shifting problem - (riding on The Noob adventures thread a little! ;)

S-works

Warming-Up
May 8, 2012
5
0
0
Toronto
#1
hey everyone,

After a little searching I came across this great site and was impressed with how well everyone talked about and solved problems and thought this is the place for me! So, even though I'm all the way from Toronto, Canada I hope to find a few friends to share some experiences with. :)

I ride a Specialized S-Works M5 which is total overkill for me, but I've had a few bikes and keep upgrading, and well, I ended up with this 25 pound beauty.

My bike is working pretty well other than a sticky Hayes rear brake for which I've ordered a replacement/upgrade for.

The problem is my son's Specialized Hardrock Comp Disc. It's entry level Shimano Alivio front deraileur/Suntour SR chainrings and is about 2 years old.

The problem is upshifts on front and chain suck.It very reluctantly shifts up from a smaller front chainring to a larger one, and often results in chain suck. The chain rides up the rear of the front sprocket and jams at the frame and everything grinds to a halt.

I took it to a LBS and they showed me the warped chain and replaced it saying that should fix it. It didn't really help much at all. :(

I've tried putting a little more cable tension on shifter and it seemed to help a little but not much. I can't see the chainrings being shot in only a couple of years, but I guess it's possible?

I'm going to try and attach some pics so you can see what I'm working with.

Thanks for reading, can't wait to hear back on this...
 

bloaker

Maximum Pace
Nov 14, 2011
1,551
1,224
433
Miura, Japan
#2
I had a similar issue last year on my Soma.
The problem ended up being a worn out middle chain ring.
I could not find the ring I need, so I priced out all three new rings and ended up buying a complete new crankset instead.
Lucky for me I have a few bikes, so I was able to test my theory prior to the purchase.

/***********/
Prior to that determination, I scrubbed my drive train.
I 'over' tensioned the cable to see if it was possibly not a solid shift.
I let others ride it to ensure it was NOT me and somehow me not being firm on the trigger shifters.

In the end, the problem still existed. SO I pulled the cranks off my old Dragon and put them on the Soma. Problem solved. So I order new cranks and all is well.
 

S-works

Warming-Up
May 8, 2012
5
0
0
Toronto
#4
bloaker,

Thanks for the quick reply, we're pretty close in timezones :)

I think you're on to something. I took a few more pics and noticed the rear changer is really scuffed up, and, out of alignment. Maybe that's causing this problem?

For budget, I was thinking about $200 all in, I do the wrenching. So new chainrings or crank set and new rear derailleur.

The more I look at the rear cassette the more I think I need one of those too. This kid is rough on his bike but at least he's using it, and he doesn't complain about it, making me more inclined to help solve this little problem.

Check out the new pics attached.

thanks again...
 

GSAstuto

Maximum Pace
Oct 11, 2009
945
242
103
tokyo
www.roadfixie.com
#6
My thoughts:

1) Rear derailler is obviously tweaked - need to re-align or even replace the derailler hanger.

2) Chain needs replacing.

3) Chainrings at minimum need to be cleaned thoroughly and probably replaced.

4) Upgrade the rear cassette

5) Actually - I'd just replace both Cassette and fron Chainset with a Deore 10sp (about 12,000 yen)
 

AlanW

Maximum Pace
Jan 30, 2007
1,214
436
103
Tokyo
#7
Ah the dreaded chain-suck! Can be a real pain to find the cause and fix it.

To echo what others have said - The chainrings are probably worn which is one cause of chainsuck. You said the bike shop put a new chain on, so there's potential for that new chain to slip on the cassette and the chainrings, in addition to your current problems.
Other things to check:
Is the front derailleur moving smoothly - they are in the firing line for spray from the back wheel and can gum up.
Is the front derailleur cage straight? If it's twisted, which it may be if you've been heavy handed trying to get it to shift, it will make matters worse.
Limit screws set correctly?

I'd recommend: straigten the rear derailleur hanger, clean and lube all the derailleir pivot pins, then add new chainrings (but you may find it more economical to buy a new crank), New 8-speed shimano cassette, and new cables. I think you'll get a nice smooth running bike if you do that.

Be aware that if you upgrade to anything other than 8-speed, you'll essentially need a full drivetrain. Cranks with rings/Cassette/Shifters/Chain and 10-speed will need a new rear derailleur as well. Having siad that, the Rockhopper is a nice frame and worthwhile to upgrade.

Good Luck.
AW​

ps. And let's see some pics of the M5!
 
Sep 2, 2009
5
0
0
#8
The problem is upshifts on front and chain suck.It very reluctantly shifts up from a smaller front chainring to a larger one, and often results in chain suck. The chain rides up the rear of the front sprocket and jams at the frame and everything grinds to a halt.
Waaaaaaay back in the day, my first MTB was a Marin, with Alivio gears, and it was the worst thing ever for chain suck. I am trying to remember the situations under which is happened, and when I do, I will post them up, as I do remember I fixed it, to an extent. Was upsetting as a youngster to see the bike I had saved up so long for getting its drive side chainstay scratched to buggery, and I set to remedying it!

I can remember that chainsuck didn't happen when just riding and was an issue, like you, when shifting. I think I also got it when shifting up on the front too, so in hindsight it was most likely a problem with very cheaply made chainrings that had no fancy machining on the inside to stop the chain snagging on the upshift.

This, combined with a cheap rear mech with a less than ultra strong tension spring in the joint between the main body and the cage meant that the chain was easily snagged, and not tensioned hard by the rear mech, so prone to being pulled up into the gap between the chainring and chainstay.

I also seem to remember at the time, reading in MTBPro and MBUK that a lot of hardtail frames were being made with a large gap between the chainstay and chainring to prevent this issue.

I realise this is nothing like a solution to you, but may shed some light on what is causing it, from my experiences. I will try to remember more of what was happening at the time for you.

Let us know how you get on.

Owen
 

GSAstuto

Maximum Pace
Oct 11, 2009
945
242
103
tokyo
www.roadfixie.com
#9
Ahh yes, the dreaded chain suck!

As worn as everything is in the pics -- just changing out any of the single components will not fix it - but move you simply to the outer edges for the chainsuck bermuda triangle.

Like Owen noted - especially cheaply (stamped) chainrings that don't have proper ramps on the smaller rings will glob onto the chain faster than an OL to a Trader at 3am in Motown.

Easiest fix is to get rid of all the old components and replace with a new matched set. Whether you go 8speed, 9speed or 10speed - it doesn't matter. And the new Shimano Deore series is super affordable and avoids much of these hassles.
 

kiwisimon

Maximum Pace
Dec 14, 2006
2,670
483
103
Japan
#10
Check the chain length, often times these are installed too long at the shop and the lack of tension on the derailler when on the smallest chainring leads to chain suck.Teach the young fella not to cross the chain too much and you'll be good. A good cleaning a fresh chain and things should really improve. Good luck.
 

S-works

Warming-Up
May 8, 2012
5
0
0
Toronto
#11
thanks for all the replies so far, very much appreciated. :D

Please take a look at these new pictures I took. I went to an external flash and dialed down the power which helped to better capture the the reflective metal. I'm hoping the rear cassette is still usable. I think it's a better quality Shimano piece than the Suntour up front...

-The chain was already replaced by the bike shop last week so that should be okay

-I used the link Bloaker sent and bought a few parts at Jensen USA:
I got the new LX crankset, an LX Derailleur for rear, and a new changer for the front. I also got (hopefully) all the necessary tools to do the work.

The original front derailleur has a lot of slop in it compared with my older s-works changer which is suprising considering it's only a couple of years old.

The rear derailleur hanger...what's the best way to line it back up? I've tweaked it a bit just by eye but wondered if there's a more exact way to line things up back there.

Can't wait to get the new parts installed and get it all setup, should be fun.

Don't laugh but does the chain have to come apart to install the rear derailleur? If so I'm not sure if the Parker multi-tool I bought will do the trick.
 
Sep 2, 2009
5
0
0
#13
Rear mech; take the jockey wheels off, twist the cage round, put the chain through where it needs to go, and put cage back in position. Then refit the jockey wheels.
 

S-works

Warming-Up
May 8, 2012
5
0
0
Toronto
#14
Hi Alan,

Thank you for your reply. Yes this chain suck situation is frustrating for sure.
Since I did already have chain replaced I'm thinking you guys are right, the chainrings need to be replaced. There is slight burring on them which could hold on to the chain a little for a ride up the back of the chainring.

The front derailleur is clean and straight and seems to be adjusted properly. The limit screws are okay as the chain never falls off inner or outer sprockets.

I've got a new crankset and derailleurs coming in soon from Jensen. I hope the cassette will hold up okay. I think it should be fine as the rear shifting is smooth and predictable, with no slippage or noise.

I was thinking about the 10 speed upgrade but wondered where I was going to stop. :confused: It's easy to get carried away with this when my original task was to fix the front shifting! I almost got thinking of an XTR upgrade to my S-Works and transferring the components over, but why would I want to upset a perfectly shifting bike? I test drove an Audi S4 the other day and that's about how positive my bike shifts, it's amazing really, even under full loads up a hill.

Thanks for the help!

Ah the dreaded chain-suck! Can be a real pain to find the cause and fix it.

To echo what others have said - The chainrings are probably worn which is one cause of chainsuck. You said the bike shop put a new chain on, so there's potential for that new chain to slip on the cassette and the chainrings, in addition to your current problems.
Other things to check:
Is the front derailleur moving smoothly - they are in the firing line for spray from the back wheel and can gum up.
Is the front derailleur cage straight? If it's twisted, which it may be if you've been heavy handed trying to get it to shift, it will make matters worse.
Limit screws set correctly?

I'd recommend: straigten the rear derailleur hanger, clean and lube all the derailleir pivot pins, then add new chainrings (but you may find it more economical to buy a new crank), New 8-speed shimano cassette, and new cables. I think you'll get a nice smooth running bike if you do that.

Be aware that if you upgrade to anything other than 8-speed, you'll essentially need a full drivetrain. Cranks with rings/Cassette/Shifters/Chain and 10-speed will need a new rear derailleur as well. Having siad that, the Rockhopper is a nice frame and worthwhile to upgrade.

Good Luck.
AW​

ps. And let's see some pics of the M5!
 

S-works

Warming-Up
May 8, 2012
5
0
0
Toronto
#15
box-o-goodies!

hey everyone,

Look what just showed up from Jensen? 2 days cali to canada, nice!

Looks like I've got my work cut out for me. :D

Wish me luck!

Thanks for the help so far...

See attached pic