Slipping gears while climbing

-Trek-

I'm having trouble with my road bike at the moment and looking for some advice. I have adjusted (cable tension) so that they change perfectly while running through the gears on the bike stand and they also seem fine while riding on rollers or on flat road.

My problem of slipping doesn't seem to happen until I'm climbing or putting significant load on the pedals (fat me trying to out run a dog and failing miserably ). The bike has roughly 10k on the clock but I haven't noticed any significant wear on the cassette or chain (I oil them regularly).

I'm wondering is there a way to adjust for this or should I be thinking about replacing chain and cassette?

Thanks.

Mr. Grieves

It could be wear on the chainrings. Does it happen in all the rings up front, or just one? Often the middle ring (if it's a triple) gets disproportionate wear due to more frequent use.

-Trek-

Would say its mostly the middle gears in the rear cassette (sorry meant to say that). Everything up front seems fine.

Paul Kiernan

-Trek- wrote: »

Would say its mostly the middle gears in the rear cassette

They're usually the ones that go first. Have you a chain measuring tool to check if your chain is stretched? You can buy them online for under a fiver?

Or you could just buy a new chain and try changing it yourself. You can get decent KMC chains for around £15. The general opinion seems to be to change both chain and cassette at the same time but I've just changed chain before and everything has been fine.

RandomPanda

More than likely its going to be a worn out chain and cassette. Stop into a bike shop and get them to use their chain wear gauge and that will tell you straight away. Other possibility is that your hanger or drop-out is ever so slightly bent.

-Trek-

thanks, yeah I got the feeling it was time for some replacing, sigh! I will probably go ahead and replace both seeing that Ill end up ordering from CRC, maybe with shimano 105's or something, I don't know. Let the fun begin with picking the right new chain and cassette .

EDIT: Its a 9 speed so not sure if there is a 9 speed 105??

RandomPanda

No there is no 105 9sp chain

Go with this sram chain. I only run sram components now and couldn't be happier

http://www.chainreactioncycles.com/Models.aspx?ModelID=9873

Don't forget a new cassette as well to go with your chain!

http://www.chainreactioncycles.com/Models.aspx?ModelID=17902

cython

Paul Kiernan wrote: »

They're usually the ones that go first. Have you a chain measuring tool to check if your chain is stretched? You can buy them online for under a fiver?

Or you could just buy a new chain and try changing it yourself. You can get decent KMC chains for around £15. The general opinion seems to be to change both chain and cassette at the same time but I've just changed chain before and everything has been fine.

RandomPanda wrote: »

No there is no 105 9sp chain

Go with this sram chain. I only run sram components now and couldn't be happier

http://www.chainreactioncycles.com/Models.aspx?ModelID=9873

Don't forget a new cassette as well to go with your chain!

http://www.chainreactioncycles.com/Models.aspx?ModelID=17902

Lads, while I agree in this particular instance both chain and cassette probably need replacing (since sprockets on the back seem to be worn if it slips in particular ones), this is far from being the case all the time, or even "the general opinion". Have a look around past threads here and you'll see plenty of posters say that they get 3+ chains to a cassette by just being mindful of chain wear/stretch and replacing the chain before it has gone so far that it starts damaging/wearing the cassette.

victorcarrera

You did well to get 10K out of a 9sp chain you must have full mudguards.
The chain is probably too far gone now and you should notice the rollers are loose and creaking when climbing. I got 13K Km out of a 9 sp chain before it started slipping on the middle gears. At this point the length of 12 links was 12 +1/4 inches. I replaced the chain only and it is still ok after another 5K Km. It is difficult to see wear on the cassette so I would just replace the chain and see how it goes before you change the cassette. If it still slips change the cassette too or at least the suspect cogs if you can get them. 9 sp Tiagra cassettes are hard wearing and are not expensive by comparison.

2 Wheels Good

Strange, I have this on a new bike running 105. Slips in 4th or 5th gear. Swapped out the cassette for 12-27 for a cycle and same thing happens. Has been there since near the start and only 500k total on the bike

cython

2 Wheels Good wrote: »

Strange, I have this on a new bike running 105. Slips in 4th or 5th gear. Swapped out the cassette for 12-27 for a cycle and same thing happens. Has been there since near the start and only 500k total on the bike

Does the chain slip or slide over the teeth on the sprockets, or jump between sprockets? If the latter, I'd suggest looking at your gear indexing, and the tension in cables. They could start have stretched a bit after 500km. If the former, however, then yeah it sounds a bit odd

victorcarrera

2 Wheels Good wrote: »

Strange, I have this on a new bike running 105. Slips in 4th or 5th gear. Swapped out the cassette for 12-27 for a cycle and same thing happens. Has been there since near the start and only 500k total on the bike

Assuming all the parts were new when you got the bike your chain is probably jumping due to the gear cable outer ends bedding in (aka cable stretch). Not unusual in a new bike. You should notice a difference in your pedal cadence if the chain is jumping as distinct from slipping under load.
Turn one of the barrel adjusters at the rear mech, downtube or shifter 1/4 turn anticlockwise test and repeat as necessary (this tightens the cable). If that doesn't solve it go back by the same amount of turns as it must be something else.
Check that the rear mech and cable moves freely also.
Tip: When you park your bike shift the chain into the smallest front and rear gears, it eases the rear mech spring and relieves the tension on the cables.

fletch

I recently got a new rear wheel, new chain, new rear cassette and two new front chainrings and my gears are still slipping when in the middle gears! Any ideas?

victorcarrera

fletch wrote: »

I recently got a new rear wheel, new chain, new rear cassette and two new front chainrings and my gears are still slipping when in the middle gears! Any ideas?

Slipping or jumping? Under load or not? Other possibilities are chain too long/loose. Sticky or frayed cable especially the short outer cable at the rear mech.