Hi Tim and Nigel D. I'll try to remember to attend to the silencer.
I can't bring myself to ride it when there are so many things that need attention. I didn't anticipate quite this level of renovation being needed. I'd hoped it would be a "new chains/sprockets/steering bearings/tires now let's go ride" kind of fix up.
I've cleared the frame fixture and so far I've determined that the swing arm is twisted. Looking from the back, over a distance of 6.7" the right side of the rear axle is .252" higher than the left. The swing arm doesn't seem to be bent sideways though, only twisted.
I don't know if I can securely clamp the swing arm to the base of the fixture so I can try and pry on it. I'll have to give it a try. I'm not going to be too surprised if it doesn't take a lot of effort to move the swing arm. There are a lot of vintage bikes where you can grab the top of the tire and pull and watch the swing arm flex.
The front axle doesn't seem to be in the same plane as the swing arm pivot when the two spindles are parallel (ie, the forks want to be turned a little to the side to get the axle to lay flat). I'll get the bare frame up on the frame fixture this afternoon and see if it is just the frame, the forks, or a combo of the two.
I'm really hoping this doesn't get to the point where it seems easier to build a new frame and/or swing arm.
Seems like they must have been using ones from the KXs that were current with the KT - 1975/76. I suppose you might be able to compare clutch cover gasket part numbers. I don't know if you'd have to change any additional relase mechanism parts inside the clutch or cover.
Can anyone comment on how well the front and rear rims should line up with each other and the center axis of the bike?
The front rim is centered in the forks.
I've set the rear axle so it is pretty well parallel to the swing arm pivot spindle, and that gives me good alignment on the front and rear
sprockets (with a long straight edge held across them).
But I've got the drum (left) side spokes on the rear wheel almost bottomed out, and the right side spokes without a lot of engagement in
the nipples, and it looks like I've still got to move the rim over another 6-8mm to the left, and that's just not going to happen with this spoke set. The left sides of the rims are pretty much in plane with each other. The rims are nominally 2.15 and 1.6" which means the front rim needs to go over a bit more than 1/4" inch.
Some bikes, like the early Z1 Kawasakis, came from the factory with the wheels offset. It probably isn't as critical on a trials bike as it would be for a roadracer but I'm not wild about that idea.
However, if that is the way the Sherpa T's normally run then I'll just pull the rim over as far as I can and try to not worry about them being out of alignment with each other.
FWIW, I'm not seeing any obvious signs of the frame being bent, but I haven't taken it back apart and put it on my frame fixture to check it. I've been hoping that I'd eventually get to the point where this thing would be going back together without finding another stumbling block in the process.
The muffler is a little lighter and allows you to repack it. The OEM pipe is not designed to be disassembled.
The clutch cover is, I think, mainly to look cool. My stock clutch setup has never given me any problems. Changing a cable on the KX cover would be faster to do.
13.2.1 TIRES AND WHEELS Any pre-1975 hubs and any type of rim from the proper era for that machine are acceptable. Only the Modern Classic class may use pre-1980 components.
<snip>
13.2.4 No major components may be later than 1974 (specifically, engine, frame, gearbox, forks and hubs). Only Modern Classic may use components later than 1974 (but limited to pre-1980). Hydraulically assisted brakes and clutches are prohibited.
13.2.6 ALL MODIFICATIONS MUST BE CONSISTENT WITH THE SPIRIT OF THE CLASS. Period modifications have been extensively documented and machines with obvious non-period or excessive modifications will be disqualified or required to compete in the next-higher-level class.
13.2.7 When entering a “special” constructed from various pre-1974 components of different classes and eras, the machine must be entered in the latest class that either the chassis or the engine dictates. Example: Triumph Cub engine in a Bultaco frame rides in the Modern Classic class. Otter type chassis are not allowed in Premier and must run in Classic or Modern Classic.
It doesn't seem like it would be a problem, unless of course you are winning all the events and someone decides to snivel.
The trials folk seem less inclined to snivel, but it is never a good idea to push the rules envelope too vigorously.
Morley's "classic british two-stroke trials bikes' book has a chapter on them. Here are a few photos from my website of a Triumph in a Sprite frame and the Sachs engined bikethe sold complete:
I'd think that any major vintage Bultaco shop probably offers a similar service. You could weld it all up and machine a new thread or maybe put in a big thread insert. Or consider converting to spring mounting with a slip fit exhaust.
I started a page for my Mo. 159 project and consolidated the various photo links there. I've got the new inner bushings made for the swing arm and I show photos of them and discuss how I made them.
Kim Nelson sent me a couple of photos he took at the Kansas City, MO national, probably about 1976. He says the KT250 shown was ridden by Steve Darrow, who I think is from the SF Bay Area though I didn't find him listed in the current PITS roster. The noticeable changes are no frame tubes under the engine, Miller muffler, and a KX250 clutch cover. The headpipe looks to be stock length, and not a long one like I built for my bike.
The photos were rather faded so I did what I could to enhance them, but I'm far from being a Photoshop expert.
No one can do much until the reasons for voting "nay" are given.
If they have a valid reason like Nationals being oversubscribed due to the twinshocks, that's one thing. "We decided "no" and we aren't giving details" is quite another.
My personal impression is that there are often some personal biases at play in AHRMA. In the past some of those have appeared to be "anti-Japanese bikes" and others have been "we just don't like that kind of technology, even if it was in the period, and so it is out."
Unless you have details given on why things are considered good/bad there can't be any meaningful discussion. Hopefully some details will be printed in VV so that people can write in to respond to it.
Otherwise, people will need to write in to point out that since AHRMA is a membership organization there needs to be more detail given so the members can give some informed comments.
If AHRMA was a private company owned by XXX, or a non-profit structured to not have members other than the Board of Directors (I've been on one of those) then a reason such as "XXX has decided s/he doesn't want to do things that way" is legitimate. But AHRMA is set up as a membership organization so "the members" do have some rights to know what their elected representatives are doing. Rules are not the same as confidential interactions with employees.
I laced up the new Excel rims and SS spokes from Buchanans last night. They do a better job of getting the spoke holes in the rim at the right angles than some that I've seen.
Truing will have to wait until I can get them into the forks/swingarm to ensure they are aligned with the steering axis.
Of course, the shiny new rims and spokes and cleaned up hubs make the frame paint look even uglier so I may have to do something about that after I finish all the welding.
The stock rear brake lever isn't going to work with the lowered foot peg/pivot location. The swing arm comes down on the top of the lever where the brake rod attaches. I haven't yet figured out how I'm going to address that.
A few days ago I sent an email in support of adding the later bikes to the Western representatives that had email addresses listed by AHRMA and copied that to Ed Peacock. The AHRMA website (www.ahrma.org) has contact information listed there.
A number of those later bikes don't look appreciably different from bikes within the Modern Classic cutoff (like a 79 vs 78 Sherpa T). Actually, as I pointed out to the AHRMA folks, there are Premier bikes being entered that look a LOT more modern than some of the "twinshock" bikes.
People on those excluded bikes aren't going to be taking trophies away from people in other classes. It is still going to be up to the rider to make a successful run through a section, and if the 1 lines are too easy for someone on a twinshock, they can always find a modern trials club to ride with.
" I would like to know why they are anti-twin shock."
That would be interesting to know, wouldn't it? I think that overall AHRMA does a pretty good job of things, but they do get the occasional rule or stance that leaves me sorely puzzled. Those items can be either hugely restrictive or hugely lenient.
For example in 250GP roadracing they say "Any of the following types of fully GP-kitted motorcycles built before December 31, 1968, and like design . . . . Benelli 250 four-cylinder, street-bike based replica".
Excuse me, but the 254 Benelli/Guzzi/Motobi (I've seen them badged all three ways) didn't show up until 1976, there is no prior production 250/4 in the Benelli line up, and it doesn't share much of anything with the "quattro" works GP bikes other than number of cylinders. It is a neat little bike but clearly not a bike of the mid to late 1960s or a derivative of one, yet it is allowed to run. The one (or maybe two) that have shown up haven't proven to be very competitive, but it is still a modern bike that pushes period bikes behind it down one place in the results. This is pretty curious because the RR crowd often seems a lot tighter about eligibility than the MX or Trials folks.
I've just finished lowering the footpegs on my KT250. Some text and photos are at the bottom of my KT250 page. The rear brake lever is going to need to be arched up as it now is prevented from being depressed by the bottom cross-frame tube.
Not yet, it only just came into my hands late Monday. I'll be taking it down into major bits for a general cleaning/lube/inspection and the brakes will be part of that. Cleaning out the forks and fresh fork oil is also in the plans.
I took the easy way out on the carb this morning and called Bob Ginder and ordered a 26mm Mikuni kit from him. I might have something suitable around, but I'd have to find it and then I'd have to figure out how to jet it. Buying something ready to bolt on from Bob will free up that time.
I just pulled the carb to see what size it was. This must have been a rare works SSDT bike meant to do well on timed road sections as the Mikuni is a 34mm.
There was rather more dirt in the carb bellmouth and carb->airbox boot than I care to see.
Your local Kawasaki dealer should be able to order the OEM silentbloc/metalastic bushings for you.
You may find them seized in the fork/to the spindle (very common on BSAs). I drilled out as much of the rubber as I could, then pushed out the inner bushing and used a grinding point in a die grinder to carefully cut through the outer bushing so I could collapse it with a punch and remove it.
Inspect the central frame tube for collapsing at the ends and the outer pivot support plates for signs of wear. If the central tube has shortened itself you may want to file it off square and then use some thin shim washers to keep the inner bushings located in their proper position.
There are some photos of the damaged parts from my KT on
Fixing scoring in the outer support plates is going to be a lot more bother. I suppose you could weld up the damage and grind/file it back down but making new plates and welding them on in place of the old ones may be simpler.
The cables at minimum need a better routing, and after doing that I'll see how the lengths look. The person I bought the bike from didn't seem to be a very technically/mechanically savvy person.
I just looked at the teeth on the countershaft sprocket. Ohh, the horror!
New sprockets, a flywheel puller, parts/workshop manuals and some tank sealer are now on order.
Sherpa T Model 159 Wheel Alignment
in Sherco
Posted