Friday, November 7, 2008

Awsome custom cafe racer. UPDATE!!

Brian sends in the following...
"You asked for pictures of custom cafe racers. This one is my custom built 203lbs cafe racer that gets 115mpg. Thanks for looking. Brutallly honest crititcism is appreciated. "

Hi Brian! I think your bike is absolutly freaking brilliant! I'd love to know a little more about it. Tell me about that cool frame fork and wheel setup. What size engine? etc... really really terrific build there. Where are you from? I can think of a few twisty roads that I'd love to ride that beauty.

Here is Brian's response. This is is even more trick than i Imagined. Way to go!

Thanks for the reply. This bike was built completely with lightness being the key issue. I made the frame completely form scratch using thin wall tubing. The back cowl was hand formed. The forks are inverted dirt bike forks but I had to make new triple clamps and clip on handle bars to fit the wider front tire an also the fender mounts.

The rims are from the fat rear Schwinn chopper bike. The rear rim was respoked to a dirt bike hub and the front on respoked to the most rugged down hill mountain bike hub i could find. The Schwinn chopper bike rims are 4" wide and just happen to fit the Pirelli Sport Demon 110/90-16s perfectly. Total weight if the
front wheel totally assembled with the tire is a hint under 11lbs. The rear a little heavier, due to the heavier dutyu dirt bike hub with the sprocket and heavier disc brake. Running friction was also a consideration.

The front disc brake is an Avid BB7 which is a ball bearing mechanical mountain bike brake, which totally releases the front disc when not braking. Since my rear swingaem pivot point is further back than normal and you get into the distance between the motor sprocket and the rear sprocket changing as the swing arm pivots, I needed a different type of chain tensioner. There is a ball bearing idler sprocket mounted to the swingarm and as the distance between the 2 sprockets becomes smaller due to rear suspension compression the idler sprocket deflects the chain and keeps the chain tension constant at all points of the suspension
travel. Calculating this point where the idler sprocket should be mounted was a real bitch. The bike looks a little small but dimensions of the wheelbase, seat height, seat to handlebar relation is the same as a Yamaha YFZR6-S. The only difference is the seat to peg distance is longer by 4" on this because I"m a tall guy.

The engine is Honda crf230. I chose this because it's air cooled and has an alternator for lighting an electric start. Top speed is 78mph. I took this up the mountains toour 10000 foot peak on really windy roads and it stuck to the corners like glue. It's like driving air since its so light. This was partly inspired by the new version of the 50cc Honda Dream Cafe Racer, but i wanted more power for the highway but still thelightness of the Dream. The speedo is also a frictionless system, using a magnetic sensor for the digital speedo, a TrailtechVapor which also is a tach.

Some of the bikes posted on your page has been a great inspiration to me. Thanks for putting the time into it for all of us to share ideas and see what others have come up with.
I will be building more bikes, each one is a new learning and engineering challenge, and having web pages like yours is a good source for inspiration and ideas. Please keep up the good work.
If you have any questions or want to share ideas, please feel to email me. I hope my bike is worthy of your website.
Thanks again,

The Pleasure's all mine Brian. Keep them coming!!

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