Total Beginner confused with gearing

[HappyToNotFallOff]

Hi there,


I've just bought an 18 speed bike. The last time I was on a bike was when I was 8 years old (23 years ago!).


On the two run outs I have had with the bike, I'm getting confused with the gearing - with hills.


Peddling is MUCH too easy when I am on even the slightest of down gradients. In most cases I end up in a freefall and the pedals do nothing. I've switched to the highest gear 3/6 but it makes no difference. So I freefall to the bottom of the hill. As I am getting to the bottom (ready for a steep climb), I can't pedal in anticipation for the climb because they just spin and I can't change to a lower gear for the ascent because the derailleur won't work without me pedalling. I have to wait until I'm on the ascent and slowed right down before slogging away in a high gear to the top!


Another issue with the bike is that when I set the rear gear to say 3 on the handlebar, the 4th cog is engaged, so it's always 1 out. Is this just a matter of adjusting the rear derailleur?


Thanks

 

[Aperitif]

Hello 'HappyTNFO' - welcome to the forum. Post an image or link to your bike to elicit some helpful comment, as I'm sure someone will know.
Without certain information, all the experts on here cannot help you - even though they know a lot... from no gears, to 30 electronically controlled ones! Meanwhile, enjoy your bicycle.

Have fun!

.

 

[HappyToNotFallOff]

Thanks.

This is the bike http://bit.ly/pjOkr4

And it's specs -

• Brake Type: V-Brakes
• Chainset: 42/34/24T
• Exact Frame Size: 17"
• Frame Colour: Light Brown
• Frame Material: Aluminium
• Frame Size: 17-18
• Front Brake: Tektro Alloy V-Brake
• Gear Shifters: Sram MRX 204
• Gender: Mens
• Handle Bars: MTB Steel W:580mm
• Headset: 1-1/8" Ahead type black water proof
• Hubs: KT-122
• Number of Gears: 18
• Pedals: Resin platform BMX style
• Quick Release Front Wheel: Yes
• Quick Release Rear Wheel: No
• Rear Brake: Tektro Alloy V-Brake
• Rear Mech: Shimano RD-TZ50D
• Rims: Aluminium rims
• Saddle: Black vinyl covered soft foam
• Seatpost: Candle type 27.2mmx350mm
• Stem: 90mm
• Suspension: Rigid
• Tyre size: 26 X 1.6
• Tyres: Hybrid Tyres
• Wheel size: 26"x1.50

 

[4F]

I think this is the issue <LI>Chainset: 42/34/24T

Gearing fine for cycling up any mountains but large cog not big enough for any decent speed.

 

[wheres_my_beard]

You will get used to your gearing, and recognising when to coast (decents are the easy part of cycling), and at what point to apply the power once you need to, and when you can buzz along at a comfortable pace.


You may find your top speed feels limited on the flat by your gearing, but there is nothing wrong with pedalling faster to go faster (having a higher cadence) to squeeze out some extra mph.


The rear cog isn't going to be smaller that 14 is it? So at best the gear inches are not more than 78, meaning that at 100rpm your speed will be about 23 miles per hour.

That means pedalling quite fast when you are new/ coming back to cycling. So when going down hill your gearing will mean that your pedalling requirement will feel too fast to engage with the gears (you would need to be pedalling at 130 rpm to engage the gears at 30mph)

 

[tyred]

I would suggest it's best to start out on an under-geared bike as it will teach the rider to spin rather than grind.

18 gears suggests 6 speed freewheel block so probably a small sprocket of 14 teeth. 42/14 combined with a typical mtb 26" wheel should give ~77" which is higher than any of my fixed/ss bikes.

With practice, the OP should be able to get sufficient speed for most purposes in this gear.

 

[HappyToNotFallOff]

Thanks for the prompt and useful advice so far!

I should point out that I'm a runner with an injury so taking up biking is really for cross training / fitness purposes so I'm interested in pedalling more than free-falling. I'm not looking to break any speed records or ride marathon distances (My Bum is certainly too sore for that!) :-)

I guess that my expectation was that I could go downhill and still pedal to keep my cadence up - perhaps that is a false perception and I should just freefall? With that in mind, should I just stick to a medium to low gear on the way down, ready to engage again on the way up?

Also, does anyone have advice on the misaligned derailuer? I've read that you should set the gear to the lowest point and then adjust the "High" screw and then go to the highest gear and adjust the "Low" screw.

Thanks again.

 

[calibanzwei]

I'm just writing up my own notes (geek!) for derailleur adjustment - the best written down instructions come from the Park Tools blog...

Front Derailler Adjustment

Rear Derailleur Adjustment

 

[tyred]

The derailleur cable may need adjusting but just double check that it isn't bent first of all. Have a look at this. Always remember that the single most important adjustment is to ensure that the derailleur can not overshift enough to catch the spokes.

 

[HappyToNotFallOff]

Thanks. I'll have a tinker tonight and see what I can adjust.

 

[Arch]

I can't pedal in anticipation for the climb because they just spin and I can't change to a lower gear for the ascent because the derailleur won't work without me pedalling.

You don't have to be putting power through the pedals to change gear, just to be turning them. So turn the cranks gently while freewheeling, and change in anticipation, before it gets too hard.

Although if I'm freewheeling downhill and into another uphill, I just turn the cranks gently until I can feel some pressure, and then start changing down.

 

[perplexed]

Thanks. I'll have a tinker tonight and see what I can adjust.

If you can't sort it, a decent bike shop should be able to fix it for you for not much money. I couldn't get the indexing sorted for love nor money on one of my bikes, took it to the local bike shop. I picked it up later, the gears were absolutley perfect, and it cost me just over a fiver...

 

[abo]

Peddling is MUCH too easy when I am on even the slightest of down gradients. In most cases I end up in a freefall and the pedals do nothing. I've switched to the highest gear 3/6 but it makes no difference. So I freefall to the bottom of the hill. As I am getting to the bottom (ready for a steep climb), I can't pedal in anticipation for the climb because they just spin and I can't change to a lower gear for the ascent because the derailleur won't work without me pedalling. I have to wait until I'm on the ascent and slowed right down before slogging away in a high gear to the top!

Thanks

Is this a mountain bike (or a MTB-style hybrid) with that 6-speed cassette? I'm *guessing* it is with that triple on the front so yeah; your gearing is too low for a balls-out downhill blast. Just like my 3/8 MTB, down steep banks I can't get above 31mph just because I physically cannot pedal any faster. With roadbike gearing we would go quicker.

As for shifting gears for the uphill, you *can* pedal. Yes they'll spin, but you can still shift and select the gear you want. If you can't then something needs adjusting IMHO

 

[Sir Humphrey Appleby]

Wow, 10 posts and nobody's tried to blame it on the fact the OP got it from Halfords? WTFIGO?

As said, the chain has to be moving forwards for it to change gear, it doesn't have to be making the wheels go faster.

 

[jay clock]

I disagree with 4F. And noone seems to have offered any practical help.

The bike has two gear changers, which appear to be twist grip ones. The left one controls the front gears (where the pedals attach to the bike) and the right one deals with the back (a cluster of 6 cogs)

YOU CAN ONLY CHANGE THESE GEARS WHEN PEDALLING.

Very roughly you want the left gear changer in the Number 2 position on flat roads, number 1 position going up steep hills and number 3 for downhills. Practice will tell you how this feels.

The right gear changer (assuming it is set up right) should have the "easiest" gear (ie the one that feels least effort) as number 1 and the hardest as number 6.(you also should go and get Halfords to set up the gears right as it sounds like a slight misalignment)

Get a friend to help you get it into L2 and R1 (should be on the middle ring at the front, and biggest cog at the back). Pedal off down flattish road, and use right hand changer to go up and down through gears.

Find a slight uphill. As you go along the flat, once you start to struggle, change to L1 and R4 (approx). Then as it gets harder, changes to R3,2 ,1 etc. When you turn round to go downhill change to L3 and then change to gears R3,4,5,6, etc..

Contrary what someone said above, for the bike you have if you pedal down hill in L3 and R6 you should still be able to apply pedal pressure at 25mph+

ENJOY