Powerful sports bike with lower seat height.

Powerful sports bike with lower seat height.

Author
Discussion

rat840771

Original Poster:

2,023 posts

165 months

Monday 5th October 2015
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I've got a mate who after 10 years has gone and bought himself an MV F4 750. He bought it online and had it delivered without even testing it, all for £5.2K! Numpty.

Anyway he hates it, gutless, all top end and just no go. Being an ex racer and a wheelie king he wants something with a bit more power.

He is also only about 5ft6 so on MV he is on tip toes. Can you recommend any other powerful bikes that he would be able to reach the ground on. He is looking at exchanging it for an 04 R1 or an 08 ZX10R, But will these be even higher off the ground? Does lowering the bikes effect the handling greatly?




Yoda400

386 posts

108 months

Monday 5th October 2015
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I'm looking forward to seeing the answers on this. All i can offer is that I knew a girl of 5'1" who rode a lowered Hayabusa! For the speeds she did, road only, she said it handled fine, but it did look slightly odd.

conkerman

3,301 posts

135 months

Monday 5th October 2015
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You mate needs to get to a couple of dealers and actually swing his leg over some bikes.

Seat width is also important.

I'm 5'7 with teeny tiny short legs and have a R1200GS (with lowered seat).

Prof Prolapse

16,160 posts

190 months

Monday 5th October 2015
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If he's a racer he surely knows about geometry?

Complete amateur but curious as well. I'd have thought he'd be dragging parts across the deck pretty quickly I should think if he's significantly lowering the rear and he's fast. He's also got the squat vs. anti-squat at the rear so on a powerful bike I'd have thought that could be an issue.

http://www.sportrider.com/more-fun-geometry

Then he'll also needs to lower the front or it'll be a mess, so altering rake/trail, which means less stability which may or may not be an issue. Pre-load is also altered, as 10mm drop in yokes = 10 mm pre-load adjustment, but that's not an issue with the correct springs I'd have thought.

Is 5'6" really an issue? I'd have thought he'd of been fine on his tip toes.



rat840771

Original Poster:

2,023 posts

165 months

Monday 5th October 2015
quotequote all
Back in the day he had a CBR600 and also a 98 blade which he was fine on.

I can't believe he bought it online, so now his main option is to swap with another bike on offer from the dealer loosing about £700 in the process.

I completely agree with getting to dealers and just trying them, but for some reason he hasn't bothered.




andburg

7,290 posts

169 months

Monday 5th October 2015
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might be worth checking ...but as he bought online he may be able to return the bike under the distance selling act.

Mr2Mike

20,143 posts

255 months

Monday 5th October 2015
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Prof Prolapse said:
Pre-load is also altered, as 10mm drop in yokes = 10 mm pre-load adjustment,
Pre-load is not affected. Irrespective of the location of the forks within the yokes, the amount of pre-load required to obtain the specified rider sag will be the same (assuming the rear has been lowered by the same amount).

spareparts

6,777 posts

227 months

Monday 5th October 2015
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Dani Pedrosa is only 1.58m / 5'2"


trickywoo

11,791 posts

230 months

Monday 5th October 2015
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spareparts said:
Dani Pedrosa is only 1.58m / 5'2"
RC213V then /thread.

Yoda400

386 posts

108 months

Monday 5th October 2015
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spareparts said:
Dani Pedrosa is only 1.58m / 5'2"
Yes, but he's quite good. And besides, he often has some bloke to catch the bike when he comes into the pits. Even I can ride tall bikes if I have that (unless I need to stop inbetween, as we found out when I ill advisedly rode a Buell Ulysses off-road).

Prof Prolapse

16,160 posts

190 months

Monday 5th October 2015
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Mr2Mike said:
Prof Prolapse said:
Pre-load is also altered, as 10mm drop in yokes = 10 mm pre-load adjustment,
Pre-load is not affected. Irrespective of the location of the forks within the yokes, the amount of pre-load required to obtain the specified rider sag will be the same (assuming the rear has been lowered by the same amount).
I don't think that's correct is it? If I lower my bike 10mm, I have reduced the travel of spring by 10mm, and the spring is 1mm/kg, I have added 10kg of preload.

Am I being daft or something?




pozi

1,723 posts

187 months

Monday 5th October 2015
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Prof Prolapse said:
I don't think that's correct is it? If I lower my bike 10mm, I have reduced the travel of spring by 10mm, and the spring is 1mm/kg, I have added 10kg of preload.

Am I being daft or something?
If you slide the forks 10mm down in the yokes the preload and travel stay the same, the bike just sits 10mm lower.

Do the same at the back (admittedly slightly harder to achieve) and the overall bike geometry stays the same.



rat840771

Original Poster:

2,023 posts

165 months

Monday 5th October 2015
quotequote all
It appears he has done the deal on swapping for an 04 letterbox R1, plus 1K back.

He will definitely have the power but may have to pull up next to kerbs!


Prof Prolapse

16,160 posts

190 months

Monday 5th October 2015
quotequote all
pozi said:
Prof Prolapse said:
I don't think that's correct is it? If I lower my bike 10mm, I have reduced the travel of spring by 10mm, and the spring is 1mm/kg, I have added 10kg of preload.

Am I being daft or something?
If you slide the forks 10mm down in the yokes the preload and travel stay the same, the bike just sits 10mm lower.

Do the same at the back (admittedly slightly harder to achieve) and the overall bike geometry stays the same.
I understand the travel doesn't change, that is just me offering an incorrect explanation. It doesn't compress more unless it's topped or bottomed out. I get the front and rear sort of cancelling rake/trial out as well. Schoolboy error but we all have to learn!

But I still don't follow the preload bit. When you add 10mm of preload, the front end of your bike gets higher, and it works both ways so you need to look at preload and geometry together. You lower it in it's stanchions, you've lowered the weight. This alters preload.

I'm not arguing with anyone by the way... Just curious.








Edited by Prof Prolapse on Monday 5th October 13:33

Biker's Nemesis

38,652 posts

208 months

Monday 5th October 2015
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Tell him to get a Fireblade, they're built for midgets.

EagleMoto4-2

669 posts

104 months

Monday 5th October 2015
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Oh dear, Yamaha tend to have quite high seats on their sportsbikes so he will struggle on an R1.
GSXR's have low seats, I have a 750 and am 5'6" and have no trouble touching the floor.

upsidedownmark

2,120 posts

135 months

Monday 5th October 2015
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Prof Prolapse said:
I understand the travel doesn't change, that is just me offering an incorrect explanation. It doesn't compress more unless it's topped or bottomed out. I get the front and rear sort of cancelling rake/trial out as well. Schoolboy error but we all have to learn!

But I still don't follow the preload bit. When you add 10mm of preload, the front end of your bike gets higher, and it works both ways so you need to look at preload and geometry together. You lower it in it's stanchions, you've lowered the weight. This alters preload.

I'm not arguing with anyone by the way... Just curious.

Edited by Prof Prolapse on Monday 5th October 13:33
Crikey.

Think of it this way. Preload is the 'internal' tension between the top and bottom parts of the fork/shock unit at rest (very ish, but it will do). If you add preload, the overall unit will lengthen, if you reduce it will shorten.

If you lower the bike by dropping the fork through the clamps, you've not changed the length, or the preload at all. you've just got a bit sticking out the top of the clamp now.

black-k1

11,926 posts

229 months

Monday 5th October 2015
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conkerman said:
You mate needs to get to a couple of dealers and actually swing his leg over some bikes.

Seat width is also important.

I'm 5'7 with teeny tiny short legs and have a R1200GS (with lowered seat).
A GS is definitely the answer! As we know from previous threads, it's faster than a sports bike in the real world, has loads of low down grunt and can be used by vertically challenged riders ....

https://www.youtube.com/watch?v=kRFyw57o_Ic


Prof Prolapse

16,160 posts

190 months

Monday 5th October 2015
quotequote all
upsidedownmark said:
Crikey.

Think of it this way. Preload is the 'internal' tension between the top and bottom parts of the fork/shock unit at rest (very ish, but it will do). If you add preload, the overall unit will lengthen, if you reduce it will shorten.

If you lower the bike by dropping the fork through the clamps, you've not changed the length, or the preload at all. you've just got a bit sticking out the top of the clamp now.
Well that's what I thought at first, explain how this is wrong then;

"Two settings that will feel almost identical: We lowered the front end of this bike during a test using the preload adjuster (above). Back at the shop, we raised the fork tubes in the triple clamps 8mm so that we could put the preload adjuster back in the middle of its range (below). The two setups feel identical."

Figure 5. - http://www.sportrider.com/suspension-setup-guide


Johnny50

543 posts

172 months

Monday 5th October 2015
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I found any of the newer 600/750/1000 GSXR's to be a lot lower in seat height than any of the other manufacturers i tried.

Aside from that, the new R1200RS is tiny with a low seat on it!