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Question on gears
#1
Hello,
I have a 21 speed Schwinn Jet Star that I got about 2 years ago, haven't done much riding but want to start up again. The highest gear seems 'moderate' to me (not very hard at all, I'm looking for a good workout when I ride and prefer higher gears). I had a guy adjust everything today and he said I could either let air out of my tires or try to get a new flywheel but he said that wouldn't improve things too much. I'm not looking to spend a ton of money since I'm currently unemployed. Any suggestions are appreciated. Thanks!!
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#2
Welcome to the forums Kutz!

Is this the bike you have? If so you could change the front crankset to one with larger chainrings. The replacement crankset should have roughly the same side profile or you may have to replace the bottom bracket as well. You'll likely also have to lengthen the chain.
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#3
(03-12-2010, 12:46 AM)Alex Ramon Wrote:  Welcome to the forums Kutz!

Is this the bike you have? If so you could change the front crankset to one with larger chainrings. The replacement crankset should have roughly the same side profile or you may have to replace the bottom bracket as well. You'll likely also have to lengthen the chain.

Hello,
Yes, that is the bike I have. There are a few bike shops in town but I'm kinda leery of going in and trying to be sold a new bike or things that I don't need. Thank you!!!
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#4
Well, if they try to sell you stuff you don't want, first tell them. If they continue: leave.
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#5
My problem is that I don't know a lot about bikes and what can or can't be done so I'm trying to get some knowledge before walking in there. I feel like I have 21 gears and I'll only use about 2 right now and it's aggravating. Thank you for the reply.
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#6
There are only 2 ways of getting higher gearing.
A larger chainring at the front or a smaller cog at the rear.
The usual smallest at the rear is an 11 tooth sprocket.
The front largest can be as big as you want.
We need to know what sizes amd make you have on your bike?
Both will cost some cash so shop around for the best option.
Letting air out of your tyres will cause extra drag but will be more prone to punctures and bad handling.
[font=Trebuchet MS]Ride hard or ride home alone![/font]
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#7
Also note that cycling with a higher cadence (> 90 rpm) is better for your knees. So unless you have a really small largest chain ring (let's say less than 42 teeth) you should be fine (my opinion). Mount a road cassette on the bike, they have (in general) smaller sprockets and less "spread" (the largest and the smallest sprocket on an MTB about: 32 - 11, road: 25 - 11 or even 23 - 11). This will give you more "useable" gears. To calculate gain ratio / speed @ certain rpm take a look at http://sheldonbrown.com/gears/ put in the sizes you have at the moment to get a feeling of what you can do. My setup ("cyclocross" turned Peugeot: front: 45, rear: 11 - 32, I don't use the largest front chain wheel - 54 teeth - 'cause my front derailleur broke).
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#8
Hello,
Thank you for the replies. Honestly I have veeeeeery little knowledge about cycling so I apologize. I may just have to deal with what I have. I'm unemployed right now and can't afford to spend a ton of money. Went into one shop, they said 'nothing you can really do, you need a new bike' so I left. I'll see how much cycling I actually start to do and will go from there. Thank you again for your help!
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#9
kutz, what Joe said about keeping you cadence up is a wise suggestion. There are very few people that need higher gears than you likely have on this bike, if they are pedaling properly.
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#10
(03-15-2010, 07:19 PM)kutz Wrote:  Hello,
Thank you for the replies. Honestly I have veeeeeery little knowledge about cycling so I apologize.
No worries, none of us started out as an expert
Quote:I may just have to deal with what I have. I'm unemployed right now and can't afford to spend a ton of money. Went into one shop, they said 'nothing you can really do, you need a new bike' so I left. I'll see how much cycling I actually start to do and will go from there. Thank you again for your help!

That shop sucks. 'nuff said.
If you could post the manufacturer and model of the front crankset (not only the group name but also the little numbers that are on the right crank arm) we can probably work something out. A larger chain ring will set you back about 40€.
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#11
annnnnnnd bike shop #2 said the same thing 'you need a new bike' and once again I said 'thanks' and left. What ticks me off is I had a 10 year old bike that I loved but didn't take care of it (new baby at the time) so it rusted out etc., I got rid of it, got the new bike and I hate it. I'm not biking for speed, more leisure but I'd like a harder workout. I feel like the Wicked Witch of the West on her bike right now. Hopefully I can get out in the next few days and I'll see how it goes. If I find the info you were asking for, I will post it. Thank you again for the help!!
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#12
I'm having a heck of a time finding any info on this bike. It's a 21 Speed, Schwinn, Women's Jet Star, purchased at Target. The only number I can see is on the rear largest gear, it says "34T", can't see any of the other numbers, too small. The frame has model S5977WM, 1002JG for a date.

Gear info from booklet:
4.0 Pro rear shifters
Rear derailers - SRAM 9.0SL / 9.0 / 7.0 / 5.0 / 4.0 / 3.0 (1:1 actual ration)

MRX Pro rear shifters - rear derailers - Shimano (2:1 actual ratio)

MRX Prod Rapid Rise rear shifters - 2:1 actuation ratio

4.0 Pro/MRX fron shifters: front derailers SRAM & Shimano

I'm sure I just typed all that and it means diddly... thanks!
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#13
Step one is to figure out what actual gears you have on the bike. Easiest way is to count the teeth. What you care about is the tooth count on the smallest cog in the back and the big ring in the front.

It is cheaper and easier to change the back. You may not get as big an increase in gears, but still noticable. For instance, if your smallest is a 13 tooth and you go to a 12 tooth, you'll get about an 8% increase in your highest gear. (1/13)

Changing the front probably has a bigger total impact, but will cost more. Note that a 1 tooth change in the front won't do much. But changing from a 42 to a 46 would give you a similar increase in gear ratio. If you try to go too big in the front, you'll probably have shifting issues.

"I feel like the Wicked Witch of the West on her bike right now." - I suspect the gearing isn't the only thing about the bike you don't like. Nothing wrong with that. But if you go into a shop and start telling them how you liked your old bike and dislike this one and then ask what you can do, they'll say "get a new bike". If you go in and say, "I would like to have a little bit higher gearing, what's the cheapest way to do that?" You should get much better advice. Note also that the stem on this bike is adjustable. If you don't like the upright riding position, it can be adjusted to stretch you out a little more.

There are a lot of idiots in bike shops. But there's also a lot of people who will just answer the question you ask without digging in and trying to figure out what the real issue is. Make sure you're asking the right question. Good luck
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#14
(03-16-2010, 12:46 PM)kutz Wrote:  annnnnnnd bike shop #2 said the same thing 'you need a new bike' and once again I said 'thanks' and left. What ticks me off is I had a 10 year old bike that I loved but didn't take care of it (new baby at the time) so it rusted out etc., I got rid of it, got the new bike and I hate it.

Well, the question is: do you want to spend money on a bike you hate? A new cassette will set you back about 20€, depending on the condition of the chain, you might want to get a new one, too. It all adds up... (I've been through that, though in my case I still like the bike). I agree it is cheaper than a new proper bike though.
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#15
I know times are hard and they are trying to make a sale. There's another shop in town I haven't hit yet. Maybe if I go in with my boyfriend, I'd get different results (sad to say but it can be true). I think I need to get some more rides in so I can truly see what I do and don't like. I really appreciate the advice, I hate walking into the shops 'blind' per se. Thanks and happy riding!
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#16
The tooth count for the back is 13, for the front is 42. Not sure if I'll explain this well but I feel now that the highest gear is a 'medium' speed for me. When I'm on long/flat surface I feel like I'm peddling faster than I'd like, I'd rather be at a higher gear so I'm not peddling as fast and get a better leg workout. Hope that makes some sense. I apologize I don't know what a 'road cassette' is and I'm in the US and I think some prices were quoted in pounds?? The shops I've been to said "you'd spend more money in parts to get a few more gears than I would buying a new bike.' Somehow I don't believe them but maybe I am wrong.
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#17
If you want "more gears" they are correct: you have to change the derailleurs (at least rear), shifters, cassette, maybe hub, probably the crankset (and the bottom bracket) and the chain. Price tag (assuming you buy online, outdated parts, do the work yourself): ~ 200€ probably (easily) more.
You want different gearing.

First some numbers: If I calculate your speed at 90 rpm cadence (90 crank turns per minute) with the gearing you told us, then I get 37 km/h (about 23 mph). I keep my cadence above 100 rpm. It takes some time to get used to that but you should do it. It is much better for your knees and provides a better workout. My average speed over longer distances does not exceed 30 km/h (in fact I only have those averages on my bike splits in Triathlon... yeah, I don't train hard enough).

What you want to do:
  • get that cadence up!
  • get another cassette with the correct number of sprockets (7) and install it (11-30 teeth)
The first point will cost nothing, the second will be about 15€ (euros), dunno, 20 USD? plus work (if you buy at a shop they maybe do it for free, the cassette may be more expensive, though).

A "road cassette" is a cassette used for road cycling rather than an "MTB cassette" (for mountain bikes), though those terms are.. well... rough at most. The cassettes by Shimano and SRAM are actually interchangeable if they have the same number of sprockets and the rear derailleur has the capacity (is long enough to keep the chain under tension in all gears). Road cyclists have no use for sprockets as big as 34 teeth. On an MTB those gears are important for steep ascends. Road cassettes have maybe 12-28 teeth (smallest - largest sprocket, and that is one with huge sprockets), other common sizes are 11-25 or even 11-23. This gives you finely spaced gears to keep the cadence at your preferred rate.


Edit: You have to think about the maximum and minimum number of teeth on the cassette: Do you ever use that largest sprocket in the rear? The second largest? This will be (an estimate for) the largest sprocket you want. Smallest sprocket: 11 teeth. And get that cadence up!
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#18
You are correct, I don't want 'more' gears, but different ones. I've only been out twice this year so far, always on the smallest gear in the back, largest in front, only shifting lower if I'm going up a hill. My friend just told me her father-in-law used to work on bikes so maybe he'll be able to help me. Thank you all for your advice!!
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