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240+tubeless


htrdoug
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Got a 305 rim laced to my 240 hub.gotta tension and true it up yet.

tubelessconversion.jpg

had to shift the long spokes over one hole in the hub due to the rim being drilled opposite as far as the valve stem hole position.

Same length spokes as stock rim.

Rim strip and valve stem from Mike.

Cracked the original rim due to jumping up on rocks and smacking it where it was already dented :)

ebay wheel was actually fairly straight :rotfl: good enough to be worth lacing up.

Will replace the front rim later as it's beat to hell too.

Unfortunately I'll miss the first trial of the season this coming weekend,gotta trail building session tomorrow night(I've got about eight sections built at a friends property,room to make probably 30 more!) and then a club meeting thursday where we redirect the club back into trial riding from putting on races(kind of a little coup)

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Hi Doug, thanks for that. I am in the process of doing the same. I thought the spokes would be shorter, but thats even nbetter.

I am not sure what you mean about "moving" the long spokes.

You said" had to shift the long spokes over one hole in the hub due to the rim being drilled opposite as far as the valve stem hole position."

Can you explain that a bit, maybe with a picture?

Thanks

lee

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If you want the valve stem to come out between two groups of four spokes you'll see that they need to be shifted over,lay a 305 rim on top of a 240 rim and line up the valve stem holes,on one rim the holes will be angled up and away from the valve stem hole left of the valve stem and the other rim will be angled down and away from the valve stem(kinda hard to describe,You'll see what I'm talking about if you stack the rims)

I didn't notice this until I had already ordered the spoke,It may turn out that I do need shorter ones for half of the long spokes,won't know until I center and tension the wheel.The rim looks to have a deeper center but on my rims it seems to be a optical illusion due to the different cross sections. If you're not in a hurry wait a few days until I can get back on this and make sure I haven't screwed this all up and have to reorder spokes,I've only really built bicycle wheels and there's online spoke length generators to get your spoke length correct for bikes,I told Buccannons what lengths I wanted and sent them samples,and screwed that up and only sent them 1 short side and 1 long side,the short side has different inner and outer spokes,duh,I just bent the outers a bit more myself and the length was ok.

I'll take a picture with a camera instead of a phone for ya when I get back into the garage.

BTW,found a cracked sprocket mount ear on my 309 rear hub after I had dissassembled the good 305 wheel I had for it's rim,now I'll have to build a new wheel around the good 305 hub,I'll have to find another good 36 hole tubeless rim(or find a later model wheel that can be adapted to fit)

Edited by htrdoug
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:rotfl: You've confused me ... Are'nt the spoke holes in the rim punched to have a spoke nipple exiting them at a predetermined angle so the nipple seats correctly ?

Yep,that's why I moved the spokes over over 1 hole. The 305 hub has a shallower spoke angle but it's slight,I just reamed the holes a little bit and deburred plus used plenty of spoke prep,I'll tension,then prestress then retension and true,she'll be fine. If it fails I won't sweat it,there's plenty of used stuff out there to build another.

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Got the wheel tensioned and centered in the swingarm tonight,1/2 of the spokes on the left(long spoke) side protruded through the nipples by about 3mm,this was likely due to either me making the false assumption that all the long spokes were the same length(I only sent 1 long and 1 short out to Buccannon's for examples) or by the way the hub is drilled,doesn't cause any issue other than having to carefully grind off the excess. Saturday morning I'll fit the rim strip and valve and mount the tire.

Can't be worse than my old rim, It was bent every direction possible,only thing that could be said about it was the tubeless Dunlop never lost the bead on the tube type rim regardless of pressure.

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As soon as possable I want a set of these http://www.nuetech.com/index.shtml Wish I had known about them before I mounted up the michelins on the excel rims last spring ... Anything to shed a few pounds !

Glenn

I need to get a set of those for my KTM,it already has tubeless shinko tires(don't laugh,they are made from the old Yokohama molds with modern compounds,really good tires)

Years ago before Stans tubeless kits existed I converted my mountain bike to a barnyard tubeless with a tube for smaller rims by inflating the tube,slipping it over the rim,deflating it,cutting it around the outside edge,butterflying the cut tube out over the edge of the rim,slipping the tire over it,squirting a bunch of tire slime in,inflating with compressor then trimming off the excess tube laying outside of the tire.They've held air for years,and I haven't even rode it for two years.

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All done, Rim strip was kinda tough(my first tubeless experience) but I managed to get it in place.Tire mounted and inflated easily,took more than 50 psi to pop the bead(didn't feel like looking for my truck tire pressure gauge) No bubbles when sprayed with soapy water.

240tubeless.jpg

Also got my 1984 Beta forks on her.Had to drill out the sleeve in the left leg for the axle to slide through. Had to make a cable stop and mount it to the brace bolts as the Beta forks are disc brake.Made a new shorter brake stay.Had to clearance the backside of the upper caliper mount a bit to clear the brake cam as I didn't want to completely cut it off just in case I want to use the fork on my 309 later.

Betafork.jpg

Here's the big news,the Beta upper clamp slid right onto the Fantic lower clamp,same offset and spacing,and the bar mounts are way forward compared to the 240.I have never seen 200 Fantic clamps but I don't see how they could move the bars any more forward without interfering with lowering the fork tube through the upper clamp. Note in the pic that I'm using the Fantic lower which is red and the Beta Upper which is black. So if'n yee cain't find a 200 clamp jus' rob some ol'junk Beta!

Betaclamp2.jpgBetaclamp.jpg

Got to put fork seals in The Beta fork,But just riding around the back yard they have a plush,well controlled feel.Managed to get good front brake action without much fuss,just holding the brake on while tightening the axle was good enough to duplicate all the braking action I had with the fantic forks.(fantic forks were cracked and the tubes were damaged to bad to hold a seal)

:wall:

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  • 1 month later...
 
What was the final length of the spokes? I have a pair of akront tubeless rims from a 243 and I want to buy spokes for a rebuild using 240 type hubs.

I don't know the measured length of the spokes, I sent one short side and one long side samples to Buchanans and asked for the same length as stock,In retrospect I should have sent two short and two long samples,one from each direction just to make sure. I had chopped all the rest of the spokes so I couldn't measure once I started.It caused no trouble as I just ground off the protruding spoke ends.

Seems to be working,still holding air perfectly and I've abused it in rocks and it hasn't loosened any spokes up at all.

I'm gonna stick with a tube type front rim when I rebuild the front wheel.

Edited by htrdoug
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Thanks for that. I am giong to use the tubeless front because it matches the rear anodised gold rim but I will put a tube in it, I dont think that the tubeless tyres are still available and they wont be as stickey as a modern Michelin.

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