Dave's shortshift

[F1 LOTUS]

Interesting stuff It shouldn't be too difficult to get a bunch of those made?
How much of a job is it to swap the parts out? Any idea what's causing the left-right stiffness

[Enright]

Interesting stuff It shouldn't be too difficult to get a bunch of those made?
How much of a job is it to swap the parts out? Any idea what's causing the left-right stiffness

I think you're probably right - not too difficult at all.
Furthermore from the looks of the selector box, I'm wondering if it could be a generic part from a similar aged GM vehicle. If so, then we may be able to find loads of them in scrapyards, and get them modded cheaply. Then they would be a straight swap without having to have vehicles off the road waiting for machining to be completed.

Swapping the parts isn't difficult at all.
It's best to loosen the coolant reservoir (as usual).
The selector mech is just under the HT leads, but they don't need removing.

Then you just:
Put the car in neutral,
Undo the gear cable ends,
Undo the 3 bolts that secure the clutch cable mounting bracket to the top of the selector mech,
Undo the 4 bolts that fasten the selector mech to the gearbox,
Remove the abutment bracket from the back of the engine and cable ends (2 or 3 bolts),
Work back up the list fitting new parts in place of the old ones.

I think the initial stiffness is just my new cables bedding-in - I had read elsewhere of others having the same issue. Also, if the movement is half of what it was, then the force required to achieve the same effect must have to be double - not that it's a big deal.

[F1 LOTUS]

From your experience, would you think modifying the 'gearbox end' is a better option than the cockpit end to achieve a shorter shift? It appears that way to me

[DeeAitch]

Been away from base for a few weeks - bluddy work - and just caught up with this. Isn't it supposed to get easier as you get older?
Basically Bill's mod was my inspiration. However I wanted a bolt on solution rather than welding as :
1. I needed to be able to 'tune' the throws with different offsets.
2. I'm daft so I make sure any mods I do are reversible in case it all goes pear shaped
Unfortunalty I've only succeeded with the fore / aft as far as bolt on is concerned although the cross gate is an easy DIY. It also means no issues with stripping off the selector box and posting it around the world. I also feel that to do a good job you would need to strip the selector shafts out to be able to jig it and avoid heat damage to seals from the welding (unless someone has a laser! )This is not really that difficult tho'

I've had a feel - ooh er - of an example of Bills shifter and think the added counterweight (most modern cable shifts have one) greatly improves the feel - this is a bit subjective tho' but anyone thinking of going down the welding route may want to consider this.
As for the cross gate the force against the Bias spring is now quite high due, as Enright correctly points out, to the decreased thro' at the lever. I'm used to mine now and ESM thinks it is OK but I guess a softer spring would do the trick as the fore aft is still quite light.

Alan, how is yours standing up to daily use? I'm sure you will have done more miles than me this year

[Enright]

Dave,

Great idea with respect to the reversibility, and well spotted about welding damaging the seals.

Hope it didn't appear as though I was trying to pull the rug out from under your feet, and sorry if it did.

I just guessed that there might be people out there that would be interested to see how Bill's obsolete parts could be resurrected, and your thread seemed to have gone quiet so I thought it may have come to a dead end.

Certainly glad that it's not the case, because the more I think about your solution, the more I like it over Bill's.

[ESM]

The short-shifter is definitely a big improvement. The crossgate shift just isn't heavy at all in my car. Fore-aft is noticably heavier. That said I only notice the shift weight when I switch car after driving my standard gearshift blue car for a while and soon get used to it again.

[DeeAitch]

No problem at all Enright, I'm not worried which way people decide to go as I'm more than happy with what I've got The important thing is to get rid of the cellery stick which has no place in our cars!

'Bill's' shifter details have been around for some time - some kind soul on here sent me pictures ages ago but I never got around to doing anything about it until this year. Just thought I'd point out some of the issues I had when developing mine. The welding thing is no big deal as the shaft is dead easy to get out. Just difficult to get it right first time on a one off!

Yes, the thread had gone dead, with only 7 or 8 parties showing any real interest. Maybe the Heath Robinson appearance puts folk off and I can't blame them for that! I would need to get jigs etc made up so I hadn't taken it any further, it just wouldn't be worth the investment. Also the cross gate mod would need to be a DIY job or ship the parts to me for modification, with all the risks associated with today'e post

My original offer still stands tho'

[F1 LOTUS]

Dave, I would be surprised if there were only 7 or 8 people interested Personally my impression was that it's still under development, perhaps others did too? I thought I read in one of your recent post that something related to this broke? If we can find a ready supply of selector units I guess this would help with the logistics of modifying the crossgate? Perhaps there are enough LEC members with spare engines who could donate enough selector units to get the ball rolling for an exchange-basis run of parts?

[John_W]

the thread had gone dead, with only 7 or 8 parties showing any real interest. Maybe the Heath Robinson appearance puts folk off and I can't blame them for that!

Dave,
I didn't realise you had got to the expression of interest stage - I thought you were still tinkering. If you are looking for interested people, I'm interested.

My original offer still stands tho'

What offer's that then?

John

[F1 LOTUS]

See What'd I tell ya






Checks in the mail John

[Candles]

Yeah sorry I didn't realise you were gauging levels of interest yet. I'm very keen.

Candles.

[Candles]

Checks in the mail John

SPELLING!

[ESM]

Blue car could do with one....

[Ultimatt]

I've only quickly scanned through this thread, but based on the fact that my shifter is feeling a little sloppy and the throw hampers speedy runs, I'd be up for one.

I don't know what cost is likely to be involved, but I've recently spend a small fortune on the car so it would be cost-dependant.

Keep me updated.

Matt

[Enright]

The important thing is to get rid of the cellery stick which has no place in our cars!

Couldn't agree more with THAT statement!
Once you've tried a combination of the short shifter and AB cables you'll never go back.

'Bill's' shifter details have been around for some time - some kind soul on here sent me pictures ages ago but I never got around to doing anything about it until this year. Just thought I'd point out some of the issues I had when developing mine. The welding thing is no big deal as the shaft is dead easy to get out. Just difficult to get it right first time on a one off!

I only have one worry with yours, which is that due to the gear lever effectively being extended, the holes in the gear lever mounting bracket may not point the cables in the right place without subjecting them to a nasty bend. I've tried to depict this in the attached pic:
The upper red line and smaller circle show the existing cable's route and the path of the linkage.
The lower red line and larger circle show the proposed route and linkage path.
My question is, to reduce the throw by 50%, doesn't the larger circle need to be twice the diameter of the smaller one? (Currently it looks like it only reduces the throw by a 25% as it's only 1/2 bigger.)
If so, can this be achieved in the space available without putting undue force on the part of the cable between the linkage and the bracket? Perhaps this could easily sorted by bending the bracket.
But furthermore, is there enough space available in the chassis tunnel?

Yes, the thread had gone dead, with only 7 or 8 parties showing any real interest. Maybe the Heath Robinson appearance puts folk off and I can't blame them for that! I would need to get jigs etc made up so I hadn't taken it any further, it just wouldn't be worth the investment.

I didn't think the part that you had made looked Heath Robinson. In fact I thought it had been CNC milled!
Other than the above reservation, I think that attaching machined parts to the gear lever end seems a far more simple and elegant solution, which is which I like your idea.
Speaking of which, I'm pretty well-in with an engineering company and often have to put special engineering jobs their way. If you can get a tried and tested sample fully dimensioned up, I could probably get them to mill a batch very cheaply.

Also the cross gate mod would need to be a DIY job or ship the parts to me for modification, with all the risks associated with today's post

Why? Because of it being a peg instead of a hole & rod?
If so, why not have a sort of clamshell arrangement?
I'm thinking that half could have a hole and use the peg as a locator, and it would bolt to the other half. The other half would have a cutout in it which was the exact size of the plate into which the peg currently fits.
Either half (or both) could be extended downwards as far as required (circle principle again).
Then you would have a hole at the bottom though which a small bolt and nyloc nut could secure the crossgate cable.

Does that make sense? If not I could try to make a sketch and scan it.

Anyway ultimately, once designed, I could probably get CNC machined parts from the same source.

[John_W]

I only have one worry with yours, which is that due to the gear lever effectively being extended, the holes in the gear lever mounting bracket may not point the cables in the right place without subjecting them to a nasty bend. I've tried to depict this in the attached pic:

Niel,
Your explanations of your reservations are clear, but I think you're referring to the KevH gear-lever end mod, not Dave's which is at the gearbox end of the cables.

The picture you show is the piece KevH machined a couple of years ago. Don't know what happened to that project. I Think KevH & Sy have the only two in captivity.

The advantage of a modification of the gear-lever end is that the additional force required owing to the reduced mechanical advantage of a shorter lever is applied at the gear-lever end of the shift cables and not at the gearbox end which is a known weak-point of the standard cables. The AB cables don't have this weak point of course.

John

[Enright]

Bugger.

You're right John, I had indeed completely misunderstood which was which, and thought that KevH's was Dave's.

I was galloping off down completely the wrong path and now am not sure what to suggest.

Other than a tromp round a few scrapyards to see what I can find...

[DeeAitch]

Thanks John, that saved me a lengthy reply
Just to add to it tho' I'm also of the opinion that modding the gearlever end is a better and more elegant solution, not to mention that it wouldn't put any additional strain on the cables. However, in my view, (apart from the universal "lop an inch of it's length" mod which I have also done) it is not really viable as it will need a completely new shifter developing.
As for development of my version I've taken it as far as I want to go. The looks could no doubt be improved with CNC machining, robot welding etc etc but I'm a function over form man and anyway you can't see the thing once its burried in the Engine bay

F1 lotus wrote

I thought I read in one of your recent post that something related to this broke?

Not sure what you refer to Brian but nothing has broke on mine or Alan's - yet Maybe you mean Alan's report that his initial install stuck in gear? Can't get my head around that one tho' and can only think that either the shift box was damaged or that the cables needed adjustment.

For the 'offer' please see the first post on this thread i.e.

I could probably get a batch of the fore / aft brackets knocked up, together with all fasteners, in 304 Stainless if there is sufficient interest, but it may be too expensive for what it is, otherwise details freely available to Forum members if you can't work it out from the pic, with the usual copyright proviso. i.e. For trackuse only, no liability implied or accepted & I will hunt you down if you try to make a profit on e-bay or the like.

In other words I could get some copies of the fore/aft lever (as shown in the pic in the first post) made up but I would need to commision some jigs so they all come out the same! Cost would depend on numbers but I can't see it coming in at less than £45 inc UK postage - this would be in 304 stainless except the cable pivot pin which is 316. I also have a limited Qty of snap pins if req'd but these are only plated. As I said in my original post, probably a lot for what it is, but I would offer a 'no questions asked' refund (less the cost of the original postage to you) on return of the lever, if it doesn't make you say "why didn't Lotus make it like this in the first place"

For this I would also supply full details for the cross gate mod. incl. a new pivot pin for the cable, for a DIY job, or I could do the mod free but you would need to cover the return cost (& risk) of getting the crossgate bellcrank lever to me. Beware, it can be a pig to detach from the shift box in situ! although you might find it easier to remove the control box from the gearbox to do the full install anyway.

BTW as far as I can tell the 'KevH' solution only mods the fore/aft throw. Would be interested to hear if it works OK tho' as it is done at the right end of the mech. as it were

What was that I said about saving me a lengthy reply?

[John_W]

Dave,
I'm still interested at the £45 estimated cost.

Can I just summarise / confirm some points?

- Your modification is to the actuator arm of the selector box which sits on top of the gearbox.
-It is a bolt-on modification and shortens the fore-aft shift; the system includes a counterweight.
- You will also supply details of how to modify the cross-gate shift to reduce its throw. This is not a simple bolt-on but is possible DIY, requiring a new hole to be drilled in the lever to fit a new clevis pin for the cable pivot.
- All supplied parts will be fabricated in 304 stainless steel, and a new cross-gate clevis pin will be supplied in 316 stainless.
- It is probably best to remove the selector control box from the gearbox to perform the full installation.
- The mod places additional stress on the cable-ends, and standard old SE cables will probably break. S2-type cables or (better still) AB cables will be required.
- The cross-gate mod may induce a stiffer feel and require replacing the bias spring with a softer version (up to the owner to find one).

John

[DeeAitch]

John, I think you have it spot on - ish
1. Yes
2. Yes
3. Yes
4. Yes - both clevis pins will be 316 st steel
5. Yes - Not 100% neccesary (I'm lazy so I did it in situ) but it will avoid any undue strain on the internals.
6. Yes - Not sure the real diff between SE & S2 cables apart from the retaining clip. Probably depends on how aggressive you are when shifting but from what I've seen breakage seems to be age related i.e. the plastic ends get brittle. Ive got mine set so that the gearlever hits it's housing on overthrow in 1st, 3rd & 5th - effectively an end stop to prevent exessive loads on the cables.
7. Yes - A softer spring will not be easy to find tho'

I will confirm costs for an initial run of 10 parts this week.