Getting higher gears?

Discussion in 'Cycling Equipment' started by Mike Jacobs, Apr 25, 2007.

  1. Mike Jacobs

    Mike Jacobs New Member

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    After one season I feel I'm topping out my gears when I have a tailwind or I'm feeling strong. I wish I had a few more big gears, and I NEVER use the little ring in front.

    It's a stock Trek 7700 (22.5" frame with a flat top tube) except for climbing bars and 23 cm tires on the stock Bontrager Race wheels. Sometimes I put the fat tires back on for levee or rail-to-trail riding. I try to keep a cadence of 90 on the road, however, and once in a while I start to bounce without any higher gears to go to - this is why I'm assuming I need higher gears.

    The crank is a 48/36/27 and the cassette is "SRAM PG970 11-32, 9 speed."

    Advice appreciated - I know nothing about modifying the drivetrain. What are the considerations for the best results?
     
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  2. ac29593

    ac29593 New Member

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    Just replace the outer chainring. Get something bigger than a 48T. A 50T would probably work well, but you can probably go bigger if you want.
     
  3. Mike Jacobs

    Mike Jacobs New Member

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    Oh man... there was at least one other reply I read before the system went down... I guess it's lost!

    If I just replace the largest, won't I lose the mid-range? When I drop from the inside to middle ring it'll be a huge difference won't it?

    What I think I'm reading is that it's probably best to focus on the front rings and leave the back. Also, I see from the replies that at least a couple of you believe it is doable. I didn't even know that much, so thanks everybody!
     
  4. Don Shipp

    Don Shipp New Member

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    The answer could be that you should learn to pedal faster. Anything below 80 rpm is slow; the top racers spin at about 120.

    Increasing chainring size can mean that you need a new front mech. (You will also need to replace the chain with a longer one.) Replacing the cassette with one intended for racing will give you a higher gear and closer steps between the gears without (probably) losing the mid range. (New cassettes can also need new chains if there's any wear on the old ones.)
     
  5. thomas_cho

    thomas_cho New Member

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    You spin out at 48X11? At 100 rpm you would be going at about 55km/h, thats pretty fast. In any case, you might be able to find a 50T chainring as suggested.
     
  6. Mike Jacobs

    Mike Jacobs New Member

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    Yeah, over 30 mph - I don't know how to do your calcs but I just know I start to bounce and I'm at the top of my gears - as I said, only downhill (we have only short downhills here in FL on bridges BTW) or even when I'm feeling strong and/or have a tail wind.

    I was surprised per Don Shipp that anybody could pedal at 120. Maybe this loops back into what somebody else said (the post was lost when the system went down I guess) about the hybrid not really being built for the kind of riding I'm doing. At a 100+ cadence I'm bouncing and rocking waaay too much - probably due to the hybrid's upright position.

    Now, I'm not racing and never will - my family and day-job will keep me from committing THAT much - and I don't *need* to go that fast training for several charity rides a year. It certainly doesn't happen much. I enjoy the speed but find sustaining 20+ mph for a few miles a lot more gratifying. So, it looks like I have a way to go before I really "top out" my existing gears.

    I like the bike, and have room in my condo for only one. Road riding is great, but my first love is levee and rail-trails. I do road more because of where I live, but I just can't imagine a break completely from the fat-tire rides. So, the hybrid works for me and you all have helped me understand that even though I sometimes top out it's nothing to be concerned about right now.

    THANKS everybody (including those lost posts)
     
  7. garage sale GT

    garage sale GT New Member

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    One of them was mine...maybe the loss is the universe's way of telling me nobody really needs to hear facetious suggestions to drill holes in your 48 and rivet a 53 to it.

    This is a subject I am interested in athough it is because I find the outer three sprockets on my cassette to be useless when I am trying to use my 52. Changing chainrings approaches the cost of a Nexave triple, but what do I need to measure to find out if it will work or if I need a new BB?

    I think one other person said if you have a four bolt MTB crank, you're not likely to find anything bigger than 48T, so you need a road crankset.

    Pull the cap out of the big end of your crank and undo the bolt that holds it to the BB axle. You can then see if it's square taper (which looks square) or octalink (which has eight rounded splines) or some other system like hollowtech.

    I think you'll also need a crank extractor though I only know the square taper system where the cranks get wedged on the BB really tight. You may need more chain and there's at least a small chance a bigger ring will interfere with your frame. Changing cassettes won't give you a smaller sprocket than 11 but may result in more ratios in the range you use.

    There my knowledge ends. When you order a crankset, how do you know what width BB it is for?

    Nashbar had a road double for $45 and a triple for $50 BTW.
     
  8. John M

    John M New Member

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    My response was one of the lost ones. It was the comment that your 4-bolt crankset will not accomodate a typical road chainring and I doubt that you will find a larger than 48T 4-bolt chainring. My second comment was similar to Shipps about learning to pedal a faster cadence. You already addressed my third suggestion to consider a road bike.

    Good riding.
     
  9. garage sale GT

    garage sale GT New Member

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    So how about it, spinners? can you train to spin a higher RPM by increasing core strength or perhaps something else? You can clearly spin higher the more you concentrate (or I could just dump my friction shifters and shift more:D )
     
  10. artemidorus

    artemidorus New Member

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    You learn to spin by setting progressively higher cadence targets in ordinary training. Edge it up by 2rpm or so every few weeks. Aim for 90-100. (I tend to sit on about 96 when cruising, 100-105 when at threshold or higher). I do no core training.
    The downside is that you start to hate cadences under 90, which feel like pushing a wheelbarrow uphill through mud.
     
  11. Albert 50

    Albert 50 New Member

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    Try to keep the power of your down stroke constant, upper body still, think & pedal 'circles' particularly at higher cadences.
    I said that for 4 years until a couple of months ago :)
    I used to be more of a spinner 12 months ago than I am now. I think it is a good idea to do some uphill training in a taller gear to adapt your body to lower cadences. If you are only accustomed to spinning gradually lower your cadence so you don't strain your knees. I've done repeat hills with my cadence as low as 30 odd.
     
  12. artemidorus

    artemidorus New Member

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    Climbed out to Berowra Heights from the ferry punt last weekend at ~75rpm. I was surprised at how good I felt after the first few hundred meters; I didn't get out of the saddle at all. Still, had I had a lower gear I'd have used it.
     
  13. Insaneclimber

    Insaneclimber New Member

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    After a lot of spin training i can now pull 67kmh with a 44 - 11 on 26" wheels, its got nothing to do with the bike its just a matter of training.
     
  14. garage sale GT

    garage sale GT New Member

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    If you don't ever use your small ring, though, why not go for the glory?
     
  15. garage sale GT

    garage sale GT New Member

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    Right...but do you just go out and spin for hours or is it a matter of doing a lot of core exercises? And if you don't mind my asking, how tall are you? Having shorter legs means they can't flop your torso around as much.

    It would seem that strong obliques and a bit of mental focus may increase the RPM at which you spin out.

    How long can you maintain that 140rpm or so?
     
  16. artemidorus

    artemidorus New Member

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    Efficiency has been shown in the lab to drop off significantly beyond a cadence of 110-115. Rather than spinning at 140, you'd go faster with higher gears for the same effort. Can you put 46T or 48T on?
     
  17. djk202020

    djk202020 New Member

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    You are aksing for more out of the bike than it was built for. Maybe look in to a road bike and keep the 7700 for trail riding. My dad road a 7700 until he tried my road bike he couldn't believe how much faster and how much easier it was to ride all around he rides a pilot 2.1 now and has never looked back. I would assume it would be a hard bike to spin high rpms on becasue of the upright ridding position you are gonna bounce alot in the saddle. The best choice would be a bigger crank upfront 52/39/30 but i dont know if the deore xt derailleur would be having it?
     
  18. djk202020

    djk202020 New Member

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    Im not sure how much speed you are looking for but I ride a 50/34 with a 11-25 and I spin out at about 43-45 mph anything I gain after that is not from me pushing the bike but rather from gravity.
     
  19. Insaneclimber

    Insaneclimber New Member

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    Im 176cm tall and i started raceing road bikes at 15 im now 34, i can hold that kind of rate for something like 5min depending on how i feel. and no its not the most efficient way to ride, i only do spinning like that to train. according to my gear calc thats just over 120rpm?
     
  20. dabac

    dabac Well-Known Member

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    Here , courtesy of the 'bent crowd, are instructions and drawings of how to make your own big sprockets if you want a combo not commercially available.
     
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