The building of my vintage racer

[FreeTheBeast]

So, let's go straight to the finished product...



This bike will be my racing bike in the USCRA race series. Its chassis is a 1970 BMW R75 /5. It has a 750 motor assembled from different sources of used parts.

But all of this began with Marcus -



I met Marcus while racing in hill climb races in Vermont. He has been building bikes and competing in vintage racing for a number of years. As you can see, Marcus is an interesting individual. Anyway, in 2011 I went to a few of the races at New Hampshire Motor Speedway and thought it looked like a lot of fun. Over the Winter, I bought the most part of a bike from Marcus.



The motor came without pistons or cylinders...wire harness...ignition system...etc.



I needed to get a lot of things to get the thing together. I brought it over to my friends at MAX BMW. I was able to get all of the used parts that I needed. The motor was assembled at MAX and the gearbox was tuned up.



I took care of the frame. I coated it using POR15 Bare Metal. It is supposed to look like naked metal. I think it looks okay for a vintage racer.





The frame went back to MAX BMW and it was put together.



I put Avon race rubber on it. I ordered a custom top brace from ToasterTan.



I'm using a Shorai battery. I have mounted it under the seat cowling.



I enlisted the help of my buddy, Pat (Adv: Mudhen), to weld on a piece of angle iron as a base for the steering damper.



I think this catch bottle will certainly make the bike go faster...



The belly pan is a custom piece of work by another friend, Mike (Adv: 280racer), who will also be racing with me.



So, the bike is done. All safety wiring is complete. The thing runs and sounds pretty good. New racing leathers should be ready any day now. I'm looking forward to it. The first races are in early May. This year is all about getting out on track and learning what's going on. The 32mm Bings aren't going to light up this bike, but I should certainly get around the track.




Rear sets: Boxer Metal
Seat and starter cover: BoxerCafe.com
Top brace: ToasterTan

[2twisted]

Nice job.

[Voltaire]

Nice work, you sure will have fun as I have recently completed a similar project.
The shorai battery...are you running total loss? would it last a whole weekend...say 10 starts and an hour or so of running? whats the model of it. Cheers John
Oh and the starter/air cleaner cover looks really smooth, did you make it?

[FreeTheBeast]

I am going total loss. I hope the battery does well. I do plan on recharging with a generator in between races.

It's a Shorai LFX36L3-BS12.

[mykill]

Nice!

[bmweuro]

Very nice.

[Renner]

can you post a video clip so we can hear it run?

[hardwaregrrl]

Very pretty!!!

[FreeTheBeast]

Here's an iPhone video of Marcus giving the bike a quick spin.

[apt13]

awesome bike! but the dreaded portrait style video. turn your phone sideways when making videos! haha.

[rambozo]

sounds and looks very nice, lotta nice mods

por looks good on the frame

[FreeTheBeast]

[Renner]

very cool, thanks for the vids

[pommie john]

Very nice work.

The only comment I'd make is that I've never been a fan of putting the battery up under the seat hump. It's a lot of weight high on the bike and it's a long way from the starter motor. That's a long hot wire to the starter which will cause voltage drop. Whether that's a practical issue or not is debatable. I put mine on top of the gearbox, nice and low, and near the starter.

[FreeTheBeast]

Originally Posted by pommie john

Very nice work.

The only comment I'd make is that I've never been a fan of putting the battery up under the seat hump. It's a lot of weight high on the bike and it's a long way from the starter motor. That's a long hot wire to the starter which will cause voltage drop. Whether that's a practical issue or not is debatable. I put mine on top of the gearbox, nice and low, and near the starter.

Yes, your points are valid. Here are my counterpoints... The battery is a Shorai. It is lithium iron - very light at about 5 pounds. It is not the typical lead acid battery we used to know. Also, I am using a custom wire to the starter. It is very heavy gauge and has gold plated (really!) terminal ends. It fires up pretty well. I may also put another battery in tandem for starting when cold - as well as using starter fluid first thing. We'll see how it goes, but I understand your points. I was initially planning to put the battery in the belly pan, but under seat was considerably easier.

Thanks for your input. I appreciate the feedback.



Battery to starter motor cable is from here:http://www.howardshorns.com/cables.htm