Kiwi Biker forums - Blogs - The Chronicles of Sled by Sully60

The Chronicals of Sled:The "Big Twin" Update -Revisted-

Sully60 — Thu, 19 Feb 2009 21:59:26 GMT

Part 2 of 2

The finishing 180 grit grinding tool valves installed into the 'jig' head .

Finished piston, ready for installation.

The Chronicals of Sled:The "Big Twin" Update -Revisted-

Sully60 — Thu, 19 Feb 2009 21:57:44 GMT

Part 1 of 2

Well back in the original update I alluded to the fact that there was quite a difference in weight between the old 44mm 125cc pistons and the new 47mm 142cc pistons. At the time I decided to try the lighter pistons without balancing the entire reciprocating assembly. The results were more than satisfactory with no appreciable difference in vibration.

Now that I'm back in my trade I have access to very accurate electronic scales used for colour matching so I decided to find out what the actual difference in mass between the two pistons actually was.

I was quite staggered to find out that the 47mm pistons are over 10 grams lighter the the 44's. The full 44mm assembly including the gudgeon pin, rings and circlips is 93.82g and the same assembly with the 47mm items is 83.55g.

The next big step to be done here is to start lightening the crank, the 11% lighter pistons should allow good scope to remove a significant amount of metal from that large fast spinning mass that is the CB125T crankshaft.

Another necessary modification to the new bigbore pistons is to cut new recesses into the crowns. The pistons I've selected are actually from the Chinese copy of the 70cc version of the old Honda Cub motor, to the younguns that would be more familiar as a pit bike engine.

The standard recesses are quite shallow and the spacing between the valves on the pit bike engine is quite narrow. The CB125T combustion chamber is a bigger diameter and the valves are set a a wider included angle. This means that without some form of modification the valve heads touch the crown if the piston even with plenty of piston to head clearance and the subsequent lowly compression ratio (can't have that now can we?)

I've contemplated setting up a mill at work to do this, it would be the best way to get the accuracy required. It would also require quite a bit of measurement and set up time and maybe even construction of something to hold the piston at the correct angle for cutting whilst keeping the whole thing rigid.

I ran this past Koba's dad who sub contracts to our company and he suggested using some of the old bits of engine to build the jig to do it. Upon further discussion we decided the it could be done using an assembled engine with a cutting or grinding tool mounted to the valve head and the valve being spun in the guide with the pistons inside the bore at TDC.

I have lots of old bits, including many unservicable valves and cylinder heads:whistle:
so I got to work and here are the results...

Before and nearly after.
The piston inside the bore has had the first roughing cut done.

This is the 'grinding tool' valve 40 grit emery cloth super glued to the valve face, for the initial roughing cut.

To get the correct depth of the recess I set the chuck of the electric drill at the same distance from the top of the valve guide and ground the crown untill the chuck hit the guide.

The electric drill installed on the engine jig.

The Chronicles of Sled: Hidden bling

Sully60 — Mon, 16 Feb 2009 09:09:14 GMT

In my earlier blog entry about keeping a good supply of lube I showed what happens to the cam bushes when they don't get lubricated properly. At the time I had plenty of spares that were still well within service limits so I was not too concerned about the same problem arising.

I did another set in running a cam that had slightly worn journals, I should've taken more time to measure them but as they say coulda, shoulda, woulda... :doh:

So I took a visit to the local Honda dealer (the absolute last resort for someone like me) and found out that new parts were available for around $70.00 ex Japan each. Blow that for game of soldiers, $140.00 is the equivalent to four days entry fees at the Slipway!

So after some research I decided to bite the bullet and machine some myself.
I contacted Mico metals and got a 250mm long section of cored (19 i.d. 32 o.d) LG2 phosphor bronze for about three quarters of the price of one of the Honda bushes.

The bushes themselves are relatively simple and the bronze machines really nicely. The only tricky(ish) part was machining the oil groove (see the tool I altered below) to the inside and pressing the locator pin/oil way into the finished bush. I didn't make the pins I just destroyed the old worn bushes and reused them.

So I machined them to the closest clearance specified in the manual and checked the cam journal to make sure it was ok this time.

Everything checked out so I assembled the motor and gave them a try. They seem to be holding up well so far as I've done five or six meetings and they're showing no sign of measurable wear.

They look flash too, pity they're hidden inside the engine!

New versus old bushes, note the oil groove inside.

New bushes installed on cam, in cylinder head.

Oil groove maching tool, reground internal thread cutting tool.

Racing this time:Pictures = words x onethousand��..

Sully60 — Wed, 11 Feb 2009 22:51:39 GMT

I just pulled my engine apart after my brutality of Saturday sprint race.:stupid:

Racing this time:Sully60's Battle of forever more, I mean Buckets.

Sully60 — Wed, 11 Feb 2009 22:47:33 GMT

Part 2.

So I fuel up the little blue FXR, use a strip of tape to change the number to 157 (did you get that Skunk Control and Rashika?) and check the tyres, hmm Vee Rubber road tyre rear, which looks like it will be fun, not! But the TZR front end looks good so this will be an interesting ride.

So I pull out onto the damp looking track towards the back of the pack on the warm up lap for the main event and give it some berries around the final turn onto the straight and the rear tyre is already moving about and I�m only in third gear, oh dear this will be fun.

I come up on Str8Jacket after the kink just in time to see her fall, it was a hard crash as the front folded under from almost upright and she rolled a few times across the top of the rumble strip. I pull up to see that she�s basically ok but obviously in quite a bit of pain, Mrs Kendog pulls up and takes hold my bike while I move Str8�s bike and try to get the Marshall�s attention unsuccessfully. Fortunately Fi5hy has seen this from the start line and alerts them to what�s going on.

We circulate back to the pits and get told off as it would appear that we might have been involved in the crash and need to be checked out. It was our mate on the ground in the middle of the first turn so I wasn�t really taking much notice at this stage.
Str8Jackets little tiki tour in the ambulance held things up briefly enough to change the tyre pressures a bit and check the bike over one more time.

By this time it was raining properly and the temperature had really dropped, and after another eventful warm up lap the race got underway in very trying conditions. I got a good start from the third row and made some places and lost some as the pack sorted itself out on the first lap.

This was going to be a long race and due to all the messing around in the pits before the race I neglected to use my winter gloves and put some warm gear under my leathers so I was dressed more for club med than deep freeze but I couldn�t let it get to me. I was wriggling my fingers and toes around all the time along the straights to keep circulation going and despite being totally soaked fairly early on in the piece actually felt okay during the race until the later stages.

I was seriously considering coming in to swap gloves and put a jacket on or something but I had seen some of the faster guys (including Fi5hy:doh: but he did get going again)and many others stop or crash so and had only been lapped twice by the leaders and thought I could be in for an okay result. So I soldiered on stayed out there until I saw the marshall at the start line holding up ten fingers, cool only ten minutes to go, or shit, still ten minutes to go! I get into putting another lap in and contemplate the rest of the race (you have time to do that on the Ruapuna B track but it�s not a distraction we suffer at the Slipway) when I round the final bend to see a white flag!
One more lap that�s all, just about two minutes of time left out on the track, I gesture thanks to the flaggies and decide to enjoy the last lap as much as possible. I catch up Mrs Kendog just before the hairpin and give her a pat of congratulations :whistle: for doing so well completing such a hard race as I go past. As it happens I caught Kendog just after the hairpin and congratulated him in a similar way.

I didn�t muck around getting back to the pits, no one did and as soon as I had stopped racing I felt the nerves coming back on line in my finger tips and the shivering set in, I sidled up towards Pamela and warmed myself on her hot bits so I could then use my hands to get some dry clothes on and pack up the bombsite where my bike used to be in the pits.
Usually at the end of the days racing everyone hangs around and tells lies and compares tyre wear and jetting but not this time. Mrs Kendog kindly informed me of the location of Joni�s yummy rolls, which were actually buns and far from plain. So after indulging myself in the hospitality of Kickaha and Divvo�s? van�s servery dept it was time to get out of Dodge before we were frozen stuck.

So overall not the greatest days racing in the scheme of things though I thoroughly enjoyed myself and really loved riding the track even in the wet. All the people I met were great and the hospitality shown by the locals really blew us away. I can�t thank Mike Stein (sp) enough for letting me ride your new bike and not calling me in after your one stopped in the main race :niceone: You really saved my weekend and I am eternally grateful for that.

Tony and Andy Mac, great hosts and even greater competitors, I really enjoyed racing with you both out there and thanks for letting us stay at your lovely house with a cool bike collection in the garage.

Dangerous, thanks for the help in getting me down there and to you and Rashika for letting me hangout despite being a Bourbon drinking heathen :dodge: I�m looking forward to being a little more organised next year so I can show you lot how to drink properly! Buddha#81 Respect! Any big boy who gets a bucket moving that fast is a brother of mine!
SpeedyGirl the aptly named taxi service, thanks a heaps for the lift home, it was good to hang out with my Welly peeps and the crew at Rashika�s so you did me a great service there, also a stoic flaggie in those bitter conditions, what can one say?
To all the other Christchurch bucket racers I met, I�ll be back next year with some more horses and taller gearing, it�s going to be on!

To all the organisers and flaggies and people behind the whole event, to put all that effort into the day and have the weather do that I really feel for you, to your credit the meeting ran well and being savvy to the weather and changing the race order made the most of a challenging day.

F5Dave who really kicked the whole show off for me by needing a seat filled, but also being another pivotal in making the whole weekend really enjoyable. Riding the KV on Sunday was most enjoyable and enlightening to what�s achievable horsepower wise, whoah, why do the other bikes look like they�re going backwards?

To all the people who sponsored me to get down there, I can�t thank you enough. You gave me more than just the financial ability to do this, you�ve given me the belief that I can make this happen and that goes way beyond the value of money. I�ve gone all funny and started feeling very special about the support that�s been shown so I will make it my mission to get into a position to help someone else get there next year so they have a chance to feel this good too!

Racing this time: Sully60's Battle of forever more, I mean Buckets.

Sully60 — Wed, 11 Feb 2009 22:46:33 GMT

Part 1.

Right this is going to be a long story so get yourself a cuppa or a shot glass and make yourselves comfortable.

A few of you know the story of how my getting to this meeting came about but for those who don�t is was down to the generosity of many people on this site who all put in to help me get there. I�ll go into details later but I�ll just say that I�ve been humbled by the whole experience and will remember the kind spirit shown and carry it with me for a long time.

So anyway after the obligatory running late interisland ferry sailing which was quite smooth we grabbed a feed at Picton and hit the road. F5Dave wanted to get to Christchurch in time to visit one the bikeshops but regular stops due to road works meant we couldn�t quite make it in time. So after finding our lodgings at Tony Maclaughlan�s place we sampled the local Shark n Tattie, told our various war stories and lamented the politics of modern motorcycle racing over a couple of ales.

After a reasonably good night sleep for a pre race night I woke to a warm (for June), sunny, norwester Canturbury day, great!
I knew it wouldn�t last based on all the talk about the weather but I was just keen to have a good crack at this place in the dry. So after F5Dave refreshed his memory of Christchurch�s geography we arrived at the much vaunted Powerbuilt raceway at Ruapuna Park.

We quickly find the rest of the Welly crew who�ve obviously gotten to the track fairly early and secured a good spot with a strip of concrete to park the bikes on and the Ezy Ups in place, all very professional looking might I add :niceone:
So we go and get in the queue for sign in and stand there for ten minutes only to be told that I couldn�t until the day licences arrived. So I wait and they finally turn up and after a few little issues to take care of after scrutineering I�m all ready to go.

I take the time to go up to the pit exit gate and watch some of the training sessions being held for the youngsters. I knew the track was big by Wellington standards but I wasn�t quite prepared for the length of the straight and the distance you actually get away from the pits,:gob: Fi5hy and I had a few laughs about taking something to set up a bivvy just in case. We also scoped some of the faster kid�s lines and figured out pretty early on that the throttle stop would not see the light of day much at this track.

Tony had told me who the riders to watch were in the buckets and we had an idea that some of the FXR�s and all of the CBR�s were fast machines and set up well for this track so we were under no illusions about how competitive we would be with our �car park racers� but only getting out there would tell the true story.

So first practice is up and after negotiating the slippery dragstrip staging area the rubber finally meets the track. Bayden, Fi5hy and I set off together and manage to stay pretty close for the whole session which only seemed like four laps.
With the back straight being as long as it is doesn�t take long to see that there are some very fast bikes and it�s all a matter of survival on our heavy, slow revving :whistle:machines. Though F5Daves borrowed KV100 is clearly the fastest bike out there (but more on that later)
So we all lacked some top speed but the infield section is a different story for us as we can make up some time through the more technical sections of the track, despite being pretty much flat out though most of those too.

After what seems like five minutes after practice finishes it�s time for the first six lap race. Now in true bucket fashion there�s no provision for grid positions to be sorted pre race so it�s first up, best dressed, I pull up to the third row as I want to learn some of the overtaking spots and being overtaken spots. I make a reasonable start and head down to pothole in the middle of the pack, everybody slows up slightly to bottleneck through the turn and we�re full throttle again down to the hairpin. I make a few spots first time through and look ahead to see Buddha#81 and Andy Maclaughlan not too far ahead of me on the track. I must have had a couple of good clean laps because I manage to catch up and put a drafting pass on Buddha. I get another good run through the infield until I get to the left hander off the connection road where I catch a slower rider and sit up briefly. I pass the rider and get around the final turn only to be repassed by Buddha and Andy early on down the straight. Damn, it�s all about track knowledge at this stage and I�m still on chapter one!
I get held up again through the infield and fall into the clutches of Bayden who is going well, despite being a team mate I didn�t want him to be in front because is bike becomes very wide and if it�s working well he�s very hard to beat. I manage to get back past Bayden and put in some good laps to try and catch Buddha again. He�s some way off in the distance and getting closer so on the last lap I decide to try really hard to catch him, unfortunately a little too hard as I over rev the engine just before the first infield right hander bending an inlet valve:doh:

I manage to get to the finish line running one cylinder only just behind Fi5hy and Bayden but the motor might as well be toasted for the weekend. I push my bike across the infield and true to his word Bayden comes and picks me up for a tow.

This is about the time that Saturday changed for everyone, I was doing some exploratory surgery on the �sled in some vain hope it was foreign object ingestion or something other than a terminal problem when the weather finally turned. After a quick disposal of the now kite like Ezy Ups we decided we would try to transplant the engine from Skunks bike into mine, which was quite an undertaking in the impending conditions.

At this stage I must pay homage to all my Norf Welly Massif team mates who despite having their own bikes to ride in the main event and the adverse conditions pitched in with gusto and made a huge effort to swap the engines. You guys have already done so much to help me get there and you all helped with such enthusiasm to get me running I�m truly honoured to know such a great bunch of people!

Our plan was coming together but we were running out of time, Mike Stein (sp)approaches me and asks who�s riding the bike we�re working on and say�s something about it not being ready in time, to which being a typical stubborn Sullivan I take a defensive stance, he counters that he has an FXR I can ride all it needs is gas and I�ve come a long way to miss out and not ride. His kind offer crushes my stubborn pride and I gladly accept.

The Chronicles of Sled: I've lost inches off my bottom!

Sully60 — Wed, 11 Feb 2009 08:32:09 GMT

Well the Leadsled has.

Gone are the mismatched 3 and 4 inch rims and the rear contact patch that was all but gone at 15 degrees lean angle.

The front wheel conversion was less than simple as the first pic will illustrate.

I bet your saying to yourself why didn't you just find bearing with the right ID/OD to make this easy, turkey!

Mr Kawasaki didn't want me to put ZZR250 wheels into my ZXR250 so he choose bearings that don't have corresponding sizes, ironically there are bearings with larger ID and smaller OD but not in the combination I need.:doh:

So from left to right in pic 1 we start with the 20mm ZXR axle that is being replaced. In the middle is the new axle that uses the 15mm of the ZZR wheel bearings and on the right the stock ZZR axle.
As you can se the thread on the ZZR axle is quite small (14mm) so would be rather sloppy in the 20mm ZXR threaded fork. We got round the by making a male/female threaded insert (bottom centre of pic 1) to take the 14mm axle thread up to 20mm, this screws into the inside of the ZXR fork that remains unmodified (because you just never know).

The ZZR also uses a single disc setup on the right side of the bike, fortunatly the ZXR had a twin disc front end so the caliper mounts were ready to accept a modified bracket carrying a caliper from a Chinese 150cc scooter

The rear axles were the same size so simple spacers and a skim of the sprocket carrier were all that was needed to complete this end.

So now I have a 2.15 x 17 front rim and a 3.5 x 17 rear, ready for nice 125gp bike slicks, yeeahh!

There's probably much easier ways of losing 1.35 inches from your bottom but they don't give you that satisfying smell of cutting metal:yes:

The Chronicles of Sled:Bring the noise! oh and some earplugs

Sully60 — Tue, 10 Feb 2009 20:58:25 GMT

I've just completed two days work of works to come up with the following:

Big thanks to Campbell (non KB master fabricator) and of course Skunk for allowing me to crash his Tuppagadgets mens BBQ and utilise the awesome Skunkworks Bucket factory.

We could only run it for a short time because it's not quite finished properly, but from what we did do we know its LOUD!

During this video you can hear the bike miss at the top end, I later found that the ignition timing was too advanced, doh!

The Chronicles of Sled:The "Big Twin" Update 1 -RESULTS-

Sully60 — Tue, 10 Feb 2009 09:14:47 GMT

The results are in hot off the press people.

I suspect Mr Speedpro may have done this before see the graph below for results.

The red line was basically where we started and we ended up with the blue line. The two lighter more spaced out dotty lines are the torque with values on the right, these are really big numbers for a 140 twin but remember there's no correction for the low gearing.

We did a total of about 30 runs all up, these graphs best represent what we achieved. Although this doesnt have the very first run on it, the 15.2 number came up first, and most often over all the runs, so well done speedpro. :first:

So we didn't really make any big numbers (thanks though slingshot, oh and sketchy, you know I need more than 13 hp to haul me and the ledsled around that Slipway) The different runs produced some interesting numbers one run we managed 15.7 right at the top like the red line but higher at the end. Another run which was more like the blue line ran to 15 at the bump at about nine grand and waved around 15 all the way to the drop off about 11500. Both of these runs were the run before or after the consistant runs like the graph without any changes made. So it pays to be a little careful with how you interperet the figures.

Rode it up the street for a we test run and race launched it and boy it feels phat now!

But there's a long way to go as I have only just started to develop this engine.
Stay "tuned" for regular updates.

The Chronicals of Sled:The "Big Twin" Update

Sully60 — Tue, 10 Feb 2009 09:08:31 GMT

It's time I got around to an update as the bigbore twin is now together and running.

As I have limited amounts of all necessary resourses I have not been able to get any of my bottom end "wish list" stuff done. I have run the bike up to the operational design speed I was aiming for, ahem :shifty:

The engine doesn't seem to be at its potential yet in terms of outright performance, I haven't done any tuning as such I just replaced the pistons and rings made sure they had heaps of clearance from the valves and left everything else the same.

See the photo's of the before and after.

The old pistons and rings were pretty shot but the bike ran ok and carburetted well enough it just wasn't sharp. I spent a lot of time with the tacho over 10k just to get the thing really moving.

Now the thing hauls ass! it pulls cleanly and is strong from about 7 to 127?? :eek:

The motor did feel a little slow to build revs and I know this is due to the lack of setup but it doesn't need to. The increase in torque is amazing, the conditions probably weren't the best for true comparison but I can say the rear tyre is starting to earn its keep.

I had to rush the assembly a bit because I didn't want to miss the weekend race meeting as I'm leading that championship at the half way point and its one I've yet to win. The results speak for themselve's so far as I managed a victory and I third to extend my lead. But there must be so far to go with compression, jetting, timing etc. I can't wait, I have a dyno run next week and have a few things to fix and sort before then.
Down to the garage!

The Chronicles of Sled: Always keep a good supply of lube!

Sully60 — Tue, 10 Feb 2009 08:47:24 GMT

It is vitally important to keep a good supply of quality lubricant on hand at all times incase of any emergent situations where intimacy of mating parts is critical.

Failure to adhere to good lube practices can result increased levels of painful stiction and friction which in turn creates a general lack of satifaction with preformance and in the long term can result in excessive clearance between the formally intimate components.

Unfortunately a friend of mine :msn-wink:was less the prudent when it came to this important issue. Despite this persons prowess with maintaining the intimate relationships in all areas of his life he was let down by there she'll be right attitude and suffered the consequences.
When questioned about this my friend says:
"I wondered why when I seemed to be trying really hard I wasn't getting anywhwere-cough-and things just got noisey and I had to really pound the poor we thing to even start to get it going.-sniff- My performance was really suffering -hoik- and I was even thought I was going to finish a bit to soon as couple of times. I thought about lube thing but was distracted by the whining from the top end.

Below are photos of the result of this persons unsympathetic attitude to lubricant and the application of it. Let this be a lesson to all who have are responsible for intimate moving parts. The ones on the right are what these parts should look like.

The Chronicles of Sled

Sully60 — Tue, 10 Feb 2009 08:17:03 GMT

Well I've done quite a bit of work to this bike over the years, I thought I'd put all my efforts in one place to make it easier to track the progress over the years.

To provide a little background to this, I started racing Buckets seriously at the end of 01 when I raced Super Moto around the Kart tracks and carparks at the bucket meetings.

I'd ridden a few buckets before then and they were all quite hard to get the best out because their chassis let them down. Then I rode an Aprilia RS50 in a 'swaps' race where all the SuperMoto riders drew a number out of a hat and that was the number of the bucket they were to ride. I won that race and the rest as they say is history.

I started with a CB125t that I brought from Bistards dad. The bike still had the cable operated front disk and run on (old) 18" slicks.
In the first race meeting I race this bike I crashed three times, losing the front at moderate lean angles, even at wide open throttle wtf?

So needless to say the 125T chassis quickly ended up in the rubbish and I purchased a complete RG50 rolling chassis, from Bistard himself this time.

Now anybody familiar with RG50's woud know that they're quite a small, narrow little machine. Shoehorning the 125T engine was going to require quite some engineering. And just because that wasn't enough of a challenge I decided 125cc weren't enough so also went about creating the 142cc capacity engine that I still run today.

This was all achieved within the month from the last meeting and I walked into work with a cylinder head and a bare frame on Monday morning. By Sunday morning the bike was ready. I managed to draw a front row grid spot for the first race, mint! The flag dropped and I made the holeshot and stayed in front to take my first ever bucket win! My how things had changed in the space of just one month!

The RG framed CB125T'Cube' in action at the Kaitoke 2 hour race

This bike was very fast compared to the rest of the F4 bikes around at the time, the power to weight ratio was very good and I usually had no problem getting past people on the straights, I used this speed to good effect to win a few more races that year (the highlight being a double race win at Kaitoke).

This machine was fun alright but it did have some funny handling characteristics leading one of the bucket sages to dub it the bucket version of the Aprilia Cube. Power understeer is not something usually associated with buckets but I was regularly exiting corners with the front wheel still pointing at the inside curb.

I wanted something more like the RS 50 I raced and that sublime feeling of peeling into the corners carrying what feels like way too much speed and getting to the apex with one's knee jammed between the side of the fairing and the ground all the while feeling like you could do this all day long around any corner.

The 'Cube' as successfull as it was had to go!

The beam frame trend was well underway by that time in Wellington, with Fi5hy, Bistard using ZXR250 chassis and a few others with GSXR and RGV frames. I was still in the trade back then working at Motorad so opportunities to obtain a better chassis were frequent. As It was Derek McAdam had a ZXR250c chassis under the his deck and not seeing himself using it in the near future donated it to me free of charge! Top bloke, top rider and top mechanic that Derek.

And so the Chronicles of Sled begin...