Stealth FUTR owners builds and pics

Thanks Rick. 3.0" it is then.

I made a bit more progress over the weekend. Epoxied both upper neck area side panels in place and drilled/cutout all slots and holes for wires, and charge plugs.

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The charge plug is the standard 3 pin XLR, and the balance adaptor is a parallel port breakout connector like this:
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The battery will be 30AH 18S Lipo, so the plan is to hook up 3 x 6S auto balancers while bulk charging to 75V. That way it should keep the cells nicely balanced during charging without the need for a BMS.

Cheers
 
Build is looking great CD, and you are in for a real treat when you take your first bush ride with the SR241 18-3.00. You may never go back to a MTB on the rear.
 
Cowardlyduck said:
So the place I was hoping to get my Shinko 241 from doesn't have the 300-18 in stock only the 350-18.
http://www.motorcycletyresplus.com.au/motorcycle-tyres/shinko-sr-241-front-rear/

I just measured and my rim is actually 1.6" wide...what do you reckon the chances of the 350-18 fitting are with the 1.6" rim?
Or are there any other tyres on here that would work well?
http://www.motorcycletyresplus.com.au/off-road-rear-18-inch/?sort=priceasc
I have no idea when it comes to MC tyres.

Cheers
Click to expand...

You can probably get it to fit the rim, but fitting it in the swingarm is another story. It is a big tire, maybe plan on getting a knobby cutter and cutting the side knobs just in case it doesn't fit. https://www.knobbyknife.com/new-products/
 
Cowardlyduck said:
Thanks Rick.
I might chance it and if it comes to it cut the side nobs down a bit. I was always hoping to get a nice fat tyre on the rear of this Alpha anyway, so looks like I might get it. :)

Cheers
Click to expand...

This tire is big, if you go this route, you will want to run a 26MTB or a 27.5MTB up front with a big tire to keep it from looking funny. I would not suggest running a 24MTB as even if you found a fat tire option, the 24MTB overall diameter will be slightly smaller than the SR241 3.50-18 tire.
 
Rix said:
This tire is big, if you go this route, you will want to run a 26MTB or a 27.5MTB up front with a big tire to keep it from looking funny. I would not suggest running a 24MTB as even if you found a fat tire option, the 24MTB overall diameter will be slightly smaller than the SR241 3.50-18 tire.
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Just as well I've already got a 26" up front then, as I ordered the 3.50-18 yesterday. :)

I laced the rim and installed my hub-sinks over the last few days. :)

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Cheers
 
briangv99 said:
hey CD, are those 10g spokes?

Brian
Click to expand...
Nah, just 12g. Based on what I read up on about these rims, 12g was the only size that would fit without needing to drill out the rim.
I also discovered that the length was a bit too long....I've basically maxed out every spoke and will have to file off a few that are poking up through the nipple, but it's nice and tight now.
In hind sight I should have ordered them at 117mm instead of the 118mm I did and they would have been perfect.
Also in hind sight, I think 11g would probably fit without needing to drill the rim, or at the very least it would only require very minor filing.

Cheers
 
Cowardlyduck said:
Rix said:
This tire is big, if you go this route, you will want to run a 26MTB or a 27.5MTB up front with a big tire to keep it from looking funny. I would not suggest running a 24MTB as even if you found a fat tire option, the 24MTB overall diameter will be slightly smaller than the SR241 3.50-18 tire.
Click to expand...
Just as well I've already got a 26" up front then, as I ordered the 3.50-18 yesterday. :)

I laced the rim and installed my hub-sinks over the last few days. :)

[

Cheers
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Perfect! I know I don't have to say, but post some pics when things are mounted.
 
Rick you weren't kidding about the 3.5 being a big tyre!
With a lot of frustration and great difficulty, I managed to mount it to the rim using bicycle tyre levers. :roll: :lol:
DSC_4467.jpg


I did a quick check for swing-arm clearance and yeah it's gonna hit, but it's not too bad (only 3-5mm) and nothing I'm worried about shaving some off the side knobs to sort out.

Had I known I was going to use such a huge tyre I probably would have opted for a 17" rim, but oh well, too late now. :lol:

I also discovered a silly mistake on my part in that the 12T freewheel is not the right size for my chain and front chain rings. I did a bit of research before realising that the smallest freewheel you can get for a standard size 2/32" chain is 15 or 16T with 16T being a lot easier to source. So I've ordered a 16T freewheel to go with my 60T front chain ring which should be good for pedalling up to about 50kph still.

Cheers
 
Cowardlyduck said:
Rick you weren't kidding about the 3.5 being a big tyre!
With a lot of frustration and great difficulty, I managed to mount it to the rim using bicycle tyre levers. :roll: :lol:
DSC_4467.jpg


I did a quick check for swing-arm clearance and yeah it's gonna hit, but it's not too bad (only 3-5mm) and nothing I'm worried about shaving some off the side knobs to sort out.

Had I known I was going to use such a huge tyre I probably would have opted for a 17" rim, but oh well, too late now. :lol:

I also discovered a silly mistake on my part in that the 12T freewheel is not the right size for my chain and front chain rings. I did a bit of research before realising that the smallest freewheel you can get for a standard size 2/32" chain is 15 or 16T with 16T being a lot easier to source. So I've ordered a 16T freewheel to go with my 60T front chain ring which should be good for pedalling up to about 50kph still.

Cheers
Click to expand...

Even a 3.50-17 is only 25mm smaller in overall diameter, (12.5mm on the radius) you would have ran into the same issue. Get yourself a freewheel extender for your freewheel and plan on using some washers to push your front chain ring out from the BB a bit, you will need to do this for chain line clearance between the chain and tire.
 
That looks awesome duck! :D

My build is on hold with a part being stuck in customs since the 11:th of January, but I've been out A LOT with my AFT mid-drive converted mountainbike drifting in the snow. Here's a quick pick I snapped today

 
Thanks guy's. And thanks for the top tip on the chain line Rick. I will see how I go to start with as the rim is slightly dished over to the brake side.

I cut the nobs off one side last night:
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I used these huge titanium coated scissors which I use for everything. They worked great with a bit of force behind them.
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I'll do the other side to keep things even, even though I may not need to because of the dishing, and that might mean I don't need to worry about the chain line. :)

Cheers
 
Outstanding CD, looks like you will make everything work. Keep the pics coming as this is an interesting build with that wheel tire combo you got going on, I have yet to try this and look forward to your findings.
 
Yah, I bet you cut off at least 1/2 pound of rubber now! So, its probably down to about the same size of a 3.00-18 tire, except a taller profile.
 
Fits like a glove! A very snug glove!
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So snug in fact that it is actually touching, but only barely, so I'm just gonna let it wear itself down a bit then it will be fine.

It would not touch at all if I centred the wheel a bit more, but then I would probably have chain line issues with it hitting the other side of the tyre. As it is now, I don't think I will have any issues with the chain hitting the tyre.

Cheers
 
Hey CD, what you may want to do is snug up the spoke tension on free wheel side just a bit and pull your rim/tire away from the swingarm 1mm or so, should be safe to do and not affect your chain clearance by more than a mm.
 
Rix said:
Hey CD, what you may want to do is snug up the spoke tension on free wheel side just a bit and pull your rim/tire away from the swingarm 1mm or so, should be safe to do and not affect your chain clearance by more than a mm.
Click to expand...
Yes, already did that in order to achieve this result...destroyed a lot of the nipples in the process. There is not really any more thread left on the spokes at this point as I ordered them slightly too long, so I'm gonna have to make do unless I re-lace the whole wheel with correct length spokes.

The other thing I've been working on, but not shown yet is my battery. I'm using HK MultiStar packs, but I'm re-wrapping them into blocks using PVC heatshrink and permanently soldering in the parallel junctions where possible. All connection points are colour coded, and the JST balance leads are all securely taped down.
Once done I should be left with a single large 'block' of battery plus a small top mounted brick with only the balance, charge and discharge wires poking out. Combined with the parallel port and 3 battery medics used when bulk charging, it should be a 'safe' LiPo setup any noob can figure out if I still choose to sell this thing.

Cheers
 
My god CD you surely make it hard on yourself. for what its worth i run a 19" 2.75 shrinko SR241, it fits perfect with about 5mm spare on either side of the frame, which is good for wobbly rims down the track.

For me putting 7-8kw into it I never get wheelspin in the dry at least so everything is traction / acceleration basically.

Hopefully by trimming off the side knobs you still have traction while cornering.

I dont want to be a debbie downer but you may have been better running a 2.75 tyre and then running lower pressure to create a bigger footprint for more traction in the mud/sand etc? The best part there would be that the bigger footprint is at ground only and not at the frame...

Now for an admission - I have 2 new MXUS 3000w's getting true'd up right now at a bike shop! started doing it myself using an alpha frame, but could never be sure of a true starting point. Thought screw this, hand em off to an expert with a truing stand and get the job done properly! Pick em up next monday all being well hopefully nice and true n taught! (and my sanity in tact)....
 
Thanks for the feedback Lee.

Yeah, TBH I did not think about wobbly rims...hopefully I don't have that issue, but with maxxed out spoke nipples I don't like my chances.

In hind-sight yeah the 2.75 probably would have been the better choice, but that being said, the 3.5 also has some advantages. I don't think I will be worrying about traction as you say and I should be able to run pretty low pressures. I've pumped it to 15PSI to start with, but may drop that to 10PSI once it's worn in a bit.

Hey, at the very least now others can know what's possible and required to make a 3.5" MC tyre work on the Alpha. :)

Cheers
 
At true 3.5" wide tire would probably fit the alpha without much problems, but experience has showed me and as CD learned, the Skinko SR241s come in bigger than there advertised size every time.
 
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