Chain Slip

[gazzab]

My bike (a Trek 6700 SLR Hard Tail) is taking a bit of a hammering (2 x 2.5 hr rides a week in wet, muddy, sandy etc conditions). So it really needs a service and bearings regreased etc....... One immeidate problem though is that I am gettiing chain slip on the rear mech - it can happen in a few different gears but mostly in '1/1'. It only happens when I am pushing hard eg up a hill at low speed. I assume that the best way to fix this is to adjust the adjustor by the rear mech? I will read my 'haynes' manual to check this out. Any ideas? (I came off 3 times last night thanks the the chain coming off / slipping).

[Roman]

Either adjustment or it sounds like your cassette & chain could simply be worn out which happens quickly in such conditions.

I would replace both at the same time if it's not adjustment

[gazzab]

Cheers. Maybe more cost effective to upgrade my LX to XT at the same time?

[neil_cardiff]

Bear in mind, if you replace your chain once it's started to slip under power, you'll have to replace your cassette, and in many cases, your chainrings at the same time.

Its all the do with the way the teeth wear on the cassett and chainrings, and if you don't change your chain frequently enough, they hook badly, and then any new chain will skip even more.

Engineers always complain, quoting "I'm an engineer, it shouldn't do that", but us bike shop lackies just shrug our shoulder and tell em' to replace it all, and sure enough, it sorts it.

However, it could just be the deraillier is our of adjustment, but if you've ridden that frequently for over 6 months, you may well have worn the components out

[gazzab]

thanks! Gosh I think my bike service could get expensive then !!! New gears, service and bearings sorted.
I have given it a very hard life over 6 months. It was a new bike 6 months ago!
Might be better value to sell it on ebay as is and buy a new bike!!! ie sell for £350 and then spend £300 extra on an 06 model (or upgrade to that full suspension, carbon bike that I deserve!).
Amazing how fast a bike can wear out if you use it hard in all weathers!

[PhillVR6]

gazzab said:

thanks! Gosh I think my bike service could get expensive then !!! New gears, service and bearings sorted.
I have given it a very hard life over 6 months. It was a new bike 6 months ago!
Might be better value to sell it on ebay as is and buy a new bike!!! ie sell for £350 and then spend £300 extra on an 06 model (or upgrade to that full suspension, carbon bike that I deserve!).
Amazing how fast a bike can wear out if you use it hard in all weathers!

Yeah and don't maintain it!

[pdV6]

Indeed. £10-odd for a new chain every 2 or 3 months vs. £200+ bill every 6 months? I know which I'd prefer...

[gazzab]

Thanks - had no idea that the chain would need replacing. I look at the chain and well it stil looks like a chain.
I clean the chain and mech after or at least before each ride (muck off, brush, water, sponge , wd40, oil).

[beyond rational]

Do the teeth on the sprockets look like shark fins, worn in one direction?

This site is the easiest way to explain things and a good resource (scroll down a bit)

www.epicidiot.com/sports/chain_length_calculator.htm

A chain wear tool is the best way of doing this, but this will work

Edited by beyond rational on Wednesday 15th November 22:08

[gazzab]

Got a new chain and cassette today. The chain was VERY stretched and the cassette was starting to go. So fitted them this afternoon. Short trail rides were fantastic. Bike feels better than ever! Will change the chain every 2 months from now on!

[rameshuk]

gazzab said:

Thanks - had no idea that the chain would need replacing. I look at the chain and well it stil looks like a chain.
I clean the chain and mech after or at least before each ride (muck off, brush, water, sponge , wd40, oil).

**TIP**

Make sure you use the correct oil for the time of year and put a little on while turning the pedals backwards.

Leave for a couple of minutes then hold a dry lint free cloth around the chain and pedal backwards again.
This removes excess oil which picks up all sorts of muck and causes more damage.

R

Edited by rameshuk on Sunday 19th November 16:28

[vrooom]

that why I went single gear now, and never looked back!!!

[neil_cardiff]

vrooom said:

that why I went single gear now, and never looked back!!!

How on earth does that make a difference - you'll experience wear at a much higher rate than you would a normal cassette and chain!?

Single speed only really gains weight and simplicity benefits over anything - and is more a fashion thing (unless your a messenger) I believe - a bit like this unhealthy experimentation with 29" wheeled MTBs...

[beyond rational]

You won't have wear at the same rate because as long the drive is aligned correctly and tension is maintained, there will be very little lateral stress on the chain, so less wearing of the bushings and therefore less stretch. Similar reasons give the sprockets more life in addition to a healthier chain. Single speeds generally run a thichker chain and sprockets not designed to shift, any sprocket that shifts has an inbuilt weakness in terms of delivering power.

Edited by beyond rational on Sunday 19th November 18:55

[neil_cardiff]

beyond rational said:

You won't have wear at the same rate because as long the drive is aligned correctly and tension is maintained, there will be very little lateral stress on the chain, so less wearing of the bushings and therefore less stretch. Similar reasons give the sprockets more life in addition to a healthier chain. Single speeds generally run a thichker chain and sprockets not designed to shift, any sprocket that shifts has an inbuilt weakness in terms of delivering power.

Edited by beyond rational on Sunday 19th November 18:55

Fair argument, however IIRC most MTB's set up to run single speed use normal componentry, i.e. chain etc, so I would say that the potential for wear is just as great.

I don't believe that that the fact that deraillier shifting introduces any level of additional stress over single speed - if anything the scope for higher stress to be placed upon the chain is greater due to the fact that there is no way for the drive torque to be reduced by using a lower gearing.

However, as much as single speeders try to smugly proclaim that they don't have any problems, its all very well, but I like my knees, and would rather replace an £20 chain every few months than have to replace the cartilidge in my knees

[beyond rational]

I could not live with with single speed myself and I agree that it is in fashion at the moment, rightly or wrongly, some people have a genuine use for it, others don't.

I don't believe that stretch is caused by torque in the large part, if at all, but mainly by the rubbing of the pivots, made worse IMHO by a derailleur (or out of allignment SS setup)as this focuses force on one side of the pivot thus increasing play. I don't know about running a 8/9spd chain in SS but in general I found that the thicker SS chains of hub geared bikes and BMXs last much longer (ok, they are thicker) but I would think a aligned 8/9spd SS would last longer than a derailleur setup purely because the force applied is totally in the direction the chain was designed to transfer it. My 2p

[pdV6]

Chain stretch is the pins wearing not the link plates stretching, so I'd expect roughly the same amount of wear using the same components in SS or 'derailed' setup if they were used in the same conditions.

That said, however, how many SS rigs are going to be sloshing through the mud and grit of a British winter off-road?

[jwyatt]

neil_cardiff said:

Bear in mind, if you replace your chain once it's started to slip under power, you'll have to replace your cassette, and in many cases, your chainrings at the same time.

Its all the do with the way the teeth wear on the cassett and chainrings, and if you don't change your chain frequently enough, they hook badly, and then any new chain will skip even more.

Engineers always complain, quoting "I'm an engineer, it shouldn't do that", but us bike shop lackies just shrug our shoulder and tell em' to replace it all, and sure enough, it sorts it.

However, it could just be the deraillier is our of adjustment, but if you've ridden that frequently for over 6 months, you may well have worn the components out

That's so true - since buying a tool to measure chain stretch, and replacing chains when close to the recommended limits, I've not had to replace a single chainset or cassette in years.

[vrooom]

Gear it right. its useful as MTB. i spend some time working out my gear ratio. I has been riding single gears for years, i never had a problem with my knees...