Vixen steering rack mounts
Vixen steering rack mounts
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tomtrout

Original Poster:

595 posts

180 months

Saturday 8th January 2011
quotequote all
I'm in the process of fitting a new rack which has come with solid ali mounts.If I set the rack up for a central position there is a gap (photo) between the edge of the bottom mount and the rack casing cheeks.Should I be worried about this and fit some spacers to fill the gaps either end or just centre the rack and nip up the U bolts?

heightswitch

6,322 posts

267 months

Saturday 8th January 2011
quotequote all
Have you tried swapping your alloy blocks around?

You say its a new rack? who supplied it and do you still have the old one as a comparison fit?
N.


Edited by heightswitch on Saturday 8th January 18:16

Adrian@

4,420 posts

299 months

Saturday 8th January 2011
quotequote all
It is unusual to see that version of rack mounts in TVR world, the OE rubber bushed design on a Triumph rack calls for a spreader tool that would spread the std 2 clamps through elongated holes and I presume that in yours the lower plates then act as a limit...for those in Triumph world to spread the set manually ....the TVR has not got elongated holes and so you end up with a gap.
BUT, the version that we normally see, does not have the lower wider version of the clamp that you have, however IT by it's design has a 'clamping force', in that, IF it was one piece, and the ID was the OD of the steering rack tube THEN you sliced it with a saw, THEN, that 'saw' thickness when the two pieces are clamped together again ends up being able to hold the rack tight, that said these can be over tightened and bend the rack damaging it over time, BUT they can also be used to 'weight' the steering, AND, although you do not want the rack to move, they can be fine tuned (adjusted equally on the 4 nuts) to allow the steering to be nice at low speeds BUT stable at high speed.....ALL this said, you need to speak to the supplier to see what the clamps are designed to do.
Adrian@

Edited by Adrian@ on Saturday 8th January 20:06

davegt6

92 posts

204 months

Sunday 9th January 2011
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Those mounts look like the usual aftermarket solid rack mounts sold for small chassis Triumph steering racks. I have used these succesfully on both a Triumph road car, two racing Triumphs and currently on a racing Grantura. Never had any issue with the rack moving or the tube distorting and yes it is normal to have the small gap. With the mounts I have used (which look exactly like these but I don't know where you obtained yours) there is sufficient clamping force from the mounts to locate the rack without movement whilst not distorting the tube.

Edited by davegt6 on Sunday 9th January 09:33

tomtrout

Original Poster:

595 posts

180 months

Sunday 9th January 2011
quotequote all
Thanks for the advice. I bought the rack plus clamps in a kit from Moss. It was advertised as a "quick" rack with a high ratio pinion (2.5 turns lock to lock). It is also "allegedly" has a stronger outer casing than the OE but who knows! The car is only for road use and I realise that this might make slow speed maneuvering a bit of a handful but I really like the idea of very tight, crisp steering. The idea of a light-wieght,nimble, but not necessary fast classic appeals to me. I have the old clamps but the rubbers are shot. I could always opt to replace these (if I can locate them). Were the original clamps TVR OE?

Adrian@

4,420 posts

299 months

Sunday 9th January 2011
quotequote all
You sort of have to assume they know that selling the pair together, they will work together..but in that...stronger body, is it larger on the OD or ID of the rack tube, in that the strength has to somewhere? (unless old/new tube is defined as stronger). Does the rack mount kit have clamping force or reliant on the alloy bottom body as limit stops (note here what I said about the other alloy rack mount kit), which it is possible to bend the rack/crush the outer tube and damage the rack, have Moss redesigned it some way to stop this possibility....I would ask the question..
In answer to the question...TVR used the standard Triumph mount kit AND ADDED a U shaped piece of 1/4 rubber between the metal housing on the passenger side too compress the clamps in place of the system of spreading that Triumph used IT IS so rare to see the rubber packers these days because as racks get removed people/garages etc. can only believe that it is a bodge they remove them!
Adrian@

A thought is to bolt the whole alloy assembly together on the rack tube away from the chassis and see if it rotates, might test the clamping force.

Edited by Adrian@ on Sunday 9th January 12:48

Astacus

3,654 posts

251 months

Sunday 9th January 2011
quotequote all
I am pleased this thread turned up today

Started reassembling my S1 Jigsaw and I too noticed that, if one uses the n/s plate on the rack as a reference, and trial fit the mounts and bush against this, there is quite a bit of a gap between the rack gearing assembly and the bush/mount assembly.



But I was also concerned that the poly bush (Superflex) protrudes so far from the mount....



Is this ususal, or do I have the wrong bush/Mount?

The mount is not identical to the standard item, but it is Spitfire and does have the same dimentsions.



Also, the John Upham Vixen parts page and the Vixen parts book from The Club shows the use of the lower mounting plates. The ones I have don't fit in the configuration shown in the parts book (plate 8)What am I doing wrong here?



Sorry for the long post

ETA: Tomtrout, I noticed in your picture, your mount fits the front pair of mounting holes. On my S1 the space beyween these holes is too narrow to take the rack mount bolts. However, the rear pair fit perfectly, so I assumed the rack went here......(help)



Edited by Astacus on Sunday 9th January 18:01

tomtrout

Original Poster:

595 posts

180 months

Sunday 9th January 2011
quotequote all
My new rack has the same OD as the OE. Moss claim the rack is made from a higher grade of steel but who knows!

Astacus, just to muddy the waters even more, my near side mounting hole is located on the forward side of the rack - I know this is right because this is how my old rack was fitted - I haven't got a clue why there are three mounting holes per side but the rack is perfectly parallel with the chassis when alternate holes are selected - see pics. I think your poly mounts are the same shape as my old rubber ones (see pic)and the little flat piece that sticks out should locate under the steering rack cheek. I'm confussed about the "bottom plate" because my original rack and mounts didn't have a removal bottom plate, the underside of the rubber just sat on the "fixed" chassis plate. I think I'm more confused than you now!

[url]
|http://thumbsnap.com/BZgFvqQh[/url]

Astacus

3,654 posts

251 months

Sunday 9th January 2011
quotequote all
Ah, thanks for the pics Tomtrout. Your OE mounting bush appears to protrude the same as mine so I suppose thats standard. As far as the plate underneath goes, I couldn't find any in my boxes of bits, so I bought a pair. The reason I thought I needed them was because the Club's Vixen parts maual shows them and John Uppham's list, lists them. Perhaps they are not needed on the Vixen, because of the flat mounting plate.


Adrian@

4,420 posts

299 months

Monday 10th January 2011
quotequote all
Re the reinforcing plate under the rack mount kit, this was never fitted to the Vixen. After speaking MY supplier of the version I sell..(he owns parts of the Stanpart brand) the alloy version should clamp tight on the outside of the rack tube BUT as we were referring to the OP's/Moss's replacement NEW rack rather than OE Triumph /TVR he say's go back to the supplier.
Adrian@

Astacus

3,654 posts

251 months

Monday 10th January 2011
quotequote all
Adrian@ said:
Re the reinforcing plate under the rack mount kit, this was never fitted to the Vixen. After speaking MY supplier of the version I sell..(he owns parts of the Stanpart brand) the alloy version should clamp tight on the outside of the rack tube BUT as we were referring to the OP's/Moss's replacement NEW rack rather than OE Triumph /TVR he say's go back to the supplier.
Adrian@
Thanks for clearing that up Adrian

Adrian@

4,420 posts

299 months

Thursday 13th January 2011
quotequote all
Thoughts from another thread that reminded me...a long time ago there was a fancy German kit that included the Moss style rack clamp and a gas strut to stabilise the steering, where the alloy rack kit did not require a clamping force but relied on the lower brackets to spread correctly (as the Triumph) and then the gas strut to stabilise the steering at speed (this cured the possibility of over tightening issues) giving a light feel to the steering when at low speeds.
Adrian@

Edited by Adrian@ on Thursday 13th January 12:54