Simons Fork on my Bill Bell Baja Bullet

chopperninja
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9/16/2016 6:49pm
Hey guys,
I have a 1977 Bill Bell Baja Bullet. It's has 16in fox factory piggy backs and it had a set of 1980 yz250 forks and front wheel. I wanted to upgrade the front end so when the opportunity arose I decided to purchase a set of Simons forks for a cr 250. I replaced the dampening rods to give me 9in of travel up front so that I can continue to run in the proper pv class. Once I installed the front end I tried to install the yz wheel but decided I would probably have too much work to do to make the wheel work since I already have the cr250 axle and brake stay. Then I pulled the front wheel off of my 79 cr250 moto x fox project bike. I noticed that the wheel was offset to the non drum side. The tire almost touching the non drum side fork leg. I referred to the simons manual and I see that I need to machine 0.25in off of the axle boss and 0.20in off of the brake boss on the brake plate. I feel that if i remove this material I still won't be centered in the forks. Have any of you ever successfully done this? Any other mods that need to be completed?

Also I set out to purchase another 78-80 cr250 front wheel and brake. As it worked out I purchased a complete wheel from 1 guy and a brake from another guy. I just tried to mate them but found the brake plate is larger then the drum. After comparing the hubs I found they are different. Anyone know what this wheel would've came on?

Thanks
Luke











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9/17/2016 6:20am Edited Date/Time 9/17/2016 6:20am
The hub is off an '81.

Cool looking bike!!


Stevie
edgo897
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9/17/2016 8:50am
Will the wheel center without any spacers on the axle?
Sidecar
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9/17/2016 10:38am
Nice looking bike... What's the history???
Yellow number plates with the yellow bottoms of the new forks looks really neat against the red bike.
chopperninja
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9/17/2016 10:43am
Thanks for the response Stevie. Do you happen to know what other years that 81 hub was available? Think it would be easier to find an 81 brake plate or should I look for another 78-80 front wheel? Do both wheels utilize the same axle and spacing on the Simons forks?



Edgo I believe the step on the axle sets the spacing as well as the axle boss on the brake plate. That's why the brake plate needs to be machined for fitment. It just doesn't seem like it wiukd be enough to make wheel centered.

The Shop

chopperninja
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9/17/2016 11:46am
Sidecar wrote:
Nice looking bike... What's the history???
Yellow number plates with the yellow bottoms of the new forks looks really neat against the red bike.
Thanks Sidecar,
While looking for parts on ebay for my xt500 I came acrossed a very similiar bike to the one you see. It's a 74 xt350 in a cms frame with a pow roll 450 kit. I contacted the seller and made the purchase. Upon pickup I saw he had an almost identical bike to the I purchased. Only that it was a 77 xl350 in a c and j frame with a pow roll 412 kit. As time went on I kept in contact with the seller and inquired about the 77 multiple times. Eventually he told me that he was downsizing his herd and that he didn't want to sell that bike in particular but he also would like to see his 2 xl350s stay together as they have been long time stable mates. So when the opportunity arose I decided to make the purchase.

Here is the history that I know of the bike. It's a 77 xl350 in a 77 c and j frame with a pow roll 412 bore kit. The bike was built by the legendary Bill Bell and is an authentic Bill Bell Baja Bullet. In 1980 it was purchased by the previous owner. I believe this bike was his favorite bike that he ever owned and at 1 point in time he had over 50 bikes. The previous owner has piloted this bike to 2 national championships. I am not sure how many changes this bike went through during his ownership other then having 3 different sets of forks up front. He shortened the travel of the yz forks and said he really enjoyed the feel of the forks cornering. I feel that the forks are a bit soft hitting jumps so that's why I wanted to upgrade.

I actually sent him photos of the simons forks on the bike and he told me about the rules of the bikes racing class and how it needs to have 9in of travel and he also informed me that the forks might change my ride height which is crucial for handling. I contacted Thor and we traded dampening rods so that my suspension now only has the 9in of travel. After installation I found that the Simons ride height is identical to the YZ forks so now everything is good except for the wheel.

When changing the bike to my numbers I put on white backgrounds because I figured it matchedthe bike better and i would pordercoat the lowers red. Soon after i found out that all PV bikes need to have yellow backgrounds. So i then figured I would run the yellow lowers with the red dust covers that were already on the yz forks. I tried to find a set of red Simons decals but only found orange and yellow. A friend of mine copied the decals and printed me out a custom set in red. I really dig the colors now.



9/17/2016 12:15pm
Thanks for the response Stevie. Do you happen to know what other years that 81 hub was available? Think it would be easier to find an...
Thanks for the response Stevie. Do you happen to know what other years that 81 hub was available? Think it would be easier to find an 81 brake plate or should I look for another 78-80 front wheel? Do both wheels utilize the same axle and spacing on the Simons forks?



Edgo I believe the step on the axle sets the spacing as well as the axle boss on the brake plate. That's why the brake plate needs to be machined for fitment. It just doesn't seem like it wiukd be enough to make wheel centered.
The 81 hub/brake assy are "one year only". (They changed every year 81-83) The axles all should work as they are 15mm dia.
I couldn't tell you if the spacers will work or not I'm afraid.
As a brake the '81 isn't much better than the 78-80 brake. The hub it's self isn't really strong enough for the DLS shoe brake assy.
Finding an replacment '78-'80 front hub would probably be easier than finding a decent '81 brake plate to be honest. (I have 2 '78-'80 front hubs, freshly powder coated with freshly zinc plated spoke flanges and new bearing kits that are for sale by the way.....) See.... I said it would be easier to find a '78-'80 hub than an '81 brake plate..... LaughingLaughing

Really interesting history on the 2 bikes chooperninja, I don't think I've ever seen one over here! I'd love to spin some laps on them!

Stevie
tydog
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9/17/2016 4:26pm Edited Date/Time 9/17/2016 4:39pm
Two very cool bikes and a great project, congratulations!!
Just as a FYI, I'm sure that your know this but the brake lugs are tapered so as the wheel moves closer towards the left slider that must allowed for. Be careful with who does this work because a loose engagement there is annoying, at least to me it is. The ones I have done, I built my own stay arm and angled the lug on the stay to keep the cable parallel to the forks and not have that change of angle in the cable at the adjuster. But after typing all of that I have only dealt with this on two Suzukis, one with the conical hub and one with the full width. The conical was a huge PITA.
Just my 2 cents worth.
Cool build, keep us posted.
chopperninja
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9/17/2016 7:05pm
Hey Tydog,
I've actually read quite a few of your post regarding Simons and I believe FFF as well. I am glad that you have replied. I have a picture of the Simons manual that shows what needs to be machined. I gave it to a good friend of mine who i trust will machine the brake plate correctly. I am slightly confused with the taper. Is it on the brake stay or the brake boss? I have an original Simons brake stay arm. I now be that you are saying that It is crucial that the brake boss and stay have proper fitment so that the brake plate is solid and doesnt move...if it moves I believe it could crack and promote further problems. If something else special needs to be done please let me know so that I can let the machinist know if changes need to be made.
Thanks a lot


tydog
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9/18/2016 6:21am Edited Date/Time 9/18/2016 6:24am
Suzukis have a pretty steep angle on the plate slot, 7 degrees if my old memory is correct. I matched that on the arm I made. I have never had an original Simons arm so I cannot speak to that, sorry. I may have misled you a little as I just check some 79 and 80 Honda fork lugs and they only taper about .01" over their length. I do not have another plate disassembled to check, sorry. All the Hondas I have done lately have all had Honda forks. The lug on the FFF that I have is straight just FYI. I'm sure Stevie D can chime in on the Honda plate slots.
The cuts on the drawing are simple and I'm sure that they will work provided the plate slot is deep enough to accept the height of the lug after .200" removed. BUT, have your machinist buddy apply some common sense to it as he progresses and be sure he has all of the pieces in the beginning. A non-tapered setup is much easier and forgiving to build!!!!!
BB67
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9/18/2016 11:16am
Very cool bike and I cant wait to hear the before and after ride report. I bought a used set of Simons way back in 79 for my 79 125 Yamaha, never really liked them. Played with oil weight/ levels, air etc, not much better that stk.I traded them for a stk set of 1980 YZ 250 forks and clamps and "BOOM" instantly fell in love. So much better everywhere.Looking forward to see what you think.
tydog
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9/18/2016 12:11pm
BB67 wrote:
Very cool bike and I cant wait to hear the before and after ride report. I bought a used set of Simons way back in 79...
Very cool bike and I cant wait to hear the before and after ride report. I bought a used set of Simons way back in 79 for my 79 125 Yamaha, never really liked them. Played with oil weight/ levels, air etc, not much better that stk.I traded them for a stk set of 1980 YZ 250 forks and clamps and "BOOM" instantly fell in love. So much better everywhere.Looking forward to see what you think.
Agreed. Simons do not work at all. Add some emulators and proper springs!
edgo897
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9/18/2016 7:29pm
Take a little off the backing plate until the wheel centers. Then cut a spacer for the other side of the axle. Then machine enough off the brake stay bracket until it fits into the backing plate slot.
chopperninja
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9/20/2016 9:56am
Here are some photos of the brake stay and the brake plate before machining it down.

I have 1 more race this season on Oct. 1st if everything goes well I hope to run this setup. If not the yz forks go back on. I have shoulder surgery on Oct 4th so I wont be back on the bike till spring either way but I am looking forward to the Simons. I think the main problem in the past was the fork seals and I'm pretty positive that the new ones I installed are a lot better then the originals. I guess time will tell.
chopperninja
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11/8/2016 7:43am
Hey guys I just wanted to follow up. I received the machines brake plate with the material removed consistent with the Simon's instructions and this is what I found. The wheel is still slightly off center. I still feel that it is rideable but won't be able to ride and test until spring. The other thing I noticed is the axle seems a little short. Refer to the pics.









OldPro277
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11/8/2016 11:04am
Luke, that axle does look a bit short,and even though it looks like theres enough to clamp effectively,Id feel better with another 10-15mm . Almost like it wasnt the right one for those Simons clamps. I have 4 sets of Simons and have never had an axle sneak in that far on the fork leg. Also, I cant tell from the pics, but definitely use the small shims with the axle pinch bolts on the fork lugs. The lugs will most likely crack when you tighten (or over tighten). Just a heads up, I've seen some tears over that lol. Cool bike and good luck, Mick
chopperninja
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11/8/2016 5:17pm
Thanks for the info Mick. I was thinking about making another axle because I just didn't like it going in that far either. If it didn't step down iy wouldn't bother me as much either. Now it's just going to be a dirt trap. Did you ever have any issues with the front wheel being centered after the the machine work was complete on the brake plate? And yes I have the shims. I deff don't want to damage these forks.
Crabman
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11/8/2016 8:13pm
This is one of two Bill Bell Honda's that were raced in South Africa. Subsequently restored and had spare motor which was used by a. Mate to create the following - it is about to join my collection

OldPro277
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11/9/2016 10:10am
Thanks for the info Mick. I was thinking about making another axle because I just didn't like it going in that far either. If it didn't...
Thanks for the info Mick. I was thinking about making another axle because I just didn't like it going in that far either. If it didn't step down iy wouldn't bother me as much either. Now it's just going to be a dirt trap. Did you ever have any issues with the front wheel being centered after the the machine work was complete on the brake plate? And yes I have the shims. I deff don't want to damage these forks.
Yeah I had new axles made as well. A couple times because the ones i received with the forks were bent and/or just sketchy. I have a master machinist friend (also an ex pro from the 70's)that made me a couple and then i had them zinc plated. I may have an extra one or two at home. Ill check later tonite when i get out of the office. As far as being perfectly centered, i have a mini- lathe at home that I make my own alum wheel spacers and other trick bits. The only time that wheel would be off center is if the Simons clamps are of a different center-tube to center-tube dimension than what your stockers were,but thats easy to correct with fabbed up spacers. The other more difficult issues Ive faced are needing a different diameter and/or length steering stem,sometimes ,necessitating some mill work on the lower clamp,steering stops ,etc etc. But its all worth it to make something work better than original and of course the "trickness" factor you really cant put a dollar amount on ,ay?Wink
chopperninja
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11/9/2016 2:05pm Edited Date/Time 11/9/2016 2:18pm
Crabman those are 2 beautiful bikes.

Old pro. I measured and it seems there is a slight difference in the inside diameter. I think if I take a little more meat out of the brake plate things will center up.Yes please let me know if you have an extra axle. At the least we can compare the sizes. I have the earlier style axle that goes through the leg and has a nut threaded on.
MaxPower
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11/11/2016 3:16am
Crabman wrote:
This is one of two Bill Bell Honda's that were raced in South Africa. Subsequently restored and had spare motor which was used by a. Mate...
This is one of two Bill Bell Honda's that were raced in South Africa. Subsequently restored and had spare motor which was used by a. Mate to create the following - it is about to join my collection

I saw a Klx roller selling cheap. After you showing us this bike I wish i had bought it. Thats a good looking machine

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