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Discussion Starter · #1 ·
I have a Voodoo Dambala that I really like. I talked my friend who is tall and with a very long torso into the buying their largest frame. After he got it and was waiting for parts I read on this forum that there might be a foot strike issue. Well it turned out to be true which is in my mind a total bummer and speaks of poor execution. He is running 180 cranks and has a large foot and the overlap is close to an inch.

How can you not design a frame around this critical measurement??? Bigger frames are for bigger people with bigger feet and probably longer cranks. Why wasn't the top tube made at least an inch longer? The bottom bracket to middle of front hub is not much greater than on my bike even though it is 2 sizes larger. I would really hesitate to recommend this bike to anyone until they figure out if they will encounter the foot strike issue.
 

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I'm 6.0 and have no foot strike. Size 42 shoe,19 inch frame. It is real close with a Wb fork.I have let a friend of mine ride my bike that wore a 10.5 shoe and he was all over the tire, might have been ok with a Reba.
 

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Dambalas run steep angles and short top tubes for quick handling. The toe overlap issue is well known with this bike. It is inherent in such a design -- not at all a matter of poor execution, though VooDoo could do a better job of communicating the unique fit issues with their frame.

In any event, the first rule of bike fitting is to size by top tube length, never by seat tube length. First you find the top tube length that suits you, then check the seat tube length to make sure standover is acceptable. Then check the front-center measurement (it would be nice if VooDoo published this figure, but you can approximate it by subtracting chainstay length from wheelbase), and see if there's going to be a toe overlap problem. If it looks like there will be a standover or overlap problem after doing these checks, then shop for a different bike.
 

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GlowBoy said:
...Then check the front-center measurement (it would be nice if VooDoo published this figure, but you can approximate it by subtracting chainstay length from wheelbase)...
Voodoo does not give a wheelbase figure either. Both wheelbase and front-center are dependent on the fork A-C length and offset. as most framesets are sold without a fork these numbers would be a guess at best. Voodoo does give the A-C length they designed the the frame around.
 

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Discussion Starter · #5 ·
To say that the foot strike with the Dambala is "well known" is not correct. Well known to whom?
Most people order these frames not built up. There is no way of knowing until you build it up if there is going to be foot strike issues.
There are no front center measurements out there available to the buying public.
My big gripe is this. It is such a close call on the foot strike issue, depending on your foot length, type of fork you put on, your crank length etc. that Voodoo should have addressed it by adding about an inch to their top tube length. BTI is the exclusive distributorship for this bike and they make no mention of the "well known" foot strike issue.
I just don't find foot strike on any mountain bike to be acceptable.
I do wonder when I see people running setback seatposts, super long stems, a stack of headset shims etc on many mountain bikes (both 26er and 29er) if the designers have forgotten how to fit people properly.
If I were to design a 29er, one of the first things I would take into consideration is the front center measurement.
 

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Fair enough. My earlier post was a bit harsh, and I didn't realize VooDoo doesn't give out wheelbase figures either.

I guess I'm writing from the perspective of a 5'7" rider who is quite aware of the handling-vs-overlap tradeoff: my 'cross bike (53cm ETT) has huge toe overlap, and both of my MTBs are designed at the absolute upper limit of quick handling possible without encountering overlap.

Ordinarily I would be surprised that a tall rider should encounter toe overlap though ... unless he has big feet and is running long cranks, as is your friend. Was the bike at least sized based on top tube length?

I do agree that 29" manufacturers ought to always give out the front-center measurement, since toe clearance can be an issue for so many riders on the big wheels. VooDoo, with its extra-short top tubes, ought to make an extra point of this on their website.
 

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but then...

richwolf said:
My big gripe is this. It is such a close call on the foot strike issue, depending on your foot length, type of fork you put on, your crank length etc. that Voodoo should have addressed it by adding about an inch to their top tube length. BTI is the exclusive distributorship for this bike and they make no mention of the "well known" foot strike issue.
I just don't find foot strike on any mountain bike to be acceptable.
so, let's assume they make the bike an inch or two longer. suddenly there will be all these people complaining that the bike is slow handling, or that it is "too long" and that the wheelbase is unacceptable in tight going... damned if they do, damned if they don't.

every single bike built has to be designed around a whole floating set of compromises. what may be unacceptable to your mind is totally fine in the eyes of someone else who is trying to find a bike that fits. while what might be perfectly acceptable to you could be seen as a total pig in somebody else's eyes.

meanwhile, the whole fit issue is compounded in this instance by a guy with long cranks and huge feet. maybe he even runs his cleats back further than most, so he gets even more toe overlap.

think bell curve, not "it must fit everyone". if a bike can be made to work "well" for "most" people, then it is probably considered a success. if some people find those parameters unacceptable, then maybe they should be investing in custom frames...
 

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Glowboy said:
VooDoo, with its extra-short top tubes, ought to make an extra point of this on their website.
While Voodoo does spec shorter TTs than some companies they are hardly "extra short." Generally within a half-inch of "normal" frames.

They do use a steeper HTA which does shorten the front center.

We must remember that toe overlap is also affected by crank arm length, shoe size and the placement of the cleat on the shoe (or the foot on a platform pedal). To some extent affected by "Q factor", too.

I have ridden bikes on and off road that have toe overlap. Can not say it has ever caused problems.
 

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richwolf said:
T...that Voodoo should have addressed it by adding about an inch to their top tube length...
Then I would be riding a Voodoo a "size" or two smaller to get the TT length I want. TT length is the first thing I look at when picking a frame size. Then the STA. I do not care how long the seat tube is as long as I can get the saddle high enough.

I would be on a 19" Voodoo. My Monocog 29er is a 17".
 

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Discussion Starter · #10 ·
I really can't believe that adding an inch to the top tube length will make the bike handle like a pig. I run the 18 inch Dambala and because I have small feet and short cranks I do not have a toe overlap issue. I in fact like the longish top tube since it allows me to run a shorter stem and it gives me the handling I really like.
Still the large frames are meant for big people and most of them are probably running 175 or longer crank arms and most big people have big feet to boot, so it isn't too much of a "stretch" to design the bike around those people rather than the tall guy with tiny feet and short crank arms. We know my friend is probably going to have to go to a custom frame but he at least wanted to try out the 29er concept before he totally committed a lot of dollars.
I think a lot of designers are too locked in on "traditional thought and geometry" to really start pushing the envelope that is required with 29er design. Things like top tube lengths and chain stay lengths come to mind. Personally I think the 26er bikes being built with short top tubes, and short head tubes that require stacks of spacers, long stems, high rise bars and set back seat posts do more to compromise fit and performance than anything.
 

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richwolf said:
I really can't believe that adding an inch to the top tube length will make the bike handle like a pig. I run the 18 inch Dambala and because I have small feet and short cranks I do not have a toe overlap issue. I in fact like the longish top tube since it allows me to run a shorter stem and it gives me the handling I really like.
Still the large frames are meant for big people and most of them are probably running 175 or longer crank arms and most big people have big feet to boot, so it isn't too much of a "stretch" to design the bike around those people rather than the tall guy with tiny feet and short crank arms. We know my friend is probably going to have to go to a custom frame but he at least wanted to try out the 29er concept before he totally committed a lot of dollars.
I think a lot of designers are too locked in on "traditional thought and geometry" to really start pushing the envelope that is required with 29er design. Things like top tube lengths and chain stay lengths come to mind. Personally I think the 26er bikes being built with short top tubes, and short head tubes that require stacks of spacers, long stems, high rise bars and set back seat posts do more to compromise fit and performance than anything.
All of which is why there are different bike companies selling bikes with different geometries. If we all liked the same type of bike there would only need to be one company selling one model.

I believe most frames have too short of head tubes (even if I did not use dropbars) and the TTs are too long and require too short a stem. I have trouble getting enough weight on the front end of many current style bikes. They just do not suit my riding style.

Voodoo's design philosophy is similar to mine. That you are riding an 18" and call the TT "longish" should have been a cue. The small GF Rig and Niner (both ~15.5" frames) have longer top tubes. Voodoo is just not the right bike company for you friend.
 

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Discussion Starter · #12 ·
shiggy said:
All of which is why there are different bike companies selling bikes with different geometries. If we all liked the same type of bike there would only need to be one company selling one model.

I believe most frames have too short of head tubes (even if I did not use dropbars) and the TTs are too long and require too short a stem. I have trouble getting enough weight on the front end of many current style bikes. They just do not suit my riding style.

Voodoo's design philosophy is similar to mine. That you are riding an 18" and call the TT "longish" should have been a cue. The small GF Rig and Niner (both ~15.5" frames) have longer top tubes. Voodoo is just not the right bike company for you friend.
Geeeez Shiggy!

You sure have been crabby lately!

I am 5 foot 6 and the 18 inch Voodoo should be "too big" for me but I run a super short stem and feel stretched out indicating for me that I am riding a bike with a long top tube for my size.

It's not the top tube issue per se that is the big problem but the toe overlap for my friend. If your design philosophy includes toe overlap then yes you are in lockstep with Voodoo. This toe overlap issue has been raised before and probably will again. I just pointed it out so others looking at the Dambabla would know what they are getting into.

I guess people just love shooting the messenger.:nono:
 

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It seems there always a little give and take on any production bike.Very Few production models have everything the way you want it. My Dambala (06 model) has been a solid bike. Great tire clearance, a little issue with the fork crown on a Reba (Ventana had a fix for me) the WB's cleared fine. No over lap for me. I've seen 26 inch bikes with the same issue especialy for smaller riders. It is funny to see 29's with the same issue for taller riders with BIG feet. You just never know what your gonna get sometimes until you try it, I guess that's what makes it so much fun. ;)
 

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pig, or stable?

richwolf said:
I really can't believe that adding an inch to the top tube length will make the bike handle like a pig.

I think a lot of designers are too locked in on "traditional thought and geometry" to really start pushing the envelope that is required with 29er design. Things like top tube lengths and chain stay lengths come to mind. Personally I think the 26er bikes being built with short top tubes, and short head tubes that require stacks of spacers, long stems, high rise bars and set back seat posts do more to compromise fit and performance than anything.
look, i'm not bagging on you here. but an inch of top tube is usually an inch of wheelbase, and that is a good increase by any measure.

you have a point about traditional thought and geometry, but i suspect that the designers are not as locked in their thinking as consumers are. personally, i hate short wheelbase 29" bikes. personally, i think that they should be at least two inches longer between the wheels than similar size 26" bikes. however, most people think i am bug nuts for holding to that belief.

so, if a designer decides to market a bike that is at least an inch or two longer than whatever else is being sold, he runs the risk of being raked over the coals for making his bikes too long. meanwhile, since so many people are okay with a little toe overlap (myself included, even though i hate short wheelbases. it just doesn't really effect the handling in 99.9 percent of the trail situations most of us encounter), a designer might choose to fudge his design in that direction rather than risk being branded a pariah on the showroom floor...
 

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shiggy said:
I have trouble getting enough weight on the front end of many current style bikes. They just do not suit my riding style.
I agree. However, my solution is longer chainstays instead of a longer stem. I don't like the feeling of my head being hung out over the front axle.

My BM Flyer has 18.5" chainstays, and the handling is excellent.
 

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MtotheF said:
personally, i hate short wheelbase 29" bikes. personally, i think that they should be at least two inches longer between the wheels than similar size 26" bikes. however, most people think i am bug nuts for holding to that belief.
Lots of people think that longer chainstays, or longer wheelbases, make bicycles turn slower. This shows ignorance of physics.

The only situation in which this matters is on really tight turns (like hairpin switchbacks), where a longer wheelbase means the rear wheel slows down more relative to the front. This doesn't make the bike turn slower, but it does make it harder to balance.

Therefore, it makes sense that trials riders want a tiny wheelbase, as do people who spend a lot of time on skinnies. It also makes sense for dirt jumpers and 4x/BMX riders: shorter wheelbase bikes don't get the back end kicked up as much when going off steeply ramped jumps.

No one uses 29" bikes for that, though.
 

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El Caballo said:
I agree. However, my solution is longer chainstays instead of a longer stem. I don't like the feeling of my head being hung out over the front axle.

My BM Flyer has 18.5" chainstays, and the handling is excellent.
Another example why we don't see one-size-fits-all geometry with the same numbers from every manufacturer: 18.5" chainstays would be unacceptable to a lot of riders. Handling considerations aside, singlespeeders -- especially shorter riders -- need that wheel tucked in tighter than that for good climbing traction. Taller riders and/or geared riders who don't stand out of the saddle may prefer a longer chainstay though.
 

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El Caballo said:
Lots of people think that longer chainstays, or longer wheelbases, make bicycles turn slower. This shows ignorance of physics.

The only situation in which this matters is on really tight turns (like hairpin switchbacks), where a longer wheelbase means the rear wheel slows down more relative to the front. This doesn't make the bike turn slower, but it does make it harder to balance.

Therefore, it makes sense that trials riders want a tiny wheelbase, as do people who spend a lot of time on skinnies. It also makes sense for dirt jumpers and 4x/BMX riders: shorter wheelbase bikes don't get the back end kicked up as much when going off steeply ramped jumps.

No one uses 29" bikes for that, though.
My best switchback bike, and easiest bike to trackstand, is my Coiler with a 46+" wheelbase (and a 14+" BB). Balance is not an issue.

Trials bikes do not have that short a wheelbase. The "long" version of this stock bike http://webcyclery.com/product.php?productid=17634&cat=409&page=1 is 1095mm/43.1". The "short" is still 1065mm/41.9".
The Mod bikes are in the 1000-1010mm range.

The Blur 4X falls right in there, too (and with nearly a 1.4" difference in WB between the med and large).

These are in the same range as the bikes used for riding "skinnies." Not much different than an XC bike. 26" wheels on the shorter end, 29 the longer. They all work.
 

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richwolf said:
...It's not the top tube issue per se that is the big problem but the toe overlap for my friend...
Just for our information, what is the actual front center measurement on your friend's bike?

I guess people just love shooting the messenger.
Not the messenger. The premise of the message.
 

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Discussion Starter · #20 ·
shiggy said:
Just for our information, what is the actual front center measurement on your friend's bike?

Not the messenger. The premise of the message.
And what is wrong with my premise??

I don't know the exact front center dimensions of my friend's bike but I will try to find it out. I do know that it is not that much greater then mine and I have a frame two sizes smaller. I guess the steeper head angle and shallower seat tube angle conspire against each other in spite of the top tube being quite a bit longer.

My Dambala with it's "long top tube" and very short stem has a "heavy" front end. Not nearly as easy to wheelie as my 26er and much more stable on steep climbs. I would think that as the top tube gets longer the front end of the bike might not feel as light as a bike with a shorter top tube based upon leverage.

And even though a bike with a longer wheelbase might handle a bit differently it is so common among just about all bike brands as you go from small to large sizes. It just doesn't seem to be that big of issue. To me foot strike against a tire is a big issue. How many people reading this post think that toe overlap is not that big of deal? When I climb a steep technical section and am moving the front wheel around the last thing I want to deal with is my feet hitting the front tire. I had a 26er years ago with that very feature and I hated it. Needless to say it didn't stay in my stable very long.:madman:
 
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