More gears?

DirkVoodoo

Ok, so i got my new bike, one of the halfords carrera subway 1 deals.

Ive got used to the whole cycling thing and my trip into college is mostly downhill so ive been climbing up through the gears. However, yesterday i was looking for a bit more "Ooomph!" and found that i was already on the 14th gear.

Is there a way to add another large sprocket onto the front assembly so i have 21, do i need a whole new gear/crank and if so, which one will fit the carrera spec?

Forgive my novice-ness-ness, thx for any advice in advance!

Itsfixed

DirkVoodoo wrote:

Ok, so i got my new bike, one of the halfords carrera subway 1 deals.

Ive got used to the whole cycling thing and my trip into college is mostly downhill so ive been climbing up through the gears. However, yesterday i was looking for a bit more "Ooomph!" and found that i was already on the 14th gear.

Is there a way to add another large sprocket onto the front assembly so i have 21, do i need a whole new gear/crank and if so, which one will fit the carrera spec?

Forgive my novice-ness-ness, thx for any advice in advance!

You could just put on a larger outer chainring. For example, if your outer chainring is 46t, you could replace it with a 48t or maybe even a 50t without having to get a longer chain. I don't think you can put a third ring on unless its a smaller 'granny' ring on the inside.

You might have to adjust the front derailleur, and also remove the chainguard as the new ring may be bigger and therefore look silly.

Ghost Rider

Won't he have to replace the front shifter too?

Itsfixed wrote:

You could just put on a larger outer chainring. For example, if your outer chainring is 46t, you could replace it with a 48t or maybe even a 50t without having to get a longer chain. I don't think you can put a third ring on unless its a smaller 'granny' ring on the inside.

You might have to adjust the front derailleur, and also remove the chainguard as the new ring may be bigger and therefore look silly.

Johnny Jukebox

Ghost Rider wrote:

Won't he have to replace the front shifter too?

For best results, yes.

rubadub

You can also change the rings at the back. On some bikes you can change individual rings (cassettes) and get one with 11 teeth on the smallest, on others you must replace the whole block. If the bike is new it is best to do this ASAP since you really should get a new chain after changing rings like that, your chain gets sort of moulded to its shape.

Membrane

DirkVoodoo wrote:

Ok, so i got my new bike, one of the halfords carrera subway 1 deals.

Ive got used to the whole cycling thing and my trip into college is mostly downhill so ive been climbing up through the gears. However, yesterday i was looking for a bit more "Ooomph!" and found that i was already on the 14th gear.

Is there a way to add another large sprocket onto the front assembly so i have 21, do i need a whole new gear/crank and if so, which one will fit the carrera spec?

I'm not sure on this, but I would expect a 21 gear system to have approximately the same max and min ratio as a 14 gear one, just with more choice in between.

You can extend the top end by replacing the outer chainwheel with a larger one, or the rear with a smaller smallest sprocket. I'd guess that to get a noticable difference with a bigger front chainwheel you'd need to go for one with >=5 teeth more than your current one, and IMO that requires lengthening of the chain with the same number of links.

No need to replace the front shifter if you fit a larger front chainwheel, just adjust the front shifter a bit upwards if needed at all.

I seem to recall advice that many cyclists tend to select to high a gear, biomechanically this isn't recommended, a higher leg rhythm is apparently better for the blood circulation.

I'm guilty of that myself, watching the pro's I can clearly see that they use lower gears than I do for the same terrain.

cerebus

Membrane wrote:

I'm guilty of that myself, watching the pro's I can clearly see that they use lower gears than I do for the same terrain.

Maybe, but probably more likely that they are both pushing a higher gear and a higher rpm.

Seriously, pro riders are scary fast.

Alkers

IIRC the optimum rpm for cycling is in or around 90rpm. This means just choose a lower gear and move your legs faster.

rubadub

Simona1986 wrote:

IIRC the optimum rpm for cycling is in or around 90rpm. This means just choose a lower gear and move your legs faster.

Have you any good links about this? Experienced cyclists have warned me about using high gears as it is bad for the knees. I know junior cyclists in competetions are meant to have their gear ratios restricted so they cannot have too high a gear.

Membrane

rubadub wrote:

Have you any good links about this? Experienced cyclists have warned me about using high gears as it is bad for the knees. I know junior cyclists in competetions are meant to have their gear ratios restricted so they cannot have too high a gear.

Then I'd hate to think what state my knees are in, I'm used to lifting myself off the saddle and stand on the pedals all the way when I'm climbing :-|

Civilian_Target

Nope - best for you to go at least 60 RPM. I find that anything over about 120 just looks very silly without straps though!

Michael Collins

Lance Armstrong prefers a cadence of 120rpm I think!

copacetic

rubadub wrote:

Have you any good links about this? Experienced cyclists have warned me about using high gears as it is bad for the knees. I know junior cyclists in competetions are meant to have their gear ratios restricted so they cannot have too high a gear.

i'll back up sinoma on this, have loads of books and mags that recommend 90rpm as a cadence to aim for. Most cyclists do a lot less. They do say though that until you are a 'trained' cyclists lower cadences are more efficient. It is only when you are trained and capable of maintaining the higher cadence that you get the benefit of it.

some links from first 5 in google:

http://www.53x12.com/do/show?page=article&id=15

http://bicycling.suite101.com/article.cfm/cadence_for_better_pedalling

Capt'n Midnight

copacetic wrote:

i'll back up sinoma on this, have loads of books and mags that recommend 90rpm as a cadence to aim for. Most cyclists do a lot less. They do say though that until you are a 'trained' cyclists lower cadences are more efficient. It is only when you are trained and capable of maintaining the higher cadence that you get the benefit of it.

Agreed

But don't let anyone use that as an excuse to push too hard. If you can't do once per second then you are possibly in too high a gear.

Cycling and walking don't use the same set of muscles the same way. This means until you muscles aclimatise you will use them in the same way you would for walking, taking your whole weight on each foot and then the next. This is inefficient for cycling since you support your weight on the other foot too, and the handlebars and the saddle. This is why twiddling the peddles is good to learn

Bradidup

Itsfixed wrote:

You could just put on a larger outer chainring. For example, if your outer chainring is 46t, you could replace it with a 48t or maybe even a 50t without having to get a longer chain. I don't think you can put a third ring on unless its a smaller 'granny' ring on the inside.

You might have to adjust the front derailleur, and also remove the chainguard as the new ring may be bigger and therefore look silly.

Chain guards in themelves always looked silly and only add weight, that was the first thing I would have removed from a new bike along with side stands and full length mudguards etc. I dont know whether you can get seperate rings for those halfords chainwheels, you might have to replace the cotterless.