Too heavy for seatpost?

Harrybelafonte

Situation as follows:

I weigh about 92kg.
Seat post is a well worn 26.4 Campagnolo Aeropost in an 80s Reynolds frame, with a seat tube bolt which I tighten as much as possible. With the seat post at minimum the bike fits me perfectly, but everytime I ride it I can feel the bend in my knee increase. I check and find a little more of the chrome stripped as seat post has moved done into seat tube. The worst thing is it doesn't settle and the longer I ride it for the lower it sinks. Am I just too heavy for it?

studiorat

Harrybelafonte wrote: »

Situation as follows:

I weigh about 92kg.
Seat post is a well worn 26.4 Campagnolo Aeropost in an 80s Reynolds frame, with a seat tube bolt which I tighten as much as possible. With the seat post at minimum the bike fits me perfectly, but everytime I ride it I can feel the bend in my knee increase. I check and find a little more of the chrome stripped as seat post has moved done into seat tube. The worst thing is it doesn't settle and the longer I ride it for the lower it sinks. Am I just too heavy for it?

Probably a 27.2mm seat tube. What make frame is it?

CheGuedara

Have you tried/do you use assembly paste? Could help hive you a few more newtons worth of grip if not

Harrybelafonte

studiorat wrote: »

Probably a 27.2mm seat tube. What make frame is it?

No, I don't think so. I have tried to fit a 27.2 and it won't fit. Peugeot.

CheGuedara wrote: »

Have you tried/do you use assembly paste? Could help hive you a few more newtons worth of grip if not

Never even heard of it. Do you think it would be enough to hold it?

gman2k

My peugeot 501 framed bike from the 80s is a 26.2 seatpost size.
The seatpost needs to be greased before insertion into the frame, especially if its alum to steel meeting.
You could try the Finish line paste also - as mentioned above

thebouldwhacker

I was 100kg when I started back on the bike, or should I say I was 100kg so I started back on the bike and that never happened me on any saddle.

CheGuedara

Harrybelafonte wrote: »

Never even heard of it. Do you think it would be enough to hold it?

Could definitely be worth a try - its just a finely gritted paste that acts to create more friction between surfaces you want to clamp together.

The one linked by gman2k is supposed to be good and the one I use myself is made by tacx and can be picked up in cycleways if you're based in Dublin.

Harrybelafonte

gman2k wrote: »

My peugeot 501 framed bike from the 80s is a 26.2 seatpost size.
The seatpost needs to be greased before insertion into the frame, especially if its alum to steel meeting.
You could try the Finish line paste also - as mentioned above

The post is well greased and definitely says 26.4 though and it's only a little off

thebouldwhacker wrote: »

I was 100kg when I started back on the bike, or should I say I was 100kg so I started back on the bike and that never happened me on any saddle.

I'll get some of the paste but it seems a little odd to rely on that. Unless the post is worn?
I was about 110kg and I've never experienced it either. It's a bit of a kick in the teeth after the weight loss.

CheGuedara wrote: »

Could definitely be worth a try - its just a finely gritted paste that acts to create more friction between surfaces you want to clamp together.

The one linked by gman2k is supposed to be good and the one I use myself is made by tacx and can be picked up in cycleways if you're based in Dublin.

Side Show Bob

Harrybelafonte wrote: »

Situation as follows:

I weigh about 92kg.
Seat post is a well worn 26.4 Campagnolo Aeropost in an 80s Reynolds frame, with a seat tube bolt which I tighten as much as possible. With the seat post at minimum the bike fits me perfectly, but everytime I ride it I can feel the bend in my knee increase. I check and find a little more of the chrome stripped as seat post has moved done into seat tube. The worst thing is it doesn't settle and the longer I ride it for the lower it sinks. Am I just too heavy for it?

If the seatpost is only sinking and not twisting then buy one of those small flashing lights that are installed using a rubber ring. The rubber ring is used for the smaller seatposts which you have, if you fit it at the bottom of your chrome seatpost where it meets the frame it will stop it sinking, it will work and will look like it should be there.

If this is not enough I'm afraid you will have to use a drill with a 5mm drill bit and a small screw

gman2k

Side Show Bob wrote: »

If this is not enough I'm afraid you will have to use a drill with a 5mm drill bit and a small screw

WTF?????:eek:

Side Show Bob

gman2k wrote: »

WTF?????:eek:

Yes in the worn seatpost and NOT the frame The head of the screw will stop it sinking, without doing any damage to the frame

Harrybelafonte

Side Show Bob wrote: »

If the seatpost is only sinking and not twisting then buy one of those small flashing lights that are installed using a rubber ring. The rubber ring is used for the smaller seatposts which you have, if you fit it at the bottom of your chrome seatpost where it meets the frame it will stop it sinking, it will work and will look like it should be there.

If this is not enough I'm afraid you will have to use a drill with a 5mm drill bit and a small screw

I've seen people talk about going the screw route before but I'd rather not permanently damage it. What about using a seat clamp? I'll truths light tomorrow though.

gman2k

Harrybelafonte wrote: »

I've seen people talk about going the screw route before but I'd rather not permanently damage it. What about using a seat clamp? I'll truths light tomorrow though.

Do not listen to anyone who talk about screws and drills.

Clean out your seat tube and degrease the seatpost and try the grip compound.
Get your seatpin bolt torqued correctly when your ready to try again.
Also, you say your seatpin is worn? Is it the original seatpost that came with the bike? I don't see how the diameter of a seatpost could become worn to such an extent that it would cause slipping.

Side Show Bob

gman2k wrote: »

Do not listen to anyone who talk about screws and drills.

Clean out your seat tube and degrease the seatpost and try the grip compound.
Get your seatpin bolt torqued correctly when your ready to try again.
Also, you say your seatpin is worn? Is it the original seatpost that came with the bike? I don't see how the diameter of a seatpost could become worn to such an extent that it would cause slipping.

No disrespect ment here, or maye my time in Bolton St was totally wasted. Never interfere with the main product (the frame) the seatpost is an accessory so if the last resort means a screw a hose clip whatever, it docent matter, it is replaceable later, if you pour gunk, glue or loctite into the inner tube of the frame (the product) it is more damaging, and will be wonderful fun when digging it out with a coat hanger when you want to do a full restoration. Maybe I'm wrong here, but if it was me.........

kumate_champ07

how easy does it slide down with the bolt fully open?
youre better off finding the right size,
I need 26.6 for one of my frames, Ive a couple 26.2 posts but wouldnt use them as it would cause damage over time.

Harrybelafonte

kumate_champ07 wrote: »

how easy does it slide down with the bolt fully open?
youre better off finding the right size,
I need 26.6 for one of my frames, Ive a couple 26.2 posts but wouldnt use them as it would cause damage over time.

I still have to use an element of force to get the post in (nothing massive, a bit more than a few wiggles) and there is small about of space, maybe a mm, around it before the clamp is locked up.

If I have to start buying new seatposts I will, but just want to be a bit closer to an answer before I start doing that.

Harrybelafonte

I'm actually just going to get a shop to measure it. It'll be cheaper in the long run.

Harrybelafonte

26.8 in the end. Minute difference fail

justo

Harrybelafonte wrote: »

26.8 in the end. Minute difference fail

funny enough I had bookmarked this:

CAMPAGNOLO SUPER RECORD SEATPOST 26.8mm 155mm rails to limit mark ideal for some early metric tubed 753 frames excellent almost unused condition £55 found here: http://hilarystone.com/seatposts270268.html

My seat post is 27.00mm so I'm holding out until I find a Campag one.

Harrybelafonte

justo wrote: »

funny enough I had bookmarked this:

CAMPAGNOLO SUPER RECORD SEATPOST 26.8mm 155mm rails to limit mark ideal for some early metric tubed 753 frames excellent almost unused condition £55 found here: http://hilarystone.com/seatposts270268.html

My seat post is 27.00mm so I'm holding out until I find a Campag one.

Wouldn't mind getting this one: http://www.bike-vintage.com/lang-de/seatpost/572-for-sell-seatpost-campagnolo-nuovo-record-size-266-vintage.html

justo

Harrybelafonte wrote: »

Wouldn't mind getting this one: http://www.bike-vintage.com/lang-de/seatpost/572-for-sell-seatpost-campagnolo-nuovo-record-size-266-vintage.html

holy shmoley - great website - I didn't know that one.

27.0 mm are hard to find but I spotted a few there already - thanks.