Honda XR650L Weight Loss Thread

[Brtp4]

Originally Posted by oregoncoast

Hey BP, why not just get a lighter bike to start with? Be a lot easier. What a Maroon.

"2012 Mexican 1000 on a 1972 SL350"

Ahem.

BP

[xr650lwolf]

Great thread and post.

[beechum1]

Originally Posted by Brtp4

"2012 Mexican 1000 on a 1972 SL350"

Ahem.

BP

Mmm, what he said.....

[530phil]

What was the final weight on the XR?

Sent from my SCH-I500 using Tapatalk 2

[Brtp4]

Originally Posted by 530phil

What was the final weight on the XR?

Sent from my SCH-I500 using Tapatalk 2

It is still in process, but getting close. Motor has been rebuilt, head ported, new cam, etc. Frame is being modified, tank mounts changed to XR600 style, oil cooler mounts added, and subframe is being braced. These details will actually add weight, but they will make the bike better overall and are thus worth it. I am going to do a full build thread when done, but for now, here are some pics on The Blue Hole (Facebook):

http://www.facebook.com/media/set/?s...6344858&type=3

FWIW, I still think I will be able to get to the 300 lb mark.

BP

[RonZacapa]

Great thread this! Have been beevering away at my own South African weight loss program with the 650L over the last year or so. Down to 141kg dry now (no gas) - 310 lb and happy for it.
The 650L was introduced to SA for the first time in Nov. 2010 - 20 years late!. What has HONDA been thinking all these years?
As far as XR's are concerned we have had them all over the last 30 years in SA, from XR200R to XR600R but just not the 650L.
My view on things XR650L related: Great bike, can go real gnarly places with relative ease. Shedding a few pounds helps and the bike is a pleasure to ride for the low to upper midrange torque it has, and plenty of it too. Will be watching this thread closely.

One area of weight loss: Cutting all bolt threads that are too long (as in protruding)
A step up from this would be to replace all bolt fasteners (non structural areas mostly) with lightweight aluminium alloy or titanium fasteners. If that proves to be a tad too expensive consider drilling out the centre of the bolt. Since tensile stresses on any bolt (or axle) are transmitted along the outside perimeter of bolt i guess that an M8 bolt should be able to have a 3.6mm hole going through the middle

[daveyondrugs]

How about an aluminum muffler?

[Brtp4]

After a busy summer, I am finally getting back on track with this. I had stripped the frame down, and weighed it at 26.68 lbs.:



After adding steering stops, XR400 oil cooler mounts, XR600R style tank mounts, and powdercoating, it has added .68/lb.

BP

[DQook]

Moar!!!!

[Sierra Thumper]

Originally Posted by Brtp4

It is still in process, but getting close. Motor has been rebuilt, head ported, new cam, etc. Frame is being modified, tank mounts changed to XR600 style, oil cooler mounts added, and subframe is being braced. These details will actually add weight, but they will make the bike better overall and are thus worth it. I am going to do a full build thread when done, but for now, here are some pics on The Blue Hole (Facebook):

http://www.facebook.com/media/set/?s...6344858&type=3

FWIW, I still think I will be able to get to the 300 lb mark.

BP

I haven't read through the whole thread, or even know if you've already done it, but removing the starter and associated bits like the battery box, relays, excess wiring etc and replacing it with a kickstart and a tiny lightweight lithium battery under the seat would dump a good portion of the weight gain the L has over the xr600.

If you swap out the huge flyweel's mass for a 600 flywheel you'd be even closer to the xr6. The L is just a xr6 with electric start and a big-ass heavy crank and flywheel for more torque.

But honestly it would be easier to just dual sport an xr600, I did an 84 xr500 and it was easy....had a real dirt bike for the street with trick USD forks and rear shock, big bore high comp cammed motor with worked head, lightweight for a thumper, and fast as hell.

I do understand your goal tho is to get the L as light as you can, and getting it closer to the xr600 its based off of would be the route to take I would think. Just reverse the process honda used to turn an xr600 into a dual sport and you should have an ass-hauling dirt bike for the street

[Brtp4]

Originally Posted by Sierra Thumper

I haven't read through the whole thread, or even know if you've already done it, but removing the starter and associated bits like the battery box, relays, excess wiring etc and replacing it with a kickstart and a tiny lightweight lithium battery under the seat would dump a good portion of the weight gain the L has over the xr600.

If you swap out the huge flyweel's mass for a 600 flywheel you'd be even closer to the xr6. The L is just a xr6 with electric start and a big-ass heavy crank and flywheel for more torque.

But honestly it would be easier to just dual sport an xr600, I did an 84 xr500 and it was easy....had a real dirt bike for the street with trick USD forks and rear shock, big bore high comp cammed motor with worked head, lightweight for a thumper, and fast as hell.

I do understand your goal tho is to get the L as light as you can, and getting it closer to the xr600 its based off of would be the route to take I would think. Just reverse the process honda used to turn an xr600 into a dual sport and you should have an ass-hauling dirt bike for the street

I agree. While I had the motor apart, I thought really hard about that. Came close to buying an XR600 bottom end a couple times on EBay. I figure it would shave about 20 - 25 more lbs off and really improve the throttle response. I may still do it at some point. But for now I really want to keep the e-start. Plus, at some later point I am going to turn this thing into a street tracker.

Also, pretty sure you can't switch flywheels. IIRC crank end is different, and ignition system also.

BP

[Sierra Thumper]

Originally Posted by Brtp4

I agree. While I had the motor apart, I thought really hard about that. Came close to buying an XR600 bottom end a couple times on EBay. I figure it would shave about 20 - 25 more lbs off and really improve the throttle response. I may still do it at some point. But for now I really want to keep the e-start. Plus, at some later point I am going to turn this thing into a street tracker.

Also, pretty sure you can't switch flywheels. IIRC crank end is different, and ignition system also.

BP

I agree, it might be a bit more complicated then it sounds.....but imagine the difference in handling you'd get dumping that much gyroscopic weight off the bike, it would transition way quicker, and feel like you lost alot more than 25lbs I bet, and spin up a lot faster as well
Thats one reason that even tho the gsxr-600 is only a couple lbs lighter than the 750......every test rider says the 600 handles substantially better....less gyroscopic rotating mass in the engine to slow down handling

[flatfender]

I put mine on a diet also. It was getting pretty porky with all the unnecessary long range type stuff added. I cannot get near the numbers talked about in this thread.

If starting with the lighter 600R frame for measurement purposes minus its 98 pound engine (so start at 189 pounds), add the 650L engine (114) an oversize tank holding 4 gallons of fuel (24) and a Shorai battery (1.5) the sum is 328.5 and will still need a few more things to make it street legal.

Then add things that make it better, oil cooler, steering damper, 650R Ricochet skid plate, on mine heated grips too. I have also cut the wiring harness in half and am using only the bare legal limit of lighting compliance. I have calculated weight is ~340 wet.

I really applaud you for your weight savings, this will be a top tier build when done, I would really like to see more pictures, thanks.

[joexr]

Mine is 320 full of gas. Stock tank and battery. Has Harley oil cooler , 320mm rotor and Acerbis bark busters adding to weight.

[flatfender]

Originally Posted by joexr

Mine is 320 full of gas. Stock tank and battery. Has Harley oil cooler , 320mm rotor and Acerbis bark busters adding to weight.

Wow, 320, by my calculations 320 is about what a stock XR600R with the Acerbis tank would weigh full of fuel. I'm guess you have supermoto tires? Are they that much lighter? What are you using to measure the weight?