APRILIA RS 125 front end on a TZR 125 (2KR) Possible??? HELP

[Stuster]

Hi all.

I am currently building a TZR 125 and am ready to put the chassie back togeather. I have been looking at the wheels on his and they are really a massive let down, as they look like they belong on a push bike haha. I wouldnt mind putting some bigger wheels on like the RS 125. I have found a complete front end for a aprillia RS 125 2008 with the disc calliper speedomiter etc.

I think this would look great on the TZR but was wondering if this would fit? Has anyone out there done anything like this befoure?

Any advice will be great.

Stuart
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Yamaha TZR125 x 3 Lifan LF125 14-F x 3 Jinlun 125 x 1 Honda CBR 600 F1 Honda Varadero 125cc I am now starting my Honda VFR400 NC30 Project (Still ongoing 27/02/18) Daelim Roadwin 125R

[chris_m2k10]

they will fit.
but if u do not want to chance it and go through hastle i would just buy standard tzr wheels.
but yes they will defanitely fit

[Blau Zedong]

[pits]

I wouldn't of thought so, I may be wrong, but first problem really is going from Honda to Aprilia.

Just a quick look at a TZR front end from a picture, I think the front end looks slightly longer, and the mounting is completely different as the frame is fairly different, and there would be no real well of fixing it, if stuff didn't line up, you can't drill or cut the frame as that would render your bike useless, not sure about making something either.

Aprilia has upside down forks aswell, and just looking at pictures I think you may have tank clearance issues.

But I really don't know, the other question is whether the front tyre would be a good match for the rear tyre size wise and whether or not you could fit the Aprilia rear on, I honestly don't know, would bits of TZR250 not fit better? Is there any difference between 250 parts and the 125?

[andysdad]

i have put a cbr 600 f4 front end and rear swingarm onto a chinese tiny wheeled 125. it can be done. just make sure u have a shed to do it in as its a few days work on each end. if u do decide to do it i can help u with it but make sure u have a decent mig welder with gas. mines lasted 6 months with no cracks at the welds so its definately safe and then i sold it. and the wheels were twice the size of originals. ive got a tzr 125 aswell and i am definately putting the rs125 wheels on if not then bigger wheels.
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1992 TZR 125
1999 Impreza WRX

[Stuster]

[Stuster]

[Blau Zedong]

Are you regularly finding the limits of grip on the stock rims?

Do you know that bunging bigger rims and tyres on a bike not originally designed for them my cause handling issues (if it fucks up the geometry it might even make it terminally unstable)?

My opinion is you are looking to stick bigger rubber on for purely cosmetic reasons, which is pretty gay.
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18:54:48 Rob Fzs: jews don't give away stuff for free

18:54:59 Rob Fzs: unless its their clothes/ hair/ golden teeth

[Stuster]

[Blau Zedong]

[Kickstart]

Hi

Needs more than just the wheels to be in line.

The RS wheel and tyre are signicantly wider (110 rather than 90), which will change how the front and rear react as you lean over. Ie, lean over at 45 degree and the front is lifted up 6~7mm relative to the back compared to a stock tyre.

The wider tyre means more weight, which will make the suspension less effective.

The front forks will need changes to cope with the different weight of the bike, weight distribution, etc.

The benefits are pretty much non existant. A wider contact patch in itself does not give more friction (basic physics), so you are relying on using a better tyre.

Mentioning tyres the RS uses radial tyres. If you use the RS front wheel and stock tyre with the stock TZR back end then you will have the problem that the rear isn't a radial and no radials are around which are that narrow (front radial and cross ply rear is illegal). Swapping to an RS rear wheel will be very difficult as it is FAR wider than the TZR rear wheel (RS front tyre is wider than the TZR rear tyre) and almost certainly wouldn't fit in the swinging arm, let alone have the chain line up (even if you swap the wheel over as the RS chain is on the opposite side). That leaves trying to find a suitable cross ply front.

You will also almost certainly have to swap the clocks (doubt the RS and TZR speedo drives are geared the same, and the TZR one will certainly not fit the RS wheel spindle).

And that is ignoring the basics such as the forks being about the same length, being able to fit the bars in the fairing, being able to get the RS yokes to mate to the TZR steering head stem, lock stops being in the right place, getting the TZR ignition switch to fit the RS yokes, etc.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Stuster]

[Stuster]

[Stuster]

Keith, you have a TZR 250 rite? Is the wheel base on them any different? What would be the options with this? Would the swingarm and forks line up? I now the frame is different.

Regards Stuart
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Yamaha TZR125 x 3 Lifan LF125 14-F x 3 Jinlun 125 x 1 Honda CBR 600 F1 Honda Varadero 125cc I am now starting my Honda VFR400 NC30 Project (Still ongoing 27/02/18) Daelim Roadwin 125R

[Kickstart]

[andysdad]

all u need is the rs swingarm and wheel, if u stayed close to me u could have came round and we coulda did it in a day. have u went ahead with this then or did these ppl talk u out of it?
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1992 TZR 125
1999 Impreza WRX

[Kickstart]

Hi

RS125 chain is on the other side to the TZR125, and being a banana swinging arm you can really run the chain on the wrong side or invert the swinging arm. So fitting an RS swinging arm to a TZR is a bit of a non starter

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[MarJay]

Two points:

Anyone who thinks simply putting wider tyres on a bike will make it handle better is a complete moron.

last line of my sig. Read it.
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British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[MarJay]

Re-reading this thread I do despair at the state of the future of humanity.

This is why people like Stan Stephens say that advice given on internet forums is crap. Because, a lot of it is.
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[Blau Zedong]

[Digit]

Increasing the area of rubber in contact with the road will not guarantee any improvement in handling. Consider this.
Increase foot print by a theoretical 10% and you have reduced the loading per sq inch/centimetre which, depending on rubber mix, can reduce grip.

Roy.
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Happy daze!

[MarJay]

[Digit]

I've modded the front end on two bikes, one, many years ago, a Francis Barnett, ran on 18 inch rims. In those days the only tyre was the Avon Safety Mileage a misnomer if ever there was. It was flat across the tread and would fall into the corners, we used to buff the edges off to improve them.
The engine was highly tuned and the grip awful, plus the front brake was a single leading shoe, so I rebuilt the hub to give two leading shoes and a 19 inch rim as i could then buy a tyre with a round profile.
Worked a treat, till I parked, the extra height meant that the centre stand would not reach the ground and the damn thing fell over!

Roy.
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Happy daze!

[stevo as b4]

You want thin and light wheels and tyres on your TZR, maybe decent branded fairly grippy ones mind, given the limitations of tyre choice in the small sizes that are used on the TZR. If you can get Pirelli MT65's or similar in the size you need then fit them as they have excellent grip in the dry and are good in the wet too!

Thin tyres and small lightweight wheels are your friends so that you can make the most of your 22bhp or thereabouts. Look at how well the Kawasaki AR125's went in full power form 90mph, and they have 3.0/3.25" section tyres as std.

[Stuster]

Thanks for all your advice guys. Like i said i dont now a lot about bikes so was just after a little advice on the matter,

I think i will keep the stock rims on as advised as said many times in here you do no more than me. (Rookie)

Much appriciated guys and thanks.
____________________
Yamaha TZR125 x 3 Lifan LF125 14-F x 3 Jinlun 125 x 1 Honda CBR 600 F1 Honda Varadero 125cc I am now starting my Honda VFR400 NC30 Project (Still ongoing 27/02/18) Daelim Roadwin 125R