Quick question on different 33hp restricted bikes

SuprSi

I'm curious to know why different bikes, with the same bhp restriction, would have different classes of insurance. I mean, the Hyosung Aquila GV 650 came under class 4 with Aon, but if I were to get an Yamaha FZ6 in a restricted version, it would be class 6 (I think, this is comparing it to a Bandit) - why is this? Surely if a bike only has 33hp, that's the only thing to take into consideration?

Or is it that some of them might actually be quicker off the mark, hence warrant a higher insurance premium? Also, I thought a factory restriction limited the amount of revs on the bike, so acceleration must be pretty standard throughout all restricted bikes, no?

murphaph

Ah, the black art of underwriting! Seriously, you have answered your own question in part-the performance characteristics of bikes (acceleration, handling) will vary as well as the pure HP output. I imagine the primary piece of data that underwriters look at is the past history of the bike & rider combination wrt accidents-if you are a young man and the bike is a sports bike (restricted or not), there is (I believe) a higher probability (based on data collected over time) that you will be involved in an accident. This will have a lot to do with psychology as well as your bike-people who buy "fast" bikes (even restricted ones!) won't want to drive slowly all the time. This is a generalistion but I think it's pretty fair. I know if I rode a fzr or cbr that I'd open the throttle a bit more than I do on my GSX, even if the bike was restricted to 33 brake. The insurance companies know this and hence charge higher premiums.

Litcagral

SuprSi wrote:

I'm curious to know why different bikes, with the same bhp restriction, would have different classes of insurance. I mean, the Hyosung Aquila GV 650 came under class 4 with Aon, but if I were to get an Yamaha FZ6 in a restricted version, it would be class 6 (I think, this is comparing it to a Bandit) - why is this? Surely if a bike only has 33hp, that's the only thing to take into consideration?

Or is it that some of them might actually be quicker off the mark, hence warrant a higher insurance premium? Also, I thought a factory restriction limited the amount of revs on the bike, so acceleration must be pretty standard throughout all restricted bikes, no?

As many bikes are stolen to order, would the Yamaha be possibly more attractive to thieves?

(please excuse my ignorance re bike makes)

Idleater

Litcagral wrote:

As many bikes are stolen to order, would the Yamaha be possibly more attractive to thieves?

(please excuse my ignorance re bike makes)

Yes, I believe that this is a major contributing factor too. As far as I know, even the factory restricted bikes can be converted into their non restricted versions with a replacement chip (which can be done anyway to increase performance). Hence a stolen ZX6R (restricted) can be sold as an unrestricted ZX6R (tuned).

L.

a_ominous

AFAIK the insurance groupings are based on power to weight ratio (which is also a criteria in licencing).
Latest FZ6 weighs 187kg and Hyosung weighs 208kg. The FZ6 will have better acceleration and be a bit nippier all round.
Same reason why a RS125 or NSR125 are classed in group 6/7 (somewhere in the middle of CN or AON table) and my first Marauder cruiser-style 125 was a group 2.

KTRIC

a_ominous wrote:

Same reason why a RS125 or NSR125 are classed in group 6/7 (somewhere in the middle of CN or AON table) and my first Marauder cruiser-style 125 was a group 2.

Isn't the NSR125 something like 33bhp ?, and the Marauder 125 is 13bhp. That would explain the difference in the insurance catagory.

a_ominous

K-TRIC wrote:

Isn't the NSR125 something like 33bhp ?, and the Marauder 125 is 13bhp. That would explain the difference in the insurance catagory.

True. I stand corrected.
The power/weight ratio is still the metric for the insurance groupings. My current bike puts out 145 BHP, but is a group or 3 from the top group because it weighs a tonne. Well 250kg fully loaded.
A CBR1000 puts out similar power but weighs about 80kgs lighter and hence is highest group.

SuprSi

Ok, and one more question - where does the restriction hit you most? I'm seriously thinking of getting that Hyosung in July/August. I know it produces around 70hp normally and obviously 33hp restricted, but would that hit acceleration/top speed/pulling power the most? I'm not the most mechanically minded person so apologies if this results in a stupid answer.

I wouldn't be too bothered about top speed, but would fancy a bit of acceleration. I guess with the restriction I'd be hit regardless of what bike I bought anyway, unless I got something very light. The Aquila is 220kg dry, compared to 190 for the FZ6, so obviously it wouldn't be as quick as that.

Slaanesh

I had the pleasure of driving my mates bandit for my driving test. The acceleration is savage. It's only when you reach the higher speeds that the restriction seems to come into effect.

I opened it up one day from a stand still and I swear I got to 60 in about 5 seconds.

seamus

At a guess, I'd assume that restricted power will affect acceleration the most. Top speed is governed more by gearing ratios and maximum revs, more than how much power is produced.

Afaik anyway.

Idleater

seamus wrote:

At a guess, I'd assume that restricted power will affect acceleration the most. Top speed is governed more by gearing ratios and maximum revs, more than how much power is produced.

Afaik anyway.

It depends on where the restrictor is. For example, the way of restricting down a "normal" bike, is to put a set of washers at the inlet to the carbs. This makes the hole sucking air over the carburettor smaller resulting in less air to suck fuel into the cylinder. However, this messes around with the fuel mix because essentially the cylinder still must suck in the same volume of air/fuel on each stroke so essentially the air is sucked over the carb main jet quicker than normal so the standard mainjet cannot release the "correct" amount of fuel into the airflow.
These washers can very easily be removed hence why the insurance companies will give you a grand 0% discount on your 33bhp R1.

Buying a factory restricted bike on the other hand most likely has a completely different electronic ignition fitted which is better able to stem the air/fuel power mix. These bikes do qualify for a restricted insurance discount because it is genuinely more work than removing a couple of washers.

Now, as to how these restrictions change the performance of the bike is another matter. With method 1 essentially what you are doing is choking the engine so that it does not burn correctly inside the cylinder. This will impact acceleration and top end speed because the lack of power compared to the weight of the machine is not revvomg the way it was designed to run. With method 2, what you end up with is the same lack of top end speed and acceleration due to the weight but in theory a better burn cycle that is not doing as much damage to the spark plugs/engine. It quite possibly incorporates a rev limiter too (quite high I would imagine so that one doesn't run out of power at slow speeds which could be quite nasty!).

Slaanesh wrote:

I had the pleasure of driving my mates bandit for my driving test. The acceleration is savage.

I suspect that either the bandit was derestricted or the acceleration of the bike would be even better than what you felt when the restrictors are removed. Those bikes are fairly good to go, restricted or not, hence why the "restricted" ones are at best group 8 if not 10 compared to group 5 or 6 for actual "33 bhp" bikes like the Bros or ER5.

Hope that explains it somewhat.

L

SuprSi

Great explanation Nereid, thanks!

Slaanesh

nereid wrote:

I suspect that either the bandit was derestricted or the acceleration of the bike would be even better than what you felt when the restrictors are removed. Those bikes are fairly good to go, restricted or not, hence why the "restricted" ones are at best group 8 if not 10 compared to group 5 or 6 for actual "33 bhp" bikes like the Bros or ER5.
L

It's definitely Group 5 and it is definitely restricted (Max speed 90mph). But it might be quicker off the mark de-restricted, I've never driven anything more powerful.