Help fix bicycle seat slippage

dragonfly · 03-21-2010, 11:15 AM

My seat on my mountain bike is slipping, what I mean is that the place where the rails are attached to the post is made to swivel for proper adjustment, but I can't tighten it enough to keep my weight from making the seat angle upwards when I sit down.

There are grooves on the post and on the plate that sits on it, and they've become smooth for some reason. I tried to file in some new grooves, but that didn't have any effect.

What can I place between the post and the plate that attach the seat to keep it from slipping? Maybe I need a new/better seat post.

The plate on the table is upside down, it is the part that sits on the post.

I used a Vivitar 28-200 macro zoom to take the pics. You can see how it shows a green halo around the bright areas.

BPT · 03-21-2010, 11:27 AM

Putting in new grooves would work but for it to work you need make the grooves match on both sides or they wont have any effect.

A second option is to take some rubber cut it into a rectangular shape to match the shape of the top of your post, punch a hold through it and put it in between. It might provide enough grip to keep it from slipping. Maybe.

dragonfly · 03-21-2010, 11:43 AM

Originally posted by BPT

Putting in new grooves would work but for it to work you need make the grooves match on both sides or they wont have any effect.

Lol. I'll try out the rubber.

mickeyobe · 03-21-2010, 11:59 AM

Dragonfly,

Google "Star washer "

One of those over the bolt and between the seat post and the plate should do the job.

Mickey

Parallax · 03-21-2010, 12:38 PM

Originally posted by dragonfly

Lol. I'll try out the rubber.

dragonfly, I've owned a bicycle shop for over 12 years and seen every immagineable attempt to fix that prob lem. You need a new seat post. The way to prevent that in the future is to make sure that the teeth are lined up with the opposing grooves when you tighten it. Position the seat and SNUG the bolt then give the saddle a couple of good raps downward with the heel of your hand alternately on the nose and on the back. If it doesn't loosen then the teeth were lined up properly and you can finish tightening the bolt. If it did loosen up that was just the teeth slipping into alignment but repeat the snug/rap process before tightening just to be sure. Always remember to grease, or at least oil any bolt threads prior to assembly to reduce the chance of striping and prevent a galvanic reaction (aka cold weld).

forensicscientist · 03-21-2010, 01:08 PM

I'd recommend a new seat post. The cost of a new post is minimal....compared to the constant hassle you're gonna have always fixing that one. I'm an avid road racer / cyclist for some 25+ years....so take my advice as someone who's worked on bikes for a long time. Fix the problem right, forget about it, and then go ride...

good luck,
mark

**Tamia** · 03-21-2010, 01:43 PM

Originally posted by forensicscientist

I'd recommend a new seat post. The cost of a new post is minimal...

Originally posted by Parallax

dragonfly, I've owned a bicycle shop for over 12 years and seen every immagineable attempt to fix that prob lem. You need a new seat post. The way to prevent that in the future is to make sure that the teeth are lined up with the opposing grooves when you tighten it....

Mark and Jim are right. I had a bunged-up seat post like this once and tried everything I could think of to fix it. No go, just a lot of frustration. In addition to Jim's excellent advice, be sure to get a post which has the proper diameter to fit your bike.

dragonfly · 03-21-2010, 01:51 PM

I tried the star washer and the rubber, but they didn't work. I'm going to order a new post online or thru my local shop.

Thanks for all the great advice!

Ratmagiclady · 03-21-2010, 04:31 PM

A little late, but, yeah, a new part looks like the way to go. Possibly if you bunched up a few inches of inner tube over the bottom section, it'd do for temporary?

The only other thing I could think is to drill and pin it in place. Those teeth wouldn't be worn out if they weren't doing something.

dragonfly · 03-21-2010, 04:37 PM

I'm purchasing a new seat post and I was tempted by the suspension seat posts. Who uses one of those?

**Tamia** · 03-21-2010, 05:40 PM

Originally posted by dragonfly

I'm purchasing a new seat post and I was tempted by the suspension seat posts. Who uses one of those?

I used a suspension post on my mountain bike when I first bought it. The bike also has a suspension fork. Because most of my riding is on hilly roads and not singletrack, I did not like the suspension seat post because I bounced with each pedal stroke, losing power to the wheels in climbs. I swapped it for a standard post. If you have a bad back or ride rough roads/trails, though, a suspension seat post might be just what you need.

dragonfly · 03-21-2010, 05:46 PM

I just bike around town. I sit upright and don't use my hands, so all of my weight is on the seat when I go over bumps. That's why I thought a suspension seat might help.

wjt · 03-21-2010, 06:09 PM

late posting here too, but i agree, fixing stuff properly is not worth it now-a-days, the time and effort put in isn't worth it unless you are passionate about it or have access to tooling/machines.
I am very much in the buy a new one category, buy it, install it and RIDE

some fixing things quotes;
"if at first you don't succeed get a bigger hammer, if it breaks it needed replacing anyway"
"being a technician just means you know the correct size hammer to use in a given situation"

VaughnA · 03-21-2010, 06:12 PM

Originally posted by dragonfly

I just bike around town. I sit upright and don't use my hands, so all of my weight is on the seat when I go over bumps. That's why I thought a suspension seat might help.

As Tamia stated the suspension post robs you of power and doesn't do a lot for comfort in my experience. Contrary to first thoughts, you'll be more comfortable with hard seat and bike shorts than a big cushy saddle. Also play with your air pressure in your tires.

dragonfly · 03-21-2010, 06:54 PM

I use a relatively hard saddle. All the bumps are starting to get more difficult to endure.

03-21-2010, 11:15 AM	#1
dragonfly Veteran Member Join Date: Jun 2009 Location: on the wall Photos: Gallery Posts: 715	Help fix bicycle seat slippage My seat on my mountain bike is slipping, what I mean is that the place where the rails are attached to the post is made to swivel for proper adjustment, but I can't tighten it enough to keep my weight from making the seat angle upwards when I sit down. There are grooves on the post and on the plate that sits on it, and they've become smooth for some reason. I tried to file in some new grooves, but that didn't have any effect. What can I place between the post and the plate that attach the seat to keep it from slipping? Maybe I need a new/better seat post. The plate on the table is upside down, it is the part that sits on the post. I used a Vivitar 28-200 macro zoom to take the pics. You can see how it shows a green halo around the bright areas.

03-21-2010, 01:08 PM	#6
forensicscientist Pentaxian Join Date: Jun 2008 Location: DFW Texas and Michigan - I commute :) Posts: 1,012	New Seat Post.... I'd recommend a new seat post. The cost of a new post is minimal....compared to the constant hassle you're gonna have always fixing that one. I'm an avid road racer / cyclist for some 25+ years....so take my advice as someone who's worked on bikes for a long time. Fix the problem right, forget about it, and then go ride... good luck, mark

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03-21-2010, 11:27 AM	#2
BPT Veteran Member Join Date: Jul 2007 Location: Fruitvale, British Columbia Canada Photos: Gallery Posts: 310	Putting in new grooves would work but for it to work you need make the grooves match on both sides or they wont have any effect. A second option is to take some rubber cut it into a rectangular shape to match the shape of the top of your post, punch a hold through it and put it in between. It might provide enough grip to keep it from slipping. Maybe.

03-21-2010, 11:43 AM	#3
dragonfly Veteran Member Join Date: Jun 2009 Location: on the wall Photos: Gallery Posts: 715 Original Poster	Originally posted by BPT Putting in new grooves would work but for it to work you need make the grooves match on both sides or they wont have any effect. Lol. I'll try out the rubber.

03-21-2010, 11:59 AM	#4
mickeyobe Veteran Member Join Date: Dec 2006 Location: Toronto, Ontario, Canada Posts: 1,759	Dragonfly, Google "Star washer " One of those over the bolt and between the seat post and the plate should do the job. Mickey

03-21-2010, 12:38 PM	#5
Parallax Senior Moderator Loyal Site Supporter Join Date: Apr 2008 Location: South Dakota Photos: Gallery Posts: 19,332	Originally posted by dragonfly Lol. I'll try out the rubber. dragonfly, I've owned a bicycle shop for over 12 years and seen every immagineable attempt to fix that prob lem. You need a new seat post. The way to prevent that in the future is to make sure that the teeth are lined up with the opposing grooves when you tighten it. Position the seat and SNUG the bolt then give the saddle a couple of good raps downward with the heel of your hand alternately on the nose and on the back. If it doesn't loosen then the teeth were lined up properly and you can finish tightening the bolt. If it did loosen up that was just the teeth slipping into alignment but repeat the snug/rap process before tightening just to be sure. Always remember to grease, or at least oil any bolt threads prior to assembly to reduce the chance of striping and prevent a galvanic reaction (aka cold weld).

03-21-2010, 01:43 PM	#7
Tamia Site Supporter Join Date: Dec 2009 Location: Here, there, and everywhere. Photos: Gallery \| Albums Posts: 4,384	Originally posted by forensicscientist I'd recommend a new seat post. The cost of a new post is minimal... Originally posted by Parallax dragonfly, I've owned a bicycle shop for over 12 years and seen every immagineable attempt to fix that prob lem. You need a new seat post. The way to prevent that in the future is to make sure that the teeth are lined up with the opposing grooves when you tighten it.... Mark and Jim are right. I had a bunged-up seat post like this once and tried everything I could think of to fix it. No go, just a lot of frustration. In addition to Jim's excellent advice, be sure to get a post which has the proper diameter to fit your bike.

03-21-2010, 01:51 PM	#8
dragonfly Veteran Member Join Date: Jun 2009 Location: on the wall Photos: Gallery Posts: 715 Original Poster	I tried the star washer and the rubber, but they didn't work. I'm going to order a new post online or thru my local shop. Thanks for all the great advice!

03-21-2010, 04:31 PM	#9
Ratmagiclady Veteran Member Join Date: Nov 2008 Location: GA Photos: Gallery \| Albums Posts: 13,563	A little late, but, yeah, a new part looks like the way to go. Possibly if you bunched up a few inches of inner tube over the bottom section, it'd do for temporary? The only other thing I could think is to drill and pin it in place. Those teeth wouldn't be worn out if they weren't doing something.

03-21-2010, 04:37 PM	#10
dragonfly Veteran Member Join Date: Jun 2009 Location: on the wall Photos: Gallery Posts: 715 Original Poster	I'm purchasing a new seat post and I was tempted by the suspension seat posts. Who uses one of those?

03-21-2010, 05:40 PM	#11
Tamia Site Supporter Join Date: Dec 2009 Location: Here, there, and everywhere. Photos: Gallery \| Albums Posts: 4,384	Originally posted by dragonfly I'm purchasing a new seat post and I was tempted by the suspension seat posts. Who uses one of those? I used a suspension post on my mountain bike when I first bought it. The bike also has a suspension fork. Because most of my riding is on hilly roads and not singletrack, I did not like the suspension seat post because I bounced with each pedal stroke, losing power to the wheels in climbs. I swapped it for a standard post. If you have a bad back or ride rough roads/trails, though, a suspension seat post might be just what you need.

03-21-2010, 05:46 PM	#12
dragonfly Veteran Member Join Date: Jun 2009 Location: on the wall Photos: Gallery Posts: 715 Original Poster	I just bike around town. I sit upright and don't use my hands, so all of my weight is on the seat when I go over bumps. That's why I thought a suspension seat might help.

03-21-2010, 06:09 PM	#13
wjt Veteran Member Join Date: Dec 2009 Location: Perth Photos: Albums Posts: 371	late posting here too, but i agree, fixing stuff properly is not worth it now-a-days, the time and effort put in isn't worth it unless you are passionate about it or have access to tooling/machines. I am very much in the buy a new one category, buy it, install it and RIDE some fixing things quotes; "if at first you don't succeed get a bigger hammer, if it breaks it needed replacing anyway" "being a technician just means you know the correct size hammer to use in a given situation"

03-21-2010, 06:12 PM	#14
VaughnA Banned Join Date: Feb 2009 Location: Virginia Photos: Gallery \| Albums Posts: 1,363	Originally posted by dragonfly I just bike around town. I sit upright and don't use my hands, so all of my weight is on the seat when I go over bumps. That's why I thought a suspension seat might help. As Tamia stated the suspension post robs you of power and doesn't do a lot for comfort in my experience. Contrary to first thoughts, you'll be more comfortable with hard seat and bike shorts than a big cushy saddle. Also play with your air pressure in your tires.

03-21-2010, 06:54 PM	#15
dragonfly Veteran Member Join Date: Jun 2009 Location: on the wall Photos: Gallery Posts: 715 Original Poster	I use a relatively hard saddle. All the bumps are starting to get more difficult to endure.