1997 GT RTS All Terra Mountain Bike Advice on Bearings and Handlebars/Accessories Due to Hand Pain

[TheJay]

I don't know if the person who did mine would do another, you could try, he's a member on here danson67. I think the rear pivots needed slightly modifying to accept a standard small bearing, I'll see if I can lay my hands on mine, it's tucked away in a box for a rainy day.

I'm not sure I follow what you mean regarding seat post and clamping to the rails, they nearly all do that with the exception of some whacky ones like an I-beam. Rails do differ but if you've a normal saddle, your main concern is a post that's the correct diameter for your frames seat tube (usually 26.8mm on an rts frame), and length that's long enough to have enough of it in the seat tube while getting your saddle at the right height to ride.

There's also layback or inline to consider (pushing the saddle rearward Vs straight up from the post respectively).

Ah, so it seems to be 28.8, do you have any rigid spares with the built in rail clamp shown in my previous post?

 

[ishaw]

It's 26.8 you'll probably need, especially if you have a 26.6 in already. As said, the top part of the seat tube can be crushed by the clamp and an I'll fitting post, making the top part appear to be 26.6 when lower down it's likely wider.

You can spread the top.of the seat post a bit using a seat post slightly fitted, and using it as a lever, bend the top of the seat tube very gently in a circular motion to keep it round. A useful visual guide is to get the slot in the seat tube to be straight rather than squashed, as they is likely to be where it has deformed.

Easiest way to determine us Vs Taiwan build is the top tube end cap with GT stamped on it. Flat = USA, curved = Taiwan.

 

[TheJay]

It's 26.8 you'll probably need, especially if you have a 26.6 in already. As said, the top part of the seat tube can be crushed by the clamp and an I'll fitting post, making the top part appear to be 26.6 when lower down it's likely wider.

You can spread the top.of the seat post a bit using a seat post slightly fitted, and using it as a lever, bend the top of the seat tube very gently in a circular motion to keep it round. A useful visual guide is to get the slot in the seat tube to be straight rather than squashed, as they is likely to be where it has deformed.

Easiest way to determine us Vs Taiwan build is the top tube end cap with GT stamped on it. Flat = USA, curved = Taiwan.

This is what you mean right? If so, Taiwan.

 

[ishaw]

Yes, that would indicate a Taiwan built frame, and RTS2, 3 or the later labelled RTS.

 

[bikeworkshop]

So it should be 26.8.

If the seat tube has been distorted with the wrong size post, or bent by a large rider with too little insertion, you might even want to get the tube reamed.

 

[TheJay]

Yes, that would indicate a Taiwan built frame, and RTS2, 3 or the later labelled RTS.

Awesome, so we now know it's definitely 28.8. Do you have any spares?

 

[bikeworkshop]

Its definitely NOT 28.8!

It's 26.8

@ishaw kindly offered a source:

 

[bikeworkshop]

What sort of seat post are you after? Got a few spares in 26.8mm and longer than you mention.

 

[TheJay]

I mean as long as it's not a seat post that connects to the saddle like this.
View attachment 949009

I like the seat posts with the saddle rail clamps built in.

The existing seat post diameter is 26.76mm (although the part that accepts the seat post looks like it would have been happier for the post to be approximately 2mm larger) and 340mm length. I think the post needs to be maximum of 260mm.

26.8 saddle rail clamp built in like this around 260mm. Thanks

 

[bikeworkshop]

That's called a "microadjust post"

As opposed to "seatguts":


Not many retrobikers will use seatguts on a post1980 bike - they are for kids bikes, bsos and bmx