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  1. #1
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    geometry of road and touring bikes (and cross?)

    Hello! I've tried asking this in the utility cycling, but I realized maybe it's more relevant in touring.

    I was wondering what about a touring bike's geometry makes it handles heavy loads steadily? I am not as interested in the comfort part, but specifically carrying loads. I know head tube angle, chainstay length, and center of gravity matters, is there anything else? Can i tell if a bike will handle heavy loads well by looking at it?

    To give you a bit of where I'm coming from-- I have a surly cross check and a lotus international. The Lotus I've heard rumors that it was supposed to be a touring bike, but I am not sure. Anyway, I found the Lotus very twitchy when carrying a week's worth of grocery. The cross-check, on the other hand, is so steady yet still responsive I often forget that I was carrying a ton of stuff in my panniers. Even up hills.

    I'm starting to look for a bike for my sister, and I want to get her something that she can tour on if she wants to. My Lotus has longer wheelbase than cross check (by almost 2 inches), but the BB is higher by almost an inch, the chainstay lengths are the same, seat tube angles are the same, but the Lotus has steeper headtube angle with almost the same fork rake.

    Are there anything else other than geometry that effects load handling? I was going to tour on the Lotus, then I realized that i couldn't steer it with some groceries in the pannier, so I bought the cross cehck.

    Thanks!

  2. #2
    Senior Member robow's Avatar
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    Quote Originally Posted by atetrachordof3 View Post

    Are there anything else other than geometry that effects load handling?

    Thanks!
    Something that doesn't get talked about much on this forum because it's difficult to quantify and the bicycle manufacturer doesn't supply data is rear triangle stiffness or rigidity. This makes a world of difference in stability. I once had a European touring frame that lacked the stiffness needed in the rear triangle so that when I jumped out of the saddle when climbing, you could feel the whole rear end sway terribly. Of course, the rear triangle stiffness is determined by the diameter of the stays, length of the stays, shape of the stays, thickness of the walls, and the actual material used.

    Hence why a Cannondale aluminum touring frame that might feel too stiff, non-compliant, or harsh when unloaded but when you load it up, it handles like a dream.
    Last edited by robow; 01-19-10 at 01:51 PM.

  3. #3
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    Quote Originally Posted by atetrachordof3 View Post
    To give you a bit of where I'm coming from-- I have a surly cross check and a lotus international. The Lotus I've heard rumors that it was supposed to be a touring bike, but I am not sure. Anyway, I found the Lotus very twitchy when carrying a week's worth of grocery. The cross-check, on the other hand, is so steady yet still responsive I often forget that I was carrying a ton of stuff in my panniers. Even up hills.
    Looking at the distance between the rear tire and the seat tube, the "Lotus International" isn't quite a "touring" bike.

    http://sandiego.craigslist.org/nsd/bik/1553912594.html


    Quote Originally Posted by atetrachordof3 View Post
    I'm starting to look for a bike for my sister, and I want to get her something that she can tour on if she wants to. My Lotus has longer wheelbase than cross check (by almost 2 inches), but the BB is higher by almost an inch, the chainstay lengths are the same, seat tube angles are the same, but the Lotus has steeper headtube angle with almost the same fork rake.
    Why not get her a Crosscheck?

    Wheel base = headtube angle+fork-rake + toptub length + chain stay length. I'd guess that the Lotus is a bigger bicycle (ie, has a longer toptube).

    The LHT is a fairly standard touring geometry.

    Longer chainstays allow the weight to be more ahead of the rear hub without banging your heels against the panniers. Slacker headtube angles (and rake) increase tracking. (Increased cargo weight tends to decrease tracking.) "Low rider" racks increase tracking a bit.

    Quote Originally Posted by atetrachordof3 View Post
    Can i tell if a bike will handle heavy loads well by looking at it?
    You can get some idea. But the best thing is to look at the type/purpose and get a sense of the real-world reputation of the particular model.
    Last edited by njkayaker; 01-19-10 at 02:29 PM.

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    Quote Originally Posted by njkayaker View Post
    Looking at the distance between the rear tire and the seat tube, the "Lotus International" isn't quite a "touring" bike.
    what a silly statement.

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    To answer your question: aside from the things you mentioned, BB drop and fork trail can make a big difference in load stability.

    Additionally, the rack used can factor in quite a bit- a wiggly rack is no good, and a rack that is too long is no good. What njkayaker is referring to above (I guess) is the idea that longer chainstays allow you to place more weight in front of the rear axle (on the rack) than do shorter stays. Weight between the axles and low is good, weight outside the axles and high is bad. Of course you can also move the load forward on the rack or in the panniers. Eventually, your heels will hit the bags, which limit you moving it any further forward, and lead to the idea that touring bikes have to have long chainstays. However, this is largely marketing... my trek 620 has 47cm stays, and my chas roberts roughstuff has 42 cm stays. The roberts is FAR more stable and will easily carry 100+ pounds, due in part to the OS tubing and compact geometry frame (stiffer).

    Tubing gauge (and frame design) will affect the load bearing abilities, with stiffer bikes being better weight bearers. This is why the reynolds 531c and reynolds 531ST tubing sets are different... the ST (super tourist) tubes are thicker and heavier and designed for tandems and touring bikes.

    if you want a really good load hauler, you want a STIFF frame that can handle large tires. The stiffeness of the frame will help with stability, while the large tire volume will remove the need to have a compliant frame by providing some shock dampening.

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    Quote Originally Posted by positron View Post
    what a silly statement.
    Stupid. Why?

    Here's a an example of a "touring" bike. One that was made even when the Lotus was. The rear tire distance is much larger.

    http://www.trekbikes.com/int/en/bikes/2008/archive/520


    (Note that one could use almost anything for touring).
    Last edited by njkayaker; 01-19-10 at 02:37 PM.

  7. #7
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    Quote Originally Posted by njkayaker View Post
    Stupid. Why?

    (Note that one could use almost anything for touring).
    Geez, i dunno. You should ask Heinz Stuke or Ian Hibell why they didnt use "touring" bikes...

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    Quote Originally Posted by positron View Post
    Geez, i dunno. You should ask Heinz Stuke or Ian Hibell why they didnt use "touring" bikes...
    Still stupid.

    People tour on all sorts of different bikes. People are free to use whatever works for them.

    Regardless, that "Lotus International" doesn't appear to be a "touring" bike. I am not saying it would not work.


    http://www.crazyguyonabike.com/doc/p...=vJ&size=large
    Last edited by njkayaker; 01-19-10 at 02:52 PM.

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    Right- I dont want to get into a urinating match about this- but in my response above, I actually mentioned the marketing-hype surrounding the 'long wheelbase' criterion (used by trek and cited by you above as the criterion of what determines a touring bike). That bike you linked- the Trek 520 made way back in the 1980's... Yeah, I have that bike. Except the nicer one, the Trek 620 from 1985. It has the longest production wheelbase of ANY touring bike made, ever. Its identical (geometry-wise) to the trek 720 from the same year. IN MY EXPERIENCE that doesnt make it the best touring bike out there- in fact i own a better one. Please see above, and prevent me from having to repeat myself.

    After you called me stupid (following a well-reasoned discussion of other factors that ACTUALLY make a difference to tour-worthiness and load carrying ability) I cited perhaps the two most experienced bike tourists in history, and pointed out that according to you they dont ride "touring" bikes. Whatever that means. So, I repeat myself: pointing out the distance between the rear wheel and the seat tube is silly, which is to say irrelevant to the OP's question...

    Of course you know this, which is why you straddle the fence by saying:

    "(Note that one could use almost anything for touring)." and "People tour on all sorts of different bikes. People are free to use whatever works for them."

    so we agree then

  10. #10
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    Quote Originally Posted by positron View Post
    After you called me stupid
    No, your comment was stupid. Especially, without an explanation.

    Quote Originally Posted by positron View Post
    Right- I dont want to get into a urinating match about this- but in my response above, I actually mentioned the marketing-hype surrounding the 'long wheelbase' criterion (used by trek and cited by you above as the criterion of what determines a touring bike).
    YOU ARE PUTTING WORDS IN MY MOUTH. I didn't say anything about it being "the criterion" for usabilty.

    Quote Originally Posted by positron View Post
    That bike you linked- the Trek 520 made way back in the 1980's... Yeah, I have that bike. Except the nicer one, the Trek 620 from 1985. It has the longest production wheelbase of ANY touring bike made, ever. Its identical (geometry-wise) to the trek 720 from the same year. IN MY EXPERIENCE that doesnt make it the best touring bike out there- in fact i own a better one. Please see above, and prevent me from having to repeat myself.
    You don't appear to read what you criticise. I didn't say the 520 was the "best". Nor did I say "long chainstays" were required.

    The Trek 520 was only an example of what was marketed as a "touring" bike at about the time that that Lotus was.

    Quote Originally Posted by positron View Post
    So, I repeat myself: pointing out the distance between the rear wheel and the seat tube is silly, which is to say irrelevant to the OP's question...
    It was relevent to the OP's question. It was addressing one (below) of his comments. I don't think that the "Lotus International" was marketed as a "touring" bike (for loaded touring).

    Quote Originally Posted by atetrachordof3 View Post
    The Lotus I've heard rumors that it was supposed to be a touring bike, but I am not sure.
    =========================

    Quote Originally Posted by positron View Post
    if you want a really good load hauler, you want a STIFF frame that can handle large tires. The stiffeness of the frame will help with stability, while the large tire volume will remove the need to have a compliant frame by providing some shock dampening.
    Anyway, how likely is it, do you think, that the OP is looking for an expedition touring bike, like the Roughstuff (as nice it is)?

    As far as I can tell, his sister doesn't need a touring bike.

    Quote Originally Posted by atetrachordof3 View Post
    I'm starting to look for a bike for my sister, and I want to get her something that she can tour on if she wants to.
    Quote Originally Posted by positron View Post
    Of course you know this, which is why you straddle the fence by saying:

    "(Note that one could use almost anything for touring)." and "People tour on all sorts of different bikes. People are free to use whatever works for them."
    Anyway, wasn't "straddling the fence" (more gratious insults). All that I was saying is that what works for people is wider than any particular thing some people say is a "requirement" (and I did not say anything was a "requirement").

    ==================

    By the way, the informative stuff (without the gratuitous insults attacking words you put into people's mouths) is interesting.
    Last edited by njkayaker; 01-19-10 at 04:32 PM.

  11. #11
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    njkyaker, Im sorry if you feel I was insulting you, honestly I am. "Straddling the fence" is a commonly used saying to mean not taking any side on a particular issue. For example saying: X isnt a "touring" bike, but anything can be a "touring bike"...

    I called your comment silly because before you edited it to be substantial and relevant to the discussion, the entirety of your comment was this:

    "Looking at the distance between the rear tire and the seat tube, the "Lotus International" isn't quite a "touring" bike."

    That was all you posted.

    Which, (again, before you qualified it with all the rest of that edited and amended post) I errantly thought you meant was the ONE criterion of a touring bike.

    A thousand apologies that I did not know what you meant to mean, and only responded to the one thing you actually wrote.

    The question asked by the OP was this:

    "Are there anything else other than geometry that effects load handling?"

    I was trying to add something to the discussion of why a particular bike carries a load well. Simple one line answers like "X is not a touring bike" while arguably correct (or, in this case, not) do little to help others understand why a multitude of factors might actually matter to a particular task. Having spent more than I care to admit trying different frames, racks, wheels etc. over the years, I'm always happy to give my experience to others in the hopes that they get it right the first time. I tried to list a number of other factors that would be worth considering.

    OP: apologies for the derailment of the thread- I hope that you have a bit more info that can help you optimise your many bikes for the different purposes you have in mind. I think the crosscheck is a fine all around bike. The lotus might be substantially improved if you find a good rack, work on stabilising the load, and move your load forward on the frame. Unfortunately, It seems that it will never be a "touring" bike.
    Or something.

    best,
    p-tron

  12. #12
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    Quote Originally Posted by positron View Post
    njkyaker, Im sorry if you feel I was insulting you, honestly I am.
    Pompose ass,

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    Quote Originally Posted by atetrachordof3 View Post
    I was wondering what about a touring bike's geometry makes it handles heavy loads steadily? I am not as interested in the comfort part, but specifically carrying loads. I know head tube angle, chainstay length, and center of gravity matters, is there anything else? Can i tell if a bike will handle heavy loads well by looking at it?

    To give you a bit of where I'm coming from-- I have a surly cross check and a lotus international. The Lotus I've heard rumors that it was supposed to be a touring bike, but I am not sure. Anyway, I found the Lotus very twitchy when carrying a week's worth of grocery. The cross-check, on the other hand, is so steady yet still responsive I often forget that I was carrying a ton of stuff in my panniers. Even up hills.

    I'm starting to look for a bike for my sister, and I want to get her something that she can tour on if she wants to.



    Thanks!
    IMHO you can't tell if a bike will handle loads well by looking at it. You can guess but you won't know until you load it up and get on it. Big difference between a bike made with road tubing with a 200lb rider and 50lbs of gear and a 130lb rider with 30lbs of gear. Same bike but handling different loads.

    I have custom 26" wheeled sport/tour bike that I had made up to be an all around good handling fat tired (1.5"-1.75") road bike that could still carry a full touring load. The rear chain stays are beefy CroMo, smidge bigger than the LHT, the seat stays are average sized, the rest of the triangle and forks are regular 531 with average road angles 73degrees. The top tube is the same diameter as the down tube. Out of the seat sprint the rear triangle is very solid but loaded up there's a shimmy along the top tube that's not really enjoyable. It's got great handling and comfy but not anywhere as solid as the CC with regards to carrying weight. With 26"x1.5 tires on my sport/tour bike and 700x35 on the CrossCheck the CC is still about two lbs heavier. I don't think it's the slightly lax, 72degree, head tube on the CC that makes the difference, I think it's the heavier/bigger top and down tube.

    I had a Lippy touring bike made of 531 that was specifically designed as a touring bike and it was NOT steady with a load going down fast as it shimmied very easily.

    If your sister is anywhere near your size the CC should do it. If she's much shorter the LHT would be worth considering for the 26" wheels and better standover height. For a light person 32spoke wheels with light rims and light tires can make for snappy acceleration and strong wheels.

    The CC is a good handling tank, the LHT a Continental Trailways bus. If she's light there are LOTS of other bikes that could carry a load and have a comfy ride.

  14. #14
    Professional Fuss-Budget Bacciagalupe's Avatar
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    Quote Originally Posted by atetrachordof3 View Post
    I was wondering what about a touring bike's geometry makes it handles heavy loads steadily?
    It's not just about handling. The qualities that generally will make a bike optimal for loaded touring are:

    • Long wheelbase (increases stability and flexibility, for comfort)
    • longer chainstays (increases the wheelbase; allows for better heel clearance)
    • slacker seat tube angle (more comfortable, allows for slightly better power when climbing)
    • a fair amount of trail (increases steering stability)
    • clearance for fenders and wide tires
    • lots of rack and water bottle mounts (optional)
    • wide gearing range
    • canti brakes, for better mud clearance (optional)
    • bar-end shifters (optional/preferential)
    • rugged frame
    • strong wheels

    In terms of handling, if it's a heavy load the general idea is to keep the weight low -- but not so low that your bags scrape the ground. With a cross bike, the rack might be a cm or two higher than on a true touring bike, but it's not that difficult to compensate for that difference.

    Of course, you can do a tour -- even a loaded tour -- without most of these features, especially if you use a trailer, as long as the bike is comfortable for long distances day after day.


    Quote Originally Posted by atetrachordof3
    Can i tell if a bike will handle heavy loads well by looking at it?
    No. Bike geometries are very subtle.

    As to "what bike to get," the CC is more than capable of loaded touring, and will be a little bit snappier than most true touring bikes. It's a frame that doesn't really excel at any one specific task, but can do almost anything reasonably well. If she's going to use it for errands, commuting, general recreation and touring, it is one of many good choices for those diverse roles.

  15. #15
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    Quote Originally Posted by njkayaker View Post
    Pompous ass.
    Fixed it for you. Stay classy buddy.

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