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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  1. #1
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    Can anybody tell me how effective this "fit calculator" is?

    Fit Calculator - Competitive Cyclist

    I bought a Wahoo about 5 or 6 years ago and I really wanted to trust my LBS since the next closest one is in Annapolis which is 30-35mins away and only sells Specialized. The guy that was in there seems to be the owner of the franchise because he's the only one there whenever I go in. He's slightly shorter than me with shorter legs. Anyway, he sold me the Wahoo with the claim that the 17.5" is what he rides and it felt about right when I test rode it but once I got it home and had time to really ride it, nothing felt right. He also didn't spend anytime to make any adjustments once he sold the bike. The bike became so uncomfortable that I sold it just after a month after I bought it(back hurt, felt like I was leaning forward too much, feet were coming off the pedals slightly, etc). I was more comfortable on the $100 k-mart special I had when I was 12!

    So, after doing some research and lurking through some forums, I came across the link above which seems to be fairly comprehensive enough to get me closer to what I "should" be looking at. I want to get back into riding again and I've been looking at 3 mountain bikes at around the same price range(hardrock sport disc 29, Trek Marlin, Trail 5 29). The strange thing is that some of the measurements put me on a 15.5" or Small and then the others put me at 17.5" or Medium size bikes.

    I know it's more about what is comfortable but what should I do when you're have trust issues with your LBS?

    Anyhow, if it helps, my measurements and what the above link spit out are below:

    Your Measurements
    Gender M
    Inseam 29 in
    Trunk 23.5 in
    Forearm 12 in
    Arm 23.75 in
    Thigh 23.25 in
    Lower Leg 21 in
    Sternal Notch 55 in
    Total Body Height 65.5 in

    Standover Height Range 27.7 - 28.3 inches
    Virtual Top Tube Length 22.1 - 22.5 inches
    Stem Length 8.6 - 10.2 cm
    BB-Saddle Position 64.4 - 65.9cm
    Saddle-Handlebar 48.4 - 50.0 cm

    Thanks for any help and advice!

  2. #2
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    Online tools are a little on the generalized side of things. Fit can be a complex thing depending upon the activity.

    I am built similar, 30" inseam, 5-7...

    I can and have ridden on sz 19.5 29ers. Wouldn't want to do a lot of trail riding with them, but plain old non-technical stuff was fine. I normally feel about right on sz 16 29ers or sz 17 26ers. ???

    The best indicator of a starting point is to just toss your leg over a bike and give it a whirl. I didn't think a sz "small" or 16 would be my thing, but it ended up being what worked for me.

    Not sure I helped you... hahaha
    - The only thing that keeps me on a bike is happiness.

  3. #3
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    You do want to get the frame size right - everything else can be adjusted. The main consideration is inseam length, although most makers recommendations are based on height. If your inseam is not average for your height, then adjust accordingly.

    As OmaHaq suggests, test rides are a great way to start. A good LBS should also be able to guide you. Once you get the right frame, there are a number of tings that can be swapped out to adjust the cockpit - stem, bars, stem spacers. Also, seatposts can be had that add setback up to an inch. Work with the lbs to figure it out.
    Use it, use it, use it while you still have it.

  4. #4
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    I know it's more about what is comfortable but what should I do when you're have trust issues with your LBS?
    Igo online and learn stuff yourself. I live in a high rent area so LBS is not an option. Sounds like it's not an option for you either. I also got burned being a newbie buying my first road bike. They did no sizing, to adjustment. They just made a quick sale which I had to live with.

    At 5'7 I wouldn't go 29er. I"m 5'10 and 26er fits me great. You can go in the maker's subforums and check fit there e.g. trek, specialized. It's usually recommended to buy 29er size one lower than your 26er, but checking in specific maker's subforum is better.

  5. #5
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    Quote Originally Posted by OmaHaq View Post
    Online tools are a little on the generalized side of things. Fit can be a complex thing depending upon the activity.

    I am built similar, 30" inseam, 5-7...

    I can and have ridden on sz 19.5 29ers. Wouldn't want to do a lot of trail riding with them, but plain old non-technical stuff was fine. I normally feel about right on sz 16 29ers or sz 17 26ers. ???

    The best indicator of a starting point is to just toss your leg over a bike and give it a whirl. I didn't think a sz "small" or 16 would be my thing, but it ended up being what worked for me.

    Not sure I helped you... hahaha
    That's the thing though, I have yet to see anything smaller than a 17.5 or Med(depending on manufacturer) bike in my LBS. I stopped in there today on the way home and once again, the same guy was in there giving me the same thing about how 17.5" is the size he rides..."OH WAIT! If you like that Marlin! Here's this Rockhopper with hydraulic brakes that's on sale for $880! That upgrade alone will cost you another $400!" Really jackass?? I guess he forgot to mention that it was from 2011...

    Quote Originally Posted by Gasp4Air View Post
    You do want to get the frame size right - everything else can be adjusted. The main consideration is inseam length, although most makers recommendations are based on height. If your inseam is not average for your height, then adjust accordingly.

    As OmaHaq suggests, test rides are a great way to start. A good LBS should also be able to guide you. Once you get the right frame, there are a number of tings that can be swapped out to adjust the cockpit - stem, bars, stem spacers. Also, seatposts can be had that add setback up to an inch. Work with the lbs to figure it out.
    Maybe I'll stop by the one that's half hour away. There's another one 45 min away too that sells more than just Specialized. My reasoning for sticking with Trek, Cannondale and Specialized is the fact that all of the LBS' within an hour sell these brands. If I want to get into other makes like Giant, Diamondback or GT, then I have to go more than an hour out. This might not sound like much but where I live an hour away in normal traffic can be disastrous if anything happens on the roads to or from the bike shop

    Quote Originally Posted by bob13bob View Post
    Igo online and learn stuff yourself. I live in a high rent area so LBS is not an option. Sounds like it's not an option for you either. I also got burned being a newbie buying my first road bike. They did no sizing, to adjustment. They just made a quick sale which I had to live with.

    At 5'7 I wouldn't go 29er. I"m 5'10 and 26er fits me great. You can go in the maker's subforums and check fit there e.g. trek, specialized. It's usually recommended to buy 29er size one lower than your 26er, but checking in specific maker's subforum is better.
    Getting burned sux and it doesn't happen to me often. It left a bad taste in my mouth and this guy has really just irritated me to the point that I don't want to even go back in there for service or parts if I need it.

  6. #6
    Nouveau Retrogrouch SuperModerator
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    Can anybody tell me how effective this "fit calculator" is?

    I have yet to find an online fit calculator that puts me on the bike the way I prefer. The CC one was the worst.
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    The trouble with common sense is it is no longer common

  7. #7
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    Quote Originally Posted by shiggy View Post
    I have yet to find an online fit calculator that puts me on the bike the way I prefer. The CC one was the worst.
    I'm more into finding at least the right size frame at this point. If I can get something close and only needing minor adjustments for me to be comfortable then I'd be ecstatic!

  8. #8
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    Quote Originally Posted by bldgengineer View Post
    I'm more into finding at least the right size frame at this point. If I can get something close and only needing minor adjustments for me to be comfortable then I'd be ecstatic!
    I found the CC "fit" calculator very accurate when it comes to putting me on the correct size frame, as the CC does take into account torso length, which I feel is the most important factor.

    The CC fit calculator isnt designed to take the place of a proper professional fitting which can tell you the proper seat height, setback, handlebar height, stem length, etc..

    and yes, you can still get back pain from being on the correct size frame but having the handlebars to low or seat too far back/forward

  9. #9
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    I wouldn't consider any fit calculator anything more than something to try. Bodies are a complex blend of proportions, musculatures, and preferences with variations of bike, terrain, age and positions of the stars thrown in. Like I said, concentrate on getting a frame that feels good, then you can tinker with the other stuff til it feels right. And what feels right today can change as you age, increase skill, fitness, trails or any of the other things I mentioned.
    Use it, use it, use it while you still have it.

  10. #10
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    OP, I have my theory about what size you ride. But it seems you've had enough theories. The problem with fit calculators is that they don't measure the most important (IMO, of course) parameter - your preferred reach. It correlates with some other things, but correlation is not causation, and it's not like fit calculators measure your CG or how you articulate your back anyway.

    You've got a couple of data points now. You know the Fisher you bought was wrong. You know your walbike is at least closer. I'm typing with my thumbs right now, so I'll let you do the Googling - read about reach and stack, and take a look at the article on fitting a bike qualitatively on the Peter White Cycles web site.

    I bet you can figure out one or two sizes of any given model that will fit you. Phone around, and don't bother going to shops that don't have the right thing in stock.

    FWIW, bicycle specs have been sliding and prices have been climbing for the last few years. I wouldn't turn my nose up at a clearance hardtail from a couple years ago. The warranty starts when you buy it, and clearance pricing can stretch a buck or leave you with more money for a nice dinner.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  11. #11
    I Tried Them ALL... Moderator
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    I'm nearly same dimensions as OP and I ride a size Small(15.5) FS 29er. It fits like a glove. I run a 70mm stem, 711mm bars, 170mm crank and my saddle top is exactly 27.25" from the center of the BB axle. The FS 29er feels great. Instead of sitting ON the bike - I am now INSIDE it. I corner more confidently, faster and the bike just plain stays fast, once up to speed.

    Forget fit calculators.....pfffft. I came to my ideal size, by riding nearly every FS 29er race bike ever made. It's an exhausting search - but well worth it.
    "The mind will quit....well before the body does"

  12. #12
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    Can anybody tell me how effective this "fit calculator" is?

    I think the CC calculator is great. It can definitely get you on the right sized bikes, IMO. The CC calculator was within single-digit millimeters of a professional fitting I had done for my triathlon bike by an experienced fitter in Maryland. I'm now also riding a trail bike I originally set up using the CC "all mountain" fit, and it's working great. I think it is very important to have someone else measure you accurately using a seamstress tape to get really good results from the CC calculator.

    The big difference in the stock geometry on my Scalpel and the actual setup I'm now riding was raising the handlebar. In my experience, a lot of shop bikes roll out the door with a low handlebar for a "pro" look" .... flat bar and a slammed, flipped stem. I used a riser bar and 15mm of spacers on the stem to get the hand position up about 35mm. My hand position is now dead level with the high point on the saddle.

    I'm 6-1 and copied in some of the specs from the CC Calculator versus my current setup.


    CC CALC XC AM My Scalpel
    Virtual Top Tube Length 24.6 - 25.0" 24.1 - 24.5" 24.3"
    Stem Length 10.7 - 12.3cm 8.2 - 10.6cm 10.0cm
    BB-Saddle Position 81.6 - 83.2cm 77.1 - 83.2cm 79cm
    Saddle-Handlebar 58.2 - 59.8 cm 56.3 - 58.1cm 58.5cm

  13. #13
    Nouveau Retrogrouch SuperModerator
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    Can anybody tell me how effective this "fit calculator" is?

    Quote Originally Posted by Scott In MD View Post
    I think the CC calculator is great. It can definitely get you on the right sized bikes, IMO. The CC calculator was within single-digit millimeters of a professional fitting I had done for my triathlon bike by an experienced fitter in Maryland. I'm now also riding a trail bike I originally set up using the CC "all mountain" fit, and it's working great. I think it is very important to have someone else measure you accurately using a seamstress tape to get really good results from the CC calculator.

    I'm 6-1 and copied in some of the specs from the CC Calculator versus my current setup.


    CC CALC XC AM My Scalpel
    Virtual Top Tube Length 24.6 - 25.0" 24.1 - 24.5" 24.3"
    Stem Length 10.7 - 12.3cm 8.2 - 10.6cm 10.0cm
    BB-Saddle Position 81.6 - 83.2cm 77.1 - 83.2cm 79cm
    Saddle-Handlebar 58.2 - 59.8 cm 56.3 - 58.1cm 58.5cm
    Still too many variables.

    It worked OK for my road bike fit.

    The mtb fit was pitiful. Off by several inches for me.
    Even your example has a total mtb fit range (XC to AM) of more than a inch for most every dimension.

    No provision is made for seat tube angle, BB drop, or front center in either road or mtb.
    mtbtires.com
    The trouble with common sense is it is no longer common

  14. #14
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    Thanks for the advice and some encouragement. I think what I will do is call around to try to find a place that has small/15-16" bikes in stock and make sure they fit the bike before I leave with it.

    The Specialized store is one of their new concept stores so I can't see them try to mess with people too much. I also found that a few of the further away stores have fit stations in them.

  15. #15
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    So I got a chance to try out some bikes today. I didn't get a chance to get to the Specialized shop as it closed at 4pm and I had to watch my kids until the wife got home at 3.

    I tried a wahoo 15.5 since they didn't have a marlin in that size and it felt great! I did try the marlin in the 17.5 again since this shop was sizing the bikes to me and they convince me to give it another shot. My legs were over extending with the seat all the way down and they said they could cut the seat post but I would most like be leaning too far forward and I'd be putting more weight on my wrists.

    I also tried out a couple of different sized cannondales and the medium on the trail 6 29er seemed to fit me best. To be honest if they had the trail 5, I probably with have bought it.

    What irked me some was they weren't showing the sale price on the Marlin. They undercut the hell out of the wahoo down to $500! They told me that the sale was for 2012 models only and if I wanted the Marlin in a 15.5" it would be $689. Anybody know if this is true? I looked on Trek's website but didn't see anything about that so I emailed them to find out.

    I'll be taking a change of clothes and my normal shoes with me to work tomorrow so I can change out of my uniform and boots and stop by the Specialized store on the way home.

    What do you guys think?

    Cannondale Trail 5 with all shimano drivetrain and brakeset?
    Trek Marlin with Tektro Novela mechanical brakeset?
    or
    Specialized Hardrock Sport Disc with hydraulic brakes?

    If not concern with hydraulic brakes, it looks like the cannondale would have the better components

  16. #16
    Hi There!
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    return the bike and go to a place that has a proper fitting system and people that care about getting you the right fit. if it's an hour away, so be it. are you going to ride a bike that doesn't fit you because the shop was close to your house? an hour ride will trump hours and hours of riding a bike that doesn't fit.
    NTFTC

  17. #17
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    I don't have a bike yet

  18. #18
    I Tried Them ALL... Moderator
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    Generally, size S MTBs are tough to find in shops. I had to drive 75 miles to demo a 2013 size 15.5 Trek Rumblefish Pro and medium 17.5 Trek Superfly 100 AL, to compare against. I'm glad I did though, because I was gonna pull the trigger on another medium, 2010 Gary Fisher Superfly 100 - which had me stretched over the bars and plain did not feel right. Once I demoed the 15.5 Rumblefish...it was the Cat's Meow.
    "The mind will quit....well before the body does"

  19. #19
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    Quote Originally Posted by Zachariah View Post
    Generally, size S MTBs are tough to find in shops. I had to drive 75 miles to demo a 2013 size 15.5 Trek Rumblefish Pro and medium 17.5 Trek Superfly 100 AL, to compare against. I'm glad I did though, because I was gonna pull the trigger on another medium, 2010 Gary Fisher Superfly 100 - which had me stretched over the bars and plain did not feel right. Once I demoed the 15.5 Rumblefish...it was the Cat's Meow.
    Exactly how I felt today riding the 15.5. I think if it was a 26er, I still would have the same issue with a 17.5

  20. #20
    Hi There!
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    "Anyway, he sold me the Wahoo with the claim that the 17.5" is what he rides and it felt about right when I test rode it but once I got it home and had time to really ride it, nothing felt right."

    Sorry, I saw this and stopped reading your original post. My advice is still the same...if you want a bike that fits go to a shop that will do a proper fitting.
    NTFTC

  21. #21
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    lol kinda reminds me about that lesson you learn school about reading the entire question before answering it sorry, I get a little long winded at times

  22. #22
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    Hydraulic brakes are not categorically better than mechanical brakes. I think they have more potential, but I wouldn't assume every design realizes it. In other words, if the Hardrock stops better in real life, that's a plus. But if you can't tell the difference or it's underwhelming, give that credence too.

    As a side note to the original question, I just took delivery on a new bike. From geometry numbers and comparison to my old bike, I thought I should ride a 16". But I demoed a 16" and found I had to stretch it out to make it work. I bought the 18" and am feeling very confident in the decision. So, I think you're on the right track.

    For bike prices - these are a retail, branded product. The 2014 models are coming out as we speak. So however the components on the two Treks you're considering compare, the dealer has an interest in moving the '12 at a discount that his contract may not even allow for a current-model bike. In general, I don't anticipate a lot of wiggle room on the price for a bike that has to be ordered. Doesn't hurt to ask, though - sometimes these things hang around in warehouses, so your dealer may be able to get you a small '12 or return or demo (or a '13 demo) at a nice price.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  23. #23
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    Well the specialized place didn't have anything in my size in stock besides a couple of road bikes so that was a wasted trip. It's looking more and more like either the cannondale trail 5 or marlin. Neither of which anybody, within 2 hours anyway, has in stock in my size.

  24. #24
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    I know, most lower brakes have a chance of squealing, but after a few rides, I know first hand that the Tektro Novela's will squeal horribly. So bad that I used to use it as a bell while riding on paved trails before I had my road bike. I remember seeing the new Hardrock's brakes, and I was actually impressed for hydraulic disc brakes at that price, with all the components it had. I honestly recommend trying to spend a little more and at least get a bike like the Trek Mamba. You'll appreciate having the better wheels, better fork, and better components in general.

  25. #25
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    Measure your inseam and multiply by .883, that will give you and approximate frame size.

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