848 Forks on a 1997 748....what's needed for the swap?

[mpaschetto]

Hi Gang,

I'd like to swap some 848 (53mm) forks onto my 1997 748 over the winter.
Have any of you guys done this swap before?

I tried to search the archives, but the search terms '848' and '748' don't help much.
I did manage to find two similar threads, but not exactly what I want to do:

999 showa to radial mount kit? Can 848 showas fit?
1098/1198 Ohlins forks in a 916

Let's assume for a moment that I've already got the 848 forks, calipers, and brake line.

- Which axle would be used, 748 or 848?
- Can I reuse my 748 wheel?
- Can I reuse my 748 rotors?
- Will my 748 fender bolt up?
- Will the speedometer still work?

Are there any other details I'm forgetting?
Thanks in advance for any help you can provide.....

[DukeDesmo]

Answers in Blue;

- Which axle would be used, 748 or 848? - 848
- Can I reuse my 748 wheel? - Yes
- Can I reuse my 748 rotors? - No
- Will my 748 fender bolt up? - Yes
- Will the speedometer still work? - Yes (I think)

As per the other thread, I did this with 1198S Ohlins, the only difference being the Ohlins are 56mm at the bottom so need a bigger lower triple. I didn't use the speedo drive but I see no reason why you couldn't - although there would be no locating lug on the fork so you would need to be careful positioning it.
You need some 15mm offset rotors (748R/998R) and the RH side spacer for the 848 axle.

[CrimsonCloak]

Buy these rotors to retain stock front wheel but correct offset:

748R HP rotors

Might need a slight shimming of lower triple...think the old bikes had 54mm lowers.

[DukeDesmo]

Originally Posted by CrimsonCloak

Buy these rotors to retain stock front wheel but correct offset:

748R HP rotors

Might need a slight shimming of lower triple...think the old bikes had 54mm lowers.

I have those exact rotors.

The triples are 53mm on 748/916/996/998 as they are on 848/1098/1198, except for Ohlins which are 56mm.

[mpaschetto]

Hi Duke, I was hoping you'd chime in, since you've completed the swap!
Thanks for the info so far....Crimson, thanks for the link.

DAMN! Those rotors are pricey! What is the difference in offset between these rotors and my stock rotors?
Is there any reason I couldn't machine a spacer and mount it behind my existing rotors?

[ducracer081]

DAMN! Those rotors are pricey! What is the difference in offset between these rotors and my stock rotors?
Is there any reason I couldn't machine a spacer and mount it behind my existing rotors?

If you dont want to spend the money right now although recommended you can have a 5mm spacer machined to place behind each of your stock rotors. Is what I have done on mine and they work like a champ. I'll be getting 15mm offset rotors once I have the time and money to do it.

[CrimsonCloak]

Actually I think those are half price of a normal set. Unless that is an "each" price?

What you can't see is that these are much much better rotors than stock. Light carriers, real floating buttons, extra friction material. Normally a ~$650 item.

[moto]

Originally Posted by mpaschetto

DAMN! Those rotors are pricey! What is the difference in offset between these rotors and my stock rotors?
?

5mm

The 848 uses 15mm offset
The 748 uses 10mm offset

-M

[mpaschetto]

Originally Posted by ducracer081

If you dont want to spend the money right now although recommended you can have a 5mm spacer machined to place behind each of your stock rotors. Is what I have done on mine and they work like a champ. I'll be getting 15mm offset rotors once I have the time and money to do it.

Ducracer,

Are your spacers flat like the rendering on the left, or were you
able to squeeze a pilot in there like the rendering on the right?

If flat, do you have any problems with the rotors 'wobbling'?

[mpaschetto]

Originally Posted by CrimsonCloak

Actually I think those are half price of a normal set. Unless that is an "each" price?

What you can't see is that these are much much better rotors than stock. Light carriers, real floating buttons, extra friction material. Normally a ~$650 item.

Yep, that's 'each'.
At least there is some small performance advantage...