question on seat post fitment

[Rusty_S85]

I just got my 1" laid back seat post in, I have to grind the weld on the gusset down some to get it to slip between the pinch groove on the frame so it will sit low enough for my feet to sit flat on the ground.

Problem is though the inside diameter of my GT2A frame is 32mm so this seat post flops around. I am afraid if I set the gusset in the groove of the frame it wouldn't have enough give to pinch around the post. But I wanted to ask should the seat post fit snug off the bat without a clamp attached?

Cause I'm looking at clamps and they are an add on item on amazon but I can buy a regular straight seat post in 1" on prime and get it on Sunday. Just need to know

 

[FurryOnTheInside]

If your seat tube is 32mm ID, or more likely 31.8mm, then why do you have a 25.4mm seatpost?
Yes it needs to fit just right. There are shims, although I have never seen one as thick as that.

 

[Deleted member 27811]

If your seat tube is 32mm ID, or more likely 31.8mm, then why do you have a 25.4mm seatpost?
Yes it needs to fit just right. There are shims, although I have never seen one as thick as that.

MBRebel has one you might look @, 1"- I had to shim mine but it made a perfect fit. The tube is 25.5mm got the shims on Amaz. in seat posts

 

[FurryOnTheInside]

MBRebel has one you might look @, 1"- I had to shim mine but it made a perfect fit. The tube is 25.5mm got the shims on Amaz. in seat posts View attachment 78511

You shimmed from 25.4mm to 25.5mm? How thick is the shim, 0.05mm? Thats pretty darn thin. Not at all what the OP seems to need. I guess he can look for a shim but I have only seen/used shims for very close sizes personally, so idk about availability.

 

[Rusty_S85]

Mine fits loose enough to wobble. I guess i could go with my caliper to lowes or home depot and try to find a pipe with a 1" diameter inside and a 32mm outside diamter well 31.8mm outside.

I bought this one in like in the pic above cause the specs for this frame listed the seat tube as 1" and i didnt bother to check it. If i could find this same style laid back seat post in 31.8mm i would just return this one and not waste time with shims. Saw a few talking about how their seat creaks when pedaling with the shim.

My other option is to just buy a 31.8mm straight post tube and sit the seat all the way down. At least i could order that tonight and have it sunday.

 

[Rusty_S85]

I misspoke my id is 1 1/8" my od is 32mm for the clamp for the seat tube.

 

[FurryOnTheInside]

I misspoke my id is 1 1/8" my od is 32mm for the clamp for the seat tube.

28.6mm ?
Bicycle parts are nearly always measured in metric and 28.6 is a very common size. You might find a shim, although it is still quite thick not a next size up/down. But if you type the metric size into searches you'll find more stuff more quickly.

Prevent creaking and seizing with copper grease.

 

[Rusty_S85]

I did the conversion just spent $8 with shipping on a black 25.4mm to 28.6mm. Hopefully it doesnt fit too snug in the seat tube as there is always the possibility i migh run a straight seat post if i dont like this one. But i will be grinding on my seat post to knock the weld down smooth on the gusset so i can place the flat lay back bar flush with my seat tube. That should get me low enough. If not i could chop up to 10mm off the seat mount on the seat post to lower the seat there is enough material there.