[racer630]

I am looking for a primary drive pinion gear for my Derbi 50. The part number is Piaggo 00h02601381 There are two types of pinion gears, one with a tapered hole and one with a straight bore. I am looking for the tapered bore.

Thanks,
Steve

 

[dirtbkr188]

You sure you don't mean THIS ONE?

 

[racer630]

I sure wish it was . That is the one I have. I am building a motor to race in the USCRA flyweight class. So I bought a Stage 6 crankshaft and a Malossi top end. The crank that showed up has a taper on it. It took quite a while for the order to come in and my first race meet is on June 11. Not enough time to try and figure out a swap if they have one that will work. I thought I would try some of the forums. This one looks pretty entertaining. It will be fun to poke around when I have a little time. Thanks for the response.

 

[dirtbkr188]

Okay, good luck, the part number you provided does not come back as a valid Piaggio part number, here's the screenshot of the search results

 

[racer630]

The number does come up on some sites, PRIMAY GEAR Z-22 - 00H02601381 and a few more that need translating. It makes me feel optimistic but they say unavailable. Which bums me out. Finding one will be pure luck it will most likely be used. I guess the story goes that they changed manufacturers in mid run of the engine. So there may be some out there. I would be reluctant to try and order another crankshaft.

 

[cycletechperformance]

If everything is the same with both cranks minus the one having a tapered shaft on one half, then I can disassemble both cranks and rebuild it using the straight shaft crank half and true it? I've rebuilt cranks in the past where I've done this and just did one for a customer a couple months back for a XR motor (Kick-start to E-start has different left side crank webs) being converted from kick to electric start.

 

[racer630]

Hi there, didn't mean to just fade away. I had two quick options to try and fix my problem for race day. So I ordered a new crankshaft with a straight shaft for the pinion gear. Then I ordered a pinion gear with the tapered hole. I think one was ordered from Denmark and one from Belgium. I figured the first part that shows up gets used. The crank showed up first and in it went. The tapered hole pinion gear showed up a few days later. We ran into a few other problems and I figured it would be better to make one of my other racebikes track ready and get the Derbi ready for the next race. Which is in three weeks. So still working out some new to me racebike problems but I think I am under control. I'll post how things went. Thanks for the information. It's always good to find new sources of help.

 

[cycletechperformance]

Hi there, didn't mean to just fade away. I had two quick options to try and fix my problem for race day. So I ordered a new crankshaft with a straight shaft for the pinion gear. Then I ordered a pinion gear with the tapered hole. I think one was ordered from Denmark and one from Belgium. I figured the first part that shows up gets used. The crank showed up first and in it went. The tapered hole pinion gear showed up a few days later. We ran into a few other problems and I figured it would be better to make one of my other racebikes track ready and get the Derbi ready for the next race. Which is in three weeks. So still working out some new to me racebike problems but I think I am under control. I'll post how things went. Thanks for the information. It's always good to find new sources of help.

If you ever need any engine work that is beyond your abilities and or parts machining/reconditioning don't hesitate to reach out. Good luck at the races!

 

[cycletechperformance]

Hi there, didn't mean to just fade away. I had two quick options to try and fix my problem for race day. So I ordered a new crankshaft with a straight shaft for the pinion gear. Then I ordered a pinion gear with the tapered hole. I think one was ordered from Denmark and one from Belgium. I figured the first part that shows up gets used. The crank showed up first and in it went. The tapered hole pinion gear showed up a few days later. We ran into a few other problems and I figured it would be better to make one of my other racebikes track ready and get the Derbi ready for the next race. Which is in three weeks. So still working out some new to me racebike problems but I think I am under control. I'll post how things went. Thanks for the information. It's always good to find new sources of help.

Also, by the way is this a Derbi GP50? the small full size GP replica like the Aprilia RS50? I used to have a RS50 That I built up (Lady hit me on it and totaled it).

 

[cycletechperformance]

This was about 18 years ago! 2001 RS50 built up to 75cc and heavily Modified. I had multiple different top ends that I modified from different aftermarket manufactures. You can see the impact was so hard it snapped the frame.

 

[racer630]

I really don't know much about Derbis. It has a steel frame and not very sofisticated suspention.I was looking for a different class to race in and a few friends have them and kind of pulled me in that direction. We are allowed to have 72cc I believe, I really am new to 2 strokes and 4 strokes in the class are allowed 150cc. My only experience in the class was on a borrowed bike last season. It was a Honda rs 125 frame with a KX 65 with a 72 cc kit on it. I was hooked. I don't know how the Derbi will stack up against the Honda frame but I'm looking forward to it. First get it on track then comes the cha-ching fine tuning. I had taken glances at Aprilias before but they were a little out of my price range. Now with my change of taste in racing I may have to give them another look. People ask me why I am moving to smaller racers and I tell them that I'm not here for the straightaways.