FXR front end upgrade

[Buddha#81]

Ive already converteted the rear to GSX250 so the next project was to further improve handling. I've been (along with most MotoFXR owners) keeping an eye out for a GSXR/GSX250 front ends. Well one snuck under the Trademe radar and its out of a 250 Katana which after my reserch is the same. The big gain is from 33mm - 38mm forks, wider front wheel (slicks run better profile) and bigger brakes (not that the MotoFXR's has any issues there)

Now reports are that they bolt staight in, no mods nothing. We'll see and I've manage to score the complete front end including brakes, bars and the front wheel. If its as easy as reports its only going to take 20 minutes or so I'll be changing the oil to 20wt and using the exsisting braded brake line.


Anyone need a complete FXR front end. Forks (new seals and 20wt oil), caliper, master cyl, tripple clamps and stem, clip ons and wheel (slight ding, never bothered me in 3 seasons of racing) $250ish plus freight.

[F5 Dave]

What? No radial callipers? :oi-grr:

[Pumba]

Is the photo the FXR or Katana front end? (im pretty sure its still the FXR but my eyes could be deciving me)

and what size frount wheel do they run out of curiosity?

[Buddha#81]

Is the photo the FXR or Katana front end? (im pretty sure its still the FXR but my eyes could be deciving me)

and what size frount wheel do they run out of curiosity?

That still the FXR front end (for sale). The Kat front end turned up today and its a 3" wide wheel, this may be an oversight, but free for tyres.

[Pumba]

Yea, thought the front was a 3.00 not a 2.50

[F5 Dave]

So to run 125 type tyres you can get away with a 2.15 frnt & a 3.00 rear but ideally 2.5 frnt & 3.5" rear.

A 3" front would be 'a bit out there'.

[Sully60]

So to run 125 type tyres you can get away with a 2.15 frnt & a 3.00 rear but ideally 2.5 frnt & 3.5" rear.

A 3" front would be 'a bit out there'.

2.15 fronts are the way to go. 2.5's make the 90 width slick look like a rear tyre profile i.e. too 'flat' across the crown.

Yeah. I've run a three before and the ideal size is a 110/70-17 which limits you to running road legal race tyres like Super Corsa's or Racetecs (if that size is actually available here, check with Forbes & Davies) Still fuggen heaps of grip but hard to find second hand in any usable condition and new they virtually cost the same as a 120/70 anyway.

I ran a 120/70-17 Superbike slick on the front of the 'Sled before the skinny wheel conversion and grip and steering wise it was ok but that was with a 4" rim with a 125/70-17 on the back. Me suspects you could end up with funny handling characteristics with skinny rears and wider fronts.

[F5 Dave]

Yeah hard to know with slicks, but Dunlops are quite triangular. They come in 90 & 95 sizes. My fronts on 2.15" don't go to the edge, maybe I don't lean very far. Think I've used both 90 & 95.
Old RS - '91 etc used a 2.15". Newer RS use a 2.5" so running 95s should be sweet.

[Buddha#81]

I ran a 120/70-17 Superbike slick on the front of the 'Sled before the skinny wheel conversion and grip and steering wise it was ok but that was with a 4" rim with a 125/70-17 on the back. Me suspects you could end up with funny handling characteristics with skinny rears and wider fronts.


I've done the 3" conversion to the rear, how would 125 rear and 115 fronts go?

[Sully60]

I've done the 3" conversion to the rear, how would 125 rear and 115 fronts go?

Are the 115 fronts Bridgestone or Yoki front slicks? If so, you could be ok. It's really a suck it and see thing bacause all sizes on the tyres are nominal and one brands 115 is could be wider or flatter on the rim than the others 125.

[Buddha#81]

Are the 115 fronts Bridgestone or Yoki front slicks? If so, you could be ok. It's really a suck it and see thing bacause all sizes on the tyres are nominal and one brands 115 is could be wider or flatter on the rim than the others 125.

3" rims front and rear with 115 front and 125 rear both dunlop......be ok?

[F5 Dave]

I wouldn't run the 125 on the rear with only 3", but could try it & see what it looks like.

[Buddha#81]

I wouldn't run the 125 on the rear with only 3", but could try it & see what it looks like.

looks ok on this http://www.dropbears.com/u/utilities/tyrerim.htm . Plenty of free 120's around?

[Sully60]

looks ok on this http://www.dropbears.com/u/utilities/tyrerim.htm . Plenty of free 120's around?

That list seems to be for crossply's based on the sizes I saw. Radials run more vertical sidewalls than crossies so need wider rims.

I'd give the tyres you have a go and see what happens, I imagine you'd end up with a flat looking front and a pointy rear. Have you consisdered running the same size tyre at both ends?

[F5 Dave]

Yeah I ran same size on my 50 for ages with Dunlop on front as a bit more pointy,

[gav]

That still the FXR front end (for sale). The Kat front end turned up today and its a 3" wide wheel, this may be an oversight, but free for tyres.
:innocent: Huh? You didnt check the rim size before bidding? Get ya bro to narrow it down for ya!

Otherwise, have you seen the Dunlop slicks for sale at Falsgrave?
115/50 x 17 and a 115/65 x 17, these may work better with a 120 rear?

[Buddha#81]

:innocent: Huh? You didnt check the rim size before bidding? Get ya bro to narrow it down for ya!

Otherwise, have you seen the Dunlop slicks for sale at Falsgrave?
115/50 x 17 and a 115/65 x 17, these may work better with a 120 rear?

I didn't check......silly me. But do have and option for a loaner if the 3" doesn't work. I will keep the 3" for the pre '89 motard conversion. So not alls lost. It wasn't a straight fit either. Easy fix though.

Falsgrave are selling slicks? What sizes and prices? I take it its the one in by AMI stadium?

[gav]

Heres one of them, looks like a rear.
http://www.trademe.co.nz/Browse/Listing.aspx?id=197494237

[Buddha#81]

Its done, I straightened the bottom tripple clamp and welded the stem in today and reassembled tonight. All I need to do is bleed the brakes and fit Yow Lings loaner wheel and test. I will report back after the next outing on the track. I'm hoping the bigger forks and better profile front tyre on a wider rim will make the money spent worth while. I'm still going to fit a 115 tyre to the 3" rim to see how that goes, I'm expecting it to slow the turning down.......but the is only one way to find out.

[Buddha#81]

Its finished MkII......I did some tuning over the long weekend and found both fork seals were toast, so I've fitted new seals and gone from trusty 20wt to 15wt. Yow Lings loaner front wheel has been fitted with a BrenChch had-me-down 95-70-17 Dunlop Slick. So roll on track time next month.

[Sully60]

Noice!
Just be careful when you hit the brakes for the first time, you wouldn't want to impale yourself on those forks!


P.S.I'm lovin' the blackness!

[koba]

Lovely!:woohoo:

[Skunk]

P.S.I'm lovin' the blackness!
Black is the colour you use when you have no imagination.

Looks good Buddha. Love to know how she goes.

[Buddha#81]

Black is the colour you use when you have no imagination.

Looks good Buddha. Love to know how she goes.

Cheers......Blacks the colour when its free and the best quality airasshole cans in the world. The ammount I crash I'm hardly going to shell out for a decent paint job. If you look closely in the photo the tail piece has the flat spot from the BOB crash.

[diesel pig]

Black is a traditional motorcycle colour and there fore culturally sensitive to use black as long as the motorcycle in question has no overriding colour traditional.