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Derbi—The Red Power

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toratora
Posts: 3161
Joined: Wed Oct 11, 2017 1:05 am
Location: San Francisco
Replica: Derbi GPR
Cagiva Mito
Cobra CX65
Aprilia RS50
x 1768
x 1977
Contact:

Derbi—The Red Power: Silver Bells

Post by toratora » Fri Jun 21, 2019 5:39 pm

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Today was shake down ride day for the Silver bike. Lots of good news in that the bike runs strong, and is a blast to ride. Plenty of confidence to be had, but it does act like a light switch. Probably because of the larger carb—it is running a 21 on a 50cc top end.


Unhappy news in that the rear brake doesn’t work at all, and the float valve seems to be failing too. I suspect the rear brake will just be an adjustment, but I’ll probably flush the fluids too. Considering that I just had the carb apart, and the float is still sticking open is disconcerting.

These bikes don’t currently have batteries in them, but they are on order and should be installed soon. But due to that the tach is generally spazzing out most of the time, and it is difficult to get proper readings from it. :paw_prints:
2 x

User avatar
toratora
Posts: 3161
Joined: Wed Oct 11, 2017 1:05 am
Location: San Francisco
Replica: Derbi GPR
Cagiva Mito
Cobra CX65
Aprilia RS50
x 1768
x 1977
Contact:

Derbi—The Red Power: Electron Transfer

Post by toratora » Mon Jun 24, 2019 9:39 pm

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More batteries showed up today. This time the Malossi bike would be endowed.


I did a fairly thorough pictorial of the battery setup process in the PMPR thread. Here are a few photos from the one for this bike.


Even though it looks like it had been on the charger long enough I think that I should have left it on a bit longer. I had to employ the horn on the road, and it didn’t sound nearly as strong as on the PMPR.


Installation went well, and was quite easy.

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Then it was off to the BK for an Impossible Burger. I have to say it was totally underwhelming. The bun was stale, the veggies were not fresh, and the beverage tasted moldy—not really a my way experience. However, the bike ran well. Now that I could watch the tach it showed the engine able to pull well in to 12K RPM in first and second, and almost to 12K in the other gears. This probably has more to do with the Arrow chamber than anything else. There’s not a lot of power in this kit, but it is reasonably easy to ride this bike.

I really need to work on the front brake as the current lever position is very hard to deal with. You have to cover the whole thing. It stops well enough so it’s probably solvable with an adjustment. Another odd thing that seems to be a trend on these bikes. The right hand mirrors seem to get all floppy. I wonder if this is caused by the covers. :paw_prints:
3 x

User avatar
toratora
Posts: 3161
Joined: Wed Oct 11, 2017 1:05 am
Location: San Francisco
Replica: Derbi GPR
Cagiva Mito
Cobra CX65
Aprilia RS50
x 1768
x 1977
Contact:

Derbi—The Red Power: Braking Maastaa!

Post by toratora » Tue Jun 25, 2019 5:39 pm

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Unhappy with the brake feel on the Malossi bike I figured I better do something about it. So I tried adjusting it. This didn’t work out so well. On the test ride the front locked up at a stop light. I had to drag the bike to the sidewalk by lifting the front, park it, walk home about a half mile, get some tools, and walk back in order to free up the front brake. It was a very long walk in full gear!


Making the initial adjustment. I did test it, and it seemed okay, but clearly that wasn’t the case as I would soon find out. :scream_cat:


The hang out spot for the bike while I hoofed it to and fro.


I adjusted it again and rode over to Kent’s. This is the first stop on my test loop.


Then I went to Jeff’s for a bit, then Taco Bell, and finally Target before heading home. The front brake is getting close. It has plenty of stopping power, it just needs to get the final adjustment action, and it is nearly there. But man what a walk!!! :paw_prints:
3 x

User avatar
toratora
Posts: 3161
Joined: Wed Oct 11, 2017 1:05 am
Location: San Francisco
Replica: Derbi GPR
Cagiva Mito
Cobra CX65
Aprilia RS50
x 1768
x 1977
Contact:

Derbi—The Red Power: Silver Electrons

Post by toratora » Sat Jun 29, 2019 3:39 pm


The various bikes have been getting new batteries, and today was time for the Silver Bike.


Putting the acid into the battery.


Putting on the cell caps, and charging.


Installation, and yeah then it was done. I did’t actually do any testing since I was concurrently working on the ProRace bike. Also, there is a much more detailed version of this post for the ProRace bike. :paw_prints:
1 x

User avatar
toratora
Posts: 3161
Joined: Wed Oct 11, 2017 1:05 am
Location: San Francisco
Replica: Derbi GPR
Cagiva Mito
Cobra CX65
Aprilia RS50
x 1768
x 1977
Contact:

Derbi—The Red Power: Clocks

Post by toratora » Sat Jul 06, 2019 3:39 pm

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This is a repair that I’ve been wanting to tackle for sometime, but I keep running into issues. Previously I had found some silent blocks from Amazon that I thought might work, but they were the wrong size.


So I took apart a cluster to take some measurements.


These are M5 with a .8mm thread pitch. The rubber section is about 17mm, and the bolt part is about 11mm. I ordered these from Amazon, but they were lost in the mail. I wanted to get this repair done so I decided to employ a used silent block. The Silver bike probably needs new silent blocks so I’ll eventually get back to repair then.


I also needed to replace the tach since the one on the bike lost its cover probably due to when the bike was attacked by the wind.


The broken silent block.


The mounting bracket.


Replacing the tachometer.

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And things all back together.


While I was working on the bike I found a number of issues from when the wind attacked the bike. The top headlight mount is cracked in three places, and one of the side fills is cracked at the mounting point.


With more inspection I found even more disturbing news. I knew the front fairing mount was tweaked because it was difficult to mount the side panels, but I didn’t realize how bad. The headlights are way off, and the clutch side fork is scraping the body work. :paw_prints:

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2 x

User avatar
toratora
Posts: 3161
Joined: Wed Oct 11, 2017 1:05 am
Location: San Francisco
Replica: Derbi GPR
Cagiva Mito
Cobra CX65
Aprilia RS50
x 1768
x 1977
Contact:

Derbi—The Red Power: Alignment

Post by toratora » Sat Aug 17, 2019 11:39 pm

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I finally had a chance to get back to the Malossi bike to adjust the fairing support that was damaged when the wind slammed the bike into the ground. I expected it would be a lot more effort to straighten the support. But mostly it was just removing the plastics, cleaning them, and a slight repair to the support.

On the test ride the odor of coolant was fairly strong, so that will be the next issue to investigate. Still it was super fun to get to ride this bike again. It is amazing how well these bikes can go around corners. :paw_prints:









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4 x

VT78racer
Posts: 8
Joined: Tue Oct 22, 2019 6:27 pm
Location: Kentucky
Replica: 2003 Derbi GPR race bike - CR80 transplant
2000 Derbi GPR race/street
1999 Derbi GPR street
x 2

Re: Derbi—The Red Power

Post by VT78racer » Wed Oct 23, 2019 10:56 am

Great work on the 75cc Cylinder alternative. How has it been holding up? I am looking for a solution for my 75cc trashed cylinder and this looks like it might work.
0 x

User avatar
toratora
Posts: 3161
Joined: Wed Oct 11, 2017 1:05 am
Location: San Francisco
Replica: Derbi GPR
Cagiva Mito
Cobra CX65
Aprilia RS50
x 1768
x 1977
Contact:

Derbi—The Red Power: EBE075

Post by toratora » Wed Oct 23, 2019 11:39 am

The cylinder works, but it is not a proper match. The performance of the bike is better than a non-running bike, but I preferred the stock cylinder experience. This is mostly due to not having lower end power, and even top end power isn’t spectacular. So on these levels it is somewhat disappointing. I expect that with more time I might be able to overcome some of these issues, but I just haven’t had the opportunity to work on it. :paw_prints:
0 x

User avatar
toratora
Posts: 3161
Joined: Wed Oct 11, 2017 1:05 am
Location: San Francisco
Replica: Derbi GPR
Cagiva Mito
Cobra CX65
Aprilia RS50
x 1768
x 1977
Contact:

Derbi—The Red Power: Transport

Post by toratora » Tue Dec 17, 2019 8:39 am

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It is a little difficult to see due to the bike covers being tossed in there at the end, but there are ten bikes packed into this U-Haul. Can you find them all? :paw_prints:
2 x

VT78racer
Posts: 8
Joined: Tue Oct 22, 2019 6:27 pm
Location: Kentucky
Replica: 2003 Derbi GPR race bike - CR80 transplant
2000 Derbi GPR race/street
1999 Derbi GPR street
x 2

Re: Derbi—The Red Power

Post by VT78racer » Tue Dec 17, 2019 5:30 pm

Thats a tight fit! Good luck in the move. On a side note do you know where I can find decals for the 2002 Lorenzo red/black checkered bike? I noticed you have a few.
0 x

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