Gear tuning

[Timmy35]

Okay first off I'm not a huge cyclist, so this question may seem a bit thick ( just a bit ).

I don't really bother with the front gear on my bike ( the big sproket ) as I always leave that on the highest gear anyway.

I use the rear gear/sproket array alot. I have quite a bumpy ride most days, and have noticed over time that the gear shift is getting more and more 'sticky' that is I click to change gear and there's a delay with some grinding/clacking noise before the gear shifts.

I don't really want to have to take it into a bike shop everytime this happens, and was just wondering if anyone can tell me what I need to adjust, or where I can find out.

The bike has Shimano 21 speed gears with 'Revo' shift if that helps.

Cheers and Sorry for sounding unbelievably thick.

[ccr32]

First off, work out which way the gears are struggling to shift, either up (from smaller to bigger - more common) or down (from bigger to smaller) the sprockets.

You'll see a little black plastic adjuster at the end of the gear cable that goes into the rear mech (the bit that holds the chain and moves it up and down the sprockets).

Standing over the bike and looking down on it, turn the plastic adjuster a quarter of a turn in the direction that the gears are struggling - test it out and see if its cured it. If not, repeat with quarter turns until its right.

[anonymous-user]

Even though you have 21 ratio's your only suppose to a selction of them, with a 3x7 front chainring (3) and rear sprocket/cassette (7) you should be only be using the biggest front gear with the 5,6 & 7 on the back, use the middle front with the 3,4,5 on the back and the smallest front chainring with 1, 2 & 3 on the back. One or two either way won't make much difference.

Over use of non-linear gear ratios (ie. big chain ring and big rear sprocket 1 & 1) will prematurely wear out and misalign your gearing compenents due to over stretched and mismatched chain angles.

Edited by anonymous-user on Friday 23 July 13:16

[Timmy35]

Thanks guys. Okay I'll have a go at adjusting tonight and using the gears properly, didn't realise you were meant to use them in such a manner.

[_rubinho_]

OneDs said:

Even though you have 21 ratio's your only suppose to a selction of them, with a 3x7 front chainring (3) and rear sprocket/cassette (7) you should be only be using the biggest front gear with the 5,6 & 7 on the back, use the middle front with the 3,4,5 on the back and the smallest front chainring with 1, 2 & 3 on the back. One or two either way won't make much difference.

Over use of non-linear gear ratios (ie. big chain ring and big rear sprocket 1 & 1) will prematurely wear out and misalign your gearing compenents due to over stretched and mismatched chain angles.

Edited by OneDs on Friday 23 July 13:16

I've always understood it that you can use all 7 (or 8 or 9) rear sprockets with the front middle ring but only the top 3 with the smallest front and bottom 3 with the largest front ring.

[anonymous-user]

_rubinho_ said:

I've always understood it that you can use all 7 (or 8 or 9) rear sprockets with the front middle ring but only the top 3 with the smallest front and bottom 3 with the largest front ring.

Really depends, you most certainly can use all your rear sprockets on your middle chain ring, the angle won't be as bad as complete opposites. But it will still be acentuated, therefore wearing components out prematurely. In addition, if you look at a table of your ratios then there is too much over-lap at the top and the bottom of your gear range by staying on your middle ring your not getting the best out of your bike.

My 105 Triple 9 speed road bike ratios are below

25 23 21 19 17 15 14 13 12
52 2.080 2.261 2.476 2.737 3.059 (3.467 3.714 4.000 4.333)
42 1.680 1.826 (2.000 2.211 2.471 2.800 3.000) 3.231 3.500
30 (1.200 1.304 1.429 1.579) 1.765 2.000 2.143 2.308 2.500

As you can see there is no point going on to the 12 sprocket on my middle chain ring I might as will go up to the 52 from the 42 and up from the 14 to the 15 at the back at the same time, I'll most probably be descending/pushing on at that point and the bigger jump in ratio's won't be a problem, likewise going down to the 30 with dropping down to the 19 from the 21 at the sametime, I'll be climbing so the larger jump will be needed anyway to maintain the cadence.

If I know what the road ahead brings that might slightly change my selection as I know I can push a slightly higher gear for a bit longer and avoid clunking the big ring down, or I know it's going to kick up agin round the corner so I'll just keep my cadence high and select a smaller ratio change and stay on the current chainring.

Edited by anonymous-user on Monday 26th July 09:40