1. The most important thing about buying a new bike is to make sure it fits. The only way you'll know if the bike is right for you is to size up the bike and make sure that the bike's geometry matches your body's geometry. Ask questions and do some research.
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2. If possible, try to find a shop that will let you demo the bike on real dirt. Five minutes in a parking lot won't cut it. You wouldn't buy a car without a real world test drive, and a bike should be no different.
3. Don't belive the hype. Just because your favorite rider or best friend rides a certain bike, that doesn't mean that's the best one for you. Have an open mind and be realistic about your needs and ability.
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Thread: Geometry

  1. #1
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    Geometry

    In the trail today I encountered some guys on Treks. I was on my DB Response and as they looked it over they said it had quite a slack geometry for a MT bike. I know a slacker seat post means more upright and comfy riding position with bad aerodynamics and efficiency the trade off, but I have no problem with that. When they took off I could clearly see how much more "flat backed" they were compared to my almost straight up position.

    IMO my bike has the best of both worlds.... My hands don't get sore and my neck feels fine plus I can power it up just fine all day long. Being in that flat back position looks painful for an all day ride on trails.... Kinda makes me think twice about getting a 29er Stumpy Comp as it says the geometry is aggresive....I assume that means a steep seat tube, short wheel base and quick(unstable) handling.

    Possibly the Stumpy isn't what I am looking for as I could care less about racing. I just like to trail burn and ride roads a lot.

    I'm thinking I should just upgrade my Response and keep riding my new Allez.....My Allez is effing awesome BTW.... It has a good geometry similar to the Tarmac and shares the same stiffness of the Tarmac.... I love that bike.

    Thoughts?

  2. #2
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    As long as you are happy with the DB, that's all that matters. The reason bikes have different geo's is there are many different types of riders. If a company had the perfect one for all riders, all the other companies would also have THAT one.

    Those must have been some of the more expensive treks - the ones in your bike's price range are extremely upright.

  3. #3
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    What are you asking??

    For me, usually slack or steep refers more to the angles of the bike itself, especially the head tube and seat tube, than the riding position. There's a ton of flexibility in the riding position of a bike for any given rider - it's mostly about setup. However, changing the seat or head tube angles is a lot harder.

    A slack or steep head tube effects how the bike climbs and descends. A slack or steep seat tube can effect the range of saddle positions that are possible.

    If you're planning a new bike, IMHO bolting more money to an existing, relatively low-end bike isn't the way to go. If you want a Stumpjumper and you don't want to have a racy riding position, just don't set it up that way. Riser bars, an up-angled stem and putting all the spacers under the bars should put your grips pretty high. Test-ride, and get the size that handles the way you want and can fit the way you want.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  4. #4
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    I think the OP mentioned two issues: riding position and geometry.

    As mentioned, slack geometry is usually common for a DH or AM bike where descents are a big part of the ride. The slack or flatter HT and ST angles push the rider's center of gravity rearward and provides stability going downhill. XC bikes tend to have steeper HT and ST angles and more forward CG. They climb a little better but can feel a little unstable on descents.

    Having a flat back or upright position is more about reach and drop: top tube length, stem length/angle and handlebar geo. You can have either riding position on any bike but reach/drop specs are not the same as frame geo (or, at least, that's my understanding).
    Joe
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  5. #5
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    I wouldn't trust just anyone regarding geo. It's much more complicated than what most people realize. There's also much more to a bike than geo that makes it good. For someone to go up to you and talk about technical stuff like that, they better have some credentials or their info better come from a very reputable source (without alteration or missing context) before you totally believe it. Even if they were mechanical engineers, they would have to had ridden on many many bikes, not just half a dozen or less, with the purpose of analyzing it. Even then again, their analysis would only cover their body type and the trails they rode on.

    Everyone eventually runs into some no-nothing geeks (or d-bags, if you prefer), who eat up marketing and bike articles (written by people who specialize in writing, and not analyzing bike designs in depth), which is then spit back out to others in the form of extremely simplified statements, which may be misunderstood. These forums are full of 'em, with people recommending this and that. If I had a nickel every time someone recommended an Ibis Mojo or Nomad carbon or some other popular carbon bike... then there are people riding fancy bikes that would love to share their research on how they came to the decision of how they bought their bike over others. The fewer words they use and more generalized pros/cons (using words like best, great, amazing, etc.) and the more comparisons "scientific" comparisons they make, the kind that cannot be precisely or reliably measured by the human body like efficiency, compliance, etc., the more you should treat it with suspicion.

    Good designs feel right and feel good. DB makes respectable bikes. Trek also makes respectable bikes. Many people fit on Treks pretty well, but many fit better on other bikes. Many Trek riders eventually find that they fit on other bikes better (not just sizing, but riding style fit). You sound like you have a fine bike for what your intentions are. As your riding style grows and matures, you may find that your bike no longer fits you and your riding style well, and you might just find yourself in the shoes of those Trek riders.

    That "flat backed" position is more for serious riders who are fitter and have higher ambitions. It requires a stronger back/core and basically takes pressure off your ass, so people can actually ride at a fast pace for more than 2.5 hours or 30+ miles without saddle sore. Upright positions are good for more comfort at slower paces, for shorter durations. Can't say which is better or which is best in general... you can only say which is more suitable for what kind of rider.

  6. #6
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    So you met some guys on the trail, and the best they could do for conversation was to criticize your bike? Sheesh.

    Quote Originally Posted by Varaxis View Post
    That "flat backed" position is more for serious riders who are fitter and have higher ambitions. It requires a stronger back/core and basically takes pressure off your ass, so people can actually ride at a fast pace for more than 2.5 hours or 30+ miles without saddle sore.
    I agree w/the above. I know a few people who race pretty seriously. They are the ones with large saddle-to-bar drops, who are leaned way over into an aggressive position. Core strength is required. More weight ends up on the bars. Likelihood of an OTB event is increased -- a tradeoff taken for the more aggressive position and faster speed.

  7. #7
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    Here's a review of an s works Stumpy setup flat back. The reviewer says he doesn't ride with that setup usually. It puts more weight on the front tire for traction at speed. The carbon frame seat stays soak up chatter. The frame is unchanged from 12.
    Ride impression: 2013 Specialized S Works Stumpjumper

  8. #8
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    Quote Originally Posted by RollingAround View Post
    In the trail today I encountered some guys on Treks. I was on my DB Response and as they looked it over they said it had quite a slack geometry for a MT bike. I know a slacker seat post means more upright and comfy riding position with bad aerodynamics and efficiency the trade off, but I have no problem with that. Actually, a slacker seat post is one angled further back. The most extreme examples of this are found on DH bike where maintaining a rearward bias of rider weight is important. Just remember that slack geometries are optimized for descending. A bike with a slacker geo would generally descend better than a steeper bike while climbing worse. When they took off I could clearly see how much more "flat backed" they were compared to my almost straight up position.

    IMO my bike has the best of both worlds.... My hands don't get sore and my neck feels fine plus I can power it up just fine all day long. Being in that flat back position looks painful for an all day ride on trails.... Kinda makes me think twice about getting a 29er Stumpy Comp as it says the geometry is aggresive....I assume that means a steep seat tube, short wheel base and quick(unstable) handling. Aggressive geometry is pretty much another way of saying slack. This sort of geometry means slack seat tube/head tube, relatively low BB height, and short chainstays. Also, short wheel base does not mean a bike will have unstable handling, just better maneuverability.

    Possibly the Stumpy isn't what I am looking for as I could care less about racing. I just like to trail burn and ride roads a lot.

    I'm thinking I should just upgrade my Response and keep riding my new Allez.....My Allez is effing awesome BTW.... It has a good geometry similar to the Tarmac and shares the same stiffness of the Tarmac.... I love that bike.

    Thoughts?
    I wouldn't worry to much about the geometry difference between your current bike and a Stumpy, assuming you're going for the non-FSR. It won't make much noticeable difference in your case.

  9. #9
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    For me, handlebar height is about power output. I haven't lowered my bars much, but some, and I've extended the reach on my bike a little as I've gotten to be a stronger rider. When I'm developing more power, a flatter-backed position is better balanced. Flexibility's a part of it too - too low a position murders my lower back, and I think that's about tight hamstrings. I've still gone a little lower over time because I've also moved my saddle forward a little, which opens up that angle again, although it also requires more power output to balance well.

    I don't think it takes me more core strength to be comfortable like that. But I'm pretty good about doing ab work in the mornings, and have been for longer than I've been riding this bike, so I don't really have a comparison.

    Bottom line is that riding position is all about the rider, and you'll be happiest if you're realistic about how you set it up, or get help from someone who understands that different riders will have different needs.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

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    On my DB I can climb very well and do fast decents and it doesn't feel like I am going to go OTB at all. I tried to look at where my ass is over the rear wheel and it is pretty close to directly above the rear hub almost.

    I've also found that when trying to wheelie it will totally pull the front up very quick and the bike tends to fly from under you very fast. I think this is due to the weight of myself being more toward the rear than front(slacker)

    Interesting stuff. I'm glad those guys mentioned it makes me learn more about bikes and just how more involved they are than people think.

  11. #11
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    Quote Originally Posted by RollingAround View Post
    On my DB I can climb very well and do fast decents and it doesn't feel like I am going to go OTB at all. I tried to look at where my ass is over the rear wheel and it is pretty close to directly above the rear hub almost.

    I've also found that when trying to wheelie it will totally pull the front up very quick and the bike tends to fly from under you very fast. I think this is due to the weight of myself being more toward the rear than front(slacker)

    Interesting stuff. I'm glad those guys mentioned it makes me learn more about bikes and just how more involved they are than people think.
    You can do fast descents on anything as long as it's smooth. A fast technical descent would allow a slacker gravity oriented bike to shine.

  12. #12
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    Considering the DB Response has a 70 degree head angle, I wonder what the Trek racerboys were riding?
    The suspension of your bike sucks if it's different than mine. Really. It sucks. Big time.

  13. #13
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    Quote Originally Posted by RollingAround View Post
    I've also found that when trying to wheelie it will totally pull the front up very quick and the bike tends to fly from under you very fast.
    That's what a wheelie is. I have a relatively front-biased bike, but it still does that when I commit to wheelie-ing it.

    If it does that when you don't want it to - like you have a hard time lofting the front wheel in a controlled way on a climb - a more forward riding position will help. Of course if it hurts you, it's not a very good solution...
    "Don't buy upgrades; ride up grades." -Eddy Merckx

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    i am new to riding serious bikes. looking for a 29er hard tail. i prefer a upright riding postion for my back and neck. looking at Specialized Epic Comp 29 2011 Bike and Fuji TAHOE 29ER 1.0 2011. i will find it difficult to sit on one before buying, because of this should i go for a bike with front and rear suspension because they tend to be more upright in sitting style, i do not really need the suspension as i do not do that sort of riding.
    please comment or make other suggestions. i am limited to what i can get on sale to some extent.
    thanks.
    ps
    looking at stuff on bike-sales.com has anyone bought stuff from this site, is it legitimate?
    Last edited by help; 08-20-2012 at 04:45 AM. Reason: add more info

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    not sure if this is the right place to have posted the above?

  16. #16
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    You could post more information about what type of riding interests you, the kinds of places you intend to ride. You should also goto a bike shop and at least get a "test sit" on a few bikes, noting what year and model, and what frame size, as well as how comfortable you thought the bike was.

    With that information, we'd be able to suggest similar bikes or direct you towards some bikes that could fit you and your intended use better. Also, tell us what your budget range is

    Based on what you've posted so far, I wouldn't look for a full suspension; and if you aren't going to be out on dirt trails with your bike, you may not even need a mountain bike at all. Hybrid bikes have an upright seating position, a lesser amount of front suspension travel, and you can option a higher rise stem as well as a riser handlebar to get even more upright. I could keep guessing what might work for what you might want, but it would be better if you sat on a few bikes, maybe take one or two that were promising out for a short spin in the parking lot, and share your impressions.

  17. #17
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    Thanks for your reply, i ride mostly road at present partly because i have a hybred and it is ok on a dry fire trail. i want something i can take off road but do not want two bikes hence why i was thinking a 29er hard tale might be the best compromise. I was speaking to my brother who is more into it than me and said that alot of the hard tales are set up with a bums up style which does not suit me. i sat on a fuji taho 2.0 was ok but still found it not as upright as i would like. i will try to have a sit on a few bikes to get an idea of frame size of brands but may not be able to sit on the bike i buy. i should be able to at least sit on a mountain bike of that brand even if it is not the exact one i am buying.

  18. #18
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    ^^^
    Nobody is holding a gun to your head and making you set up a bike in any particular way.

    If you want your hands a bit higher, use an up-angled stem or one with more angle and a set of riser bars. Although I think that if you get into trail riding and get in shape, you'll find you want a little lower, longer riding position.

    Since you've got a hybrid in hand, why worry about how the mountain bike is on the road?

    I'd be suspicious of any web site claiming to sell Specialized bikes over the 'net. Including last-year's. Specialized structures their contracts with their dealers such that dealers aren't allowed to sell bikes that way. Specialized doesn't sell bikes that way themselves either. Last year's bikes get sold locally on clearance or hang around in warehouses. They don't end up for sale on the 'net. Fuji doesn't care.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  19. #19
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    Andrw made a good point, reach / upright positioning can be adjusted quite a bit with a swept-back riser handlebar and a short hi-angled stem. Head angle can vary a bit between models, but it seems most are right around 70. Top tube lengths have a little more variance & some will have the seatpost angled more towards the rear tire than others.
    Name....................ETT(mm).HA..SA...size
    Fuji Tahoe 26"........ 580.......70....73....17"
    Fuji Tahoe 29".........590.......71....72....17"
    Fuji Nevada ST 26".560.......70....73....17" (this one appears to be the most upright fuji mtb)
    Spec. Rockhopper...570......70....73.....17.5"
    Spec. Hardrock 26"..563...70.25..73.....17.5" (looks like any entry level specialized bike
    Spec. Hardrock 29"..566......71....73.......17.5" will have a relatively short reach ~ upright)
    Giant Talon 29"........597.....70.5..72.5...18"
    Giant Revel1 26"......579.......69....72.5...18"
    Trek 3700 26"..........565......70.5..73.5...18"

    About as good a comparison as I can give on paper, but it looks like checking out the Specialized bikes would be worth your time. Keep in mind, we're only looking at an inch or two difference, and you can make a few more inches with stem&handlebar changes, maybe even sliding the seat forward another inch or two on the rails...
    Last edited by G0at; 08-22-2012 at 09:12 AM. Reason: had to use ... for spacing, not actual spaces

  20. #20
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    Hi thanks for your replys.
    I was thinking about what you said with regards to the hybrid. I guess I am a bit unsure how it will handle the dirt. my current hybrid is only a cheap one and I did not want to bikes with respect to storage. rather than upgrading mine I thought I would get a descent one. looking at my current set up it has 2inch rise from the frame to the handlbars and then the stem is at 50 degrees which gives a further 1 to 1.3 inches. I was thinking that if I could get a bike that was already upright then it saves a lot of mucking around with changing parts (changing parts also means spending money). I was after a bike around the $2400 RRP but would buy one second hand or on special to get it much cheaper. check the link out for this bike.

    3w.sale-bikes.com/products/Specialized-Epic-Comp-29-2011-Bike.html
    i put 3w because it would not let me put in the www dot at the begining of the link.

    Specialized Epic Comp 29 2011 Bike - Sale Bikes - Promo Discount Bike

    Specialized Epic Comp 29 2011 Bike - Sale Bikes - Promo Discount Bike
    there is also a S works specialized bike there i was looking at.
    thanks for the warning with respect to specialzed bikes on the net, this did look ligimate to me but maybe I need to be careful. I am not sure how to know if it is the real thing. I want to pay with paypal and if I can not then I am not sure if I will buy.
    Goat, you were saying that i could get a 70 degree stem is that correct? how much height could i gain here? 1.5 inches or more? how much could i get a stem for and how what would be a rough amount i could get it for?
    i was in a bike shop yesterday and they also said i should go for a larger frame size if i want to be more upright, so rather than going for a 21inch go for a 22 or 23 inch in a 29er. (i am 6ft 4 inch).

  21. #21
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    Goat how can i tell from measurements how upright things are? i guess the seat high and handlebar high give you some idea but there are also the angles and distance between the handle bar and seat etc, it seems complicated to a beginner, me (as a table with specs does not mean much to me yet, i am learning some of the lingo but do not necessarily understand the significant of measurements and how upright it makes the bike). So for example in the specifications that you quoted some of the more upright ones the handle bar high and seat high were not necessarily the ones which were closest in measurements.
    thanks
    Last edited by help; 08-23-2012 at 05:49 PM. Reason: correcting mistakes

  22. #22
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    I tried real hard to get a handle on geometry before buying my first bike in a decade+ recently. I rode a few and with a crappy back and assorted other marks from hard living, wasn't real hopeful. I finally stumbled across something that seems to fit comfortably by luck. I wouldn't be too interested in others opinions if you are comfortable and doing what you want to do. Nothing wrong with trying new things, but people vary so much you can only generalize to a certain degree.

  23. #23
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    Quote Originally Posted by G0at View Post
    Andrw made a good point, reach / upright positioning can be adjusted quite a bit with a swept-back riser handlebar and a short hi-angled stem. Head angle can vary a bit between models, but it seems most are right around 70. Top tube lengths have a little more variance & some will have the seatpost angled more towards the rear tire than others.
    Name....................ETT(mm).HA..SA...size
    Fuji Tahoe 26"........ 580.......70....73....17"
    Fuji Tahoe 29".........590.......71....72....17"
    Fuji Nevada ST 26".560.......70....73....17" (this one appears to be the most upright fuji mtb)
    Spec. Rockhopper...570......70....73.....17.5"
    Spec. Hardrock 26"..563...70.25..73.....17.5" (looks like any entry level specialized bike
    Spec. Hardrock 29"..566......71....73.......17.5" will have a relatively short reach ~ upright)
    Giant Talon 29"........597.....70.5..72.5...18"
    Giant Revel1 26"......579.......69....72.5...18"
    Trek 3700 26"..........565......70.5..73.5...18"

    About as good a comparison as I can give on paper, but it looks like checking out the Specialized bikes would be worth your time. Keep in mind, we're only looking at an inch or two difference, and you can make a few more inches with stem&handlebar changes, maybe even sliding the seat forward another inch or two on the rails...
    This might also help for hand positioning that I found in another thread;
    Attached Images Attached Images
    The ridiculousness of cycling clothes increase exponentially in relation to the distance from your bicycle.

  24. #24
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    many thanks that is a useful chart.

  25. #25
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    Someone mentioned a MSC bike which i had never heard of model WCR as being a bit more upright hard tale. anyone heard of this bike? Fuji, giant are both lower in style and scott?

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