Aprilia rx125 forks (?)

[elvisrock]

Hi guys, Just a few photos of what I've been playing with today. I got myself a cheap set of what I believe to be Aprilia RX125 forks, yokes and 21" wheel. Until I get the right size bearing for the bottom yoke i won't be sure that they fit as well as the RS 125 forks, but these bad boys are massive, any idea how I might be able lower them abit?

 

[elvisrock]

The final photo is with the back end lifted up. An option for lowering the front end would be to swap the RX forks with RS forks but keep this wheel, as I imagine they'll fit?

 

[LuckyEight]

I think RS forks are much more shorter...I have them in the garage so I can measure them next weekend if U can wait

 

[elvisrock]

That would be great, thanks LuckyEight. I think I'm gonna try and shorten these, but keep them a bit longer than stock RS forks then see how it looks. Another option, for another project might be so put them on something like this ;

 

[Charles]

Those are motocross forks. That's why they're so long. You'd need to cut the tubes and replace the springs with something shorter and designed for street use. You could use them as is, but in your last pic, they've def altered the neck and raked it out a bit. When you start messing with frame geometry, you need to know what you're doing, so keep that in mind.

 

[elvisrock]

Thanks Charles. I've tried the 21" wheel on the original forks, the xs spindle isn't much smaller so I think its possible to make one to fit. I've used the original XS spacer too but will probably need to make a new one too. But see what you think.

 

[Charles]

I'd call up allballs and tell them you have an RX125 wheel that you want to use on an XS400 front axle. Hopefully they'll have bearings that will be the OD of the wheel and the ID of the axle. If not, you can measure the thickness of the RX125 bearing and call up your local bearing manufacturer, tell them your OD, ID and thickness and they'll surely have something to fit. Last resort, get a new axle/spacers lathed out.

 

[drewpy]

best off with this as you can find the international bearing number

http://simplybearings.co.uk/shop/faq.php?cID=1

 

[LuckyEight]

Hey Elvisrock as I promised...The lenght of the RS forks is about 71 cm from the axle to the top

 

[elvisrock]

Thanks Guys, I've had a look into getting bearings but so far haven't found the right size, they are 15 x 40 x 12.

If I go with the XS forks I'm gonna try and mount the XS speedo drive too, as the aprilia one can't lock onto the the XS forks and it fits the axle. Unless anyone can suggest a way around this?

 

[elvisrock]

Great, thanks for that LuckyEight, I will try and have a look at the forks this week and see whats possible. Still not 100% which way I'm going with this but maybe this'll help shed some light on it.

 

[elvisrock]

Great, thanks for that LuckyEight, I will try and have a look at the forks this week and see whats possible. Still not 100% which way I'm going with this but maybe this'll help shed some light on it.

 

[drewpy]

Thanks Guys, I've had a look into getting bearings but so far haven't found the right size, they are 15 x 40 x 12.

If I go with the XS forks I'm gonna try and mount the XS speedo drive too, as the aprilia one can't lock onto the the XS forks and it fits the axle. Unless anyone can suggest a way around this?

well that link I posted came up with a few bearings which are 11mm deep. unless you are really needing a 12mm then I would go for them!

would have to change the outer spacers.

As I said before, bearing are standardised now, so unless you know of a specialised bearing which will cost up to £40 for one (ie output bearing on gearbox) that is your lot.