bike assistance

Discussion in 'Cycling Equipment' started by cap'n, Jul 23, 2007.

  1. cap'n

    cap'n New Member

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    hi all,

    i have 2 bikes currently in my possession. both are over 5 years old & i'm not sure which one will be better for me

    mountain bike - 18 gears, i'm riding this 5 nights a week for 10km each ride

    road bike - 12 gears. i just got this given to me. it needs some brakes, tyres & a seat

    i was wondering what the difference is between the two bikes?

    the way i ride is all on road, a few steady inclines, & a bike decline that i roar down. i do the whole 10km's in 18th gear on the mountain bike, the inclines get a bit slow but i manage to do it pretty easily

    before i go out & spend money on the road bike, will it be worth it?

    I've read in other threads that a road bike allows you to maintain a higher speed, but i ride pretty fast anyways, i'm mainly wondering what the top gear on the road bike (12) will be like in comparison to the top gear on the mountain (18)

    cheers is advance
     
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  2. Julian G.

    Julian G. New Member

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    Well, if it's a decent road bike, it should just about double your speed. I can't tell you if your particular road bike is worth putting money into, but IMO if you put money into a good road bike you won't find it a waste, road bikes are just so much more fun than a MTB for the type of riding your doing. Nothing like getting a good tailwind and keeping up with traffic from one end of the city to the other.

    As for the gears - it seems as though you might think the number of gears somehow affects gear ratio? Well, if you do, it usually only affects the variety of gear ratios.

    Both bikes should have appropriate gear ratios for the ammount of rolling resistance they have, with the road bike utilizing larger gear ratios and lower rolling resistances, and smaller gear ratios for the MTB.

    Anyway you shouldn't have any problems here.

    Or it seems as though you may be wondering about the speed at the top gears - Well at around threshold, with a good tailwind, I max out about:

    35-40 KM/H on Haro V-2 MTB with street tires (24 speed) vs. 60 KM/H on Norco Fiori Roma road bike (14 speed).
     
  3. cap'n

    cap'n New Member

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    cheers for that. i average about 25 -35 on the mountain bike at the moment, but find unless i'm travelling on a slightly downhill slope, its hard to maintain speed without standing up increasing the wind resistance

    i went out & bought some brakes for it just then, i might give it a go tonight for my usual ride (which i can do in 20mins - 10km), i like to ride between 20min-30min most nights, if i can do it quicker, i can extend my ride to go a bit further out & see some more scenery

    i had a basic understanding of gears, but nothing too complex
     
  4. warriorcliff77

    warriorcliff77 New Member

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    buy the brakes and tires, and just transfer your seat over. Cheap initial investment.
     
  5. kdelong

    kdelong Well-Known Member

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    Wow, I wish that doubling the speed were accurate! I get about 22 MPH on flat pavement on my Mountain Bike with knobbys and only about 27 MPH with my Road Bike with training tires in the same spot for the same expenditure of energy. By your assessment, I should be getting 44 MPH!
     
  6. warriorcliff77

    warriorcliff77 New Member

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    Maybe your road bike SUCKS?
     
  7. Julian G.

    Julian G. New Member

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    Maybe not double but dammn near close to it... You've got two possibilitys here - 1 you've got one of the best damn MTB's ever made... or warrior got it.

    I should note that I go mostly by eye here though(speed of traffic + what my legs are "telling me")... so that's a rough estimate. I'd still say it's fairly accurate though. Wich is why I put in "just about double" instead of "will double".
     
  8. cap'n

    cap'n New Member

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    got some tyres last night & whacked them on. without trying too hard, i did the same time for the circuit i ride when i was going flat chat on the mountain bike. i noticed that it was much easier to get to a good speed & keep it that way. riding a road bike felt a bit strange at first, but a few mins in i was all good :)
     
  9. firegooroo

    firegooroo New Member

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    I have had a road bike for over 5 years, I have always thought it was a great bike. My old bike was a FUJI ROBAIX PRO 2002 steel frame, full durace. I just purchased the new TREK 5.2 Modena full carbon with mavic wheels. WHAT A WORLD OF DIFFERENCE. Don't be affraid to spend on a new bike. Secondly, mountain bike? road wheel or off road wheels? This makes a difference in the ride comfort and speed. Lastly, in my opinion, 5 year old bike is like a 5 year old computer (ANTIQUATED)...
     
  10. cap'n

    cap'n New Member

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    yeah, new bike would be great, just can't afford anything over $50 at the moment, got some other priorities that will require attention for the next 18 or so years :p:
     
  11. artemidorus

    artemidorus New Member

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    Put 25mm slick tyres on an MTB, lock out any suspension, optimise the seat height and drop the bars to 5" below the seat - and you've got a bike that is 95% as fast as a road bike.
    This doubled speed hogwash is just that.
     
  12. artemidorus

    artemidorus New Member

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    Let me see - a five year old bike? Let's pick an alloy TCR and put 2002 Dura Ace or Record on it with Cosmic Carbone wheels. It's on the weight limit. Now we'll put Contador on it and watch him win a stage.
    5 years old makes a spot of difference? - not on your nelly! The last major advances in road bike technology were STI and dual pivot brakes in the early 90s. Since then, all much of a muchness.
     
  13. Julian G.

    Julian G. New Member

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    Ok, let's do it the politically correct way...

    The average decent quality road bike, wich consists of slick/close to slick 25mm tires, of course zero suspension, normal gear ratios, and nothing weighing it down other than the rider, will be able to achieve slightly less than double the speed on flat pavement, assuming equal wattage is plugged in, than the average decent quality mountain bike wich conists of standard width (about 1.75 inch) knobbys and a hard tail, normal gear ratios, and again nothing weighing it down other than the rider.

    And I wouldn't be surprised if you can find something within those parameters to make me incorrect... maybe I should have specified each and every part on both bikes, tire pressure, oil used...

    Seriously, the OP does not strike me as the kind of person who has a set up much off the norm. (no offence intended - if you take it that way).
     
  14. Akadat

    Akadat New Member

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    That's the way to do it - the true answer is what you find out for yourself. Persevere with the road bike to make it fit you and get it nicely tuned.

    I have built up a variety of bikes in different setups, all nicely fitted and tuned. Only one is less than 5yrs old, alloy frame, but no better than the old steel framed bikes. Each has it's own character and they all get me from A to B. It is good to change bikes now and then and I am never disappointed by any of them.

    As to the gearing - the highest and lowest gears set the limits, how many steps in between gives you more or less intermediate choices. The wheel size, tyre size and crank length are part of the gear train, so the best way to compare a mountain bike to a road bike is to use Sheldon Brown's gear calculator, or ride the bikes!
     
  15. artemidorus

    artemidorus New Member

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    At threshold, I can cruise at ~28 kph on flat tarmac on my dual sus MTB with knobbly tyres. You're giving me 50+kph at threshold on my drop bar bike?? - sorry, that's just laughable, more like 35-36kph. This forum is full of grandiose claims. The gains from new gear are always less than you think.
     
  16. hielo

    hielo New Member

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    I agree.

    I went for a 1 hour ride today on my knobby tyre MTB, average 28.09 kph. Any suggestion that 56 kph on a road bike over the same route could be achievable, is ludicrous IMO !

    More like mid 30's as posted above.
     
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