old Ground Control full suspension bikes as a reference point.



And let's not forget that rear wheel contact patch! In 29 inch sizes it conspires to bring more traction and the aforementioned comfort that a 26 inch rear wheel doesn't have. And if the 50/50 bike has "75%" of the roll over benefits of a 29"er because of the front wheel, again: Why not have 100% of the roll over benefits with a full on 29"er? :rolleyes:




Cloxxki! Rolling out the "A Team" reference! I am impressed. :p :p

Cloxxki
04-16-2006, 10:11 AM
I've tried it before I got my true 29" fix. Conversions are fun. Rear wheel was a pain.
Even rode a converted 50/50 commuter for years. A bit better than 26", much less than 29".

If someone WANTS that setup just because, to me that's cool. The quaralling starts when they try to give technical reasons for wanting it, based on attributed performance advantages.
Best reason to a 50/50 would be being a short-legged rider that loves to rolls down steep cliffs, hanging way behind the seat. You're talking stunt bike then, really.
You can't take advantages from a large wheel and not get disadvantages from a small rear.

If I'd have to ride a 50/50 today, I'd get the 26" front and 29" rear wheel. Most of the advantages, least of the disadvantages. I can find a high-end high-volume 26" front tire to make up for some of the 29" traits lost.

shapirob
04-16-2006, 11:56 AM
is interested in creating the smoothest ride possible using the properties of metals very creatively - thus the "silk" in silk ti. His elastomer shock is a design that smooths out v.small and small bumps out better than any other smooth tail or FS - its among the strongest climbers around and its ride remained pretty hard to challange until the racer-x came along for agressive xc. It could be very well the case that a hardtail 29er climbs better than a silk ti 50/50 if those are the only options for a person with a short inseam, but I suspect it might be closer than one would think, since its a master of traction on uphills and given the issue of poorer acceleration is likely proportionally greater for a smaller rider.....I will leave it at that as its just theoretical discussion at this point.

b

Cloxxki
04-16-2006, 01:20 PM
The "poorer acceleration" is in but one of the many changin parameters, the 150g extra weight, which is extremely minute. The rolling resistance more than overcomes it, working on easily 80% of all mass, rider+bike, during climbing.

protolith
04-16-2006, 02:33 PM
The "poorer acceleration" is in but one of the many changin parameters, the 150g extra weight, which is extremely minute. The rolling resistance more than overcomes it, working on easily 80% of all mass, rider+bike, during climbing.

The often quoted poorer acceleration is not attributed to the extra weight, but the mechanical difference between two wheel radii. This applies to all wheeled machines. A smaller radius takes less effort to get turning which is a benefit when accelerating, a larger radius is better when maintaining speed as fewer revolutions account for the same speed.

Think of turning cranks, you can turn in the small ring easily and accelerate quickly untill you spin out, try starting in the big ring and its obvious that it takes more effort and is sluggish to get going, but once moving you can fly.

This is the argument being applied. The failure of this argument is when the threshold of traction is being reached. At that point the 29er wheel again has an advantage as the larger contact patch and mechanical charactersitics allows for metered acceleration.

I have yet to drink the 29er cool-aid and I'm sure it shows, so go ahead and flame on...

Cloxxki
04-16-2006, 02:53 PM
The often quoted poorer acceleration is not attributed to the extra weight, but the mechanical difference between two wheel radii. This applies to all wheeled machines. A smaller radius takes less effort to get turning which is a benefit when accelerating, a larger radius is better when maintaining speed as fewer revolutions account for the same speed.
For that effect, the MTB is equipped with 27 gears. One click and the difference of 26" vs. 29" is overcome. What's left is 150g per wheel, of which the radius is not a factor towards acceleration.
At least that's how I understand it to be. The larger momentum thing is there, but I think it's mostly true due to the better roll-through and roll-over ability, which becomes more clear in high-drag situations. JRAside a buddy on a 26" bike, when we both stop pedaling, I am not shooting forward.
There's a video online somewhere of the open Dutch SS Champs where myself and Nightfire head the field, us being the only 29"ers present. I notice less floppyness (bike wandering undernneith me), but not reaching the first corner any slower. That's not too strange, as math seems to have the same idea about weight vs rolling resistance.

mvi
04-16-2006, 03:19 PM
I said it before , rotational mass is overrated.
Do 10 sprints on UNeven surface with a 26 versus 29 wheel and see what comes out.

Guitar Ted
04-16-2006, 05:59 PM
why the evangelism guys? if someone wants a 50/50 bike, mentioning it on here seems like a sure way to get flamed into a smoking pile of ashes. you should be stoked that they are at least getting one wheel bigger.

I'm not out to "flame" anybody here. Just looking for a convincing argument for this 50/50 bike. So far, I've only read one, and that was by Michael Browne of Dirt Rag fame.

for every one of you with such solid opinions of "it won't work. it's a half measure" i have to ask - have you ridden one? why are you so keen to bag on castellano, on travis brown, on carver? do you really think that the people riding and building these bikes have NOT tried all the options? or do you just like to bang the big wheel drum to hear yourselves make noise?

Again, I'm not personally attacking anyone, I just have issues with the concept of a 50/50 bike. Another thing I find amusing is all the folks that say I have to have ridden something to have an opinion on it. Okay, I've ridden mountain bikes with 26 inch rear wheels for over 18 years. I think I can say with some certainty what a 26 inch rear wheel will do in an off road situation. I've ridden the 29"er since 2003, so I think I can comment with some surety on what a 29 inch front wheel can do. Once again: A 26 inch rear wheel doesn't magically become something else just because it has a 29 inch front wheel in front of it. You are welcome to convince me otherwise.

people in here act as if 26" wheels are some sort of plague (not surprising given the forum, but seriously, the level of negativity on this forum toward any idea aside from "bigger is ALWAYS better is really pretty depressing. very closeminded and groupthink-y). they are not.

I will agree with you that the 29 incher isn't for everybody. I've never stated that "bigger is always better".

neither are 29" wheels going to revolutionize anything. they're just wheels. a bike still needs two of them, and it doesn't really make a hell of a difference one way or another without a rider what size those wheels are. slow riders will still eb slow riders. poor bike handlers will still be poor bike handlers. good riders will still beat you to the top of the hill regardless what they ride.

Here I will disagree. I can say from personal experience that, yes, 29 inch wheels did make a difference to me. They did revolutionize my riding. Alot of competitive riding is the "motor", but for me 29"ers made a huge difference.

shapirob
04-16-2006, 09:12 PM
reviewed the Carver as the best hardtail they have ever ridden - does this not include a 29er hardtail - b/c thats the wrong terminology, are they comparing to only 26" hardtails, or are the biased to make sweeping statements without much backup because they are a sponsored magazine, or something along those lines. i dont usually read that mag.

b

Guitar Ted
04-17-2006, 03:31 AM
reviewed the Carver as the best hardtail they have ever ridden - does this not include a 29er hardtail - b/c thats the wrong terminology, are they comparing to only 26" hardtails, or are the biased to make sweeping statements without much backup because they are a sponsored magazine, or something along those lines. i dont usually read that mag.

b

Your on the right track, shapirob, MBA has always taken somewhat grandiose stands in the past which haven't always worked out in the reality of the mountain bike world. There was a time when they had said that 25" wheels were the ideal size for mountain biking, that by now ( 2006) we all would be riding on tubeless tires, and that the hardtail mountain bike was dead.

You might find that a good many here on the forum do not regard that rag with much respect. Personally, I find their So-Cal-centric perspective and their "authoritive stance" on all matters regarding mountain biking to be rather boring. Your mileage may vary.

brant@on-one.co.uk
04-17-2006, 04:53 AM
RC is pretty short. Do you think that's anything to do with it :-)

shapirob
04-17-2006, 11:51 AM
what is RC?

Quasi
04-17-2006, 12:11 PM
Try endo on a steep hill.Simple. What you can't do is an OTB. It is easy to go over the end on ascent of a steep hill, well, over the rear end. :eek:

Drevil
04-17-2006, 02:16 PM
...good riders will still beat you to the top of the hill regardless what they ride.Imagine how much faster Travis (http://gallery.mtbr.com/showphoto.php?photo=24188&password=&sort=1&size=big&cat=500&page=) Brown (http://www.seaotterclassic.com/2006/187.htm) would be if he had two 29" wheels. :D:D:D

FYI, a bike's a bike to me. 26, 29, half-breed - all bikes, all good.

POG
04-17-2006, 05:41 PM
what is RC?
editor - Richard Cunningham (I think).