Various Seeley Frames (Mks)

grandpaul

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Dances with Shrapnel said:
grandpaul said:
One more interesting tidbit for those who are offended by certain racing organization's view of history - AHRMA doesn't necessarily limit bikes to '72 and older, they can be newer as long as they are "like design".

AHRMA's policy is that the RACERS police themselves when it comes to class compliance. Round up 100 old guys that want to race their homebrews and ask them to rule out other competitor's bikes that they believe aren't "like designs", or otherwise don't conform to the exact "letter of the law". I believe there's a fella that's been posting in this thread that might make a few "friends" in a big hurry.
Although grandpaul may be a member of AHRMA, I want it to be clear that grandpaul does not speak for nor does he represent AHRMA.
Quite correct.

(irony lost, like innocence)
 

lcrken

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hobot said:
Ugh, Martin I mean how much do these Seeley's weigh by themselves. I keep seeing claims a big Seeley advantage is weight savings over the iso frame so would like to know how much they weigh as I know what Combat frames weigh. Of course a solid frame will handle better than un-tamed isolastics but the fastest bikes in the world now make frames flex for side loads on purpose, so maybe Seeley ain't all that better that way either. Do the Seeley flex detectability?
Depends on what you want to compare. If you're just talking frames, you'd compare a Seeley frame with swingarm and mount plates to a Commando frame with swingarm, engine/gearbox cradle, front isolastic assembly, and top engine mount. The Seeley would certainly be a lot lighter. More to the point, you could compare a Seeley framed race bike with a Commando framed racebike, where the Commando has been relieved of a lot of weight by removing all the lighting and other unneeded bits, and replacing tank, seat, foot controls, fork yokes, wheels and brakes, exhaust system, and so on, with lighter race components. You'd still find the Seeley to be significantly lighter. Sorry I can't provide the numbers, but I've worked on both enough to be sure about the difference being significant. If you could get Kenny to tell you the wet weight of his Seeley racebike and someone like Dances with Wolves or Doug M. to tell you the wet weight of a Herb Becker race Commando, you'd have some good numbers to compare. I'm not sure what I eventually got my Commando PR down to, but I think it was something like 375# dry. For comparison, I got my featherbed/Commando race bike down to 300# dry, but that's with a lot of lightening and lots of titanium and aluminum bits, and I think I got Jim Schmidt's monoshock down near 325# dry. I'm guessing the Seeley/Commando will be somewhere around 300# dry, maybe a bit less, but that's just a guess.

Ken
 

bwolfie

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I weighed my Alloy bike dry with all the stuff hanging off of it. It came in shy of 325#. It's an 850, I remade many parts in alloy.
Since this picture I have changed the wheels to Magnesium tubeless. And will use lighter rotors and calipers.
Stock frame, converted to OIF,
So a serious built race bike could be 300# or less dry.


 
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@bwolfie You are doing real well at 325 lbs. Congratulations.


And I assume that is still with a cast iron barrel.

So when you getting the all titanium exhaust? :p
 

bwolfie

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Cast barrel. Lots of parts not installed. I saved a pound with the external fork springs. a little here and there adds up quick.
If I can sell my Dunstall project, I might get the JS kit nd a Maney 920 barrel., thats another 8 pounds dropped.
 
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Ken you are always good for a further mind stretching in all things Norton-ish. Different construction and assembly stages blurs just comparing Seeley to isolastic system. Lightness is Rightness. You know i'm befuddled by what happens to me on modern solid mounts or old factory isolastics. Both frames built for different purposes are beautiful creatures to behold. For Peels scope of operation I've had to add back about as much as drilled out. Its addictive as the more ya remove the more worthwhile percentage wise it is to remove the next little bit. Peel's crash cage triangulates stem to stern so wonder if it will mess with her tire conflict absorbing. Prolly not as would foul too soon to find out so only needed in public and off road. Peel has one more welder appointment, to add little angle iron braces behind Z plates and re-do blower side of cage a bit. There goes another dozen holes worth of mass, and some cash, but whose counting...

What a paired down airy Commando Brent has labored on. Love the exposed lines of Commando frame. At this level though its like what nationality of beautiful women do ya like the best, they all have knockouts among them. I'm trying to keep Peel light as practical but dang man you set a tough standard and more easy mass to loose yet, cool. No oil tank nor battery in sight. Still I can't see light though your axles and bet your most your spacers are still steel.

 
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@bwolfie - You have an estimate of how much lighter the magnesium wheel assembly will be compared to what you have.

As a side note, was you reduce the sprung mass of the bike (which it seems like you have done a nice job on) you are changing the ratio of sprung to unsprung mass and this may require tending to in terms of adjustments to damping or reduction in unsprung mass.

Since the wheels you propose to use are magnesium consider having them crack tested. They also x-ray but it is a bit more pricy. Crack testing can usually be done at airports where they provide airframe/powerplant services. Usually any surface coating needs to be removed prior to dye penetrant testing and care must be taken on how the coatings should be removed (don't want to peen or burnish over surface cracks). This subject just came up on another list oriented towards vintage racing.
 

bwolfie

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I estimate 8 pounds rear and 5 pounds front, the rear will be a disc brake now, so saved all the drum weight.

I am an Aircraft mechanic, not a practicing one, but one none the less.

I am going to chem strip the wheels, do a little heat treating and dye pen inspect them.
When I mentioned I purchased them, it brought the usual haters and critics out of the woodwork.
I'm not going to race the bike, And as it goes now, will see limited street use.

I am familiar with magnesium wheels, many of the aircraft I worked on used Magnesium rims.
 

SteveA

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hobot said:
Do the Seeley flex detectability?
I don't think Hobot got an answer.....here is part of one....

Not all Seeleys are equal, meaning that a MkII will flex less than a MkIII, I think the reasons are obvious....

Builders favour MkIIs for racing today! Slightly out of period for Commando engines, but legal most places as a combination (Holmslice has already addresses this elswhere).

Most who have ridden a Seeley (some regardless of whether they have actually ridden a Rickman Metisse) say they don't like the Rickman because it is too rigid!

Which means that those people must feel the Seeley flexing....right?
 
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bwolfie said:
I estimate 8 pounds rear and 5 pounds front, the rear will be a disc brake now, so saved all the drum weight.

I am an Aircraft mechanic, not a practicing one, but one none the less.

I am going to chem strip the wheels, do a little heat treating and dye pen inspect them.
When I mentioned I purchased them, it brought the usual haters and critics out of the woodwork.
I'm not going to race the bike, And as it goes now, will see limited street use.

I am familiar with magnesium wheels, many of the aircraft I worked on used Magnesium rims.
re; “I am familiar with magnesium wheels, many of the aircraft I worked on used Magnesium rims”

I take it you are also familiar with what road salt will do to any unpainted magnesium wheels :?: :shock:
 

lcrken

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Just for perspective, the listed weights for the JPN race bikes was 345 lbs. for the 1972 bike with frame similar to Commando, but slightly smaller, 368 lbs. for the 1973 monocoque, and 355 lbs. for the 1974 space frame. I don't know if those are dry weights, wet weights, half tank wet weights, or marketing weights, but they are still interesting comparisons.

Ken
 
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I raced a triton for 12 years, the Seeley frame is light years ahead of the featherbed. I've got a spare motor and gearbox and so I looked at a commando frame. I decided not to go there. About the Seeley flexing - an old A grader who used to ride a Mk3 Seeley G50 told me that he felt the front wandering. I don't use the ladder brace in front of the motor in my Mk3. I use a well bracketed , gusseted piece of chrome moly push bike tube, and I've never felt the front end wandering. I think the comment about the Rickman frame feeling 'stiff' is about steering geometry. Seeley frames were originally fitted with Metal Profiles forks and I suspect the steering would have been fairly neutral. I use TZ350 fork yokes, and the bike oversteers under power, which is superb. The bike is nimble and very effective because you can get on the gas so much earlier in corners . I don't know what the geometry of the standard commando frame is. I understand that Peter Williams used racing geometry on the very first 750 commandos, and had to change them after a few inexperienced guys chucked themselves up the road. Apparenly the 'cat's eyes' in the centre of British roads used to really upset them.
 
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If I was going to build a cafe racer, I would buy a BSA A10 or Gold Star frame, and use the fork yokes from a 1960s 650 Triumph. - Cheapest effective option.
(Note: Never use the standard BSA A10 fork yokes, you will really scare yourself).
 
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I don't have a problem with someone using mag wheels in a commando based bike, I believe some of the later JPN bikes had them. Should look really Schmick, and might even be lighter. I don't like things like electronic tachos, or upside down forks, because they were not available in the 70s. If it is a classic bike, it should actually BE classic. If it is European or American, it should actually BE that. In the same vein, I wouldn't fit Ceriani forks to a Japanese bike, unless it was a factory racer which actually used them in the era. I have very few Japanese parts on my Seeley, and I know exactly where they are.
 
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Most who have ridden a Seeley (some regardless of whether they have actually ridden a Rickman Metisse) say they don't like the Rickman because it is too rigid!
Which means that those people must feel the Seeley flexing....right?
Ok thanks for some frame sense feedback SteveA. Just because riders agree they consider one Seeley frame more rigid than another does not necessarily mean one is flexing too much as could also mean one is buzzing the pilot too much from engine or road vibes. if not for being lead down the linked isolastic path by others before me and combining their links with one of my own, I too would be hankering for something way more rigid than factory rubber baby buggy and likely stuck in same ruts as my SV50 or Nina. Looks like these moderns weigh more than old Seeleys though.



 

SteveA

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hobot said:
Looks like these moderns weigh more than old Seeleys though.

Aint necessarily so.....

Those Alloy Beam frames are not the heaviest part of a modern bike...its all the other crap like starters, batteries, alternators, lighting etc. that adds up....
 
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acotrel said:
I don't have a problem with someone using mag wheels in a commando based bike, I believe some of the later JPN bikes had them. Should look really Schmick, and might even be lighter. I don't like things like electronic tachos, or upside down forks, because they were not available in the 70s. If it is a classic bike, it should actually BE classic. If it is European or American, it should actually BE that. In the same vein, I wouldn't fit Ceriani forks to a Japanese bike, unless it was a factory racer which actually used them in the era. I have very few Japanese parts on my Seeley, and I know exactly where they are.

Here in the UK the ACU has ruled that the Peter Williams wheelbarrow Arter Matchless is the only bike that is allowed in classic bike racing to use cast wheels in this period.
 
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SteveA said:
hobot said:
Looks like these moderns weigh more than old Seeleys though.

Aint necessarily so.....

Those Alloy Beam frames are not the heaviest part of a modern bike...its all the other crap like starters, batteries, alternators, lighting etc. that adds up....
Steve - agreed. I had an early production run Triumph T595 which the factory recalled to replace the aluminium tubular frame because some of the early frames were reported to have cracked at the headstock. The replacement frame was so light you could lift it with one finger. The massive engine and single sided swinging arm made those bikes heavy.

While on the subject of frame weight, I am wary of lightweight replica tubular steel frames on classic bikes. My Seeley Mark 2 frame is a heavy old beast but I would prefer it to a lightweight item which appears to be more prone to cracking. Fine for well funded race teams which can strip and weld on a regular basis or replace frames without having to think twice, but less than ideal for an amateur racer on a budget.

I'd be interested to hear other peoples' views on this.

Dave
 
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daveh said:
While on the subject of frame weight, I am wary of lightweight replica tubular steel frames on classic bikes. My Seeley Mark 2 frame is a heavy old beast but I would prefer it to a lightweight item which appears to be more prone to cracking. Fine for well funded race teams which can strip and weld on a regular basis or replace frames without having to think twice, but less than ideal for an amateur racer on a budget.

I'd be interested to hear other peoples' views on this.

Dave
Thanks for bringing the thread back on topic.

My first Seeley (circa 2003) is a Keith Stephenson built Mk 2. It has a fair amount of track time on it with a 750 short stroke (72mm stroke) and has given no trouble whatsoever. The second Seeley Mk 2 was acquired used in 2005; it is a R. T. manufactured frame and had repair on a down tube near the engine mount. This was reportedly due to an experiment with a 500 Manx engine that did not go well. Herb Becker further enhanced the repair enabling the engine to be moved forward. This frame has the 59.6mm stroke Norton twin in it. The frame has given no trouble whatsoever. Both these bikes use solid mount head steadys.

I am aware of one very successful R.T. framed Norton road racer (89mm stroke) where one of the rear cross tubes (rear engine plate mounts) fractured once, maybe twice. I have my theories on it (yes, more than one). The owner had the same type of failure on his Featherbed road racer.
 
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I'm trying to get a real grasp of what is worthwhile in going around securely. The best modern frames are like 10 lb lighter than factory Norton frame and their extra mass tends to be centralized more rigid and moved forward for even more advantage handling wise. There is no comparison between a decent solid mount vs the un-tamed isolastic so of course Seeley should out do real Commandos even w/o weight advantage. But I've been lightening struck on the road by the power and road load handling of a tamed isolastic wonder, so personally think whole world is mislead corner cripples when push comes to shove. Only thing i've heard Seeleys compared or contested with is other vintage cycles, not recent issue sports or race bikes. Ya can look up track times for comparison. Ms Peel prey is the most elite cycles and riders out there and have tested this to be so obnoxious to keep repeating "ya don't yet know what ya missing out on" with ingenious isolastics once tamed right. But Peel is a one in a row so far so the rest of ya just make do as ya can, but Peel has left the limited counter steering arena of too floppy or too rigid compromised handling behind her. Where are all the public use Seeley's reporting their getting ahead games with moderns? Where are the reports of track day Seeley's pulling ahead of the more powerful advanced wonders when any leaning involved? The rates I'm taking about can be life ending if not really secure doing it. I think best tool of choice ain't in the direction everyone else is following.
 
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