Lowering the aprillia rs 125..

[mattyriddell]

I am planning to buy an rs 125 and i am a little on the short side.. i was told that lowering it would make the bike very dangerous and unsafe.. just wondering how unsafe this would be as i was only planning on lowering it by about 1 inch.

Many thanks Adam.

[Chriss]

How short are you? I've no problems riding this and other bigger bikes and I'm only 5'7".

As to why, well, basically the bike was designed to handle in it's current dimensions. If you reduce dog bones then you can upset the geometry. I'd suggest that it wouldn't improve the handling but be surprised if it made it 'dangerous'. I'd really be questioning if it's actually needed.
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[mattyriddell]

[Minty]

You may want to try sitting on one first, you may well find it is fine. There would be no major problems in lowering it though.

Another thing worth considering:
https://www.bluecoat.bham.sch.uk/visitors/pre-prep/pre-prep_files/BE837466-Blue-Coat-School-pre-prep-playtime-on-stilts.jpg

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[Kickstart]

Hi

Lowering can easily screw up the handling if you are not careful.

At least you want to lower both the front and rear by the same amount to preserve the steering geometry. But even that can have odd effects. Ie, under hard acceleration a bikes rear suspension will normally extend due to the swinging arm spindle being higher than a line drawn between the gearbox output shaft and the rear wheel spindle. Lower it and that will likely not be the case anymore and the rear suspension will instead compress.

Also if you lower the bike remember you will probably need to shorten the side stand. And that you will reduce ground clearance when cornering.

Practical issues are that with usd forks (like the RS uses) often they are not a constant diameter at the top, limiting how much you can move the forks in the yokes to lower it. Also the RS rear suspension doesn't use conventional separate dog bones (which are easy to make to a different length to lower / raise the bike). The dog bones are part of one of the links making them harder to make.

Further point is the effect of lowering on spring rates. If you lower the back of the bike you will change the effective rate of the spring (rising rate suspension linkage, so the more it is compressed the quicker it compresses the spring). If you shorten a spring you will make it stiffer (bodge way of lowering cars is to chop a ring from the spring which will lower and stiffen the suspension). If you just drop the front down through the yokes you will not affect the spring rate, hence possibly landing up with them mismatched (although do it too much and there is the possibility the front tyre will touch something as the suspension compresses).

Overall none of these things are insurmountable, and most people just lower it and put up with the (normally not great) effects on handling.

All the best

Keith
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[P.addy]

You will be fine, its not overly big...

[Bendy]

You're gonna have to learn sometime, might as well do it on what is probably the lightest bike you'll ever ride.

As long as you can get one tiptoe on the floor, that is all you actually need.

[Slacker24seve...]

[jimbothe]

I'm not familiar with the bike but if it's that much of a problem can you not lower the seat itself, i.e half the foam inside it.

A few people have done it and it seems to work ok, albeit with bigger bikes.
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[Kickstart]

Hi

Can be done, but there is very little foam in the seat on an RS125.

All the best

Keith
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[Wave2k]

The other half is 5"3 and ive sat her on a RS125 a few times for testers.

She fits just fine on it, youll get used to it if its a bit big, ive seen loads of people have to tip toe at traffic lights.
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[Drake]

one word.... dwarf
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[colin1]

tip toes is fine, it just means that if you want to do reverse, you have to get off the bike and push, also for moments where you need to put your feet down, you just change your seating position, so you are sat right up to the tank, with your legs straddling the seat rather than going forwards.

You can even shuffle your bum over, so one foot is flat on the floor, and lean the bike over a bit and back pedal one footed style if need by.
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[hazza]

Im 5ft 5 so not a great deal taller than you and i have no problems on much taller bikes. I used to do a lot of motor cross when i was younger and even YZ 125's/250's were okay so long as you dont mind cocking one leg up so your other can touch the floor.
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[MarJay]

[Fahd]

O.P you'll be fine on the RS125 at it's standard height. I owned one back when I was 17, it will feel high but they are very light. My girlfriend's 5'4 and she had no problems riding it when I had it. If it's your first 'bigger bike' it may take some getting used to but I'm sure you'll gain the confidence soon enough.