Top speed with chaindrive.

[pggg]

Lately I've been wringing out a chaindrive XS11 to see how fast it'll go. The bike has had a 35T rear sprocket, and I've also swapped on a 40T to see how that performs. The 40T makes the bike feel 'racier' and I prefer it to a 35T. 65mph cruising is now 3600 revs in 5th. 35T gave 3200@65. Stock is about 4200@65. Will try a 45T for close to stock gearing with some brutal kick, but the 40T is about perfect

Top speed only increases with taller gearing if the conditions are good with a tailwind. Otherwise there's not much difference as the XS is still horribly un-aerodynamic. The best thing about a 35T is you can hit big speeds with bugger all gear changing, and fast 100mph cruising feels effortless. 3rd gear pulls to 110mph quickly, anywhere anytime. With the 35T, the fastest I've seen on the digital speedo was 228kph. Thats a bit over 140mph. To hit 150mph, you'd need a long downhill run. There is some lonnnggg hills round here, and 150mph would be easy to do!! Haven't tried it though. Yeah - what a wimp.

On the flat, without one of those specialised ugly, long Bonneville Salt Flat rocket type fairings, you'd need high duration cams, race springs and a stage111 port job(top end type) 4 valves per cylinder and flatslides would surely make 150mph possible 90% of the time if so desired.

[GNEPIG]

.. very cool! .. could you hit redline in 4th and 5th gears?
what also needs mentioned to anyone just joining us is that this bike is almost 1200cc with a point more of compression.. the thing hauled butt before the chain drive conversion!

[pggg]

GNE, best I done was nudging redline in 4th at close to 220kph with tailwind. Wrung out a few more K's from 5th. No way redline in 5th without hotter cams and high range mods. May go the downhill run on a brave day - front tyre is H rated

[Winterhawk]

I'm pretty sure that Bob Jones hit 150mph on either Yellow Jacket or TNT. Forgot which custom it was on.

[pggg]

Hawk, those bikes look fantastic, BUT their performance claims are all B.S. Takes more than a big-bore kit and rejetted carbs to make TRUE 150mph on an XS11.

[Winterhawk]

The ported head holds the key to all the performance gains. The head porting is so radical that it refuses to run with the stock air box setup. Pod filters are used along with dynojets.

Believe it or not, a chain drive setup makes less horsepower than the driveshaft.

[Winterhawk]

Be careful as these bikes with the stock frames are not safe at these speeds. Speed wobbles are a very real possibility.

Some of Bobs previous race bikes were capable of 210mph.
These TZ's were so tricked out that they put the factory road race bikes to shame.

It's a shame that Pro rider Mark "Snark" Jones was killed as he was one of the fastest road racers of all time.

[TopCatGr58]

Hey Hawk,

You're raining on my parade with that last statement about "LESS" horsepower from Chaindrive than driveshaft.!?!?

Surely we're loosing considerable HP thru the middle gear and final drive transitions, where with the chain drive, the rotational forces and directions are the same once you get to the final shaft of the middle gear assembly, cutting out 2 90 degree torque transition turns. I would think(there I go again) that the chain drive doesn't actually increase the HP of the engine persae, but allows a bit more of the available HP to make it to the rear wheel instead of being wasted/spent thru the conversion transitions?
T.C.

[pggg]

A radically ported head is a waste of time without hotter cams and radically modified valvetrain along with larger smoothbore carbs taller gearing and a lightened crank. I'll say it again, this merriam outfit is full of B.S. The claimed engine mods simply don't stack up to the performance claims. Check out the engine mods of that super-modified racing XS that was posted a while back. Maybe those beautiful shiny merriam paintjobs add an extra 20 mph?

[GNEPIG]

.. yeah, what TC said plus the 20lbs or more of weight loss
pggg maybe you could gain more top speed if you rubbed baby oil all over your self and your bike before your next test ride
..if that doesnt work at least you and the missus would have fun with all that slipperyness

[mro]

Hey pggg

If you have a shop w/dyno you can put any questions to rest about hp/torque, chain vs shaft.

If you want it go close to red line in 5th,
the quick en dirty fix nitrous!!!!!!!

Been watching all the performance/goFast ideas for the XS.

My take: turbo
chain drive
nitrous

mro

[pggg]

Hey GNE the chicks say I'm snakey enough as is There's a dyno outfit in town MRO, but they want $150 for a run. Bugger that. Quick fix nitro is a bit tempting! Of course the turbo crowd will be shaking their heads at all this - just slap on a turbo and double ya power!

[Winterhawk]

Yea that would be neat. A dyno run that is for comparison

It reminds me of a few years ago. The 9mm verse 45 caliber debate.

[mro]

$150 for a run.

Must have the ONLY dyno in town
But I wouldn't "bugger" them!

I'm currently financially challenged, but been looking for a fixer-upper locally to put a turbo on for a start. If it happens and I'm still enthused I would like to do a chain conversion to "tune" the ratio for 1/8 mile (stop light) type racing.

bth
great job


mro
80G (stock, except the mirrors)

[Winterhawk]

I always thought that chains drives deliver more HP's.

Every time I bring it up a certain individual will more or less yell at me saying a drive shaft is the way to go. Sorry I've been misled.

I wouldn't pay that kind of money for a dyno run.

Actually I was Merriam Cycles original wrench when they first opened the new store back around 1982 or so. Before that I was a wrench at JoCo Motors. Never thought I would be obssesed with XS11's. Growing old and like the finer things in life now...LOL

I still learn something new everyday on this site. Lots of talent on here, too many to name as each seems to be specialized in different areas of the XS1100.

Thanks Ken your pics and site are the best.