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Just some general Q's
Spottty - 23/12/03 at 12:04 AM

Ok, I wasn't gonna make a bike powered 7 because I thought it would be a too much of a hassle.... Then I saw a video of one Amazing! I loved everything about it! The sound, the high revs, the speed!

But now I have some Q's. I have never rode a sport bike before and was wondering.

1) In the car, does it have a floor mounted clutch? I am assuming it does.

2) Do you need to use the clutch to shift between gears when you are moving? The video that I saw looked like he just pulledback or pushed forward to shift.

3) I know I would need one of those reverse boxes but is there just a lever you pull to get it to go in reverse?

I am tottaly dumb about these kind of cars. There is a company about 12 hours from me (That's close in Canada!) that sells turnkeys but they are about $45k (20k pounds) and thats abit more than I want to spend on a 7.

Any advice would be great! The first car will just be a car motor but after that one its gonna be a bike powered 7, Man they are cool!


kingr - 23/12/03 at 02:38 AM

Answers to your questions :

1) If you mean foot operated, then yes, it does, they're generally pretty light though. If you mean bottom pivoted as opposed to top pivoted, then it just depends of what you make/modify.

2) You don't need to use clutch going up the gears - just apply a little pressure to the gear lever and lift off the thottle a little.

3) Yes, as far as I know, it's as simple as that, they're not terribly reliable though, and they're expensive so I haven't really looked into them in any detail.

Kingr


andkilde - 23/12/03 at 03:55 AM

Hey Spotty

Where are you located? In Windsor Ontario myself.

Hope you don't mind if I add a few more questions in your thread.

Have some BEC questions myself -- folks in the running gear section got me interested.

I've read back through some old threads -- Mr Ison and a few others seem to dispute the unreliability bit, they seem to put some serious recreational miles on their BEC's and don't have much trouble aside from the occasional cooked clutch.

My questions are more regarding cost/difficulty.

Is a special (different) propshaft required?

If yes, can I still fabricate it myself or is it a purchase only item?

Is the shift linkage very difficult to fabricate?

Do I need to do extensive modifications on the bike, engine or tranny to make it suitable for a BEC?

CBR 929's and GSXR 1000's appear readily available for $1000 or so on EBay, are these suitable? Is it better to buy from someone face-to-face?

Many more dumb questions to follow...

Thanks, Ted


Jasper - 23/12/03 at 11:15 AM

You need a two piece prop cos of the length, with a slide in it preferably at the back. Best cut and welded by a pro who can balance it properly.

Gear linkage is easy, either with rods and rose joints, or like I did with a thick cable, I believe used by Nascars. More info on request!

No major engine mods needed - though if you use a foam filter (rather than the existing airbox which can be too big) then you will need to re-jet the carbs. I also removed the carb heating pipes, had the sump chopped and the drain plug put on the side and fitted a home made baffle plate to reduce oil surge.

GSXR1000, excellent choice, as is the R1 and the Busa, along with ZX9r's and fireblades. Avoid the no-sports bike heavier engines. Just make sure you get all the ancillaries.

Keep asking - I did.

As for reliablility, I've done 6 hard long track days with no problems at all, except that I knackered 4th gear due to my changing down too hard - has to be avoided .....

Reverse box - don't bother unless it's an electric one, they are expensive and unreliable. I don't have one and mosts BEC's I know don't bother, they are easy to push!


andkilde - 23/12/03 at 02:45 PM

Hmmn

So a two piece prop with a hangar bearing is required, even if you go the IRS/DeDion route?

If the prop is longer the engine/transmission must sit quite far forward in the engine bay then, no? I'll have to troll through the photo archive.

I've three proper Minis, plus keep my father-in-law's Mini rolling so pushing is second nature. And you've got that snazzy push-bar, err rollover hoop

Do you have to work hard to keep the car light enough for bike power? I don't really want to get into alloy welding.

Do tell more about the cable style shift linkage -- does it have a sheath and fixed end stops like a modern handbrake cable?

Thanks very much, Ted


StuartA - 23/12/03 at 04:16 PM

The two piece prop is required because there is no external gear box as with a car engine, the bike engine has it incorporated. This means that the prop needs to run from the diff to the engine bay, which is a good deal further than if it only needed to run to the back of the car gear box. Even if you mount the engine as far back as you can, the link is still in the engine bay, rather than in the tranny tunnel.

Does that make sense? It does to me, but I know what I'm trying to say!


Jasper - 23/12/03 at 04:42 PM

You do need to keep them fairly light, but you don't need to go mad. As for ali welding - no, steel frame is best as it's flexible. Ali can crack. Best to leave out heavy things like internal upholstery, heavy seats, glass windscreens and wipers, otherwise, same as a standard locost. You can have these things, but you will pay a higher price in power than with a car engine.

Cable has a sheath with a fixing for the sheath at each end. One end of the cable has a metal loopfitted, perfect for a 6mm bolt to fit through and left loose for the gear stick end for the forward/backward movement. The other end is threaded - ready for a ball joint fitting to connect to the gear lever arm on the gearbox. I'll post some pics if I get time.

And yes, Stuart is right, two piece is need for strength over that length.


andkilde - 24/12/03 at 02:42 PM

Ok, output shaft in front of the firewall explains it pretty succinctly, adds at least a couple of feet in length.

I may still take a look at a long one-piece prop, full size Ford vans and police cars over here use a large diameter Ali propshaft about six feet long that is fairly light -- handles the torque of a 7 litre V10 without complaint.

I was already planning on going heaterless and using an aero-screen. I imagine "book-style" seats are lightweight enough, no?

Anyone ever tried pulling the heating pads out of a pair of Volvo seats? I know they've got them but I've never seen them to see if they're adaptable to other seats.

I suppose if I had a hard time sourcing the heavy cable you've used, two lightweight cables (one push, one pull) could be used as well.

Cheers, Ted


Hugh Paterson - 24/12/03 at 06:56 PM

Ted, to add to Jasper's bit on the cable shift, we have used both rod with small rosejoints and bellcranks, but are currently using a push pull cable system. We adapted the "Morse" cable from a powerboat throttle and it works well, comes in a variety of lengths too.
Shug.


Rorty - 25/12/03 at 11:19 PM

If you search this forum, you should come up with a thread covering cable shifts. IIRC, I posted a pic of one I used.


Spottty - 27/12/03 at 01:19 AM

Sorry for the late reply (Christmas and all) but Thanks for all the great info!

I HAVE to build one of these! The sound sold me in about 1 sec.!