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About four months ago I decided to get back into riding. I bought an Apollo Gradient mountain bike. I know this is quite a cheap/basic bike but didn't want to spend a lot if I didn't stick with it. I have stuck with it and will eventually upgrade to something better but can't afford to right now.

Now onto the problem, the gear changes have never been particularly smooth but over the last month they have got worse. The gear changes themselves, while clunky, aren't a particular issue. What is an issue is that it sometimes misses a gear especially 3rd and 6th gears (so when I change from 2nd it will go straight to 4th or from 5th straight to 7th). This is more of an issue as you will think you are in the right gear and then it will snap back into the correct gear later on. This is a particular issue when cycling up hill as it throws my feet off the pedals. I've got massive bruises on both knees from where they have hit the handlebars at these times. This happens when riding on relatively smooth roads so isn't even anything to do with the type of terrain that I am riding on.

I have taken the bike to a shop to be serviced and they seemed to think it was ok but it is still happening. So with that information and the fact that I can't afford to upgrade my bike straight away what can I do to try and solve this issue with gear changes being clunky and gears being missed (or being missed then snapping back into them as I am riding)?

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    Are they Revoshift shifters (twist the grips to change gear)? Apollo insist on using them, and they're a pain. They can seem fine (if a little stiff) on a workstand but in actual riding they do nothing, nothing, jump.
    – Chris H
    Oct 1, 2019 at 21:09
  • Yes is 7 speed revo shift shifters. Changing between the cogs at front works fairly smoothly but changing gears on the rear cog is where has an issue. I have looked at the indexing and seems ok on a workstand but as you say the issue comes in actual riding. Likely why they said gears were ok when was serviced but hasn't been a noticeable difference when actually riding
    – woody316
    Oct 2, 2019 at 12:34
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    I used to look after a bike with exactly the same shifters and never found a satisfactory solution. Riding it I could overshift until it got in the right gear, then back it off, all while pedalling gently, but that wasn't satisfactory for the owner.
    – Chris H
    Oct 2, 2019 at 14:17

3 Answers 3

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The first thing to check is that the rear derailleur indexing adjustment is good. I.e. the derailleur cage is aligned properly with the individual sprockets in each gear. If cage is moving slightly too far at each shift it could push the chain two sprockets over instead of one. I would expect a repair shop to be able to adjust indexing properly, and bad indexing causes the chain to rattle on the sprockets - which you don't mention - so this may not be the issue.

The next thing to check for is a bent derailleur hanger resulting in the derailleur cage not being parallel to the sprockets.

Another cause of shifting problems is the shift cable sticking in the housing due to corrosion or contamination, although this tends to cause 'delayed' upshifts (from larger to smaller sprockets) as the derailleur spring cannot pull the cable through the housing.

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  • The delay seems to happen with up and down shifts particularly on the 3rd and 6th gears. I've looked at the indexing and it has been through a service and as I put in response to Chris H, it seems to work relatively well on a workstand but the issues occur when you then start riding.
    – woody316
    Oct 2, 2019 at 12:38
  • The bent derailleur hangar has been suggested a few times so I'm going to have a look at that. Do you have any good guides or videos for looking at the shift cable sticking so I can have a look at that?
    – woody316
    Oct 2, 2019 at 12:39
  • regarding cable stick: check if housing end caps are bent, check if housing ends are properly cut (straight cut, teflon properly 'opened up'). Check gear cable for bends/freying. Check if housing length isn't too short. Remove cable from rear derailleur, hold it in your hand whilst shifting with the other hand, check if it goes back and forth smootly, if it doesn't your problem is either in the cable or in the shifter but most likely in the cable..
    – Maarten -Monica for president
    Feb 29, 2020 at 1:32
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Given it was a new bike, with only a few months of use, the common cause is "cable stretch" or settling. Those twisted steel wires that run the length of your bike from the bars to the derailleurs will settle, meaning they get slightly longer, which is enough to de-tune the gears.

Almost all bikes have a "barrel adjuster" somewhere in the line. Its common to find them on the rear derailleur, though they can also be found sometimes on the downtube of road bikes, or perhaps even in the shifter on the bars.

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To adjust for cable stretch, the outer housing also has to get longer. So unscrew the rear derailleur housing by half-a-turn and then test shifting with a short ride, or running through the gears with your bike's rear wheel off the ground.

The cable will stop settling after 100~500 km.

Most good bike shops (ie not boxmovers or chain stores) will offer a free 6 week service, where this sort of thing is fixed up. Its also a chance for them to upsell you on some accessories.

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Just been given the apollo spiral as gears didnt work from day one and then owner was too embarrassed to go back as a novice female rider. I have had a look and the rear mech is intrinsically tighter than it should be and the front derailure has bent as it has caught the sprocket against the chain- It looked too low but on raising it I couldnt convince myself that unbending it would resolve the primary problem.... more likely the wrong radius of the arm for the gear ratios. Either way dont buy this bike.

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  • Hi, welcome to bicycles. Aside from seeming to be a far more serious problem than is described in the question, you also don't really answer the question of how to fix the original problem. ("Don't buy this bike" doesn't count as an answer, since it is too late for that.)
    – DavidW
    Apr 4, 2021 at 16:53

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