My first DB 30

#1
Just 2 weeks ago I picked myself up a Baja DB 30 roller off Kijiji for $100.

I've had my box stock 2011 Honda GX200 since new and it's just been sitting so what better way to put it to use then in a Baja Dirt Bug swap. I just had to build one of these because it seems like almost every mini biker on here has one in some flavor plus they have some great features that you just cannot ignore.

Much thanks to 2SlickNick for sharing his 49cc pocket dirt bike front suspension swap. All in total you can have front suspension on a Baja dirt bug for around $60.

You can see in the pics that I was able to utilize 1.000" ID bicycle seat post clamps as a alternative to welding the fork tubes to each other. This has way more than enough static holding friction to keep these fork tubes in place. These clamps can be had at almost any bike shop.

I also discovered that a lot of the funky handling traits that these bikes are known for can be traced to the front wheel hub offset. I don't think many people have noticed but the stock front wheel hub is not centered in the fork legs, just look at the uneven spacer lengths!! Anyone that builds and understands motorcycle steering geometry knows this is a big "no effin way". I simply corrected this by finding a 6x3.25inch centered hub 1 3/8 OD bearing tubeless steel wheel and then replaced the 12mm front axle with a 1/2"x9" bolt and then used 1 3/8"x1/2" flange type wheel bearings.

Took her for her maiden spin yesterday and wow, that front wheel is a huge help!

With a 12t clutch and 70t rear sprocket we have a 5.8:1 reduction going on and it pulls very nice! I made my first OldMiniBikes warehouse purchase the other day, a stage 1 jet, header, air filter, springs,flywheel key upgrade kit. Should be here any day now!

 
#5
Very nice..me not being a welder that's a cool idea. :thumbsup: i just ordered a set of those forks for my monster moto mmb80 project still working on..the front wheel on this has equal length spacers unlike my db30 i got..huh...thanks dude :punk:
 
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#6
Looks and sounds like a Pretty Kool build, :thumbsup:
Thanks man. Had it out yesterday for a good first ride. I'm quite happy the way it performs and that front wheel is a big help.

The spring loaded auto chain tensioner is a great idea and works very well.

As for the front suspension. The forks seem to really stiffen up in the cold and I think I have to place some grease or lube under the rubber dust seals.
 
#7
Very nice..me not being a welder that's a cool idea. :thumbsup: i just ordered a set of those forks for my monster moto mmb80 project still working on..the front wheel on this has equal length spacers unlike my db30 i got..huh...thanks dude :punk:
Your very welcome sir:thumbsup:

I have a feeling a lot of people will like the "no weld" option and it gives you an opportunity to service the front forks if need be.

Right on and post some pics of your build if you can. I think this mod would really be at home on one of those new Coleman CT200U mini bikes as they probably see more rough offroad action then a DB 30.

Yeah I couldn't live with that uneven front wheel, I had to get rid of it. Fortunately I had a wheel laying around in the depths of my parts collections lol.
 
#8
Your very welcome sir:thumbsup:

I have a feeling a lot of people will like the "no weld" option and it gives you an opportunity to service the front forks if need be.

Right on and post some pics of your build if you can. I think this mod would really be at home on one of those new Coleman CT200U mini bikes as they probably see more rough offroad action then a DB 30.

Yeah I couldn't live with that uneven front wheel, I had to get rid of it. Fortunately I had a wheel laying around in the depths of my parts collections lol.
yeah..i got pics of mmb80 posted under my little winter project thread.. http://www.oldminibikes.com/forum/mini-bike-discussion/134692-little-winter-project-2.html will update when i do the fork mod.... members TripleAAA and Stitch of the coleman group the mbx11 fork can bottom out because of the ct200u weight..had to have custom machined/altered .the weight of the front rim/tire alone i imagine is part of issue..these may have same problem.ok for street...
 
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#9
Thanks man. Had it out yesterday for a good first ride. I'm quite happy the way it performs and that front wheel is a big help.

The spring loaded auto chain tensioner is a great idea and works very well.

As for the front suspension. The forks seem to really stiffen up in the cold and I think I have to place some grease or lube under the rubber dust seals.
it's the cold..the lube inside thickened :shrug:
 
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#12
Okay. Teach me something about the wheel hub being centered verses off center. The only thing it changes in an auto is the scrub radius. I don't see it changing anything as the contact patch of the tire is the point of reference. :shrug: Tell me how it affects the handling of a bike please sir. I would like to understand how it can make a difference when you see one sided hub bikes on the road and custom offset one sided hub custom bikes with deep wheels.

Just trying to learn something from the 2 wheel perspective verses the 4 wheel perspective. [MENTION=17975]Sprocket86[/MENTION]

Doug
 
#13
I'll try to explain the theory as best as I can here.

Basically if the front wheel load bearing plane is not in line with the center of gravity with the rest of the machine any time the wheel is turned from center with the vehicle moving in a forward direction the steering geometry WILL be different from left to right. It has to be!

If you rode my DB 30 with the correct front wheel compared to a stock DB 30, you'd feel the difference. Plus the uneven front hub wheel looks terrible IMO.
 
#14
I'll try to explain the theory as best as I can here.

Basically if the front wheel load bearing plane is not in line with the center of gravity with the rest of the machine any time the wheel is turned from center with the vehicle moving in a forward direction the steering geometry WILL be different from left to right. It has to be!

If you rode my DB 30 with the correct front wheel compared to a stock DB 30, you'd feel the difference. Plus the uneven front hub wheel looks terrible IMO.
to me,in basic terms the weight of rim is way heavier on one side..the ct200u same way..i think they not want to retool and use the same rim as rear one less the sprocket and brake mount.
 
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#15
I'll try to explain the theory as best as I can here.

Basically if the front wheel load bearing plane is not in line with the center of gravity with the rest of the machine any time the wheel is turned from center with the vehicle moving in a forward direction the steering geometry WILL be different from left to right. It has to be!QUOTE]

So basically this is nothing more than scrub radius. Thanks.
 
#17
I'll try to explain the theory as best as I can here.

Basically if the front wheel load bearing plane is not in line with the center of gravity with the rest of the machine any time the wheel is turned from center with the vehicle moving in a forward direction the steering geometry WILL be different from left to right. It has to be!QUOTE]

So basically this is nothing more than scrub radius. Thanks.
Yep...when i corner how i react left is different than right cornering because of wheel weighs more on one side..use my weight and gas ..the worst are 90° turns for me
 
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#20
maybe this forks mod could be used on Coleman if only on street with a thiner front wheel/tire to reduce weight a little and have center..hmmm handling would for sure be better
 
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