When your gear system flips

Your bike is sparkling clean and set to go; you have a new comfortable, Novus Superflow saddle, virtually “made-to-measure”, chosen using the innovative idmatch measuring system by Selle Italia; your brakes are properly adjusted and tyre pressures are perfect. Everything’s running perfectly, but at the first gear change you hear that annoying squeak that almost makes you feel like swearing.

 

There is nothing more annoying to an enthusiast – who is quite a stickler when it comes to his equipment like any good self-respecting cyclist – than a poorly-adjusted set of gears that are noisy and imprecise.

Gears are one of the most stressed components on a bike, and working under mechanical tension they tend to lose their optimum setting with relative ease.

The best thing to do is to take our bike as soon as possible to our trusted mechanic for a good overhaul, but in the meantime let’s see what emergency action we can take “in the field” to remedy our minor setback.

Adjusting gears correctly is a fairly simple task, but you need to know exactly how to do it, otherwise you risk making the situation worse.

First thing to bear in mind: the bike should be positioned on a stand, but, whatever, it should not be turned over, because the weight of the derailleur itself could affect the adjustment.

 

Limit adjusting screws

The gear system, and in this case the rear derailleur, has an upper and a lower stop point, to prevent the chain from coming off the sprocket. These points are adjusted by two small Phillips screws visible on the body (rocker) of the derailleur, called limit adjusting screws. It is important to know that the adjusters only affect the first and last gear ratio, i.e. the top screw (H) intervenes on the movement of the chain onto the smallest sprocket, while the bottom screw (L) onto the largest sprocket.

You can act by tightening these screws (not more than half a turn) when the gear cage is not perfectly parallel to the wheel, but always with great care: in the event of small inaccuracies in the movement of the chain from one sprocket to another it is often enough to make a “fine” adjustment to the cable tension through the appropriate ratchet on the derailleur.

 

DIY adjustment

What should I do? We can start with the chain on the smallest sprocket and try to change up to the largest one and back down. To do this we should lift up the back of the bike and turn the pedals by hand, perhaps with the help of a friend, if we are on the road without a stand available.

If we notice that the chain is slow to move up to the larger sprockets, it means that the cable needs tightening, but, conversely, if the chain moves to the smaller sprockets with difficulty, it means the cable should be loosened slightly.

It is important to remember: tightening the ratchet reduces the tension on the cable, and loosening it, increases the tension on the cable.

Be careful not to overdo it; take small steps by tightening or loosening the screws a little at a time: if you “go over the top” the risk is that the chain “will jump” a gear directly, going up or down 2 gears at a time, then making it difficult to find the right adjustment again.

Summary
When your gear system flips | Restart and solve – Selle Italia
Article Name
When your gear system flips | Restart and solve – Selle Italia
Description
The gearbox is among the most stressed components of the bike, and working under mechanical tension tends to lose the optimal adjustment with a certain ease. Check out our tips for keeping the perfect bike gearbox
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Publisher Name
Selle Italia
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