Hitchcocks Forum

Hi,

After some basic upgrades I manages noe to get 145kmph with pillion and saddle bags (no wind); but the bike´s handling is horrendous.
Any advice please?

Thanks

Roeland

Hi Roeland,
1)Don't push your luck! 2)Get some good life insurance! 3)Wake up?

My B5 speedo over reads by about 10km/h at indicated 60, so unless you checked your speed with a GPS, perhaps a tad over 130 might be more realistic. BTW, what were the basic upgrades.

Best regards,

TrevorCH

Hi ROELAND, ----- Can a C5 EFI actually do that then ??? First, could you be a lot more detailed with the changes you've done----- and second } I make 145Km/hr to be 90.099 Miles/hour !!! My Suzuki Marauder 800 is "Horrendous" at that speed and my GL1000 Goldwing also !!....You are obviously not riding here in the UK are you ??? Accept a bit less ie}-- cruise at 70mph (120 Kph approx.) and enjoy a lot less hassle. But that's just my OPINION after all.

Roeland, like other people who've replied I'm surprised you can achieve 145 km/hr. My B5 will get up to 135 and will cruise happily at 120, but is as steady as a rock. I'm assuming your C5 is what is known as the "classic" which has smaller 18 inch wheels and a slightly different frame with more rake. As a result I understand that these bikes are prone to weaving at higher speeds and our hosts sell a set of Electra EFI 19 inch wheels to help cure this.

Ha ha ha ha ha. A tad under 91 full size imperial miles an hour.....with passenger and luggage, and you didn't have the wind? I bet you did. Roeland this sounds like a 1960's rocker/ton up boys tale at the caff. You know the one "I just did a ton on my BSA C15 and saw off a Triumph Saint police bike....he just couldn't keep up". Seriously if that is what was indicated then so be it BUT I think you need to do a couple of things. Check you top gear ratio and then match it to the maximum revs you managed. Get a new speedo. Check the speed over a measured mile (or maybe a kilometer) with an accurate stop watch. Get a lighter pillion then it will go even faster. LOL. Don't be offended but you did make me smile.

Wish you luck with this speed trial,I can only manage 70kph on my 1965 350 bullet ,but thats fine by me ,I always think of the film back to the future, anything makes the machine vibrate can only lead to trouble.

As I mentioned I had to make some modifications to reach to 145 kmph (about 15kmph faster than the unmodified bike). I have not checked the speed with GPS as yet, but judging at the traffic flow and on the freeway the speed seems rather accurate.

Modifications included a power commander, Autotune, Goldstar Exhaust and front pipe, K&N airfilter, seperate crank breather filter, 19 th sprocket, removal of the PAV system. The bike came standard with a 19 inch front wheel.

I'm considdering the front fork brace and bushes for the rear arm - both on offer from our host - to gain some stability. But will these realy make such a difference?

Regards

Roeland

Roeland, can you say what is actually wrong with the handling? Is it weaving, vibration, or what? There are many causes and therefore solutions so before we dive in give us a bit more info please!
REgards, Mark

"The speed seems rather accurate". Well that explains it all. There is nothing like precision when "tuning" a motorcycle engine. What BHP did it have on a dynno before the mods and how much did it increase after the mods? Speed is a function of the final gear ratio. By raising the gear ratio you might gain a couple of mph, but frankly to increase by approximately 15mph you will need to increase engine speed as well, so how did you do that. Remember valve bounce will hinder engine speed increase.

----------------as will "Bum-Bounce" on these machines !!Ho-ho