Haynes Forums  

Go Back   Haynes Forums > Haynes Roadster Forums > Bodywork and interior
FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
  #1  
Old 11th December 2015, 04:17 PM
SteveH SteveH is offline
Member
 
Join Date: May 2015
Posts: 76
Default rivnuts or not?

ive been trial fitting my seats recently and have decided im going to mount them on 25mm x 25mm tube thats welded to both chassis rails
my question is what would be the best or preferred method of fixing the seat runners to the tubes
do i drill straight through the tube and put crush tubes in and bolt all the way through the floor
or do i use m8 rivnuts and bolt them up that way
using the crush tubes would make it very solid indeed but does the roadster need to be like that
Reply With Quote
  #2  
Old 11th December 2015, 04:24 PM
RichardH RichardH is offline
Senior Member
 
Join Date: May 2015
Location: fife scotland
Posts: 177
Default

i dont think rivnuts are up to the job, may not even be acceptable
Reply With Quote
  #3  
Old 11th December 2015, 04:36 PM
flyerncle flyerncle is offline
Senior Member
 
Join Date: Mar 2008
Location: gateshead,near cobbly bit of A1 North
Posts: 3,188
Default

Why not use 25x3mm flat bar across floor and weld to outer chassis and trans tunnel,25x25 may be a little too high.
__________________
Cost : Little as possible.
Thanks : To those who by their generosity my build has progressed.
Its a handmade sports car not a flaming kit car !!!


If at first you dont succeed,avoid skydiving...

No parachute require to freefall,only if you want to do it twice.
Reply With Quote
  #4  
Old 11th December 2015, 04:37 PM
voucht's Avatar
voucht voucht is offline
Senior Member
 
Join Date: Jun 2011
Location: Lautrec, Tarn (81), Occitanie, France
Posts: 879
Default

Hi,

I would not use rivnuts because in my opinion, they are way too weak to resist the constraints of a seat + a person, especially in case of a crash.

I think crush tubes are not necessary here. They are on high tightening torques only, and the torque you need to tighten M8 bolts to fit your seat is not high enough for you to need to put crush tubes in the 25x25 tubes the runners are fitted on in my opinion.

I did exactly like you want to do: 2 transversal 25x25 tubes welded to the chassis tubes. Seat runners are fitted with M8 bolts, washers and nylock nuts through these 25x25 tubes, and no crush tubes. So far so good!

Hope that will help

Good luck!
Reply With Quote
  #5  
Old 11th December 2015, 04:40 PM
SteveH SteveH is offline
Member
 
Join Date: May 2015
Posts: 76
Default

i did think about some 25mm flat bar but thought it might be a bit flimsy and maybe flex a bit

Quote:
Originally Posted by flyerncle View Post
Why not use 25x3mm flat bar across floor and weld to outer chassis and trans tunnel,25x25 may be a little too high.
Reply With Quote
  #6  
Old 11th December 2015, 04:43 PM
flyerncle flyerncle is offline
Senior Member
 
Join Date: Mar 2008
Location: gateshead,near cobbly bit of A1 North
Posts: 3,188
Default

Depends on what floor you have,but if fixed to side chassis rails and trans tunnel I would have thought it would be ok.
__________________
Cost : Little as possible.
Thanks : To those who by their generosity my build has progressed.
Its a handmade sports car not a flaming kit car !!!


If at first you dont succeed,avoid skydiving...

No parachute require to freefall,only if you want to do it twice.
Reply With Quote
  #7  
Old 11th December 2015, 05:05 PM
SteveH SteveH is offline
Member
 
Join Date: May 2015
Posts: 76
Default

my floor is 1.5mm aluminium
Reply With Quote
  #8  
Old 11th December 2015, 06:25 PM
norton norton is offline
Senior Member
 
Join Date: May 2015
Posts: 434
Default

I did the 25x25 tube but welded in some threaded steel inserts which the seat bolts screw into.

I have nothing protruding below the floor this way, very neat.
Reply With Quote
  #9  
Old 11th December 2015, 06:44 PM
SteveH SteveH is offline
Member
 
Join Date: May 2015
Posts: 76
Default

i like that idea where can you get them from without going on ebay
Quote:
Originally Posted by norton View Post
I did the 25x25 tube but welded in some threaded steel inserts which the seat bolts screw into.

I have nothing protruding below the floor this way, very neat.
Reply With Quote
  #10  
Old 11th December 2015, 09:21 PM
norton norton is offline
Senior Member
 
Join Date: May 2015
Posts: 434
Default

Ah, I got them eBay...
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT +1. The time now is 07:45 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.