1980 SR250 - Gravel and Backroads Runner

sbruton

Where the fvck is that money you owe me?!?
Hi all,

It's been quiet a while since I've been on DTT. I posted up an "intro" a short while ago, and thought I should get a build thread started. I took some time off from street bikes a couple of years ago for a variety of reasons, but won't bore you with the details. It was mostly a time issue due to "life stuff" and just couldn't get the last project to a finished state. To make a long story short, recent circumstances have afforded me the opportunity to get another project bike - a very clean 1980 SR250... which brings me to this post. My last 2 projects were 78 KZ650Bs, so I'm quite excited to be working on a single cylinder street bike. I'm primarily a dirt rider and have worked on various dirt bikes over the years, and thought this would be a great platform to make a dualsport type bike to ride around the mountain roads. I'm still pondering concepts and where this project will go, but initial plans are to make the bike a little more "off-road" worthy without straying too far from original (for now). If I could end up with something like this I would be very happy:





I'nitial plans are to simplify the dash, remove unnecessary electrical components, change tires but ultimately retain the road legal status. I might swap the rear wheel for an 18" but that is still up in the air. Without further adieu here is a pic of the bike as I received it from the previous owner:





Once home, I gave it a once over and got it running easily with the purchase of a new battery. Shockingly, the battery in it said that is was from 1981! No wonder it wouldn't take a charge...All the other wear parts (tires, chain, sprockets, brake shoes, cables etc) appear to be in good shape and should be usable for the short term. I ordered a factory service manual and started to disassemble the bike.



Anybody need any stock SR parts?? I'll probaby use some of the bits and pieces but most of this will go up on Ebay in hopes of helping to fund the project...



Carb was very clean... I was surprised that it wasn't gummed up. Apparently the bike has been sitting for over a year...



The only other work that has been started to date was a quick change of handle bars with a set of stock bars off a DR650 and the start of modifications to the wiring harness. I will be removing the starter safety circuits, the dash lights, and keyed ignition. Here is the modified wiring diagram that I am working to but still showing the keyed ignition:







That brings me up to the current state of affairs, but hoping to get more done this week. The next tasks on the "to do list" will be:

1.) Completely dismantle the bike
2.) Trim frame and install rear loop
3.) create space for electrical tray and reinstall required bracing
4.) Complete wiring harness mods

Thanks for looking and certainly welcome feedback and comments!
 
Found some time yesterday to get a bit more done on the dismantle. Nothing too exciting, but getting close to being able to do some cutting and welding and cleaning up the engine.







There is a clean spot on the frame that seems like a good spot to cut. I've placed the stock rear fender and the loop on to mock up the approximate location. The gusset around the shock mount on these bikes is a bit tricky, but will deal with that once I get the section cut off.

Here is what I'm thinking:






Any thoughts?
 
Alright! Got down to business today with the angle grinder and cut the rear-end and removed some of the unwanted tabs. I was pretty happy with the results and look forward to getting the loop welded in. At the same time we will put a bead along the cross brace that was modified in the process. The rear loop I have will fit in the existing gussets with minor modifications and should work well.



 
This is going to be cool man. Clean little bike to start with too!

What are the plans for the custom wiring? Much that needs to be done?
 
Thanks fellas.

The plans for the wiring aren't significant, but entail the following changes:

1.) Remove the safety circuits (clutch and neutral switches)... I'm a dirt bike guy and don't want anything "extra" that could cause issues with starting down the road
2.) Remove keyed ignition switch and replace with on/off buttons under the seat
3.) Remove all the dash "idiot" lights

I will retain the stock handle bar switches and headlight, but will replace the signals and tail light assy with something more discrete and off-road friendly.
 
I managed to squeeze in a bit of time on the bike over the past week and have a couple small updates. No major progress, but picking away when time permits. I'm hoping to finish removing unwanted brackets and get the tail welded/ finished this weekend and then I can move on to the electrical box, battery box and complete the wiring.

My plan is to make a comfortable custom seat that will be more-or-less flat, but fairly thick and match the contour of the rear hoop. In the past I have sold the stock seats from my project bikes, but this time I'm going to try and modify the stock pan and foam to come up with something interesting. I'm unsure if this will actually work, but thought I would give it a try. I've carefully removed the seat cover and separated the pan, foam and vinyl. Next up, I will cut the pan to match the contour of the frame rails and rear hoop. First I'm going to see if I can get away with leaving the seat pan "hang over" the frame rails (like stock). If that looks like garbage, I'll cut it back to expose the frame.

Stock Seat Pan and Foam





Next up I tidied up the wiring from the handlebar controls and routed them through the bar. This is a bit of a test for now and will see if I keep it this way. If I upgrade the bar at some point I will re-run the cables. I do like how clean the front end will be with the wires hidden:

Control wires routed through bar



Lastly, I received some tasty bits from Jadus Motorcycle Parts (www.jadusmotorcycleparts.com) that I'm looking forward to installing! Thanks Jake!
I *think* I'll use the fender on the front and create a bracket so I can mount it up high off the bottom triple, but time will tell. I'll mock this up once I get further along and look for feedback.

Tank levelling kit, Fork Brace, Polished Fender



 
The last few days were quite productive and got a few things checked off the "To Do" list.

First of all, was the installation of the Jadus tank leveling kit. This was a very straight forward process and the decal templates to locate the new holes worked great. After installation the lines of the underside of the tank match the top rails of the frame perfectly. I think it makes a huge difference with the overall look.

Stock position tank mounts



Carefully drill out spot welds



Pop off stock tank mounts



After the stock mounts are removed



Apply supplied templates to locate new holes



Drill hole and install new mount with supplied hardware



Install tank in new position with riser plate

 
Yesterday I was able to "convince" my buddy with 2 flats of beer to hang out in his shop and throw some sparks for a while. We removed the remaining tabs, welded in the rear hoop and removed the passenger pegs. The hoop took some finessing to get it to marry up to the frame and make the gussets look right but eventually got it done and looking pretty good.

The first few pics were posted previously but I wanted to repost to show the gussets, and the hoop before the installation.







A little bit of prep work with the knotted wire wheel to remove scale, paint etc. The flats of beer actually served a second purpose to hold the frame up for some of the work!





After some cutting, blending and manipulating the gusset we ended up with this:







Here is a picture of the final product also showing the new welds on the cross brace where the seat mounts were cut from. A bit of sanding and black paint should make this look much nicer!

 
While we were in the groove, I wanted to remove the passenger pegs. The issue with these bikes is the passenger peg mounts support the side stand on the left side and hold the brake return spring on the right side. In order to retain the functionality we made a couple small gussets and then capped the end of the remaining tube by welding in a carriage bolt on each side. I could have made the left side much smaller, but the idea was to keep the symmetry.







 
magazine said:
I really like the new tank position. Good work!

I do too! Thanks.

I plan to make the seat to match the contour of the frame rails and mate up with the front of the tank so I *HOPE* that it will look good when I'm done.
 
I like the look of that hoop and how its welded to the shock mounts did you use plugs?

Maybe some speed holes in the gussets for the kickstand/brake lever? Its looking good.
 
adventurco said:
I like the look of that hoop and how its welded to the shock mounts did you use plugs?

Maybe some speed holes in the gussets for the kickstand/brake lever? Its looking good.

Thanks man. We didn't use plugs ... just a butt joint and then utilized the gusset for additional strength.

I didn't think of putting in speed holes, but like the idea! The flat bar is rather boring and that detail might spice it up a bit. Thanks for the tip!
 
Nice welds! Great idea the way you cut the rear frame rails out to leave the gussets there. That'll be as strong as anything! Great documentation too ;D Cheers
 
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