MB Racer

Build 2007

Having ran across the RatRodBike.com orums I changed course on using the rear half of this mountain bike as a soft tail chopper and decided to try a quick Rat Rod type build based on the look and feel of an antique race motorcycle. I am not sure how the end product will “look and feel” yet but it will be fun putting the thing together. No way it will be competitive but hopefully fun none the less.

Update: 2017 Bike has been disassembled and is in parts – too hard to ride

Here is the original bike as picked up at a garage sale. Actually I have added a de-railer here as the bike was pretty stripped when I first found it. I was mainly interested in the rear triangle to build a soft tail chopper as noted above.

Here is the pulled rear where I was laying out a chopper setup. This could be made to work with a custom frame but keeping chain tension was going to be a challenge.

Playing with how low can you go here. I had dropped in an old fork to replace the shock fork but the bike uses a 1 1/8″ steerer so this was just stuck in there for mock up. I have to get a different fork is this is the direction I am going.

Picked up some whitewalls and a proper fork that works today. The bars are some old Azonics that are extremely wide… but I like it that way so far. I had to work out something to replace the shock and ended up with a heim joint that will have a cut off bolt dropping into the frame.

I plan on running a side number plate out of steel that will also be used to hold the swing arm and solid to the rest of the chassis. Here you can see the wide bars.

Just to get an idea what a number would look like on the side plate.. of course I hope it looks better when I tape it off and pin stripe it.. 🙂 Also playing around with how to dress up the front fork in some manner.

A little better view of the funky mock up for a possible front fork add on. Not sure if this will make it but it needs something up front to me.

Cut the side plates today. I ended up having to buy some sheet metal since I couldn’t find anything that was large enough and thick enough in the scrap pile. The air nibbler made quick the cuts and is pretty easy to control

Also cleaned the seat up with some carb cleaner and made an adapter to use the old handle bar bend in the larger seat post on this bike. The handlebar goes inside the black pipe. I’ll drill a small hole and plug weld it together to keep it from slipping.

Here is the left plate stuck in place. Still needs the middle hole and a couple others to hold things in place.

I was going to make this a fixed speed but I like this old derailer with the huge bottom sprocket. Reminds me of the large rear sprockets on the speedway bikes.

I pulled the large front sprocket off to modify the look. I am not using a front derailer so I really do not need the small one either but might leave it there for now.

Here’s the right side with the smaller sprocket and a chain stuffed in to see how the derailer sets.

Based on a suggestion from RatRodBikes.com user VicXsaN, I swapped the truss looking thing (an OCC Stingray sissy bar) to the back of the forms. Looks better to me.

New Forks…??

10/20/2007 After messing with the original forks I picked up I ran across this beefy triple tree fork at my local bike shop. Not having any big tube frame bike that it would look good and not being happy with the old fork setup. Looks better to me.

New Old Seat and Pedals

I also picked up a set of old block style pedals at the LBS. I was surprised they had a set in 9/16″ I also pulled an old fake leather seat off one of the old bikes I recently picked up to give it a try. I still haven’t decided on a seat.

New tire as well…

I was running the same front tire on both front and rear initially but found this tire at the LBS. It looks better to me even with the four leaf clover design. Also a better shot of the seat here.

Just about read to blow apart…

Besides a final seat selection I believe I have everything setup and working the way I want. Almost time to blow it apart for cleanup and paint. I was going to go white/black with red trim but with those new front forks I have having to re-think that.

Just and artsy shot with the sun going down…


After messing around with fork ideas over and over I thought I’d try a little home brew springer. Used the shock from the rear, some 3/8″ bar and some plate to lay out a uni-shock front. With the stiff spring it will likely not actually ‘spring’ much but it’s a start.

Here’s the working version. Used some 3/8″ heim joints for the bottom connection. Different looking at least and not quite so normal/modern as the triple clamp tubes

Full shot with the front forks. Really need to blow it apart and prep/paint at this point.

Front shot of the springer. This was pretty easy to do. Bending the bar to the right curve was the hardest part. Fortunately I had and old header extension (3″) off the Mustang that fit the bill to wrap around. I still have to form/clean up the top plate to look better by rounding it all off.

Just a different view of the whole bike. I still need to cut off the V Brake mounts as well to clean things up.

11/12/2007 – Blown apart for clean up and paint

11/24/2007 – As done as it’s going to get… The goal of this project was to take something “new” and make it look “old”. I think that was accomplished.

A couple problems were encountered with paint and stripping but that is how it usually goes. I used some off brand white paint I had on the shelf. It blew up on the number and the clear coat mangled it as well.

I used small acorn nuts to fill in the hold on the sprocket. Hard to tell here but it looks nice in person.

Leave a Reply

Your email address will not be published. Required fields are marked *

Website Security Test