Slipping Gears

Discuss light weight issues concerning mountain bikes & parts.

Moderator: Moderator Team

User avatar
paulm2322
Posts: 65
Joined: Thu May 30, 2013 6:59 pm
Location: Liverpool, UK.

by paulm2322

Hi folks, I have a 2012 Trek 6000 MTB that has done approx 500 miles, most of it in bad weather. The gears shift perfectly on the LBS bike stand. It has been serviced and looked after. The problem I have is when I am out riding and put some power down it slips badly. Shifts perfectly on bike stand/slips badly when giving it some. After 500 miles, surely the cassette/chain rings/chain would not need replacing? Or am I wrong?

Any advice much appreciated.

Thanks
You can't 'out train' a bad diet : )

miceden
Posts: 250
Joined: Mon Mar 09, 2009 5:38 pm
Location: Hampshire, UK

by miceden

I take it the slippage happens at the back? Quite often this is down to the cassette so check the sprockets that the slippage occurs in for wear/damage. If possible borrow another wheel and test on your bike, if the slippage still occurs check your chain to see if its stretched, alignment of the derailleur and that the hanger isn't bent. Also check your jockey wheels for excessive wear.

After 500mi and in most cases the drivetrain shouldn't need replacing no, one of the parts could just be a dud.

by Weenie


User avatar
paulm2322
Posts: 65
Joined: Thu May 30, 2013 6:59 pm
Location: Liverpool, UK.

by paulm2322

miceden wrote:I take it the slippage happens at the back? Quite often this is down to the cassette so check the sprockets that the slippage occurs in for wear/damage. If possible borrow another wheel and test on your bike, if the slippage still occurs check your chain to see if its stretched, alignment of the derailleur and that the hanger isn't bent. Also check your jockey wheels for excessive wear.

After 500mi and in most cases the drivetrain shouldn't need replacing no, one of the parts could just be a dud.


Sorry, yes, slippage always occurs at the back on the cassette. I was thinking about buying a new cassette and seeing if that solves the problem. Don't know wether to buy identical cassette or a better version of the same 11/36 set up.

No chance of me borrowing a wheel as my buddies are roadies.

So if I replace the cassette and it's still slipping should I replace the chain next? Alignment and derailleur should be ok as the LBS gave it a good service and said it shifted perfect - on the stand.

I'm not confident in the mechanic though. He told me 100% that a certain front chain set would not be compatible with my road bike. I took it to Evans and they fitted it and it shifts flawlessly.

Just wondering whether to see if the Evans mechanic can identify the problem before I start spending money replacing parts.

Thanks for the response.

Paul
You can't 'out train' a bad diet : )

rijndael
Posts: 395
Joined: Tue Sep 20, 2011 12:54 pm
Location: Haines, AK - Temporarily

by rijndael

If you're going to get a cassette to solve the issue, I would also get a new chain.

User avatar
paulm2322
Posts: 65
Joined: Thu May 30, 2013 6:59 pm
Location: Liverpool, UK.

by paulm2322

rijndael wrote:If you're going to get a cassette to solve the issue, I would also get a new chain.


Good idea. I will replace cassette and chain and hope that solves the issues.

Thanks

Paul
You can't 'out train' a bad diet : )

User avatar
Benno
Posts: 752
Joined: Sat Jan 13, 2007 10:24 pm
Location: Fort St John
Contact:

by Benno

Doesn't sound like worn out components, more like things are not adjusted/set up correctly. Get a new mechanic or learn how to do the work yourself. It could be many things like derailleur hanger alignment, cable tension, gunked up cable housing, B-tension, chain length......
Light. Strong. Cheap. Pick one.

User avatar
yourdaguy
Posts: 2206
Joined: Thu Mar 17, 2005 3:25 am
Location: Southern Indiana USA
Contact:

by yourdaguy

What Benno said!
For certain parts stiffer is more important than lighter.

Nicholas68
Posts: 69
Joined: Wed Jun 19, 2013 1:30 am

by Nicholas68

Shifting under power and on a bike stand are two completely different things. Since it's new and I doubt anything is worn out I would say the rear shifter cable as stretched (which is normal for a new cable) and the derailleur is out of alignment.

You should be able to look at it from directly being on 5th or 6th gear and the chain should look straight, adjust the tension knob as needed to make it straight, and then make minor changes based on how it shifts. If it all appears straight then check your derailleur for any bends. Then I would think about new cassette and chain. If you are ordering through a bike shop maybe take it to a different one like evans and get a second opinion first.

User avatar
Benno
Posts: 752
Joined: Sat Jan 13, 2007 10:24 pm
Location: Fort St John
Contact:

by Benno

Whatever you do don't go randomly replacing potentially good components for no reason at all. I've heard the same thing over and over about shops just throwing parts at a problem and not fixing a simple issue. I can't tell you how many times I've blown customers minds by taking 10min to properly set up the shifting on a bike. Usually they are completely frustrated, saying they just dropped up to $1500 on a new drivetrain and the bike still didn't work. Surprises them even more when I hand them a $10 invoice for a simple derailleur adjustment.
Light. Strong. Cheap. Pick one.

Colin
Posts: 709
Joined: Mon Mar 02, 2009 4:50 am

by Colin

Check your chain, I recently had a similar problem where it appeared to be fine on the stand, but slipped on every gear when I was actually riding. Turned out to be a broken link in the chain, it just had yet to completely fall apart.

EDIT: It looked like this, only it hadn't separated. Go through and double check every link just to make sure. This was the second time this has happened to me, and both times it took me a few looks to realize there was a broken link.
http://forums.bicycletutor.com/attachment.php?aid=361
Last edited by Colin on Thu Oct 24, 2013 3:22 am, edited 1 time in total.

User avatar
paulm2322
Posts: 65
Joined: Thu May 30, 2013 6:59 pm
Location: Liverpool, UK.

by paulm2322

Benno wrote:Whatever you do don't go randomly replacing potentially good components for no reason at all. I've heard the same thing over and over about shops just throwing parts at a problem and not fixing a simple issue. I can't tell you how many times I've blown customers minds by taking 10min to properly set up the shifting on a bike. Usually they are completely frustrated, saying they just dropped up to $1500 on a new drivetrain and the bike still didn't work. Surprises them even more when I hand them a $10 invoice for a simple derailleur adjustment.


Great advice! Can you fix it for me?? [WHITE SMILING FACE]️ I'm in Liverpool UK area. Failing that, I will hope the Evans mechanic can fix it. Thanks for the help.
You can't 'out train' a bad diet : )

User avatar
Benno
Posts: 752
Joined: Sat Jan 13, 2007 10:24 pm
Location: Fort St John
Contact:

by Benno

Would love to man but I live in Peterborough Canada lol so not really practical. Good luck though.
I have a few different maintenance articles that might be of some help if you ever feel like getting your hands dirty.

Here are a few related to rear shifting....
http://bennosblogandmore.blogspot.ca/20 ... lleur.html
Last edited by Benno on Tue Oct 22, 2013 7:28 pm, edited 1 time in total.
Light. Strong. Cheap. Pick one.

User avatar
paulm2322
Posts: 65
Joined: Thu May 30, 2013 6:59 pm
Location: Liverpool, UK.

by paulm2322

Benno wrote:Would love to man but I live in Peterborough Canada lol so not really practical. Good luck though.
I have a few different maintenance articles that might be of some help if you ever feel like getting your hands dirty.

Here are a few related to rear shifting....
http://bennosblogandmore.blogspot.ca/20 ... lleur.html" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;


LOL worth a try!! Thanks for the link, I will give it a go. It's not that I think I'd be incapable if fixing it, just worried I'd make it worse! If I do I'll take it to Evans : )
You can't 'out train' a bad diet : )

User avatar
paulm2322
Posts: 65
Joined: Thu May 30, 2013 6:59 pm
Location: Liverpool, UK.

by paulm2322

I have tried the high/low adjustments screws on the rear derailleur and the problem still persists! This is so annoying because the bike is perfect apart from this regular problem.

Here are some pictures for the more experienced of you to see if you think any components have worn and are causing the slippage.

Thanks

Image
IMG_5682 by p.t.mainwaring, on FlickrImage
IMG_5681 by p.t.mainwaring, on FlickrImage
IMG_5680 by p.t.mainwaring, on FlickrImage
IMG_5679 by p.t.mainwaring, on FlickrImage
IMG_5677 by p.t.mainwaring, on Flickr
You can't 'out train' a bad diet : )

User avatar
paulm2322
Posts: 65
Joined: Thu May 30, 2013 6:59 pm
Location: Liverpool, UK.

by paulm2322

I have just thoroughly cleaned the whole drive train using white lightening degreaser. I studied the photos I uploaded and realised it was extremely dirty/full of gunk/old lube. Is it possible that this might have been the problem? I won't get to ride it until tomorrow now. Failing that its a trip to Evans to see if the mechanic can solve the problem.

Cheers

:(
You can't 'out train' a bad diet : )

by Weenie


Post Reply
  • Similar Topics
    Replies
    Views
    Last post