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et flywheel alternatives


berty

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Posted

hi all, so my et had a katana flywheel (smaller in size from standard et) which was fine until one day it spun up and wore itself down . they are difficult to replace from what I see - and most used ones have some wear due to spin up or the dreaded "clang" experience.

so does anyone know of any other flywheel alternative ? perhaps a modern day Suz has one the same size ?

 

Posted

Forget modern alternatives - virtually no one uses crank mounted rotor / alternators anymore! You may get a GSX ET type but there getting rarer - you'll have a small crank nose taper so later EFE types won't fit. It'd have to be a pretty bad spin to wear enough that the damage can't be filed / polished / lapped out!

  • 1 month later...
Posted

Forget modern alternatives - virtually no one uses crank mounted rotor / alternators anymore! You may get a GSX ET type but there getting rarer - you'll have a small crank nose taper so later EFE types won't fit. It'd have to be a pretty bad spin to wear enough that the damage can't be filed / polished / lapped out!

Think you are wrong here.

Most modern bikes use crank mounted rotors these days - all GSXR's from 2000 onwards for example. Also Yam R6, Blades etc. Anyway back to the question, a GSXR600, 750 or 1000 flywheel from years 2000 to 2005 will fit but it has holes in the back of the flywheel so it would be difficult to mount the starter clutch. There are most likely other candidates too but you will have to spend hours looking at pictures in Google just like I did until you spot a likely candidate.

There is an alternative however which I am part way through right now. A GSXR600/750 K6 model onwards flywheel & starter clutch looks like it will fit. The flywheel needs a little bit of metal removing & the existing starter gear needs machining to fit the GSXR starter clutch. I am part way through this but it all looks promising. The flywheel taper is the same & after machining it fits well. The GSX starter gear has been machined but it is very hard but can be turned with carbide tooling. It now fits the GSXR starter clutch

Final thing will be to mount the GSXR generator coils into the casing.  

Hopefully if all this works it should result in a lighter flywheel, a better generator output & a stronger starter clutch. 

In a couple of weeks I will have finished & will put all the stuff on here with all the info

Nick

  • Like 2
Posted

Now this could be exciting, but I'm struggling to see exactly how this would all hang together. Not familiar with the K 6 starter clutch.

 

just how small is that rotor, or more to the point, how narrow?

 

Posted

Rotor is 108mm i/d whereas the standard ET rotor is 105mm (maybe??). Anyway it is slightly larger internally but has a much thinner wall. The o/d is 118mm. The internal depth in 27.5mm. 

According to my quick measurements, the stator needs to move 12,5mm approx closer to the engine. This means I will need to make an adapter spacer but it would be possible to make the cover narrower by at least that amount & maybe more if you had the means to machine a new custom cover. I will probably use a spacer so I can make it myself but the potential to modify the cover is tempting me to think a little harder before committing. 

Posted (edited)

Looking forward to seeing this in the metal. Got a back project for a water jetted LHS engine cover plate in 10mm  so that it can withstand a whack in an off. This was originally intended to just have a cone cover for the crank end for a total loss system. I've stalled that project in anticipation of  how compact this could be.

Phase One have a touch-down problem

P1010321_zps3yxpbik6.jpg

This was an early cover and we can shave the lower 2 bolts heads and trim that chamfer on the cone.

We now gain an additional 5mm by milling back the fastener landings and milling deeper into the cover, plus we cut the crank end and nut to gain a bit on the cone.

Sorry, may not be obvious, we've got the starter gear and sprag clutch in there as we need a starter motor in the races that we do. It's a safety issue. We're really fast and should be in the top 3 of a mixed ability field of up to 60 bikes. If we run total loss, we can get the ground clearance, but have to start with a push from the back of the field, if we've got no starter motor. Now, we may be about to race for 2Hrs minimum, but that first couple of laps is dangerous. From that push start at the back, we've been known to be in P3 by the end of the second lap. Can you imagine doing 50+ overtakes in 2 laps in race conditions. :D dodgy.

We do like the concept of chasing down a leader who's belted away from pole, but it's much less perilous if it's us.

Now as we can see there's not a great deal of structural integrity in doing this to a standard cover and we've bent a crank on a near virgin engine after a heavy landing.

P1010224_zps6cf8e87e.jpg

This was a 4k mile motor that died when a fookwhit riding a modern superbike ride got frustrated by the pace of a 30yr old classic and block passed an experienced rider who could brake 100m later into a 100mph left at the end of the Aragon straight.

We'll never find another one this good, it was totally standard and the lap times that it could turn were impressive. Certainly 10s faster than the guy on the S1000RR Bmw that killed it. Bastard. 

 

Back on theme, We need that 10mm plate. I'm in touch with Nick and given that he's local, we'll open our doors if he needs any help to sort this project out. 

If we can squeeze a modern Genny in this area , we can put together a kit that might be useful to the whole OSS community.

I like.

 

Edited by markfoggy
Continuing/check photo
  • Like 1
Posted

Ok , thanks. Useful.

Was expecting a smaller diameter, which is screaming GSXR750 kit at me, but they're unobtanium and getting the sprag drive is not an option.

Whatever, we'll get the drawing together for the crank centre and mounting holes/dowels. So the basic plate is a piece of piss. Knocking a bigger hole in the centre and making a cap is simple enough.

I need to think about this a little more laterally, I think that I've seen another Suzi genny that is a bit smaller, just can't be sure that I'm right. Plus the research will take a bit of time.

Of course we could also tackle this in another way. We're probably gonna comission another chassis from P&M.  Last night in the pub I was suggesting that we should build one around a Bandit motor or a.n .other oil burner. Plan would be to offer a road base Endurance Racer P1 rep.

Could do the mad thing though, we've  changed the head angle from the traditional by a degree, plus we've moved the swingarm pivot by about 10mm. This suits the GSX engine output shaft sprocket better, and gets the front turning a bit better. This was the first GSX 1100 frame that Richard at Peckett had ever built. We'd built our first one out of a GS100 bike that he'd built back in the day (frame 43..46  or something). Think proper OSS stuff, drilling through round tubes, welding in bosses, making engine plates, getting Ti bolts made.

The next Iteration of frame should be to move the crank centre up and forward, think 10mm each way. This seems like a lot, but we're talking about development of a chassis that's now designed to run on radials, compared with the original cross-plies. this would probably allow us to run an Alternator. We'd not have to change a lot.

New swing arms - longer

New tanks

New exhausts

new, curved oil coolers

And making sure that everything else fits,

That'll be a job for the winter then, last race of the year gets me home on 2nd Nov FFS. :D

 

 

 

 

 

 

 

 

  • Like 1
Posted

The race alternator kits that Durbahn.de sell are based around Ducati ST3?4? alternators - they're an aluminium hub with rare earth magnets in it - 75mm diameter, ~20mm wide, with the coils run around them (Bevel Ducati guys use them as a bolt in upgrade in their old shitters). There's enough room before you hit magnets to bore them out big enough to slide over the hub of the small crank GSX alternator, and clamp them with a stepped washer under the crank nut. would be the absolute lightest alternator you could run, very narrow too.

Converting to a modern sprag clutch is interesting - I was just looking at the item out of a SV650 wondering if it could be used...

 

Posted

The race alternator kits that Durbahn.de sell are based around Ducati ST3?4? alternators - they're an aluminium hub with rare earth magnets in it - 75mm diameter, ~20mm wide, with the coils run around them (Bevel Ducati guys use them as a bolt in upgrade in their old shitters). There's enough room before you hit magnets to bore them out big enough to slide over the hub of the small crank GSX alternator, and clamp them with a stepped washer under the crank nut. would be the absolute lightest alternator you could run, very narrow too.

Converting to a modern sprag clutch is interesting - I was just looking at the item out of a SV650 wondering if it could be used...

 

Hey that's interesting stuff. Never thought of looking at Ducati. Now if it could be combined with the Gsxr k6 starter clutch or maybe R6 as they are similar that would be something! Big problem I think would be the need for a taper to match the crank  for the starter clutch to provide the drive. The loads are quite high. 

I have been looking at the Electrex World race generator kits wondering if they could be adapted to include a starter but they are big money to start with. 

 

Posted (edited)

Oh, meant to ask - what angle is that taper?

Also - were you starting with a small crank, or the later Big ended crank (EFE etc)?

What size is the puller thread?

How much lighter than stock do you reckon it all is?

Edited by Gammaboy
More questions
Posted

Also - were you starting with a small crank, or the later Big ended crank (EFE etc)?

 That's I would like to know too ;)

I'm watching this with great interest. Especially if the flywheel fits on the large taper cranks. Lighter flywheel with more charging output sounds tempting.

 

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