Derbi DRD [81,4cc] | Testing.. 7.5.

[tracing]

U are keeping a nice pace in things.
Hopefully everything goes well and you can make the Dyno test.
Looking forward to it.

Keep it up!

[J11]

Yea, well I'm building the bike outside.. tools are everywhere. It's a real mess. It's quite shitty job to build a bike outside, when there's like -20C and snowing.
But I like to re-build the engine, while keeping things clean.

I've now teared the transmission, cleaned everything carefully and checked needle bearings.
I'll pick up FAG 6204 C3/Tn9 bearings and some needle bearings for the transmission and clutch from the local bearing shop.

[rené]

okay understandable, what is the brand of your crankshaft?

[J11]

ARP Racing. I bought the crankshaft, bearings and the clutch from Animotos.
They arrived today.

2 problems:
-Small end needle bearing is 12x16x16mm | 2 options to fix it: 13x16x14mm needle bearing OR modify the conrod (from 16 to 17mm).
-The cylinder head's combustion chamber didn't get finished, because the job failed (my friend was doing it), so the cylinder head is going for a machinist who'll work on it and makes sure the measurements are accurate.

But in the other hand.. I'm very happy with the parts. Thought the Animotos should have informed, that the needle bearing is not 17mm (their site says it's 17mm).

[kevrie]

Wow! Sick looking project! I'm shocked that i never saw this kind of modification on an airsall before (In an project topic). And those gold wheels, my god they are sexy! But why runnning an derbi that is breaking all the time while having an 125cc bike. U should really consider to put that 125 engine in the derbi and just modify that to the max. u can get an easy 40HP out of it

Gonna wish you luck making the bike u want to, really love the idea!

[J11]

Thank you!

It's quite a challenge to build it properly.. but definately worth it.

I wanted to build a bored & stroked engine for cheap, so the EBS050 engine was perfect for it.
My wallet won't allow me to build a 125cc 2-stroke engine with more than 40bhp.. the parts cost way too much.
E.G crankshaft for a japanese motocross engine (Suzuki RM 125, Yamaha YZ 125..) costs more than 300€ and a new piston (Wössner, forged) about 120€.

Also, the Derbi Senda/DRD frame is very weak. It's welds aren't really good, so the frame would collapse with more than 40bhp engine. 20-25bhp is enough for a moped.

After I have finished this project, I'll be starting a new build on spring. All I can say about it right now, it'll be a Suzuki RM 125 or 250cc with a register plate ("legally") and will have A LOT of horsepower & torque.

I've swapped the Cagiva Mito to a Yamaha YZF-R125 '09 and sold the YZF-R125 for 1 150€. Now I'm going to buy a Suzuki TS125R (registered) frame for the next project.

[J11]

UPDATE

Here's how the bike looks right now..

-KX125 '97 radiator ordered, should arrive on Wednesday. Frame is getting welded, because there are some cracks.. too much power
-Brembo brakes fitted
-Drilling new holes for the 46H rear sprocket - currently I have 12-53 gearing on it (way too short - it'll be a wheelie machine with those sprockets!)

Did some more porting for the crankcases, before fitting new bearings..

-Takashi 6204-TB P63 bearings for the crankshaft
-Nachi Quest 6203 C3 bearings for the transmission and clutch
-New needle bearings for the transmission, also by Nachi Quest

Also, the Airsal got some more porting to the transfer ports

I'm happy with it.

The crankshaft is going for a machinist to be modified. Then I can use Stage6 13x17x15mm needle bearing and the VHM 47,90mm forged piston. Cannot promise any date for the first start.. hoping it to be on the weekend (Saturday).

Going to buy a Suzuki TS125R '93 on Saturday for 800€.. it's going to be re-builded on summer with RM 250 engine, suspension and plastics etc.

[Mclaren]

We also have a motorcycle section here, I would love to see that project as well.
And keep up the good work of course!

[J11]

I'd say, you can start placing your bets.. will I get more or less than 20bhp from back wheel.
Tomorrow I'll take the conrod for machinist.. the dyno will be on next week's Friday. Bike is going to be running on this week's Friday or next week's Tueday.. depending how quickly the machinist finishes the parts.

And I'm going to build a Suzuki RM300 with insane power.. the goal is to get more than 58-62bhp from backwheel. Stock is 47-49bhp@back wheel. + it's going to have a register plate hanging under the rear light (= "streetlegal").

[tracing]

I think around 22bhp.

But we will see.

[kevrie]

I guess it will make around 25 bhp

[derbi-ftw]

I guess 21Bhp or 21,5

[Koerake1]

No news?

[J11]

Dyno run is on 16.1.2015 (friday). The shop is closed for this and the next week.. so that's the reason why the dyno is so late.
I sold the current cooling system and I'm waiting for YZ250F '08 (used) radiators now.

Changes to the setup so far:
-YZ80 '86-92 connectin rod // 94mm length (vs. original 90mm) and larger big end bearing (18x24x15mm)
-Maybe methanol + Klotz Supertechniplate (3,5%) .. requires atleast custom mainjet and powerjet and more abjusting to the ignition
-The combustion chamber has been modified a little bit more; 0,60mm squish-clearance, 30% squishband and 9,36:1 corrected compression ratio (~15,2:1 uncorrected)

I'd say, I can get easily 20-22bhp with meth. Going to laugh at my classmates face, when he sees the dynopaper..
He said I can get at the most 8bhp.

Now there's like -15C degrees outside, so I am not able to even start it. And the bike cannot be ridden, because I don't have any kind of winter tires.

I did buy a '97 Suzuki TS125R.. I have started modifying it and the engine should be able to produce more than 30bhp soon.
Getting some more porting tools also.. Btw, it's running on E85.

[Koerake1]

Holy shet, waiting for the results

[tracing]

I did buy a '97 Suzuki TS125R.. I have started modifying it and the engine should be able to produce more than 30bhp soon.
Getting some more porting tools also.. Btw, it's running on E85.

Can u post pics of that to?

Can't wait to see dyno test, wanna see how much Hp u can get.

[J11]

I'll order 10L of methanol and a litre of Klotz Super Techniplate tomorrow.

Tomorrow I can post some pics of the TSR.

[Mclaren]

I'm curious, judging by this thread alone I've got high expectations!

[tracing]

I'll order 10L of methanol and a litre of Klotz Super Techniplate tomorrow.

Tomorrow I can post some pics of the TSR.

Nice How much is a Litre Methanol in your area?

[J11]

2,25-2,50e. If I would buy 200L of methanol, it would cost only 1,20E per litre.
Going to buy on Friday a low-pressure fuel pump.. max. 0,10 bar and 120L/hour flow rate.

It costs about 60e per 100km if the fuel consumation is 20 litres per 100km.
But I'm using this bike only for fun - not as a daily. It would cost about 100-120e per week if I would use this as my daily ride!
+ the services.. piston every 5-15h and bottom end 80-100h.