Seat Posts
01-16-2015, 10:58 AM
#21
Platinum Member
Hi Mario, When we tested the original springs on "SideWinder" they read out at around 180/200 ft lbs.
Which would be reasonable for a male body as a static load with the damper taking care of the dynamic force on the return stroke as and when required
Ian.
Which would be reasonable for a male body as a static load with the damper taking care of the dynamic force on the return stroke as and when required
Ian.
01-16-2015, 01:13 PM
#22
Registered
VIP MemberThread Starter
I believe the shock is a Gabriel "classic" series. I don't have part number unfortunately. I do know i just took old one to auto zone and matched it up. I believe it was for a 1962 Corvette front shock. It was a little longer so all we did was drill hole in floor/deck under mounting plate and it work great. You do have to replace the spring as well though. It is from Century Spring ph 800-237-5225 part #4405 $46.27each.
Hope this helps. They turned out great and work great fantastic.[ATTACH=CONFIG]535768[/ATTACH][ATTACH=CONFIG]535769[/ATTACH]
Hope this helps. They turned out great and work great fantastic.[ATTACH=CONFIG]535768[/ATTACH][ATTACH=CONFIG]535769[/ATTACH]
01-17-2015, 03:23 PM
#24
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Awesome info! Thank you both! I was originally going to switch to Bolsters, but with my engine saga and another issue the budget needs to get reeled in . . .
Ian, you added a PTFE collar, I presume you bored out the outside collar and fabbed a sleeve? My present posts are loose and for me to be happy, I need to get this tight, it's no fun sitting on a loose seat that is seized and absorbs nothing.
Ian, you have two teak grates against your cabin bulkhead, are these on hinges so they tip down as foot rests in heavy water?
Ian, you should create a webpage or an online photo gallery of your boat . . not that we would all copy it ;-) but it's a great boat and helps those of us restoring and building these to our own specs.
Thank you!
Ian, you added a PTFE collar, I presume you bored out the outside collar and fabbed a sleeve? My present posts are loose and for me to be happy, I need to get this tight, it's no fun sitting on a loose seat that is seized and absorbs nothing.
Ian, you have two teak grates against your cabin bulkhead, are these on hinges so they tip down as foot rests in heavy water?
Ian, you should create a webpage or an online photo gallery of your boat . . not that we would all copy it ;-) but it's a great boat and helps those of us restoring and building these to our own specs.
Thank you!
01-18-2015, 08:19 AM
#25
Hi Mario,
Many thanks for your kind comments, what ever information you feel would be of benefit to you please ask and I will happily provide the details.
The seat posts as you are aware comprise of several components each with their own fits and tolerances, the upper slide, the seat base socket and the tube to tube fit therefore there will always be some movement somewhere unless you rebuild everything with a procession fit.
My PTFE external upper bearing works very well and has been tested undependably by that well known "Minnesota Ice Man" and International traveller Mr Jeff Hall, who also owns
a Magnum Sport 27 and has the same issues about the inner tube seizing after compressing. He reported that it "works well"
My design is simply a large diameter piece of PTFE round which was bored out to slide over the outside diameter of the fixed outer base tube leaving a !" wall 2" deep socket sat on a shoulder at the top off the counter bore.
We measured the OD of the top tube and bored out the PTFE to be a good close slide fit. This then forms a positive shoulder stop for the PTFE onto the top end of the fixed tube ensuring that the two tubes now remain concentric at all times and thus maintain tube to tube clearance.
The bearing length for the slide interface is also about 2.5" ( Check the Maximum Stroke you will have once you select your shock absorber/spring combination) and make the bearing as long as you can without the seat base clamp socket bottoming out on to the top of the PTFE.
Make sure that the fit of the lower bore for the PTFE to the upper part fixed base tube is a good " Drive Fit" and there you basically have it. Make sure that you polish the OD of the inner tube before you measure and machine the upper bore of the PTFE so as to ensure a good slide bearing fit.
Because it is almost impossible to bond PTFE a friction fit the main base tube is essential so as to ensure that the bearing does not "lift off" with the inner tube on the return stroke.
In order to ensure that could never happen on my seats I also fabricated an outer cover sleeve in mirror finished stainless steel with a welded top flange to go over the whole PTFE bearing and fasten to a lower spacer ring around the bottom of the fixed tube to act as a physical restraint and finishing trim.
Job done, it works a treat plus taking out the tube to tube "slop" fit.
Yes you are correct the Teak gratings are hinged up to the bulkhead and lowered when required as angled footrests, which as it happens in my case is most of the time because it is a more natural angle to sit at if you wish to brace yourself I have found.
"SideWinder" is just my version of a Magnum27 Sport rebuild and to my taste, others I am sure will have done better but not just talked about it in the same way,
But that said I am very pleased to learn that you should feel that my work may help to inspire or assist others at some time when they may be looking for ideas.
I will willingly post more detailed pictures should you so wish.
Would you like to see the pictures of my "new Navigation lights" in place?. I am very please with that purchase thank you they look great.
Ian
.
Many thanks for your kind comments, what ever information you feel would be of benefit to you please ask and I will happily provide the details.
The seat posts as you are aware comprise of several components each with their own fits and tolerances, the upper slide, the seat base socket and the tube to tube fit therefore there will always be some movement somewhere unless you rebuild everything with a procession fit.
My PTFE external upper bearing works very well and has been tested undependably by that well known "Minnesota Ice Man" and International traveller Mr Jeff Hall, who also owns
a Magnum Sport 27 and has the same issues about the inner tube seizing after compressing. He reported that it "works well"
My design is simply a large diameter piece of PTFE round which was bored out to slide over the outside diameter of the fixed outer base tube leaving a !" wall 2" deep socket sat on a shoulder at the top off the counter bore.
We measured the OD of the top tube and bored out the PTFE to be a good close slide fit. This then forms a positive shoulder stop for the PTFE onto the top end of the fixed tube ensuring that the two tubes now remain concentric at all times and thus maintain tube to tube clearance.
The bearing length for the slide interface is also about 2.5" ( Check the Maximum Stroke you will have once you select your shock absorber/spring combination) and make the bearing as long as you can without the seat base clamp socket bottoming out on to the top of the PTFE.
Make sure that the fit of the lower bore for the PTFE to the upper part fixed base tube is a good " Drive Fit" and there you basically have it. Make sure that you polish the OD of the inner tube before you measure and machine the upper bore of the PTFE so as to ensure a good slide bearing fit.
Because it is almost impossible to bond PTFE a friction fit the main base tube is essential so as to ensure that the bearing does not "lift off" with the inner tube on the return stroke.
In order to ensure that could never happen on my seats I also fabricated an outer cover sleeve in mirror finished stainless steel with a welded top flange to go over the whole PTFE bearing and fasten to a lower spacer ring around the bottom of the fixed tube to act as a physical restraint and finishing trim.
Job done, it works a treat plus taking out the tube to tube "slop" fit.
Yes you are correct the Teak gratings are hinged up to the bulkhead and lowered when required as angled footrests, which as it happens in my case is most of the time because it is a more natural angle to sit at if you wish to brace yourself I have found.
"SideWinder" is just my version of a Magnum27 Sport rebuild and to my taste, others I am sure will have done better but not just talked about it in the same way,
But that said I am very pleased to learn that you should feel that my work may help to inspire or assist others at some time when they may be looking for ideas.
I will willingly post more detailed pictures should you so wish.
Would you like to see the pictures of my "new Navigation lights" in place?. I am very please with that purchase thank you they look great.
Ian
.
Last edited by Kalaazar; 01-18-2015 at 08:35 AM.
