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PPMPR: Project Poor Man’s Pro Race

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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
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PPMPR: Wind Repairs

Post by toratora » Fri Oct 26, 2018 11:39 pm

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A bit ago I went up to Twin Peaks to get some photos, and the wind blew over the bike breaking a number of things including the right bar, front right blinker, and a few other things. I had hoped to get the bike ready for the Halloween Friday Night Ride. I nearly did, but I couldn't find the spare bar. Today I did find it, and set about installing it.
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It's a little difficult to see, but the bar broke where it was still attached, but totally loose. Was interesting riding the bike home this way!
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The new bar is from a Cagiva so the Derbi bar ends don't work.
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While putting things back together the reservoir mount failed. It must have broken in the fall, but was still partially together.
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For the time being I did a hack repair with zip ties.
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And for the blinker another hack. I forgot to grab one of the spare blinkers. ¯\_(ツ)_/¯

Tomorrow I should be able to get in a test ride.
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kaldis12
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Re: PPMPR: Project Poor Man's Pro Race

Post by kaldis12 » Sat Oct 27, 2018 12:10 am

Hope you are okay :) as for the bike, bikes can be repaired but we cant repair life. :)
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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:

PPMPR: Twin Peaks

Post by toratora » Sat Oct 27, 2018 1:39 am

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I'm totally fine. I got off the bike to take a photo. It was one of those slow motion moments as the bike was falling over, and I was running to catch It, but there was no way I could catch it in time. The wind up there can be quite strong.

Here's the shot. I saw it going from the phone, and well I just couldn't move fast enough. The corner is the one near the top of the map by the water reservoir.


Twin Peaks on a Windy Day
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kaldis12
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Re: PPMPR: Project Poor Man's Pro Race

Post by kaldis12 » Sat Oct 27, 2018 5:04 am

Whoaahh Christ, is the wind that powerful there?
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MTBWALLY
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Re: PPMPR: Project Poor Man's Pro Race

Post by MTBWALLY » Sat Oct 27, 2018 1:28 pm

Timberrrrrrrrrr....
That really sick happen to my '01 derbi in the garage. It's like falling off a bicycle clipped in with cleats at a stop light. Slow motion.

You need to thin out some of those spares you have anyway. Most likely you found some more goodies you forgot you had boxed away. Am I correct.
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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:

PPMPR: Project Poor Man's Pro Race: Well Blow Me Down!

Post by toratora » Sat Oct 27, 2018 1:39 pm

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I've had the wind blow my bikes over four times now. The first time it happened I didn't believe it. I was at the local Taco Bell. Someone came in and said the wind blew your bike over. I was not convinced. I lifted the bike back up, started going back into the restaurant, and the wind blew it over again! I became a believer. :P

The third time was on my birthday in 2016. There was a storm in the morning. The Silver bike was blown over, and took a lot of damage. It took me all day to get the bike ridable.

One thing I've learned about these bikes is that you can never have too many spares. :shock:
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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:

PPMPR: Project Poor Man's Pro Race: More Time at the Peaks

Post by toratora » Sun Oct 28, 2018 6:39 pm

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Derbi GPR 50 R—San Francisco Twin Peaks

Today was another GP race so I met up with some friends at the D-Store to watch the race. Philip's Island is a great track. The riders all love it, and because of that the races are usually fantastic. Today didn't disappoint! After the races I swung by Twin Peaks for a little GPR testing, and Kodak moments. ;)
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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:

PPMPR: Stage6 Big Racing BR77 in Stock!!❤️

Post by toratora » Tue Oct 30, 2018 11:39 pm

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Stage 6 Big Racing BR77

Maxiscoot has the BR77s back in stock. Four of them. If you are in the States ask Treats to get one for you.
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toratora
Posts: 3161
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Location: San Francisco
Replica: Derbi GPR
Cagiva Mito
Cobra CX65
Aprilia RS50
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PPMPR: A Real Ride

Post by toratora » Mon Nov 12, 2018 10:39 am

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Yesterday on the Eleven Eleven Eleven II ride I finally got to enjoy the Stage6 BR77 in the twisties. Up til then it was all in City riding, where it can be hard to gauge how effective the kit actually performs. We went out into the Marin area where some of my favorite roads are located including Panoramic.

We also rode up out of Muir Woods, which is generally a difficult rode to ride well. Sadly due to the fire conditions Pan Toll was closed down keeping us from getting to enjoy Bo-Fax, but 21 corners was open, and wow what fun.

The weather was a mixed bag. Temperature wise it was great, but the air quality due to the Butte fires was quite horrible. I would imagine this must have had some effect on how the bikes ran, as it made it difficult for the animals, like us humans, to breath. It also had an effect on vision. My eyes were frequently watering.

Keeping the bike in the power band wasn't too difficult. The gearing on the bike assists in this endeavor. Currently it's set at 14-52. That's one tooth below where I would like to see it on the front. The reasoning being the top speed is greatly compromised by the 14.

Power delivery was pretty amazing. It always had plenty of power to give. I never once felt like the bike wasn't ready to perform. This contrasted heavily with the city riding where it is a struggle to stay in the power band. City riding on this bike isn't what I would call easy. It's a lot of work.

Compared to twisty riding however what a difference. This bike is a joy. It just wants to go. Slow riding isn't much of an option as the bike will quickly shift through the gears pulling hard at each click—as long as the RPMs are kept above 10K the next shift is nearly instantaneous. The draw back here is the vibrations at 10K plus are quite noticeable. I might have to find some heavier bar ends for this bike.

Still with the gearing set this way it is much easier for a rider in my skill bracket to keep the RPMs in the happy zone. If the bike had a 15T front sprocket on it I would have to be riding at a higher level than I currently feel comfortable. I would have to exceed my limits!

Another thing I noticed is that either the bike started developing more power as I rode it, or I became more adept at pulling power out of the bike. I'm rather convinced it was the former, as it is more likely that as the bike was running in it started working even better. This was after all the first time the bike was allowed to really explore the BR77's potential.

After this ride I am now highly motivated to get the EGT sensor hooked up. Currently there's a head temp sensor on the plug connecting to the Mychron, and room for one more temp sensor. Eventually I would prefer to get the head temp swapped out for an H2O sensor, but it's been a little difficult sourcing a proper adapter from the Mychon sensor to the Derbi M14x1.5.

And this bike sadly needs a proper battery. The garbage Shorai presently in the bike is such a huge disappointment. It's not even employed starting up the bike, and it cannot keep up with with just the blinkers and clocks. How Shorai can be proud of a product this compromised is beyond me.

There are a few other things that need attention. The bracket holding the front master resiviour needs to be replaced—it was broken in the Photo fall. An on/off switch needs to be installed on the MyChron so that it doesn't vamp the battery—currently I just disconnect it. The pipe needs a slight modification so that it stops melting boots. The front fender needs some attention again. The front brake needs a good flush. The rear disc needs to get updated like the front disc—I have the disc, it just needs to be installed. And the carb needs some attention as the air screw seems to have developed a leak. Lots of little things to attend on this bike!

Overall yesterday was a lot of fun, and I'm starting to actually enjoy the BR77 the way in which it was intended. That said I still couldn't keep up with Alex in the corners, but that's okay. He's at a higher level than I am—which gives me something to aspire.
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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:

PPMPR: Lead Acid over Lithium

Post by toratora » Tue Nov 20, 2018 5:39 pm

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Hello my dear readers. Today I had to enlist the help of a Catholic Priest to pray over my bikes, and perform a lithium exorcism.

Years ago I sinned by buying into the lithium battery hype only to endure hardship and frustration at the hand of batteries that are just totally incompatible with these motorcycles.

Bill tells me that a lithium battery needs upwards of around 15 volts to charge, and the pathetic charging circuits on these little replicas produces nowhere near that amount. Thus the lithium batteries are prone to not charge up, and even worse burn out cells.

The first lithium batteries I tried were the Ballistics. These failed and were ultimately replaced with Shorais, which also failed. Yes they were significantly lighter than the 2.9 lbs batteries that replaced them, but if they don't work, then they are useless weight.

The best performance I've had with any battery in these bikes have been the Yuasa lead acid batteries. They are inexpensive, and work great. I probably should have ordered a couple of those, but I wanted something red.

After a fair amount of searching around I discovered a motorcycle battery company in Florida, with the moniker Neptune Power Products. They produce an AGM GEL Sealed Lead Acid battery specifically for motorcycles, and it just happens to be red.

Neptune refers to the technology an iGel, but really it's an AGM gel design—which as it turns out is one of the better technologies for motorcycles. It's a maintenance free design that comes with a 30 day guarantee, and a 12 month warranty.

The Neptune version of the YTX4L-BS (the battery type that these bikes employ) comes in at a reasonable 2.9 lbs., and costs about $23. Compared to the Shorai which weighs in at just under a pound, and costs around $100. The major different between the two is one will work, and the other (the Shorai) wont.

Another possible option would have been to go with the YTX4L-BS from Pirate Battery. It's not made as nicely, nor is it a GEL, but the guarantee is twice as long, and the warranty half again as long. However, it would not have been red. ;)
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