Help needed to decide is it safe to buy this?

[RS_Patrick]

Hey Patrick do you have the port mapping for the TP Rose?

Also, gearing will have a large effect on crank snapping. If you run smaller front sprocket you will be exerting significantly more force on the crank. A larger front sprocket wont pull you off the line nearly as fast, but it will give your crank significantly more longevity. There are many factors involved with snapping a crank. However I do agree with you in that if you have one around swap it out. : )

The Crank snaps on the Flywheelside... its the torsion from the big and heavy fleewheel that does it.

I dont have a portmap of the pink kit.


Here is something to help you do the math: http://www.af1racing.com/store/Scrip...idproduct=1165

75mph is a piece of cake at less than 12000rpm.

ToraTora, the D50B and the AM-6 are really totaly difrent engines mate, if your into racing and the rulles alouw you to swap the engine i would drop a AM-6 in your bike.

[Glen1990]

shit i just saw that crank photo im soo glad i changed my stock crank

[szimat]

Thers no Black TP 75.. its 73cc, the pink one is 75cc.

Black one is less powerfull and has a lower rpm powerband, the pink one is much more agresive.

Black one is bit more reliable and really good if your not really demanding like szimat, 100kmh is easy (screeming in 6th with stock gearing) with blistering acceleration with that kit, if you turn the throttle back wen your shifting to 6th you can comfortably drive 80kmh or so and easly accelerate to 100kmh to pass someone with out shifting down and up again, wich is from what i understand all he wants out of the bike.

Yes, this is exactly what I would like to have with my RS: not really demanding as you said Patrick. Basically, I'm not so far from this, since the all stock setup gives me 75km/h top speed, but still some 30kmh needed to reach 100kmh. Blistering acceleration, comfortable drive 80kmh (not with full throttle) but to have some power reserve in case of overtaking or any other situation where a reserve in power would be of great help. I do not intend to drive it at 100kmh for long time, but 75-80kmh only.

Considering this, the TP black 73cc is a good choice. The crankshaft would be the Doppler you have suggested. If you have some time, could you please put the correct links for all the parts I would need?

1) TP Black 73ccm (I would need a link, since I can not find it, and I'm not sure which is for my RS)
2) Doppler ER1 crankshaft
3) Dell Carb 19 or 21 (perhaps 17,5?) but which model? + adapter kit/manifold set
4) Gianelli, LeV v6 or Arrow pipe (perhaps a used one if someone has for sale at reasonable price?)
5) reeds (but exactly which one?)
6) stiffer clutch spring (exactly which one?)

Anything else I'm might missing here?

I will probably buy these parts on a longer term, especially the pipe will be expensive. If I do not overkill the bike, and use good quality oils, regular maintenance, what would be the average km the piston and the crankshaft would last? Or most probably I can change the piston only?

One more thing regarding the oil (especially the 2T): at the local garage the guy said that I should use Xado 2T full synthetic oil as it is one of the best oils he has ever used, even better as Motul 710. Do you think Xado is really that good?

Thank you!

[RS_Patrick]

1: Minarelli AM(3/4/5-6) engine http://www.easyparts.nl/showarticles...5-6_Ø49mm.html
2: ...
3: http://www.easyparts.nl/showarticles..._Variabel.html and http://www.easyparts.nl/showarticles..._Cod.2631.html and http://www.easyparts.nl/showarticles...met_Kabel.html
4: What ever you like the most, keep in mind that carbon/kevlar silencers usualy sound better than aluminium/metal silencencers.
5: http://www.easyparts.nl/showarticles...40_Val.Or.html
6: http://www.easyparts.nl/showarticles..._Frizione.html

I think he just tells you to use Xado because thats what he sels (i never heared/seen any Xado 2 stroke products...), Motul 710, Castrol Power 1/RS Racing 2T, Shell Advance Ultra 2 are really good oils of wich i use the last one for all my 2 stroke engines.

[ToraTora]

The Crank snaps on the Flywheelside... its the torsion from the big and heavy fleewheel that does it.

I dont have a portmap of the pink kit.

Here is something to help you do the math: http://www.af1racing.com/store/Scrip...idproduct=1165

75mph is a piece of cake at less than 12000rpm.

ToraTora, the D50B and the AM-6 are really totaly difrent engines mate, if your into racing and the rulles alouw you to swap the engine i would drop a AM-6 in your bike.

It's amazing to watch you complain about the AM6, and then claim it's the best thing in nearly the same sentence. You really should do some research on these engines. The Derbi engine employs the same flywheel as the AM6, and it isn't nearly as big and heavy as you make it out. I've never seen a Derbi crank break like the AM6 crank you have in the photo, and based on my knowledge of physics the reasoning given for the break isn't congruent. It is more likely that something caught the flywheel that triggered the snap, the person that work on the engine did something to cause the failure, or maybe it just had a defect. To be fair outside of your photo I've never seen an AM6 crank fail that way, and there are plenty of kitted bikes around here running on stock cranks.

Patrick as I've explained to you before I no longer race (that was years ago and in the dirt--never on this class of bike). Additionally, the DB050 (that's the actual name) came in the later not exported to the States bikes. All of my Derbis have the older EBE/EBS/Senda engines (which you know because we've gone over this previously--and is easily seen in the recent photos to anyone that has a clue about these engines).

If the AM6 was so wonderful then why didn't Aprilia keep it in the bike? They went back to their frame, and if they could do that they could surely spec the engine they wanted--for instance they still employ the Rotex in the larger bikes. The answer is that the Derbi engine (and in this case for Aprilia, the DB050) is just a better engine. The stock crank is better, the transmission is better, etc. just a better design. While I have no direct evidence I can hypothesize that Aprilia worked with Derbi to upgrade the engine, and thus the DB050 was designed. Having a worthy "in-house" engine with a better transmission was a win for all.

Now lets address your sprocket speed chart. First there's nothing there to help with the math. For that you need information about the primary drive, transmission, sprocket ratios, as well as wheel/tire size etc. I've found all of that and I have done the math for both the AM6 and the Derbi engines. They are comparable with maybe a slight mechanical advantage on the Derbi transmission due to the primary drive. Also, the Derbi has a slightly wider ratio in the lower gears, a closer ratio in the mid gears and then a very slightly larger ratio for the top gears. This provides for more toque for take off, more ease for keeping in the power band in the gears which are ridden the most, and a more consistent 6th gear. The AM6 has its largest jump between 2nd and 3rd right where you want it to be close for a better transition. Before I looked into this I use to wonder why there weren't as many trany mods available for the Derbi. Well now I understand--there is clearly less need for them on the Derbi.

Theoretically yes those sprockets with a stock sized tire and the stock transmission in the AM6 could reach that many rotations of the rear wheel at 12K. The problem is most builds of the AM6 wont reach those RPMs with that gearing, and most of the ones that could will take so long that the bike wont really be fun to ride. The very few that are built such that they have to power to perform that way will require more than just bolt on power. Having now done the math I have confirmed what my intuition suggested.

One more thing. I want to make clear that while I'm singing a little praise for the Derbi engine the AM6 is quite serviceable. It currently holds the world land speed record for a 50cc (turbo-charged no less!), and there is much support for it. Suggesting that either engine be swapped for the other to gain a significant advantage is ludicrous.

[Glen1990]

you do know that they got derbi engines just cause aprilia got bought out right thats why they didnt use the am6 and the rotex ? ive heard of many many stock cranks breaking in the same way as patricks

[szimat]

1: Minarelli AM(3/4/5-6) engine http://www.easyparts.nl/showarticles_info/01529919250/0-4019-968-1681-1981-265-3235-3769/6183/Cilinder_Top_Performances_Minarelli_Am_345-6_Ø49mm.html
2: ...
3: http://www.easyparts.nl/showarticles..._Variabel.html and http://www.easyparts.nl/showarticles..._Cod.2631.html and http://www.easyparts.nl/showarticles...met_Kabel.html
4: What ever you like the most, keep in mind that carbon/kevlar silencers usualy sound better than aluminium/metal silencencers.
5: http://www.easyparts.nl/showarticles...40_Val.Or.html
6: http://www.easyparts.nl/showarticles..._Frizione.html

I think he just tells you to use Xado because thats what he sels (i never heared/seen any Xado 2 stroke products...), Motul 710, Castrol Power 1/RS Racing 2T, Shell Advance Ultra 2 are really good oils of wich i use the last one for all my 2 stroke engines.

Thank you Patrick! So basically these are the things I have to buy to have an excellent running RS 50 with great quality parts. Everything else can remain untouched, nothing else that needs to be changed?

It would certainly take some time to get all these, since even without the pipe it is more then EUR 500, and the Giannelli with Carbon muffler is an additional EUR 160, and if I add the fee I have to pay for the job, I'm easily around EUR 800-900. This sounds quite much, considering that I bought the bike for less I thought I would be able to find a kit around EUR 100 and no need to change the crankshaft. Anyway, I will still consider if I'm willing to spend this much money or not.
The bottom line is: the bike goes very good as it is now, and I hope it is going to perform well for at least a year or two, but i would really love to have the performance we were talking about and that would involve the upgrade to parts listed. If I have a bike like that, I might find it good enough on a long term without need to upgrade to bigger ccm bike.

I do have some questions, just to have a clearer picture:
- if I do the upgrades and I drive the bike in normal way, no racing and not at the top speed, how much the Doppler crankshaft and the TP kit (piston) can last? I know it is hard to tell, but with good quality oil and with care what is the approx km it can function well?
- will the engine use considerable more fuel? Would 5 l/100 km be enough?
- which one would you prefer, the Giannelli Carbon or the Arrow system? (Perhaps the LeV v6)? Are there any special reasons why to get one or the other one? I find the Giannelli very popular and at best price

Regarding the Xado oil: you are probably right, he sells Xado and that is why he prefers it. Anyway, I just wanted to know is Xado is really that good or just another oil-religion story. This is the oil he is talking about: Xado Atomic 2T

[RS_Patrick]

I cant even find Xado 2 Stroke oil anywhere... i dont think it exists, but on the engine oils etc. i did not hear to many good things... they make quality/performance promises that dont hold up in independand testing...

Mine has done 10.000km fine mate with the Doppler crank.

Note that Giannelli pipes usualy seem cheaper at first glance, but they do not include a silencer normaly, so you would have to add atleast 50 euro's for that.

I dont like the new Arrow and Giannelli pipes to much, there street legal pipes and perform less good than the old "race" types wich where only "retail" legal because they fitted a big reduction in the manifold.
Leo V6 is a good pipe but... i dont like there sound as much.

Bike might make 1 liter to 20 kilometers if you drive relaxed.

You could skip the crank if you install a 19mm carb with that big bore kit... but theres a big risk that it will snap, so you can wait for that to happen (if it happens) but if it happens, it might send debris flying off into the barrel damadging it and the piston.

[ToraTora]

more like 75mph.
15/47 gearing would be better, your than looking at over 80mph probably.

With a 15/47 sprocket system, stock tire with no deformation (and there is always deformation), no air resistance, 12K RPM (the one Patrick likes to quote) the theoretical top speed would be 79.997 mph. So even without the real world hindrances it's not going to hit 80 mph.

Math it is a beautiful thing, you might like to try it sometime.

[RS_Patrick]

Tire deformation would be freom centrifugal forces at high speed wich means the diameter increases a little bit on these light bikes, the tire isnt gonna shrink mate.
Air Resistance has nothing to do with RPM/Speed Ratio, so at 12k with a 15/47 sprockets that means a speed of ~77,3mph depending on the tire a bit more or a bit less.
Oh and with that setup his bike probably will pull past 12k easly in 6th gear... so you do the math.

Your pissing people off mate, not just me, so why dont you do us all a favour and go to your "friends" at B.A.T.S. and stay there from now on ok?

[ToraTora]

Patrick you are pissed because you are being challenged. If you are going to go around misinforming people then you are going to get challenged. The cure for this is to stop misinforming people Patrick, or you could change your title to Tecnologia Reparto Disinformazione.

By the way air resistance is a factor in the top speed of these bikes.

[RS_Patrick]

I am not a Mod,(i was years ago though, hence the altered text under my name) and do not have any more user controles than any of the other users... really sad of you to think i would do such a think... but hey, if i was a mod, i would have banned your ass to BATS...

[twinturba]

I am not a Mod,(i was years ago though, hence the altered text under my name) and do not have any more user controles than any of the other users... really sad of you to think i would do such a think... but hey, if i was a mod, i would have banned your ass to BATS...

It's not beneficial to all concerned to ban people for sharing their knowledge.

I got an idea! Why not just refer all questions from USA members, that you can't knowledgeably answer, to the BATS?

It really pains us to see fellow USA two stroke enthusiasts misinformed, as some have been, by advice and opinion without the proper knowledge behind it.

If we can agree to disagree then everyone can learn

[RS_Patrick]

He only argues, and than accuses me of altering my posts later on with Moderator rights to correct them... but if you dont agrea stay on BATS with your friend mate, maybe the 2 of you should start your own forum just for RS50's in the USA so you can help people even better with out others giving the wrong info...

[szimat]

Hi! I will do the cleaning of the bike and the engine this weekend, finally I got the TW PTFE (it was not easy to find). I will wash the whole bike, including the engine, remove the fairings and clean everything thoroughly. As you said, I'm going to put on all parts (even the metal frame) PTFE, but will not rub it, only rub it on the plastic parts. I will also put the PTFE on the exhaust, but should I put it on the muffler as well and on the whole pipe, all the way trough the engine?

In the case of engine: it is quite dirty since it was not cleaned for a long time. I will use an engine cleaning fluid that removes the oil and dirt, I use it on my car's engine as well. The I will probably take it to a gas station and use the manual car washer high pressure water to clean off the engine (from longer distance), I guess it should not do any damage to the engine? Is there any part of the engine I might cause some damage with water?
Can I use the PTFE to cover the engine or it is not recommended? Or perhaps something else that protects the engine?
Won't the PTFE burn out from the great heat of the engine and exhaust?

Thanks!

Patrick: any help on the above, I did not manage to clean it this weekend, we were away at a lake, but intend to do it this week, after I have the answers for above!