Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 02-09-09, 07:30 PM   #1
sknhgy 
Dirt Bomb
Thread Starter
 
sknhgy's Avatar
 
Join Date: Aug 2006
Location: Illinois
Bikes:
Posts: 2,621
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 79 Post(s)
Shifter is gonna break my thumb

I have a Trek 820 mtb. The front derailler takes a lot of effort to shift from 2nd to 3rd gear. So much effort that it hurts my thumb. I believe that these are brifters. They are labeled Shimano Topswing S1S or 515. With this shifter you downshift with your trigger finger and upshift with your thumb.

I have cleaned and lubed the shifter and the cables. It seems like the return spring is very stiff.

I have another bike with the same shifter, but the cable on it comes up from underneath the BB and it wraps around the actuator. That bike shifts fine. On the Trek, the cable comes to the top of the actuator and it pulls up. I know this isn't a very clear description.

Is there something I can do to decrease the shift effort? Can I easily upgrade this shifter?

Thanks in advance.
__________________
more cops have been killed by donuts than guns in chicago it is a medical fact ask any doctor.
sknhgy is offline   Reply With Quote
Old 02-09-09, 09:00 PM   #2
sknhgy 
Dirt Bomb
Thread Starter
 
sknhgy's Avatar
 
Join Date: Aug 2006
Location: Illinois
Bikes:
Posts: 2,621
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 79 Post(s)
Any ideas? This has got me stumped.
__________________
more cops have been killed by donuts than guns in chicago it is a medical fact ask any doctor.
sknhgy is offline   Reply With Quote
Old 02-09-09, 09:24 PM   #3
wrk101
DRF aka Thrifty Bill
 
wrk101's Avatar
 
Join Date: Jan 2008
Location: The NC Mountains
Bikes: 86 Katakura Silk, 87 Prologue, 87 Cimarron, 14 frame school custom, 73 Paramount
Posts: 19,965
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
I wouldn't call these brifters unless the brake lever is integral to the shifter, these are trigger shifters. Have you tried cleaning them? How old is the bike? I have replaced some old ones with Shimano shifters sold by Niagara. The 6 speed shifters go for about $8, the 7 speed go for $12, complete with cables.

I have never had that good of luck rebuilding these shifters, probably a lack of skill on my part. So I tend to toss the old ones. Some report decent luck getting them working again. But for $12 complete with cables, hard to justify much work on old ones at least.

Neither of these below have integral brake levers:

7 speed:
http://www.niagaracycle.com/product_...ducts_id=15889

6 speed:
http://www.niagaracycle.com/product_...oducts_id=6144

Last edited by wrk101; 02-10-09 at 07:18 AM. Reason: clarification
wrk101 is online now   Reply With Quote
Old 02-09-09, 09:40 PM   #4
Panthers007
Great State of Varmint
 
Panthers007's Avatar
 
Join Date: Sep 2008
Location: Dante's Third Ring
Bikes:
Posts: 7,479
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Some of these shifters from Shimano are designed to turn into a mound of parts if you so much as try to replace a cable. This happened to me with my Trek FX 7.5 when the cable broke. Also original equipment. But here's one thing you can try: Check the cable-tension with the bicycle resting with the chain shifter to the small cog in the back, and smallest chainring.The cable should have zero slack, and not be super tight. A bit tight - but not so tight that if was on a bow it could put an arrow through a tree. A little tight. If it is super-tight, release the cable anchor bolt and relax the cable. Then pull the cable as tight as your fingers will allow and tighten the cable-anchor bolt securely - careful, it's alloy and can strip if you go to far.

The solution I finally came up with was to junk the Shimano shifters. I replaced them with SRAM Attack shifters. I've had no problems since. And installing new cables is painless.

I'm all ears/eyes to other suggestions regarding the Shimano shifters.
Panthers007 is offline   Reply With Quote
Old 02-09-09, 09:44 PM   #5
sknhgy 
Dirt Bomb
Thread Starter
 
sknhgy's Avatar
 
Join Date: Aug 2006
Location: Illinois
Bikes:
Posts: 2,621
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 79 Post(s)
OK. Trigger shifters.
That looks a lot like them, but not exactly. I did open up the offending shifter and it looked clean. I did not lube it.

It seems like the return spring down on the derailler is very stiff and all the effort comes from having to overcome the spring tension.

Can just the derailler be upgraded?
__________________
more cops have been killed by donuts than guns in chicago it is a medical fact ask any doctor.
sknhgy is offline   Reply With Quote
Old 02-09-09, 09:45 PM   #6
800over
Big Mac and No hills.
 
800over's Avatar
 
Join Date: Oct 2007
Location: Ontario
Bikes: Trek 1500, Raleigh Tarantula
Posts: 245
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Yes they are brifters.

Brifters: shifters that break my thumb.
800over is offline   Reply With Quote
Old 02-09-09, 09:54 PM   #7
Panthers007
Great State of Varmint
 
Panthers007's Avatar
 
Join Date: Sep 2008
Location: Dante's Third Ring
Bikes:
Posts: 7,479
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The spring in the front derailleur (FD) is supposed to be very tight - it's job is basically taking a moving chain and throwing it across the chainrings. But this would not cause problems with shifting. The trigger-shifter is pulling, and relaxing, the cable over small distances inside. The shifters should require a bit of force - unless the cable has gone slack - to move them. A bit of force. Nothing like what you're describing in your original post. If your FD is dirty and grimy, I'd suggest removing it and cleaning it thoroughly. Then apply good oil to all the moving parts.

To your question on upgrading. Sure! FD's are available so you can. And spend any where from $15 up to $150.
Panthers007 is offline   Reply With Quote
Old 02-09-09, 11:02 PM   #8
bikinfool
I have senior moments...
 
bikinfool's Avatar
 
Join Date: Oct 2008
Location: Woodside, CA
Bikes: Many
Posts: 2,152
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
An issue that comes up with older trigger shifters is the grease inside gets gummy after a number of years. While actual access by disassembly isn't much of an option, you can spray liberal quantities of a solvent type spray (WD40 works well enough) into the mechanism from an opening (like the cable access point), work it a while with the levers, and then relube (as the WD40 isn't much of a lube, more a water displacement with solvents). You really can't regrease due to access. That process has saved many a trigger shifter.

Yours might still be brifters if your shifter units are integral to the brake levers...that's all that brifter means...
bikinfool is offline   Reply With Quote
Old 02-09-09, 11:45 PM   #9
Mondoman
Senior Member
 
Join Date: Apr 2008
Location: A Latvian in Seattle
Bikes:
Posts: 1,020
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
It certainly won't hurt to lube the pivot points and perhaps spring of your FD (front derailleur or "actuator"). Something like Boeshield T9 is great for this, but a light oil should be fine, too. It may also be that your FD and/or cable tension are not adjusted quite right -- see the FD adjustment instructions at the parktool.com website, or a good book such as Zinn's.
The different FD types you described are called "bottom pull" (cable comes up to FD from below BB and pulls down) and "top pull" (cable comes from above and pulls up).

Last edited by Mondoman; 02-09-09 at 11:49 PM.
Mondoman is offline   Reply With Quote
Old 02-10-09, 01:12 AM   #10
shea2812
Senior Member
 
Join Date: Apr 2005
Location: Malaysia
Bikes: an old Marin
Posts: 66
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
replacing shorter BB or BB axle may help! will place the chainrings a little bit closer to the optimum range for the FD to work more comfortable. Also check the way you attach the shiftcable to FD!
shea2812 is offline   Reply With Quote
Old 02-10-09, 02:15 PM   #11
illwafer
)) <> ((
 
illwafer's Avatar
 
Join Date: Mar 2008
Location: San Diego, CA
Bikes:
Posts: 2,396
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
you can also throw in a Falcon 5-speed friction thumb shifter for $.99 with your next Nashbar order to see if it is a shifter issue or not.
illwafer is offline   Reply With Quote
Old 02-10-09, 02:46 PM   #12
LarDasse74
Guest
 
Join Date: Jul 2008
Location: Grid Reference, SK
Bikes: I never learned to ride a bike. It is my deepest shame.
Posts: 3,769
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The issue is likely the cable routing on the front derailleur. I am guessing that you have a bottom-pull front Der, as they are most prone to this problem if set up incorrectly.

After the cable comes up fron under the bottom bracket the cable should pass OVER a small tab on the cable arm of the derailleur, then behind the pinch bolt and tightened down.

Running the cable under the tab looks better, but significantly shortens the lever-arm that the cable gets to pull on and makes the shifter feel stiff.
LarDasse74 is offline   Reply With Quote
Old 02-10-09, 07:02 PM   #13
nonfortuna
Junior Member
 
Join Date: Oct 2008
Location: Midwest
Bikes: Zion EBB, Steamroller, Zaskar LE, Top Fuel
Posts: 23
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
This sounds to me like you are fighting against the high limit screw. The OP states that the issue arises when shifting from 2nd to 3rd, nothing about the 1st to 2nd shift. Try backing out the screw labeled "H" 1/4 turn or so.
nonfortuna is offline   Reply With Quote
Old 02-10-09, 08:32 PM   #14
wrk101
DRF aka Thrifty Bill
 
wrk101's Avatar
 
Join Date: Jan 2008
Location: The NC Mountains
Bikes: 86 Katakura Silk, 87 Prologue, 87 Cimarron, 14 frame school custom, 73 Paramount
Posts: 19,965
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Quote:
Originally Posted by nonfortuna View Post
This sounds to me like you are fighting against the high limit screw. The OP states that the issue arises when shifting from 2nd to 3rd, nothing about the 1st to 2nd shift. Try backing out the screw labeled "H" 1/4 turn or so.
This is a really good point. Look at the derailleur and see if you are up against the limit. If so, back it off slightly. Being up tight against the limit would give the symptoms you are seeing.
wrk101 is online now   Reply With Quote
Old 02-10-09, 09:00 PM   #15
Herbie53
Senior Member
 
Herbie53's Avatar
 
Join Date: Nov 2008
Location: Texas
Bikes:
Posts: 7,085
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 31 Post(s)
I had a similar front shifting issue after changing out a FD on my Trek 850. Messed around a good bit, and posted here somewhere. Eventually sorted that I had routed the cable a bit differently than it was.

The cable routing made a huge difference -- it should be on the side of the fixing screw that is farthest from the pivot point. A screw width doesn't seem like a big diff, but it made a mine go from a thumb killer to shifting like butter.
Herbie53 is offline   Reply With Quote
Old 02-10-09, 09:03 PM   #16
Herbie53
Senior Member
 
Herbie53's Avatar
 
Join Date: Nov 2008
Location: Texas
Bikes:
Posts: 7,085
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 31 Post(s)
Quote:
Originally Posted by LarDasse74 View Post
The issue is likely the cable routing on the front derailleur. I am guessing that you have a bottom-pull front Der, as they are most prone to this problem if set up incorrectly.

After the cable comes up fron under the bottom bracket the cable should pass OVER a small tab on the cable arm of the derailleur, then behind the pinch bolt and tightened down.

Running the cable under the tab looks better, but significantly shortens the lever-arm that the cable gets to pull on and makes the shifter feel stiff.

ooops. just realized this is the same thing I just said... so, +1
Herbie53 is offline   Reply With Quote
Old 02-10-09, 09:09 PM   #17
sknhgy 
Dirt Bomb
Thread Starter
 
sknhgy's Avatar
 
Join Date: Aug 2006
Location: Illinois
Bikes:
Posts: 2,621
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 79 Post(s)
I ended up backing the high limit screw off a full turn. No change.
I checked the cable tightness with the chain on the small chainring and small cog. The cable was just barely slack with the chain in that position, I I don't think I'm fighting against an overly tight cable.
This FD is designed as a bottom pull but it's rigged as a top pull. That's how it came from the LBS.

This bike cost $275 new 3 years ago, so it's not high quality. Since then I've put a lot of money into it, including a hand built rear wheel after I had gone thru two previous ones.
My point is I like the bike, and I would not mind upgrading the front derailler if that would solve the problem. If I did go that route what would I need to get?
__________________
more cops have been killed by donuts than guns in chicago it is a medical fact ask any doctor.
sknhgy is offline   Reply With Quote
Old 02-10-09, 09:46 PM   #18
Mr. Underbridge
Senior Member
 
Join Date: Mar 2007
Location: Reston, VA
Bikes: 2003 Giant OCR2
Posts: 2,369
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Might the cable be frayed? Last time I was having a lot of trouble shifting, the thing snapped a week later. Did you check the cable when you had it open?

Alternately, shoot some WD-40 in there and see if things loosen up. Sometimes the grunge is deeper in the works than you can immediately see so the spray helps.
Mr. Underbridge is offline   Reply With Quote
Old 02-10-09, 11:05 PM   #19
neil0502
My bike's better than me!
 
neil0502's Avatar
 
Join Date: Feb 2005
Location: Northern Colorado
Bikes: (2) Moots Vamoots, (1) Cannondale T2000 tourer, (1) Diamondback Response Comp mtb
Posts: 2,041
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Can you simply remove the cable, and then see how freely the shifter does or does not move??

If it moves freely, and springs back nicely, withOUT the cable, then your problem is farther downstream (cable, housing, bb cable guide, FD, etc.).

If, OTOH, it's STILL a thumb-breaker, then you know your shifter is either gummed up or FUBAR.

Hosing the pi$$ out of the shifters, with WD-40, though, quite often gives them a new lease on life!
neil0502 is offline   Reply With Quote
Old 02-10-09, 11:14 PM   #20
Panthers007
Great State of Varmint
 
Panthers007's Avatar
 
Join Date: Sep 2008
Location: Dante's Third Ring
Bikes:
Posts: 7,479
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Agree with ^^^. But after using the WD-40 to clean out any embedded grunge, be sure to use a good quality oil on all the moving parts - including the spring itself. I recommend one that contains Teflon, it lasts longer in my experience.
Panthers007 is offline   Reply With Quote
Old 02-11-09, 08:03 AM   #21
sknhgy 
Dirt Bomb
Thread Starter
 
sknhgy's Avatar
 
Join Date: Aug 2006
Location: Illinois
Bikes:
Posts: 2,621
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 79 Post(s)
I will try hosing it with lube.
Last night I worked on it around 8-9pm. Then I just had to take it for a test ride. Bad thing is I ended up doing about 5 very hilly miles. I was so wound up after that I did not sleep well last night.
__________________
more cops have been killed by donuts than guns in chicago it is a medical fact ask any doctor.
sknhgy is offline   Reply With Quote
Old 02-11-09, 08:39 AM   #22
Kotts
Recreational Commuter
 
Join Date: Apr 2006
Location: Central Ohio
Bikes: Two brand-less build-ups.
Posts: 1,010
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
This FD is designed as a bottom pull but it's rigged as a top pull. That's how it came from the LBS.
Ummmmmmm, I suspect that that might be exactly the problem.
Kotts is offline   Reply With Quote
Old 02-11-09, 08:47 AM   #23
LarDasse74
Guest
 
Join Date: Jul 2008
Location: Grid Reference, SK
Bikes: I never learned to ride a bike. It is my deepest shame.
Posts: 3,769
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Kotts View Post
Ummmmmmm, I suspect that that might be exactly the problem.
This used to be quite common - usually with a little pulley mounted down low on the seat tube. From the OPs description, though, I can't figure out how his cable is routed.
LarDasse74 is offline   Reply With Quote
Old 02-11-09, 10:36 AM   #24
sknhgy 
Dirt Bomb
Thread Starter
 
sknhgy's Avatar
 
Join Date: Aug 2006
Location: Illinois
Bikes:
Posts: 2,621
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 79 Post(s)
Quote:
Originally Posted by LarDasse74 View Post
This used to be quite common - usually with a little pulley mounted down low on the seat tube. From the OPs description, though, I can't figure out how his cable is routed.
The cable runs from the shifter to the top tube, along the top of the top tube, then down the seat tube to the Derailler. It pulls up on the actuator. I can see the groove in the actuator that is meant for a cable, but the cable has never been routed through the groove.

Like I said, my other bike has the same components, and the cable runs under the BB and around the actuator.

I will try to post a picture this evening.
__________________
more cops have been killed by donuts than guns in chicago it is a medical fact ask any doctor.
sknhgy is offline   Reply With Quote
Old 02-11-09, 11:03 AM   #25
nonfortuna
Junior Member
 
Join Date: Oct 2008
Location: Midwest
Bikes: Zion EBB, Steamroller, Zaskar LE, Top Fuel
Posts: 23
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
http://bike.shimano.com/media/techdo...9830638259.pdf

Top right of the page shows a derailleur that can be set up top or bottom pull, and the manner in which one should do so. Whatever your problem is, I bet your LBS could spot it before the bike made it to the stand.
nonfortuna is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 07:43 AM.