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  1. #1
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    Sizing:Reach really make a difference?

    I'm looking at picking up a Bronson to replace my Tallboy LT for racing and all-around riding. The TBLT is a med with 70cm stem and it's done great for me, but I've felt it could be slightly too small at times. The med Bronson has a microscopically shorter TT, but is a bit longer on the reach.

    Will the longer reach actually make a difference?

    I rode a large Bronson with a 60cm stem and wider bars and the thing felt big and not overly inspiring. It was hard to loft the front and felt like I was fighting it during the turns. Sitting on a med feels pretty small, however.

    I know someone can compare sizing and riding.

  2. #2
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    Reach is the important measurement for length, the HTT length+ST angle combo is not that important because saddles and seatposts have big front/back adjustment range.

    I loved the bronson L for my height, no issues in lifting the front wheel, and thats coming from a Blur LTc, which is a bike that has issues keeping the front wheel on the ground

    There are many factors to consider on the bike you rode:
    Rebound on the fork, did you play with it a little bit? Huge difference in front happiness.
    Saddle position and seat post offset
    Wider bar is something you have to get use to, its not like you go wider and suddenly everything is better. Acquired taste.
    Bikes handle differently, especially with different wheel size.

    Interestingly between the bronson L and the TBLT L I had the opposite impression, that the bronson is the more playful bike, though both felt good. They were set up very similar with almost the same components as they were stock demo bikes.

  3. #3
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    I'm not sure I understand all the geometry relationships. For example, I don't understand how the Tallboy has a slightly longer effective top tube length than the Solo, but it has a shorter reach.

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    Sizing:Reach really make a difference?

    Quote Originally Posted by jabrabu View Post
    I'm not sure I understand all the geometry relationships. For example, I don't understand how the Tallboy has a slightly longer effective top tube length than the Solo, but it has a shorter reach.
    Simple.
    Slacker STA = less reach
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  5. #5
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    Quote Originally Posted by shiggy View Post
    Simple.
    Slacker STA = less reach
    I still don't get it. Looking at the medium TR and TB, the TT length is the same (within a few mm). ST angles are 72.4 and 72.5 (0.1 greater on the TR). But the reach is 14mm longer on the TR.

  6. #6
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    Steeper HA = more reach?

  7. #7
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    Quote Originally Posted by wheatgerm View Post
    Steeper HA = more reach?
    Nope. The TB has a steeper HA but has a shorter reach.

  8. #8
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    Lifting the front wheel has everything to do with weight distribution and frame geometry.

    Reach is a factor of 3 things: effective top tube length, bar width, stem length (and angle). But only one of those, stem length, has a significant impact on weight distribution when you are comparing two different frame sizes of the same bike.

    How much reach you need depends on your body and your riding posture. On a road bike when you're nose down ass up for hours, you better have your reach, saddle position, cleat position, all nailed down perfectly. Dialing in fit isn't as critical, or even as feasible, on a MTB compared to a road bike because you alter your body position so often on a MTB.

    I for one don't see the advantage in ultra-wide handlebars in and of itself, but I do see the value in tuning weight distribution with stem length and then using wider or narrower bars as appropriate to dial in reach for better comfort in the saddle and/or better ability to get back on the back for steep descents.

  9. #9
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    Quote Originally Posted by ColinL View Post
    Lifting the front wheel has everything to do with weight distribution and frame geometry.

    Reach is a factor of 3 things: effective top tube length, bar width, stem length (and angle). But only one of those, stem length, has a significant impact on weight distribution when you are comparing two different frame sizes of the same bike.

    How much reach you need depends on your body and your riding posture. On a road bike when you're nose down ass up for hours, you better have your reach, saddle position, cleat position, all nailed down perfectly. Dialing in fit isn't as critical, or even as feasible, on a MTB compared to a road bike because you alter your body position so often on a MTB.

    I for one don't see the advantage in ultra-wide handlebars in and of itself, but I do see the value in tuning weight distribution with stem length and then using wider or narrower bars as appropriate to dial in reach for better comfort in the saddle and/or better ability to get back on the back for steep descents.
    This is all true, but I think people here are discussing the physical Reach measurement - a horizontal line from the center of the bottom bracket to the center of the headtube at the top.

  10. #10
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    Sizing:Reach really make a difference?

    Quote Originally Posted by jabrabu View Post
    I still don't get it. Looking at the medium TR and TB, the TT length is the same (within a few mm). ST angles are 72.4 and 72.5 (0.1 greater on the TR). But the reach is 14mm longer on the TR.
    Yup. Steeper STA and lower stack. The TB's front end is higher, so the top of the HT is closer to the BB horizontally.
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  11. #11
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    Quote Originally Posted by Dogboy View Post
    This is all true, but I think people here are discussing the physical Reach measurement - a horizontal line from the center of the bottom bracket to the center of the headtube at the top.
    The first two posts talk about cornering and lifting the front, and different sizes of the same model of bike. So I think the type of reach my post addressed is on the mark. :-)

  12. #12
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    Wow, this has gotten pretty technical now! Honestly, the reach vs TT length doesn't make a ton on sense in my mind, but I'm happy to accept how it works. In practice though, it doesn't seem to hold out. I took a short spin on a med Bronson with the same bars/stem as my TBLT and it felt much smaller despite having a longer reach.

  13. #13
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    Quote Originally Posted by jselwyn View Post
    Wow, this has gotten pretty technical now! Honestly, the reach vs TT length doesn't make a ton on sense in my mind, but I'm happy to accept how it works. In practice though, it doesn't seem to hold out. I took a short spin on a med Bronson with the same bars/stem as my TBLT and it felt much smaller despite having a longer reach.
    Its hard to explain without a diagram, there are plenty of diagrams on manufacturers sites. The short story is that ST angle + horizontal top tube + head tube stack create one final number, the reach. Everything else can be moved around and tweaked, but the reach is the frame size measurement that you cannot change, other than switching to another frame size.

    The TBLT felt to me like a big bike too. I think because of the bigger wheels more than because of half an inch here or there. It really brings a point that many people brought before, that a 29er between the TB and TBLT would be great. I would guess that if that bike existed it would not feel much bigger than a bronson.

  14. #14
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    Not trying to hijack this but I'm having a similar issue trying to wrap my head around the numbers.

    I'm playing around with the idea of trying out another bike. Looking at the TBLTc, Ripley and Devinci Atlas, the Devinci has an inch longer TT length, but only a .3 mm longer reach.
    Since there isn't a chance in hell I'll be able to put a leg over the Devinci, I am trying to figure out how the numbers will translate to ride.
    The Atlas has the shortest WB and chainstays, but an inch longer TT with the same reach. Stack is also very close to the others. How does the longer TT translate to feel when actually riding?
    13 Lenz Lunchbox punkass

  15. #15
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    Quote Originally Posted by jselwyn View Post
    Wow, this has gotten pretty technical now! Honestly, the reach vs TT length doesn't make a ton on sense in my mind, but I'm happy to accept how it works. In practice though, it doesn't seem to hold out. I took a short spin on a med Bronson with the same bars/stem as my TBLT and it felt much smaller despite having a longer reach.
    It's more about foot to hand distance than seat to hand distance. You can tweak the cockpit distance with stem length, seat fore/aft adjustment, and seatpost offset, but you can't change the distance between the BB and head tube. Really though, it's just one metric and IMHO they are ALL important and it's important to understand how they relate to one another.

  16. #16
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    Quote Originally Posted by CrozCountry View Post
    Its hard to explain without a diagram, there are plenty of diagrams on manufacturers sites. The short story is that ST angle + horizontal top tube + head tube stack create one final number, the reach. Everything else can be moved around and tweaked, but the reach is the frame size measurement that you cannot change, other than switching to another frame size.
    Stop right there.

    There are five contact points on a bicycle: two grips, two pedals, one saddle.

    These contact points should be located in the position most appropriate for the following-- rider body dimensions, intended usage of the bike, ergonomics and comfort.

    WE CAN ALTER THE CONTACT POINTS.* Yes, absolutely, the frame geometry of a bike in a given size matters a lot. But it is VERY possible to get the same effective reach on 3 sizes of the same bike. The smallest bike would use a long stem and wide bars. The middle size would use a shorter stem and maybe same bars, maybe narrower. The largest size would use a short stem and narrower bars. Would you really ride 3 bikes of such different sizes? Of course not, the small one would have weight distribution issues for MTBing (roadies love to ride tiny bikes with 140mm stems, though), and the largest size probably would not have much seatpost exposed which would be an issue if you wanted a dropper post.

    However, in all cases you can draw a line from the nose of the saddle (or middle, if you prefer) to the handgrips and have the same actual reach. Not the reach measurement of the frame that you're hung up on. The actual reach from the saddle to the grips, connecting three of the five contact points on the bike!

    If you take good measurements of your current bike you can use simple math or online geometry / fit calculators to determine what stem length, saddle setback and bar width you should have on a different bike. Of course, that's in a static position. Once you start riding the bike, you may want something different to alter the weight distribution, make it easier to climb or descend, or some other reason.


    *footnote - it is admittedly difficult to change the position of your feet very much, other than the Q factor of your cranks and pedals. but when you change your saddle relative to your feet, and your bar position relative to saddle and feet, you still have control of the points of contact.

  17. #17
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    Quote Originally Posted by Dogboy View Post
    It's more about foot to hand distance than seat to hand distance. You can tweak the cockpit distance with stem length, seat fore/aft adjustment, and seatpost offset, but you can't change the distance between the BB and head tube. Really though, it's just one metric and IMHO they are ALL important and it's important to understand how they relate to one another.
    YES.

    And I agree for mountainbiking with the bold part, because we ride technical stuff and jump while standing. If you're grinding away miles on fireroads or doing >25mph in the saddle in an XC race, seat to hand distance becomes more significant.

  18. #18
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    Quote Originally Posted by Dogboy View Post
    You can tweak the cockpit distance with...seat fore/aft adjustment, and seatpost offset...
    No, no, no. You should never use the saddle position to try to fix issues with reach to the bars. Saddle fore/aft should only be used to get you in the proper position in relation to the bottom bracket.

  19. #19
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    Colin, you seem very knowledgeable, but the reach you are thinking of isn't the measurement SC and other manufactures are posting. This pinkbike article does a good job explaining it, and has a diagram,

    Reach and stack based sizing for mountain bikes - Pinkbike

    This is an attempt at trying to come up with a more legit measurement for a baseline on frame sizes, where as ETT has a large fudge factor. Granted it still ahs its challenges, cause 2 bikes with the same reach, could have different BB heights, wheel bases, front centers, etc...

  20. #20
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    Quote Originally Posted by dansMTB View Post
    Colin, you seem very knowledgeable, but the reach you are thinking of isn't the measurement SC and other manufactures are posting. This pinkbike article does a good job explaining it, and has a diagram,

    Reach and stack based sizing for mountain bikes - Pinkbike
    Actually, I am familiar with it, and I do think Reach and Stack are more valuable than eTT and especially seat tube length.

    There seems to be a notion that you can't do anything about the Reach a particular frame has.... which is untrue. Within a certain range of adjustment, you can optimize your weight distribution and fit on bikes with varying Reach.

  21. #21
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    Also should add, agree 100% with Colin that different changes to the cockpit - bar width, stem length can be used to change the overall feel of the bike. The manufacturers reach stat is just one of many to help folks figure out the best sizing for them. usually is always said in any of these sizing/geometry threads, a lot of this is personal preference and a test ride is the best way to find out what you yourself prefer.

  22. #22
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    For the OP, regarding geo numbers, you can get really lost in them (I frequently do). There are a lot of factors that work in concert to produce a great riding frame. My opinion is that reach is a pretty important number, but definitely not the only number.

    Early spring I was really torn between a L or XL Blur LT. I had a L, and there were some aspects I really liked about the ride quality. One thing I didn't like was running a 90-100mm stem to get the right extension for xc type riding and climbing (this had my weight too far over the front when going downhill). So I explored the numbers of the XL to figure out if that would work better for me. By my math, it would make the ETT 1 inch longer (approximations here, dont beat me up for exact measurements) but the reach would only be about .6 inch longer. So that .6 inch would make it so I could run a 70 or 80 mm stem and have the same cockpit setup, but now my weight would be a little further back (not so over the front wheel, a good thing for going downhill). Now this all sounds great, but it also increases the wheelbase and front center. These things will affect how nimble the bike is in tight and twisty trails. Hmmm, so how much of a wheelbase difference would I feel? Is getting the longer reach and running a shorter stem enough of a benefit to outweigh a little lost maneuverability? I opened a similar thread in the frame building forum : Geometry questions - how they affect ride quality

    I wasn't initially to happy with the responses I got, until Walt squared me away. I had no idea that sometimes I looked at a certain ride quality as a negative, but in a different scenario I viewed that same quality as a positive. specifically, the longer more stretched out bike would keep the nose down on climbs (good that the front doesn't come up too easy), but then when I'm in the flats or jumping, the nose wouldn't come up as easy (that's bad, I liked the nimble aggressive feel).

    I came to realize that geometry is trade offs, and what works good in one situation, is a problem in another situation. The hardest part is figuring out what you really want in the bike, and being honest with yourself about how much you want that aspect. This is also why many folks have more than one bike.

  23. #23
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    Quote Originally Posted by savechief View Post
    No, no, no. You should never use the saddle position to try to fix issues with reach to the bars. Saddle fore/aft should only be used to get you in the proper position in relation to the bottom bracket.
    I didn't say you should, only that you could.

  24. #24
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    Quote Originally Posted by dansMTB View Post
    For the OP, regarding geo numbers, you can get really lost in them (I frequently do). There are a lot of factors that work in concert to produce a great riding frame. My opinion is that reach is a pretty important number, but definitely not the only number.

    Early spring I was really torn between a L or XL Blur LT. I had a L, and there were some aspects I really liked about the ride quality. One thing I didn't like was running a 90-100mm stem to get the right extension for xc type riding and climbing (this had my weight too far over the front when going downhill). So I explored the numbers of the XL to figure out if that would work better for me. By my math, it would make the ETT 1 inch longer (approximations here, dont beat me up for exact measurements) but the reach would only be about .6 inch longer. So that .6 inch would make it so I could run a 70 or 80 mm stem and have the same cockpit setup, but now my weight would be a little further back (not so over the front wheel, a good thing for going downhill). Now this all sounds great, but it also increases the wheelbase and front center. These things will affect how nimble the bike is in tight and twisty trails. Hmmm, so how much of a wheelbase difference would I feel? Is getting the longer reach and running a shorter stem enough of a benefit to outweigh a little lost maneuverability? I opened a similar thread in the frame building forum : Geometry questions - how they affect ride quality

    I wasn't initially to happy with the responses I got{...}

    I came to realize that geometry is trade offs, and what works good in one situation, is a problem in another situation. The hardest part is figuring out what you really want in the bike, and being honest with yourself about how much you want that aspect. This is also why many folks have more than one bike.
    Excellent post. Your issue back then is similar to the issue the OP in this thread is describing, it's just the reverse. His front center is too forward; yours is too rearward.

    Regarding having multiple bikes, a cheaper option is to have multiple stems. I ride a size XL Blur classic which has a very short top tube, nearly the same as a size large in most of SC's newer offerings. (I'm considering a Blur TR or Solo, and would buy a large.) For gravel roads and XC, I use a 100mm 0 deg stem. For everything else, I use a 70mm 0 deg stem. This changes my front center pretty radically; it's much harder to manual and wheelie the bike with the 100mm stem, but it gives me the reach I need to get low when riding 15-20 mph into the wind. The 70mm stem makes the bike handle more the way I want, but I sit very upright and it's inefficient for a lot of pedaling on smooth terrain.

    BTW, that first response in your linked thread is pure snob BS. The brand of your bike and where it is made had nothing to do with your question.

  25. #25
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    Quote Originally Posted by dansMTB View Post
    For the OP, regarding geo numbers, you can get really lost in them (I frequently do). There are a lot of factors that work in concert to produce a great riding frame. My opinion is that reach is a pretty important number, but definitely not the only number.

    Early spring I was really torn between a L or XL Blur LT. I had a L, and there were some aspects I really liked about the ride quality. One thing I didn't like was running a 90-100mm stem to get the right extension for xc type riding and climbing (this had my weight too far over the front when going downhill). So I explored the numbers of the XL to figure out if that would work better for me. By my math, it would make the ETT 1 inch longer (approximations here, dont beat me up for exact measurements) but the reach would only be about .6 inch longer. So that .6 inch would make it so I could run a 70 or 80 mm stem and have the same cockpit setup, but now my weight would be a little further back (not so over the front wheel, a good thing for going downhill). Now this all sounds great, but it also increases the wheelbase and front center. These things will affect how nimble the bike is in tight and twisty trails. Hmmm, so how much of a wheelbase difference would I feel? Is getting the longer reach and running a shorter stem enough of a benefit to outweigh a little lost maneuverability? I opened a similar thread in the frame building forum : Geometry questions - how they affect ride quality

    I wasn't initially to happy with the responses I got, until Walt squared me away. I had no idea that sometimes I looked at a certain ride quality as a negative, but in a different scenario I viewed that same quality as a positive. specifically, the longer more stretched out bike would keep the nose down on climbs (good that the front doesn't come up too easy), but then when I'm in the flats or jumping, the nose wouldn't come up as easy (that's bad, I liked the nimble aggressive feel).

    I came to realize that geometry is trade offs, and what works good in one situation, is a problem in another situation. The hardest part is figuring out what you really want in the bike, and being honest with yourself about how much you want that aspect. This is also why many folks have more than one bike.


    Fantastic insight and post!

    I thought my large Heckler was too small for me @ 6'2", it gave me knee pain in fact due to a cramped position, got a 1" layback seatpost and knee pain disappeared. But it kept the instant chuckability and aggressive handling that the XL I tried out didnt. So on the verge of L > XL sizes, and large in the end won.
    [SIZE="1"][SIZE="2"]i can't ride for sh*t but i'm good at extreme pushing[/SIZE][/SIZE]

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