any way to raise intensity of gears?

Seraphina

right, i've just got a crappy mountain bike for getting about the place, but i spend the entire time in the top gear. its frustratingly low and i reckon travelling would be alot more energy efficiant if i could do something about it.

can it be done? (i dont want to go into a bike shop and sound like a tool)

Civilian_Target

That sounds unusual. How many times are your pedals rotating a minute, I understand that you should be pushing the pedals down about 90 times a second...

Any bike I find often tend to have redundant overly-high gears that could only be used on the flattest of roads...

Pherekydes

Civilian_Target wrote:

That sounds unusual. How many times are your pedals rotating a minute, I understand that you should be pushing the pedals down about 90 times a second...

90 times a minute!

uberwolf

Slow coach wrote:

90 times a minute!

yes really, 90!

Seraphina - Are you seeking to make the most difficult gear on your bike more difficult to push?
That is if you've a geared bike - big cog on front, small cog on back?

Civilian_Target

Slow coach wrote:

90 times a minute!

Thats the one!

Seraphina

uberwolf wrote:

yes really, 90!

Seraphina - Are you seeking to make the most difficult gear on your bike more difficult to push?
That is if you've a geared bike - big cog on front, small cog on back?

thats it. is it possible?
so not exactly highest gear all the time, but i've 21 and about 18 are useless to me. even my completely downhill cycle to college ends up with me in a sweat because the pedals are so easy to push, i cant seem to work up any kind of decent speed, even on downhill/flat ground.

the gear system is a second hand one (my decent bike was robbed over a year ago and i've been making-do with a pieced together one since)

would i be better off replacing the gear system? i intend to use the bike alot more over the summer for getting in and around town (i live southside right now) so the frantic pedalling is completely impractical, especially since town is much flatter than the area i live in.

edit: heh just took a look at that other thread and some of the links on it, there's alot more to cycling than i thought
perhaps longer cranks or something might help actually, my circles always do seem rather small...

uberwolf

TBH that sounds completely wrong. I would find the most difficult gear on a MTB reasonable for cruising on the road. So I'd have to suggest the most difficult gear on your bike must be inaccessible for some reason.

Don't go into a shop and ask for them to replace the gear system. Cos they will. And that'll be a big bill.

21 gears. 3 cogs on the front, 7 cogs on the back? (you'll have to excuse the patronising tone :$ ). When you're in the hardest gear you should see the chain on the largest cog on teh front and the smallest cog on the back. Where is it?

brainstorm

i'd agree with uber, in that you cant get at your biggest gear for some reason.. mind you ive seen some mountain bikes with tiny chainrings (front cogs) the biggest one what looks like at most 39 tooth from a distance. Maybe this is the case with your bike. So you would need new (standard sized ) front cogs and possibly new chain, cogs on back. not cheap!

mockerydawg

The easiest and cheapest solution is to get a bigger drive ring (the biggest cog on the front.) It sounds like yours is only a 38, (38 is the number of teeth on the cog, fairly standard on low end bikes that aren't made for speed.
Changing it for a 42 or 44 will make a huge difference and make you faster. A new ring should be no more than €20 or your paying far too much

Seraphina

uberwolf wrote:

21 gears. 3 cogs on the front, 7 cogs on the back? (you'll have to excuse the patronising tone :$ ). When you're in the hardest gear you should see the chain on the largest cog on teh front and the smallest cog on the back. Where is it?

actually, you're right. im in the second highest gear. for some reason the gears aren't aligned properly and i cant actually get into the highest gear unless i do it manually. which doesn't make a whole heap of difference.
yes i know what the cog system looks like, yes i am aware its weird.
bleh. so there's nothing i can do short of replacing it?

uberwolf

accessing the gear with the shift would require either adjusting the tension on the cable or the swing of the derailleur. Neither of which are difficult but diagnosing which one would me tricky from this end of a laptop

If thats not the problem then putting a larger cog in place is the only solution open to you I'd say. Again - nothing major for labour and parts shouldn't be too extreme

Seraphina

cool, thankies. gonna check my large cog and see how many teeth it's got. at least i've a good idea of what the problem could be now.

Seraphina

ok what the ****? i check the largest cog at the front today. 48 teeth.

now i'm just baffled. the crazy bike of mystery parts im gonna call it. back to square one

uberwolf

Seraphina wrote:

ok what the ****? i check the largest cog at the front today. 48 teeth.

now i'm just baffled. the crazy bike of mystery parts im gonna call it. back to square one

thats big, very big in fact - racers only have 52!! (some 53).

Next step - the smallest cog at the back - how many teeth (shouldn't take as long to count )

Seraphina

smallest cog at the back has 14

the cog at the front doesn't really look that big, but im assuming there's a standard difference between the teeth? seems strange...

Mucco

14 at the back is a bit big, 11 is more normal and should speed you up quite a bit. What speed cassette is it? ie how many cogs at the back.

M

Seraphina

7 cogs at the back, and they're all pretty big

Mucco

Seraphina wrote:

7 cogs at the back, and they're all pretty big

Aah, if it was 8, I was going to say I have a spare. Your best bet is to try to get a new cassette with smaller cogs. Problem is, they can be a bit pricey.

M

brainstorm

48x14 is fairly standard on a mountain bike. never seen anything lower like a 12 but i guess you can get them. Try looking for an 8 speed block, you might have to get a new rear derailleur as well depending...

if you find 48x14 really really easy to turn over, then i would see if you can get bigger chainrings as well.

Capt'n Midnight

Yeah you can get 11's fairly handy - but they have to be from a good brand or they ain't up to it.

Never did like microdrive chainrings - puts more stress on the chain and teeth which can't be a good thing. Once upon a time chainrings were 52/42 teeth as posted above it can be as low as 38 nowadays - so from that perspective you'd be on the lower set of gears - but the 52/42 used to be matched with 14 teeth at the back.

It's all about the ratio between the gears. But make sure you are twiddling the pedals and not forcing them - some people prefer to push hard at a slow place but that ain't good unless you are sprinting.