Building a GP100 with an SR100 motor

[supersport]

My dad was a BS dealer in Minnesota, and I was doing TT scrambles up there when I turned 12. Last year I bought a GP100 with a good title (but a bad crank) from a friend of my dad's who we used to race with.  He also gave me his old SR100 motor and seat, plus one pipe from a SR175. What a blast from the past! I'm making a GP/SR scrambler out of it, and might add lights and a silencer and a plate to it in the future. I plan to finish this project this winter.

[Mike Anderson]

Wow,
Cool piece, you will have a neat ride when finished. I have a sr100 hope to do it soon. Have some 350's to finish first. They seem to be multiplying. Please keep us up to date on your progress, it will encourage me to start my SR-100.
Thanks Mike

[william anderson]

hi that is  a neat project you have going on , i also have a couple projects  an i noticed that you had the stock seat on the gr100 , an replaced it with the sr seat , by any chance you would want to sell the gr seat i need one for a restoration project , have any taka , tmx parts you want to sell as well iam always interested , thanks william

[supersport]

The seat is yours for free, William. I have some other parts, too. Give me a call. 608-617-5090. Randy

[Mopar5426]

I found this a interesting article   I live in minnesota an the dealer ship that I got my first bridgestones was in sandstone mn   My friend big mikes father owned the dealership   so i was wondering where yours was.           I also im building a 100sr  I have both 100 & 175s so im doing something different also     I had a 100sr with a very rusty frame and restoration did not seem easy and because i had a restored 100 i disided to purchase a vanteck frame & tank  Iused a 100 tmx bike i had for the swing arm wheels & tires  I cant diside on the front forks between the 100 tmx or a front of a taka  I got the 100sr running sweet so iam in the assembly mode now  There is a lot of Vanteck racers out there  even 1 350 on the web but i never saw a 100sr or any other bridgestone   hope  to have the only one  when done and  when I learn how to post pictures i will   GENE

[supersport]

He Gene- my dad's shop was in Duluth. Super Sport Motorcycles. Sold Norton, Ducati and Bridgestones from about '65 to '71. He also put on the TT races in Duluth, the races at the Barnum fairgrounds and some hillclimbs outside of Duluth. I used to race down by you in Cambridge and Mora.

[rocketman]

 I was wondering what you were going to do with your motor. I'm glad to see you decided to go ahead with the GP/SR project. Already different, a streetable finished project would be over the top for sure. Nice conversion on the pipe, keep up the good work. Thanks,Mark.

[supersport]

The motor... I pulled they top end and side covers for spares. The bottom end is laying around and is free for the shipping or, preferably, pick-up. Has a spun main bearing, though. Muffler and handlebars are free, too. Are the pistons interchangeable? Or the cylinders and heads?

[rocketman]

Hi randy,I was referring to your SR motor. I recall talking to you about this project a while back when you were contemplating selling the stuff instead. I like what you've done with it.  I think you are saying your GPs motor has a spun bearing? Which side? Thanks,Mark.

[rocketman]

 Sorry to overlook the rest of your question Randy, the cylinder, piston, and head are all different than the SR parts. So is the crank and just about everything else on the right side of the motor. The top end as a whole could be used, but without spending some bench time with your porting tools, it would be a serious de-tuning. Thanks,Mark.

[supersport]

Which side... I don't know. I didn't take it apart. I thought it was spun by the sound it made when it was still mounted to the frame and I kicked it over. Why? Do you want to bottom end?

[rocketman]

I guess you could say I am mildly interested in the lower end Randy. I could use it for parts, mainly I need a left center case. If the bearing on the left crank has spun in that case,it would probably not be of any use to me. I would suggest you keep it around till you get yours running and the bugs sorted out anyway, as you never know what may arise. I noticed you have no battery mounted on the bike. Have you switched the ignition over from 12V constant loss? I will give you a call. Thanks,Mark.