Joined: May 2018 Posts: 2,110 Threads: 110
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Location: Llandrindod Wells
Car type: 29 Special, 30 RK, 28 C Cab
Hi All
In a former life I was a structural engineer so forgive my ignorance on mechanical matters. Could those mechanical engineers explain to me why we use u bolts to secure the front (and rear) springs?
The reason I ask is that it would be so much easier to remove and replace front springs if they were secured with bolts and clamping plates. It is not as though the u bolt is round and restraining a tube!
Cheers
Howard
Joined: Aug 2017 Posts: 2,748 Threads: 31
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Location: Auckland, NZ
07-07-2020, 08:28 PM
(This post was last modified: 07-07-2020, 08:32 PM by Bob Culver.)
Saving weight was very much the goal with the early cars (see the recent magnificent photo of an early chummy) and every little counted. Maybe a plate tends to make the centre of spring too rigid. Perhaps also an element of traditon from horse carts. No need to restrrin the bolt head whilst tightening. Also commercial hardware may not have been as cheap as today.
Some tasks on the Seven are slightly more awkward than could have been, but all is a dream compared with the typical modern for which just the right tool assemby and/or hands like a child seems to be needed for everything.
Joined: Aug 2017 Posts: 952 Threads: 38
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Hi Howard, I see no particular reason to use U bolts, cant see why HT bolts into a flat plate wont work.
I would have thought this to be a stronger arrangement
Be interesting to see what others think.
Gene
Joined: Aug 2017 Posts: 1,049 Threads: 108
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Location: Cheshire
As Bob said - light - and quick to fit.
Had one of these fail a few years ago - not the most accessible item on the car.
Joined: Aug 2017 Posts: 952 Threads: 38
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Colin, your statements seem contradictory. Certainly not an easy or quick to fit item.
Joined: Aug 2017 Posts: 1,049 Threads: 108
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Location: Cheshire
On initial build, when everything is accessible, a u-bolt is easy - lines itself up and quick to tighten. The problem I had 70 year later was access - so much in the way I could hardly see or reach the nuts - can't remember if I removed the radiator or not now.
Joined: Aug 2017 Posts: 1,746 Threads: 42
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Location: Malvern, Victoria, Australia
07-07-2020, 11:56 PM
(This post was last modified: 07-07-2020, 11:57 PM by Tony Press.)
I think the spring U bolt is a neat and tidy solution compared to a clunky plate and bolts - which need two spanners to tighten.
How would you fit the plate/bolt combination on the rear springs ?
Joined: Aug 2017 Posts: 2,748 Threads: 31
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Location: Auckland, NZ
Riding in Sevens tend to think the springs not doing much but the trials shots are a revelation. I suspect if totally clamped in the middle would snap at the ends.
Joined: Aug 2017 Posts: 952 Threads: 38
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Tony, I don't think you could use plate and bolts at the rear because the fixing needs to be below the top of the sidemember, and no point anyway as the nuts are readily accessible
Joined: Aug 2017 Posts: 1,746 Threads: 42
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Location: Malvern, Victoria, Australia
Hence my comment !
"I think the spring U bolt is a neat and tidy solution compared to a clunky plate and bolts "
