RC51 Forums banner

1 - 20 of 21 Posts

·
Registered
Joined
·
86 Posts
Discussion Starter #1
Are SP2 forks the same as SP1 forks?

Ive spotted a pair for a very good price, but need to know if they'll fit my SP1 before someone else gets there first!

Cheers
 

·
Registered
Joined
·
140 Posts
The forks will fit. only the forks though. I believe. I think the steering stem in the SP2 is different from the SP1. But the SP2 forks should slide right into your existing triple clamps. Also there is something about the preload adjusters that is different I believe. I am sure someone with more knowledge than me can clarify.
 

·
Registered
Joined
·
110 Posts
So would you be able to swap the SP2 steering stem into the SP1 frame with the sp2 race and bearing installed or is it more complicated than that? I am finding SP2 triples much more abundant than the SP1 which have become popular prey by VFR riders wanting to modify their 5th gen vfr suspension and brakes. I ask because I'm a tightwad who wants to spend less on getting an SP1 track ready and more time riding the muthah. I have done plenty of searches but appears nobody has seen fit to try a swap. Any help would be appreciated.
 

·
Premium Member
Joined
·
4,617 Posts
I believe the head stock is larger om SP2, the difference is not only in bearing size. You need SP1 triples only for an SP1. You could check by cross referencing SP1 & SP2 steering bearing part nos on www.ronayers.com when you want to compare fitments of things like this. ;)

As for forks - SP2 will fit in SP1 triples, but you will need the SP1 carriers to work with SP1 calipers. I assume you have those & if so - you're good to go.
Be careful to make sure the forks aren't leaky (worn stanchions needing re-chroming) or slightly bent. Depends on how much you trust the seller, I guess. Good luck.
 

·
Registered
Joined
·
43 Posts
I was under the impression that SP2 caliper carriers will bolt to both SP1 and SP2 forks but SP1 carriers will only mount to SP1 forks? SP1 and SP2 calipers will physically interchange but they have different sized pistons so the correct master cylinder would have to be used
 

·
Premium Member
Joined
·
4,617 Posts
Yeah, I meant the brackets John, sorry. I'm in the middle of a work day so my attention isn't 100% at the moment. I'm only going by what I read somewhere here, but I believe there is a difference in the mountings. Voodoridr - Why not cross reference part numbers on www.ronayers.com - that'll answer your questions more accurately. Perhaps then post your findings here. So others can benefit from this.
 

·
Premium Member
Joined
·
4,561 Posts
No you can not take sp1 bearings/races out and put in sp2 hardware...
No way, no how.

The sp2 fork tubes fit in sp1 triples fine.
The preload adjusters are different.
The internal top out springs are different.
The caliper brackets are fork specific.
Sent from Motorcycle.com Free App
 

·
Premium Member
Joined
·
2,010 Posts
No you can not take sp1 bearings/races out and put in sp2 hardware...
No way, no how.

The sp2 fork tubes fit in sp1 triples fine.
The preload adjusters are different.
The internal top out springs are different.
The caliper brackets are fork specific.
Sent from Motorcycle.com Free App
The caliper brackets are different, but SP2 will fit on both, and SP1 will only fit on SP1 caliper brackets will only fit on forks.

More information on forks:



SP1 forks:



SP2 Forks:



 

·
Premium Member
Joined
·
2,010 Posts
I haven't heard anything definitive on the bearing being the easy way to swap triples, or been able to figure it out through part number stuff off the web. The easiest way to find out would be to order the bearing races for both and compare them. My intuition says that it won't be as easy as swapping bearing races. Milling out the frame is always an option.

More information on the steering stem and other stuff:

http://www.rc51forums.com/forums/showthread.php?t=15497

http://www.rc51forums.com/forums/showthread.php?t=7158
 

·
Super Moderator
Joined
·
6,481 Posts
I was under the impression that SP2 caliper carriers will bolt to both SP1 and SP2 forks but SP1 carriers will only mount to SP1 forks? SP1 and SP2 calipers will physically interchange but they have different sized pistons so the correct master cylinder would have to be used
I have both SP1 and SP2 forks, and I have measured both.
There is no dimensional difference with the caliper mount locations between the two.
The caliper mount brackets will interchange with no problem.
While the calipers look identical, the piston diameters do differ between SP1 and SP2 calipers (look in the service manual. The master cylinders piston diameters differ as well.
 

·
Registered
Joined
·
43 Posts
I was just commenting because the SP1 forks I have at home have two individual tabs for the caliper bracket and the SP2's sitting next to them have one full length tab for the caliper bracket, the SP1 caliper brackets I have, have extra aluminum that "fills in" between the two tabs on the SP1 forks. The SP2 caliper brackets (I have 2 sets) are completely recessed between the bolt holes to fit around the full length, one piece tab on the SP2 forks.
I've bolted the SP2 brackets onto the SP1 forks and they do fit.

Wow that was long winded
 

·
Super Moderator
Joined
·
6,481 Posts
I was just commenting because the SP1 forks I have at home have two individual tabs for the caliper bracket and the SP2's sitting next to them have one full length tab for the caliper bracket, the SP1 caliper brackets I have, have extra aluminum that "fills in" between the two tabs on the SP1 forks. The SP2 caliper brackets (I have 2 sets) are completely recessed between the bolt holes to fit around the full length, one piece tab on the SP2 forks.
I've bolted the SP2 brackets onto the SP1 forks and they do fit.

Wow that was long winded
That's true, the fork bottoms are slightly different between two, but the mounting offset and bolt hole centers are the same.
The fork uppers are slightly different as well, with the SP2 uppers having more metal milled off, which is where they saved a few grams of weight.

The fork caps and preload adjusters are definitely different, and the removal and disassembly is different between the two, and the two must not be confused when disassembling the forks or the rebound adjuster can be permanently damaged. It's happened before.
And the SP2 portion is missing from the service manual, but the 954RR uses the same fork cap design, so it's procedures can be referred to for SP2 forks.
 

·
Super Moderator
Joined
·
6,481 Posts
I have not tried that...yet.
I only compared various external dimensions between the two fork types, but I had no pressing need to disassemble both fork types for internal compatibility matching.
 

·
Premium Member
Joined
·
4,617 Posts
LOL, I love the way we can find out so much information on this forum though sharing & discussion. There's a lot of differences between SP1 & SP2 when you really look into it in detail. Someday, someone should collect a list of them all. Then when someone asks - just refer them to the sticky list. :D
 

·
Premium Member
Joined
·
2,010 Posts
That's true, the fork bottoms are slightly different between two, but the mounting offset and bolt hole centers are the same.
The fork uppers are slightly different as well, with the SP2 uppers having more metal milled off, which is where they saved a few grams of weight.

The fork caps and preload adjusters are definitely different, and the removal and disassembly is different between the two, and the two must not be confused when disassembling the forks or the rebound adjuster can be permanently damaged. It's happened before.
And the SP2 portion is missing from the service manual, but the 954RR uses the same fork cap design, so it's procedures can be referred to for SP2 forks.
Yep, the 954 and early 1000rr have similar caps to the SP2. My DIY fork seal thread should be a good reference for doing it without effing up your forks.
 

·
Premium Member
Joined
·
2,010 Posts
Now the $10,000.00 question, can SP1 upper tubes be put on SP2 forks?
I have not tried that...yet.
I only compared various external dimensions between the two fork types, but I had no pressing need to disassemble both fork types for internal compatibility matching.
I don't see any obvious issues with swapping them over. I believe the lengths on everything are the same, along with the diameters of course. The fork seals are the same, and I believe the fork bushings are the same. LDH should be able to say wether the fork caps have the same threads (I can't image those would be different).

I think the more important question would be if the internals will all swap over, or if any of them are compatible. For example: can an SP1 damper rod attach to a SP2 fork cap? Are the bolts for the attaching the cartridge to the fork lower the same?
 
1 - 20 of 21 Posts
Top