TWF bearing for curvy f/e swap. - SV650.org

05-07-09, 10:34 AM

Hi guys,
Does anyone know where to actually buy one of these? My old bearing and race are a little knackered, knock under breaking etc and need swapping out, unfortunately. I have an '03 GSX-R 750 front end. I can't seem to find the bearing anywhere, which is a little annoying- also, do I need to buy a GSXR headrace if it's a little notchy?

Finally, is there a way to just simply adjust the bearing without having to basically take the whole front end apart?

Thanks in advance,
Conrad

yorkie_chris · 05-07-09, 11:21 AM

If it's notchy it's probably f#cked.

You can get the bearing from (shock, horror!) TWF.

Top bearing is NOT GSXR one, OR SV one. It is special one to take up the difference, they are a f**ker to get hold of in proper spec (there is a radial ball one of right dimensions, but a very wrong configuration!)

It doesn't matter what forks you have really, if it has been done with SRAD yokes. Or indeed the 03 yokes, all GSXRs after the WN/WP slingshots (>95 for 750 (i.e pre-SRAD), none of the 1100s) use the exact same head bearings.

NSK hr32906 taper roller = i/d 30mm x o/d 47mm x height 15mm
But they're pretty rare. So, probably as easy to buy from TWF.

But, did you fit the forks? Are you sure they are TWF bearing kit? Or has fitter of the forks swapped the stem on the GSXR yokes for an SV one?

northwind · 05-07-09, 07:21 PM

Yup, speak to Twin Works Factory, Zoran will sort you a new one easily enough. There's other people selling similiar products, but his works and wasn't ripped off.

TSM · 05-07-09, 08:01 PM

Quote:

Originally Posted by yorkie_chris

Top bearing is NOT GSXR one, OR SV one. It is special one to take up the difference, they are a f**ker to get hold of in proper spec (there is a radial ball one of right dimensions, but a very wrong configuration!)

You say this but did you know the Triumph TT600 has a radial (wheel type bearing for the top and it a perfectly handling bike, so mabey its not so wrong.

northwind · 05-07-09, 08:33 PM

Presumably it's designed to work with that though? I can't see how you could effectively combine the 2 types with a head designed like the SV's, it's effectively a big cup-and-cone bearing so having the bottom bearing angular and dependant on torque to set it, and the top bearing radial and sensitive to side loading, would presumably cause problems?

TSM · 05-07-09, 09:16 PM

Quote:

Originally Posted by northwind

Presumably it's designed to work with that though? I can't see how you could effectively combine the 2 types with a head designed like the SV's, it's effectively a big cup-and-cone bearing so having the bottom bearing angular and dependant on torque to set it, and the top bearing radial and sensitive to side loading, would presumably cause problems?

All i remember was that it had a standard taper bearing for the bottom and a raidal bearing (RS2 type) for the top, it its fitted in like wheel bearings.
The way i look at it is, when you are riding the vertical forces are handled by the bottom bearing, but the for/aft movement is handled by the top bearing and a radial bearing seems better for that.

northwind · 05-07-09, 09:26 PM

Hmm. You're spot on about the forces but radial bearings don't like lateral forces, and that's exactly what you'd apply here to tension the bottom bearing. It'd be a bit like leaving out a wheel spacer then tightening. Maybe it does work fine (or maybe the triumph uses a different design), I've never seen it but it does seem like a fudge purely from a mechanical point of view.

TSM · 05-07-09, 09:28 PM

Quote:

Originally Posted by northwind

Hmm. You're spot on about the forces but radial bearings don't like lateral forces, and that's exactly what you'd apply here to tension the bottom bearing. It'd be a bit like leaving out a wheel spacer then tightening. Maybe it does work fine (or maybe the triumph uses a different design), I've never seen it but it does seem like a fudge purely from a mechanical point of view.

Ile offer Sid Squid a call on this as he saw it, put it together and adjusted it.

northwind · 05-07-09, 09:38 PM

Yeah, cool, it's interesting this...

yorkie_chris · 05-07-09, 09:50 PM

It would work if spindle is stepped, otherwise any nip on the bearing would translate to popping the inner and race out of the outer.

05-07-09, 10:34 AM	#1
chakraist Guest Posts: n/a	TWF bearing for curvy f/e swap. Hi guys, Does anyone know where to actually buy one of these? My old bearing and race are a little knackered, knock under breaking etc and need swapping out, unfortunately. I have an '03 GSX-R 750 front end. I can't seem to find the bearing anywhere, which is a little annoying- also, do I need to buy a GSXR headrace if it's a little notchy? Finally, is there a way to just simply adjust the bearing without having to basically take the whole front end apart? Thanks in advance, Conrad

05-07-09, 11:21 AM	#2
yorkie_chris Noisy Git Mega Poster Join Date: Apr 2007 Location: Halifax/Leeds Posts: 26,645	Re: TWF bearing for curvy f/e swap. If it's notchy it's probably f#cked. You can get the bearing from (shock, horror!) TWF. Top bearing is NOT GSXR one, OR SV one. It is special one to take up the difference, they are a f**ker to get hold of in proper spec (there is a radial ball one of right dimensions, but a very wrong configuration!) It doesn't matter what forks you have really, if it has been done with SRAD yokes. Or indeed the 03 yokes, all GSXRs after the WN/WP slingshots (>95 for 750 (i.e pre-SRAD), none of the 1100s) use the exact same head bearings. NSK hr32906 taper roller = i/d 30mm x o/d 47mm x height 15mm But they're pretty rare. So, probably as easy to buy from TWF. But, did you fit the forks? Are you sure they are TWF bearing kit? Or has fitter of the forks swapped the stem on the GSXR yokes for an SV one? __________________ Currently Ex Biker Now rebuilding a 63' fishing trawler as a dive boat

05-07-09, 07:21 PM	#3
northwind Moderator Mega Poster Join Date: Jan 2004 Location: In the garage where I belong Posts: 17,083	Re: TWF bearing for curvy f/e swap. Yup, speak to Twin Works Factory, Zoran will sort you a new one easily enough. There's other people selling similiar products, but his works and wasn't ripped off. __________________ "We are the angry mob, we read the papers every day We like what we like, we hate what we hate But we're oh so easily swayed"

05-07-09, 08:33 PM	#5
northwind Moderator Mega Poster Join Date: Jan 2004 Location: In the garage where I belong Posts: 17,083	Re: TWF bearing for curvy f/e swap. Presumably it's designed to work with that though? I can't see how you could effectively combine the 2 types with a head designed like the SV's, it's effectively a big cup-and-cone bearing so having the bottom bearing angular and dependant on torque to set it, and the top bearing radial and sensitive to side loading, would presumably cause problems? __________________ "We are the angry mob, we read the papers every day We like what we like, we hate what we hate But we're oh so easily swayed"

05-07-09, 09:26 PM	#7
northwind Moderator Mega Poster Join Date: Jan 2004 Location: In the garage where I belong Posts: 17,083	Re: TWF bearing for curvy f/e swap. Hmm. You're spot on about the forces but radial bearings don't like lateral forces, and that's exactly what you'd apply here to tension the bottom bearing. It'd be a bit like leaving out a wheel spacer then tightening. Maybe it does work fine (or maybe the triumph uses a different design), I've never seen it but it does seem like a fudge purely from a mechanical point of view. __________________ "We are the angry mob, we read the papers every day We like what we like, we hate what we hate But we're oh so easily swayed"

05-07-09, 09:38 PM	#9
northwind Moderator Mega Poster Join Date: Jan 2004 Location: In the garage where I belong Posts: 17,083	Re: TWF bearing for curvy f/e swap. Yeah, cool, it's interesting this... __________________ "We are the angry mob, we read the papers every day We like what we like, we hate what we hate But we're oh so easily swayed"

05-07-09, 09:50 PM	#10
yorkie_chris Noisy Git Mega Poster Join Date: Apr 2007 Location: Halifax/Leeds Posts: 26,645	Re: TWF bearing for curvy f/e swap. It would work if spindle is stepped, otherwise any nip on the bearing would translate to popping the inner and race out of the outer. __________________ Currently Ex Biker Now rebuilding a 63' fishing trawler as a dive boat

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