Been thinking- fork swap
- Thread starter BrentMartell
- Start date
BrentMartell
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Springs are weight sensitive and valving is speed sensitive. I agree with you. I also know that according to the experts with my weight and rider level I should be running .46 springs with stiff valving on a 2 stroke. I should actually be running .51 on the Honda. I don't where it will all wind up in the end but it is a starting point. I am looking for a set of .42's. Mix and match and have .445's. The 250F comes with .45's so I might be able to find a set of those for a decent price as well if I need to just got that rate.
BrentMartell
New member
I don't think boring the axle clamp is going to work. To bore the brake side the ID will butt up against the threads. Even though the showa fork is considerably thicker in the entire area then the zoke I am worried about weakening the area where the bolts go through. I have no clue how much pressure the axle clamp does and can endure.
BrentMartell
New member
I know you did and appreciate it. I was just not sure until I got a fork in hand how much material I had to work with. I think a person could easily bore out 1-1.5mm. The non brake side is about that much thinner.
Anyway, I have an axle coming and will work with spacers stepped to the dimenions we need. The KTM rear axle spacers will be a good template to work from I think.
The remaining big question is boring the lower triple. Fingers crossed.
Anyway, I have an axle coming and will work with spacers stepped to the dimenions we need. The KTM rear axle spacers will be a good template to work from I think.
The remaining big question is boring the lower triple. Fingers crossed.
Front end swap from GG to CRF
I have an old race bike ('07 CRF250R) that's not worth selling but I LOVE the revalved Showa's on it. My idea is to just bolt the fork/axle/wheel brake from my CRF into the 2011 GasGas300 triple clamps (currently sporting 45mm 'zokes). It looks like all I would need is a 48mm lower triple clamp (gofasters?). From the dimensions earlier in this thread, it looks like that should work....comments?
This would essentially disable my Honda (which is currently trail ridden by my wife) but the 45mm zokes would be great for her. Could the stock Honda triple clamps be modified/shimmed to hold the 45mm Marzocchi's? That seems like a WAYYYY easier proposal than putting larger forks into smaller triple clamps. I'd like to essentially swap everything from the forks down between the two bikes
Comments?
I have an old race bike ('07 CRF250R) that's not worth selling but I LOVE the revalved Showa's on it. My idea is to just bolt the fork/axle/wheel brake from my CRF into the 2011 GasGas300 triple clamps (currently sporting 45mm 'zokes). It looks like all I would need is a 48mm lower triple clamp (gofasters?). From the dimensions earlier in this thread, it looks like that should work....comments?
This would essentially disable my Honda (which is currently trail ridden by my wife) but the 45mm zokes would be great for her. Could the stock Honda triple clamps be modified/shimmed to hold the 45mm Marzocchi's? That seems like a WAYYYY easier proposal than putting larger forks into smaller triple clamps. I'd like to essentially swap everything from the forks down between the two bikes
Comments?
BrentMartell
New member
Yep, brake system, wheel, forks. You will need the lower clamp. Let me know what gofaster says, I was quoated 300 with shipping and 4-6 weeks. LOL. At the time I thought things would come together quicker. If we can get a better deal for two I will probably jump in with you. I will know very soon if boring my clamps will work. Speaking of, yeah just shim/sleeve the honda lowers with sheet metal or whatever. Just something that won't move and takes up the gap enough to tighten the clamp.
Update on forks- ebay seller tried to screw me. Well did I guess. The rebound adjuster bol was broken and they said it is my fault, there is a nasty ding as well I had to sand out. I ordered a new part to fix this issue.
Also, I made deal with a local guy who has the full race tech set up and we swapped out the internal assembly. Super stoked about that. He is an a/aa mx "dude" and he went plush with better bottom resistance. Might be perfect for me. At least I have a much better place to start. I also have a set of .46 newer springs and 1.6 inner spring. Should be just about perfect.
Update on forks- ebay seller tried to screw me. Well did I guess. The rebound adjuster bol was broken and they said it is my fault, there is a nasty ding as well I had to sand out. I ordered a new part to fix this issue.
Also, I made deal with a local guy who has the full race tech set up and we swapped out the internal assembly. Super stoked about that. He is an a/aa mx "dude" and he went plush with better bottom resistance. Might be perfect for me. At least I have a much better place to start. I also have a set of .46 newer springs and 1.6 inner spring. Should be just about perfect.
Good news on the trade.
Thanks for the feedback on my swap. One issue I was concerned about is that the inner bore of the upper clamp is 0.5mm smaller (54mm) than the outer diameter of the Showa's (54.5mm) from the chart posted earlier in this thread. Do you think the "spread" of the clamp will accommodate the larger tube? Other than that, it looks like I'm home free.
To take up the space between the 45 Zoke and the lower triple clamp of the Honda, I thought I could roll on metal foil tape like tin badgers use to seal up ducts. I could just roll it on till it calipers to the right diameter. What do you think of that?
Thanks for the feedback on my swap. One issue I was concerned about is that the inner bore of the upper clamp is 0.5mm smaller (54mm) than the outer diameter of the Showa's (54.5mm) from the chart posted earlier in this thread. Do you think the "spread" of the clamp will accommodate the larger tube? Other than that, it looks like I'm home free.
To take up the space between the 45 Zoke and the lower triple clamp of the Honda, I thought I could roll on metal foil tape like tin badgers use to seal up ducts. I could just roll it on till it calipers to the right diameter. What do you think of that?
pscook
Platinum Level Site Supporter
I don't think the upper will spread properly to be safe. The clamp bolts will be out of alignment and not provide proper clamp-up force. Boring out the uppers might not be too difficult for a proper machinist.
Don't roll tin tape around the fork lower to make up the gap as the adhesive will compress and loosen over time, you can have a sleeve made to the proper dimension for a cheap price, I would assume. You could conceivably purchase some shim stock in the proper thickness and make a spacer, too. Roll it around the tube and cut to fit.
Find a good machine shop and ply them with the proper beverages to get the best price. Sometimes you can find a fellow that likes challenging projects and will help you for sport.
Thanks
Thanks for the feedback. Good ideas there.
I will trial fit the top clamp fit tonight and if it spreads too much to properly align the bolts, I will likely have them machined out to increase the ID by 0.5mm. I assume that will not weaken them too much as the previous discussion contemplates boring the lower by as much as 1.5mm and there is speculation that the GasGas 48mm lower clamp is the same OD as the 45, just thisnner walled. If I do need to bore the top clamp, I can always shim it as well when its time to put the Marzocchi's back on the GasGas if the clamps won't take up the slack.
I will probably roll a spacer for the lower from aluminum stock.
Should be interesting.
Thanks for the feedback. Good ideas there.
I will trial fit the top clamp fit tonight and if it spreads too much to properly align the bolts, I will likely have them machined out to increase the ID by 0.5mm. I assume that will not weaken them too much as the previous discussion contemplates boring the lower by as much as 1.5mm and there is speculation that the GasGas 48mm lower clamp is the same OD as the 45, just thisnner walled. If I do need to bore the top clamp, I can always shim it as well when its time to put the Marzocchi's back on the GasGas if the clamps won't take up the slack.
I will probably roll a spacer for the lower from aluminum stock.
Should be interesting.
BrentMartell
New member
That is what I would try as well. The aluminum rolled with a top and bottom edge or tabs bent over to hold it in place would be nice. I am going to be pulling my bike apart tonight to work on measurements etc. It is time.
Rode the GG this weekend and back to back to a suzuki 250 2 stroke with showa's. My worked over zokes handled the tight and gnarly extremely well, rocks disappear, but the higher speed hack and g's tweak this bike to the point I have to roll of the throttle and go to cruise pace. The showa's were nervous and a little hard in the slow and but took the fast stuff well. I am looking forward to this experiment. The showa's are really close to what I want and I think with base shim mods, and a little tweak to mid valve stack they will be spot on.
Rode the GG this weekend and back to back to a suzuki 250 2 stroke with showa's. My worked over zokes handled the tight and gnarly extremely well, rocks disappear, but the higher speed hack and g's tweak this bike to the point I have to roll of the throttle and go to cruise pace. The showa's were nervous and a little hard in the slow and but took the fast stuff well. I am looking forward to this experiment. The showa's are really close to what I want and I think with base shim mods, and a little tweak to mid valve stack they will be spot on.
Brent,
I was suprised to hear you found the 47mm Showa's LOOSE in the triple clamps after looking over the diameter data posted towards the start of this thread. I got out my digital caliper and indeed measured the Zokes at 54.79mm at the top clamp and the Showa's at 53.46. Do you think 1.3mm is too much discrepancy for the clamps to "suck up"?
I guess a roll of 0.6mm thick sheet metal (aluminum?) is the ticket. This should actually be pretty easy.
I read and reread through all your previous posts. Having seen the forks in your hands now, can you summarize the steps you will have to take to make this work with the GasGas front wheel? I'm gonna take the easy road and use an entire Honda front end so I won't have the compatibilty of bearings/axle/brake issue you will have to face.
I was suprised to hear you found the 47mm Showa's LOOSE in the triple clamps after looking over the diameter data posted towards the start of this thread. I got out my digital caliper and indeed measured the Zokes at 54.79mm at the top clamp and the Showa's at 53.46. Do you think 1.3mm is too much discrepancy for the clamps to "suck up"?
I guess a roll of 0.6mm thick sheet metal (aluminum?) is the ticket. This should actually be pretty easy.
I read and reread through all your previous posts. Having seen the forks in your hands now, can you summarize the steps you will have to take to make this work with the GasGas front wheel? I'm gonna take the easy road and use an entire Honda front end so I won't have the compatibilty of bearings/axle/brake issue you will have to face.
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BrentMartell
New member
Yeah me too. Irritated actually. I thought it would fine but I tighted the bolts all the way and the top of the showa is loose. It will have to be shimmed for sure.
There are two thoughts about this entire project:
Complete front end
Mixed.
The mixed was to see if we could do it, CHEAPER. Not necessarily easier. Also, which front end is better to mate to gasgas, KX, Honda, Suzuki? We have a Honda and a suzuki in the line up now to test from. I choose the honda because we had it first. My buddy jus picked up a trick RM 250 2006. Really nice bike, low time, clean.
There are two thoughts about this entire project:
Complete front end
Mixed.
The mixed was to see if we could do it, CHEAPER. Not necessarily easier. Also, which front end is better to mate to gasgas, KX, Honda, Suzuki? We have a Honda and a suzuki in the line up now to test from. I choose the honda because we had it first. My buddy jus picked up a trick RM 250 2006. Really nice bike, low time, clean.
BrentMartell
New member
Just had a thought: wondering if the trail/rake or whatever is going to be OK. Need to compare the zoke and showa axle positions. Talked to my bud and we are going to have look at this as well. LOL, more learning.
BrentMartell
New member
Update: buddy took the clamps to the machinist. All is set. He is boring the clamp to Honda clamp dimensions and then building a compression sleeve for the top clamp. Perfect. At rest the gg clamp only needed to be bored .25mm each side or .5 overall. I know it is weird but that is what he mic'd it at. I will not argue this guy, amazing facility and knowledge.
The Honda axle placement is roughly 3mm closer to the fork than the gg. I guess a less steep t clamp offset would be required to keep all the same. I think I will try it and see what happens.
The Honda axle placement is roughly 3mm closer to the fork than the gg. I guess a less steep t clamp offset would be required to keep all the same. I think I will try it and see what happens.
Another thought....
GMP...Good point about steering offset. Stock Honda clamps are 24mm. GG is 22. I have a set of RG3 clamps for the CRF that are a custom 22mm offset.
So....Now I'm thinking about using the RG3 clamps with the 37mm Honda Showa's. That would mean all i need is a steering stem with the correct diameters (to press fit to the RG3 bottom clamp and match the ID of the GG steering stem bearings) and the right length to match the GG steering head. Does that sound correct?
On the other side, I would need a steering stem to match the GG clamps and Honda steering bearing diameters and steering tube length....
So....in an ideal world, IF the portion of both stems that press into the triple clamps were IDENTICAL in diameter, I could just swap steering stems.
In the likely scenario that they are not, could I just turn down the bigger one to press into the smaller and space the smaller to fit the bigger bored lower clamp?
If the GG stem is smaller in diameter than the bore of the lower RG3 clamp, I'm not opposed to permanently altering the lower RG3.....Could I permanently occlude the lower bore (Weld in a plug?) and have it rebored smaller?
This is a lot of speculation. Brent, do you have any data on steering stem press fit diameters into lower triple clamp or is it easily accessible/measurable to you? I assume you have both bikes apart at this time....
I'd appreciate any thoughts/info/ideas/suggestions you guys have on this.
Steering stem swap/custom manufacture seems way more sano than rigging clamps to fit wrong sized forks.....
Thanks for listening
GMP...Good point about steering offset. Stock Honda clamps are 24mm. GG is 22. I have a set of RG3 clamps for the CRF that are a custom 22mm offset.
So....Now I'm thinking about using the RG3 clamps with the 37mm Honda Showa's. That would mean all i need is a steering stem with the correct diameters (to press fit to the RG3 bottom clamp and match the ID of the GG steering stem bearings) and the right length to match the GG steering head. Does that sound correct?
On the other side, I would need a steering stem to match the GG clamps and Honda steering bearing diameters and steering tube length....
So....in an ideal world, IF the portion of both stems that press into the triple clamps were IDENTICAL in diameter, I could just swap steering stems.
In the likely scenario that they are not, could I just turn down the bigger one to press into the smaller and space the smaller to fit the bigger bored lower clamp?
If the GG stem is smaller in diameter than the bore of the lower RG3 clamp, I'm not opposed to permanently altering the lower RG3.....Could I permanently occlude the lower bore (Weld in a plug?) and have it rebored smaller?
This is a lot of speculation. Brent, do you have any data on steering stem press fit diameters into lower triple clamp or is it easily accessible/measurable to you? I assume you have both bikes apart at this time....
I'd appreciate any thoughts/info/ideas/suggestions you guys have on this.
Steering stem swap/custom manufacture seems way more sano than rigging clamps to fit wrong sized forks.....
Thanks for listening
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Omg!!!!!!!!!
Phoned All Balls to discuss a lame@$$ swingarm bearing issue and guess what popped up when I searched for their phone number and LOOK WHAT I FOUND...
http://www.allballsracing.com/index.php/forkconvertion
Holy $h!t!!!!!!
Plug and Play Fork Swap. All perms and combs of front end swap bearings. I simply click and order bearings to swap entire triple clamp, steering stem, fork, brake, hub, axle, wheel assemblies between my two bikes. UNBELIEVABLE!
Not too good to be true. Had a lengthy discussion with Paul at AllBallsRacing. They have done the work of cataloging, inventorying and selling bearings for this exact purpose....and have all makes and models of GasGas in their database.
This is a NO BRAINER!
WOOHOO!
Phoned All Balls to discuss a lame@$$ swingarm bearing issue and guess what popped up when I searched for their phone number and LOOK WHAT I FOUND...
http://www.allballsracing.com/index.php/forkconvertion
Holy $h!t!!!!!!
Plug and Play Fork Swap. All perms and combs of front end swap bearings. I simply click and order bearings to swap entire triple clamp, steering stem, fork, brake, hub, axle, wheel assemblies between my two bikes. UNBELIEVABLE!
Not too good to be true. Had a lengthy discussion with Paul at AllBallsRacing. They have done the work of cataloging, inventorying and selling bearings for this exact purpose....and have all makes and models of GasGas in their database.
This is a NO BRAINER!
WOOHOO!
