Delta trike rebuild - starting with half a Kettwiesel

Bad Machine

In the garage .....
Location
East Anglia
I'm planning the winter project - I have half a Hase Kettwiesel (....yeah, it's a long story !), and need to find replacements for parts missing.

Hase remnants July 2019.jpg


Threadless, or threaded headset - any reason to go one-way or the other ?

I'm going to be working from front to the back, so first of all: Front headset and fork needed. The front boom has a head tube that's only 56mm tall, and the remnants of the previous owner's headset suggest a 1" threaded fork.

I'm thinking there's no need to insert a quill stem into the fork tube (the fork will be turned by either brazing a steerer arm to the left above the crown, as on older Hase trikes, or fabricating a lever arm to connect to the crown's brake/mudguard boss), so it really shouldn't matter what type of headset I use.

What makes it interesting is 1" forks for 20" wheels look to be threaded from 100-110mm above the crown, so I reckon I'll need to have additional thread cut into the chosen fork if I'm going to use a threaded headset.

Am I right to think choosing a 1" threadless headset would be simpler (I can just cut the fork at the required height) ?
 
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Any good cycle shop with a thread cutting tool can extend the thread on the fork tube , you won't find any forks threaded down that far as upwrongs don't have short head tubes.
Personally I don't like threadless forks but that is me.
A headtube size die and stock is about £70 from eBay or the like .
Good luck , an interesting winter project in the making .
With a change of thread name it would make an interesting rebuild story.
regards Emma
 
:rolleyes: Can't see much of a problem, we welded a bracket onto a pair of bmx forks when we built a delta.
seat , fabricate from ply and cover or there is an interesting thread out there in interweb land on bending up tube to make a mesh seat. USS mount isva relatively easy job to fabricate from a alloy bmx clamp on stem . Few days work but little money .
Handlebars are the worst to source , we end up making our own.
:becool::becool::becool:
 

404 Not Found Anywhere

Well-Known Member
That looks like one of the newer aluminium frames... in which case the OEM forks use a “hiddenset” type headset, and I think the steerer is considerably larger than 1”. That’s not to say that you can’t add reducers to use a smaller headset, threaded or threadless... you can get reducers to go from 1 1/4” to 1 1/8” to 1”. Personally although I’ve always preferred threaded headsets it’s getting harder to get quality ones in 1” and I think I’d stick with 1 1/8”. The front wheel of a Kettwiesel is lightly laden but I think the bearings probably experience some unusual loadings for a bicycle headset as the trike doesn’t lean in bends.
 
OP
Bad Machine

Bad Machine

In the garage .....
Location
East Anglia
The boom is indeed aluminium, but the rear (in red) is steel. I'll retrieve the headset remnants tomorrow, and re-measure, but according to my notes, the head tube currently has races fitted, with the upper race having a (central) internal diameter of 26.4mm, and the lower race diameter at 26.3mm.
 
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404 Not Found Anywhere

Well-Known Member
If it’s a steel frame, is that a titanium boom then? That was an option originally (along with an all Ti frame, but I think they were prone to breaking...). I can see now that it’s not alu - the arrangement of tubes around the rear axle is different, it was that boss in the top arch which threw me. The boom won’t be a retrofit from a later model as the newer machines use a much bigger tube (60mm diameter, I think)

Sound like a 1” headset is required from your account, Velo Orange make some threaded quality ones but Tange is just as serviceable. 1” threadless headsets are pretty rare but do exist (Mouton TSRs use them)
 
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OP
Bad Machine

Bad Machine

In the garage .....
Location
East Anglia
Any ideas on how would you tell the difference between a titanium boom and one made of aluminium ? Knowing that this Kett was originally configured as a handcycle maybe no help, unless Hase only used titanium on the handcycle variant.
 

404 Not Found Anywhere

Well-Known Member
From what I can see online the handcycle variant was a bolt on attachment and used the basic frame; someone might know the actual weights of the booms, the only thing a brief Google turned up was that Ti was 1lb lighter than Al. I suppose with scales and a bath you could work out the density and guess from there...
 
OP
Bad Machine

Bad Machine

In the garage .....
Location
East Anglia
Acutal weight of titanium boom - 780g (there's one on well known auction site at the moment: link

(Not that it'll be allowed anywhere near scales sensitive enough to weigh it accurately, for the moment.......)
 
OP
Bad Machine

Bad Machine

In the garage .....
Location
East Anglia
I've given them a quick clean up, and think I may well have a complete headset. All were together on a zip tie, but they were in the wrong order - so I've laid them out in the photo below, my best guess at what should work. I was pleasantly surprised to spot what I think is the crown race ? (top left)

Headset cleaned 5.jpg


Measurements - the ID of the crown race averaged at 26.4mm, and the ID of the notched spacer (last but one, bottom right) in the upper assembly averaged at 25.5.
 
OP
Bad Machine

Bad Machine

In the garage .....
Location
East Anglia
Shaun, our postman, delivered three parcels this week whilst I was working away from home. My daughter correctly guessed they
were all destined for the shed.

Parcels November.jpg


I can re-use the 1" headset components that came with the frame; I had contacted the seller of the new fork before ordering to ask about the length of thread on the steerer, and had made enquiries with my local bike shop about cutting additional thread to suit. Sadly, they no longer can. Rather than chase up some other LBS further away, I researched what I'd need to do it myself.


Parcels November Test fit.jpg

A quick check on what's going to be needed next - now I just need to wait until I've got some time at home.
 
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OP
Bad Machine

Bad Machine

In the garage .....
Location
East Anglia
That's not a bad idea. I'm having to cut new thread onto the steerer, and then cut it to required length, so I've also wondered whether a steerer arm could be clamped onto the threaded headset, above the normal locknut, but below an additional locknut ? The groove on the fork tube will need to be redone anyway (I've a rather nice notched light bracket waiting in the wings), so would cutting a bigger notch on the last few mm of the fork tube allow me to use a notched steerer arm, set at 90 degrees to the fork ?

Working away this week had me pondering how to do the USS set-up (enquiries to Oliver at London Recumbents drew a blank on Hase seat and steerer parts; I'd previously asked Kevin too, but he had warned me of the difficulty and likely costs involved, even if someone, somewhere had anything useful stashed away).

Latest revision uses two stauff-type clamps around the Kett boom, and a bespoke plate underneath to hold the USS axle (the top of the stauff clamps could be used as the forward mount for the seat)

Kett rebuild steerer axle.gif


Just two more weeks at work, then the fun can begin !
 
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This was the last one we made for a tadpole with offset steering link . Two stock size ballraces are clamped either side of an internal nylon bush locked in position with a grub screw , a 12mm ht bolt will attach it through the boom with anticrush spacer.
 
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