"Po' White Trash" stretched DB30s payoff test ride

Daniel Coop

Well-Known Member
#1
After a long build, I finally had the opportunity (time/weather) to break it out and bring it's Childish Concepts Racing built 5 bolt Grayhound clone to life and go for a quick test ride.
 
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Daniel Coop

Well-Known Member
#5
Thank you gentlemen... That sweet music is courtesy of A CL3 camshaft pushing air through a ported, polished head out through a LBA Stinger exhaust. Now it's time to play with gearing. At 6,000 RPM I'm doing 49MPH. My motor is good for about 6,800-7,000RPM. My goal is 65mph, maintaining at least some, of my low end torque so I am ordering a DB sprocket adapter and some split sprockets to play with. One thing holding back my top speed is the smaller diameter, lower profile Street tire on the back. It still gets with it though
 
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#7
One of the nicest Db's Iv'e seen Daniel!! Cool vision and execution!! Red, white and shiny stuff go together nicely!! :thumbsup:
 

Daniel Coop

Well-Known Member
#11
Thanks Doug, but that is actually a 90% matte white powder coating. Believe it or not, I actually got that seat from a buddy first and liked it so much, I built the bike around it. The red was all painted by me.
 

Daniel Coop

Well-Known Member
#13
Try out this 67t split sprocket and adapter. I didn't want to go to extreme, as this Jackshafts drive gear is 15t. I am not sure I like this jackshaft system and clutch setup and am considering trying out one of those Cheetah disc clutches. I like how the Cheetah comes with 3 different tooth count sprockes. The ARC Mongrel clutch works good while it's clean and lubed, but requires frequent service, otherwise it starts acting up, making noise and hitting irregularly.
 
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#15
Try out this 67t split sprocket and adapter. I didn't want to go to extreme, as this Jackshafts drive gear is 15t. I am not sure I like this jackshaft system and clutch setup and am considering trying out one of those Cheetah disc clutches. I like how the Cheetah comes with 3 different tooth count sprockes. The ARC Mongrel clutch works good while it's clean and lubed, but requires frequent service, otherwise it starts acting up, making noise and hitting irregularly.
Nice! Scroll down two good links to consider..cheers. https://www.OldMiniBikes.com/Mini-B...tches/3-4-clutches/?target=search&mode=search Burris Racing Jackshaft Calculator
 

Daniel Coop

Well-Known Member
#16
Thanks everyone! I am aware of the jackshaft and mini bike speed calculators. I like playing with gearing options
I took off the clutch again for service and figured I would share.

Here is the Mongrel clutch with it's snap ring, spacers and drum removed.

You can see the odd wear pattern on the shoes and the streaking on the inside of the drum. I suppose this is from the mismatch in the shoes and drum? I then spray off the shoes and drum with dechlorinated brake cleaner and wipe down the drum with a clean rag before lubing the bronze bushing with a couple drops of gear oil before putting the snap ring back on.

As you can see, the PMR jackshaft system came with 2 spacers to space out the clutch from the jackshaft plate and mounting bolts. The Mongrel clutch also came with a small chamfered spacer they say to install chamfer side down and then you can mount the clutch inboard or outboard. The problem I see is that the clutch then no longer slides completely on the shaft, and is sandwiched on with the clutch retaining bolt.
Had a slight issue... While removing the clutch retaining bolt, I noticed that it came out stiff. When I went to re-install it, it got hella tight. Enough to turn the engine over! So out came my Matco Tap and Die set
 
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Daniel Coop

Well-Known Member
#17

Problem solved. Not sure what happened. Maybe too much stress on the stupid bolt with all the spacers on the clutch? Got a tiny bit of metal out like a thread or two was buggered up.
 
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#19
Yeah ..think i saw somewhere a clutch wear issue was solved by sanding shoes on side contacting bell well.. i think taking due care with that idea..... I was thinking of using a 14 or 15t clutch on a db30 at one time..maybe in future project and found max torque had many choices with even bigger ones..a 15t w a rear sprocket 70t w 14" tire looks to be 4.66 to 1 ..a 14t clutch 5 to 1 i was thinking this coz was going to retain stock rear sprocket......i see looks like your clutch not go flush with shaft..if thats true maybe a custom spacer behind bolt would make that up
 
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