Is it possble to covert 26x4 to 3 onch tire and rim combo

[PCeBiker]

I just sent them another asking about a 29 as I don't see anything wider than 24mm width id on their website.

What about asking them about a 27.5" rim?

Maybe they know of a better option than what's on my ebike?

That's the rabbit I jumped in to and didn't find anything.

 

[Marcela]

Comparing the 27.5 x 2.3 to the 29 x 4, the height difference didn't look to be more than a little over an inch, and figure to lose 3/4" height on the bike. Interestingly, the pedal height was 1" higher on the 26x4 tired bike, so dropping to the 27.5 is going to put the pedal height in the range of the other bikes and make the ground reach easier. The way it is now the seat has to be way too high to make pedaling normal and touching the ground is tip toe. Dropping it down an inch isn't going to hurt anything.

This pic makes the closer tire appear larger.

 

[Marcela]

Velocity dually 650B with the 39mm id rim $170
Schwalbe pick up 27.5 x 2.6 $60

The dually also comes in the 26 and 29 same 39mm id rim if a suitable tire could be found but the 27.5 2.6 is real close to the 26 x 4. The 2.6 tire is available now and the 2.35 is not. Wonder what the weight rating difference is between the 2.35 and 2.6 if any. I figure to need 300 lbs carry capacity for the rear.

 

[PCeBiker]

Velocity dually 650B with the 39mm id rim $170
Schwalbe pick up 27.5 x 2.6 $60

That's It !!
That's Exactly what I was looking for !!

It's got a wide rim, with a low profile (longer spokes).
The spoke holes are staggered around the convex rim, so the spokes are slightly angled towards the motor and "closer" to the motor (less reach, and angle) because the holes are towards the sides of the rim.

Both of those things should really help with the Shitty angle of the spoke heads at the motor as well.

That rim was built to do exactly what we want for our fat motors.

The rims are all custom built with just a few in stock, but that means that you choose the spoke hole count, but I didn't notice a choice of spoke hole gauge, or whether the valve hole is drilled for presta or Schrader?
I would assume it's drilled for Schrader because that's kinda the standard for the fat and semi-fat North American market.

If you go tubeless, flats are Easy to fix, just plug the hole (just like a car tire) pump it back up and be on your way.

That saves weight on the wheel as well.

If you go tubeless the valve choice doesn't matter much, because it's not attached to a tube that has to be properly sized.
Fat bike stuff is normally Schrader though, and I kinda like the larger valve.
(Presta works but it harder to get tube sealant through the valve)


I'm guessing that the spoke and nipple choice isn't all that critical with the Dually rim, because the spoke angles should be Way Better?

Maybe not "standard generic" but I don't think we'd need top of the line (my 12 gauge spokes are just standard spokes)


My Voltbike used the wrong rim. (I should file a grievance. )

It's quite expensive though, so I'm gunna wait for the rest of your parts list, and your opinion about the finished product before I start buying stuff.

I also have to try and take some accurate measurements of my unlabeled proprietary "Das-Kit" motor to make sure that it has the same specs as my Bafang motor.
I would think that fat motor measurement specs are standardized.
(They all lie about what’s inside the motor casing, but that's a separate issue. )

 

[RunForTheHills]

On the Endless Sphere forum, it is has been discussed that it is almost impossible to get sufficient tension on a 12 gauge spoke on a bicycle rim without risking cracking the rim. If you search for "bicycle rim 12 gauge tension" you will find the discussion.

For this rim in particular, the maximum tension they recommend is 130kgf:

https://velocityusa.com/products/dually-rim-27-5?variant=40783711207503

"We recommend building to spoke tension between 110kgf and 130kgf."

 

[Marcela]

On the Endless Sphere forum, it is has been discussed that it is almost impossible to get sufficient tension on a 12 gauge spoke on a bicycle rim without risking cracking the rim. If you search for "bicycle rim 12 gauge tension" you will find the discussion.

For this rim in particular, the maximum tension they recommend is 130kgf:

https://velocityusa.com/products/dually-rim-27-5?variant=40783711207503

"We recommend building to spoke tension between 110kgf and 130kgf."

Interesting, I missed that. Good point to know. How does that convert to in lbs. I tried a convertor and 110 kgf converts to something like 240 lbf but that doesn't tell me anything. I perused the endless forum torque topic. Lot of things a guy can do, few are going to get the best results.

 

[Marcela]

That's It !!
That's Exactly what I was looking for !!

It's got a wide rim, with a low profile (longer spokes).
The spoke holes are staggered around the convex rim, so the spokes are slightly angled towards the motor and "closer" to the motor (less reach, and angle) because the holes are towards the sides of the rim.

Both of those things should really help with the Shitty angle of the spoke heads at the motor as well.

That rim was built to do exactly what we want for our fat motors.

The rims are all custom built with just a few in stock, but that means that you choose the spoke hole count, but I didn't notice a choice of spoke hole gauge, or whether the valve hole is drilled for presta or Schrader?
I would assume it's drilled for Schrader because that's kinda the standard for the fat and semi-fat North American market.

If you go tubeless, flats are Easy to fix, just plug the hole (just like a car tire) pump it back up and be on your way.

That saves weight on the wheel as well.

If you go tubeless the valve choice doesn't matter much, because it's not attached to a tube that has to be properly sized.
Fat bike stuff is normally Schrader though, and I kinda like the larger valve.
(Presta works but it harder to get tube sealant through the valve)


I'm guessing that the spoke and nipple choice isn't all that critical with the Dually rim, because the spoke angles should be Way Better?

Maybe not "standard generic" but I don't think we'd need top of the line (my 12 gauge spokes are just standard spokes)


My Voltbike used the wrong rim. (I should file a grievance. )

It's quite expensive though, so I'm gunna wait for the rest of your parts list, and your opinion about the finished product before I start buying stuff.

I also have to try and take some accurate measurements of my unlabeled proprietary "Das-Kit" motor to make sure that it has the same specs as my Bafang motor.
I would think that fat motor measurement specs are standardized.
(They all lie about what’s inside the motor casing, but that's a separate issue. )

It's either that or the DT Swiss U663 with the 30 mm rim width and the Schwalbe Pick Up in 2.3 which is shows out of stock at the moment on their web site. Haven't made any decisions yet. Both the 30mm and 39mm rim overlap in tire useage. $500 for a wheel change is kinda expensive dive to take. I was hoping you would be the first. I missed that Velocity rim was asymmetric, was hoping to stay symmetric.

 

[PCeBiker]

All that I know for sure, is that if I build a wheel, I'm going to use the rim that you found.
I don't care what you use.

But thanks for pulling that jewel out of the 🕳 for me ️

On the Endless Sphere forum, it is has been discussed that it is almost impossible to get sufficient tension on a 12 gauge spoke on a bicycle rim without risking cracking the rim.

All I know is that my rim ain't cracked, and I've torqued and retorqued my rims Many Dozens of times.

I'm not a downhill racer, and the only thing close to thd abuse of a downhill race for me is plowing through a pothole no-hands.

For this rim in particular, the maximum tension they recommend is

"We recommend building to spoke tension between 110kgf and 130kgf."

Can you please convert that a 0-45 scale for me?

Or maybe the musical note corresponding to the proper tension.
Keeping in mind that different metals have a different pitch, so the timber will be spoke specific. Lol

I just used the graph in the instructions for a 12 gauge spoke

Spoke Tension

I have just over 1,000 miles on my Aventon Level. Last week a spoke next to the valve stem broke off at the rear hub while I was checking tire pressure. So I ordered replacement spokes and a spoke tension gage. I discovered that the outside spokes were very tight. The gage goes from 0 to 50...

forums.electricbikereview.com

 

[RunForTheHills]

Well, I have built a few wheels, but not with 12g spokes. So I am not an expert. I haven't lost a spoke on the ones I built (knock on wood). I don't know if it is cool to post a link to another ebike forum here, so look it up if you are interested. It was mostly Chalo pushing the idea, so there is lots of hyperbole in the thread, but he is a good/professional bike mechanic and gives good advice on mechanical issues. I am 99.9% sure Apartunis is his new moniker after he got booted from the forum for offending everyone he disagrees with.

 

[PCeBiker]

Well, I have built a few wheels, but not with 12g spokes.

Apparently there's a big difference.?
Regular spokes are kinda like pre-tensioned torsion rods.
12gauge is more like rebar.

So I am not an expert.

I have no credentials or credibility.
But I can fly an ebike with no-hands.

I haven't lost a spoke on the ones I built (knock on wood).

I never lost a spoke.
They stay connected when they break,.. lol

I don't know if it is cool to post a link to another ebike forum here, so look it up if you are interested.

I'll let @Marcela search through the 🕳 for me. Lol

It was mostly Chalo pushing the idea, so there is lots of hyperbole in the thread, but he is a

Is Chalo a mathematician?

I wanna be right here at the Cracking point between two opposing viewpoints,..

I really don't know what the Hell you guys be takin bout?

I like pictures graphs and mathematics

 

[Marcela]

I have the park tool tension gauge similar to above, didn't have any luck with it. I have found truing motorcycle rims, remove the spokes one at a time and lube threads and nipple with anti seize, it will keep the threads from slipping and much easier to feel the amount of torque used. If a torque wrench is used with thread lube the torque has to be reduced and use 75% of a value. I do it by feel, toward the end only turning the nipple 1/8 or less, you can actually feel them pull tight, that is when to stop, going all the way around the rim and watching the dial indicators. Spec is within .020 lateral and axial for the motorcycle, I can easily get .010 and sometimes .005, depends on the rim. This is using two dial indicators, lateral and axial. Dial indicators are a must. Getting the spokes close to same tension won't be a problem using this method. Have to start with the same amount of turns on the nipples, then go from there. Finding center laterally/axially 180 degrees apart on the rim and using that as the benchmark and go from there. The rim will continually try to taco that is why have to take it slow when things starting getting tight, otherwise it will do all kinds of weird things.

 

[RunForTheHills]

Is Chalo a mathematician?

I thought I mentioned it, but Chalo is a professional bike mechanic. He is intelligent, but I have no idea what his mathematical background is. The idea is that if the tension is too low, the spokes will work loose. If the tension is too high, the rim may crack. The balance is hard to achieve with a 12g spoke and a bicycle rim. Obviously, some people have reported success.

Funny story from my high school years in pre-Calculus:

Me (in front of the whole class): I checked this problem with my Dad and he thinks I got this problem right.
Teacher: It's not. Is your Dad a mathematician?
Me: Yes. He has a PhD in mathematics.

It turns out my Dad was wrong, despite the teacher being a (female dog in heat).

 

[PCeBiker]

I have the park tool tension gauge similar to above, didn't have any luck with it.

I didn't have much luck with it either, especially on the hub motor.
The spokes are too short and I could barely get the tool in there to get it on a spoke, especially on the brake rotor side of the wheel.

I ended up going mostly by feel.

,..The idea is that if the tension is too low, the spokes will work loose. If the tension is too high, the rim may crack.
,..Obviously, some people have reported success.

All I know is that my wheel is "working", and I did manage to eventually get it straightened out.
(It turned out that my rim was straight all along, and it was my tire that wasn't seated properly. )


I just always thought that the rear wheel looked wrong based only on my own observations.

That Dually rim was what I thought would be a better option, simply based on what I think is a better design.

I just checked my original wheels and both the front and rear rims appear to be the same (they aren't labeled) but the front wheel has 13 gauge spokes, and the rear has 12 gauge.

Both the rims and spokes appear to be "generic" standard, but they are working for me, and unless the Dually rim is not as strong as what I have, (which I really doubt?) then it should be an improvement over my rim.


The only thing that I can think of that might make my rim work better, is that the bending spokes put pressure on the nipples so the threads are binding and less inclined to loosen up if they are undertorqued.
(I just made that up. I have no idea if that makes any real sense.)

 

[Marcela]

Went down to wally world and looked at their bikes. They had a mtb with 29 rims with the 2.6 wheel that looked real good. There were also the 27.5 with the 2.3 tires. Think cause the weight of my bikes the 2.6 tire would be preferred and not go any thinner than the 2.3 range. The tires were suggested 35 psi so they prob aren't designed for much weight, otherwise a guy could spend $3-400 and get a tire and rim set and parts bike thrown in.

 

[PCeBiker]

The tires were suggested 35 psi so they prob aren't designed for much weight,

It depends on the tire size and volume.

My 27.5 x 2.8 has a suggested pressure range 20-45 psi with a maximum load capacity of 155 Kg. (each tire)

The 27.5 x 2.4 version has a suggested pressure range 30-55 psi with a maximum load capacity of 145 Kg.


The Schwalbe Pickup 27.5 x 2.3 has a suggested pressure range 30-65 psi with a maximum load capacity of 165 kg.

The Schwalbe Pickup 27.5 x 2.6 has a suggested pressure range 30-55 psi with the same maximum load capacity of 165 kg.

(I'm pretty sure that the Heavy Duty Pickup is designed for maximum load, so the difference isn't as much as with my Super Moto-X tires?)

Went down to wally world and looked at their bikes. They had a mtb with 29 rims with the 2.6 wheel that looked real good. There were also the 27.5 with the 2.3 tires.

I'll bet that all those rims had 32 spoke holes?

I'm thinking that generally, bicycle wheels are "normal duty" and have 32 spoke holes.
(I found All Kinds of 27.5" rims but almost nothing with 36 spoke holes.)

I'm thinking that when a wheel steps up to 36 spoke holes, it's a "heavier duty" rim with heavier guage metal?

Bicycle riders HATE heavy duty because they are heavier and the purists go to EXTREME Measures to shave off every gram of weight possible.

So I'm thinking that there isn't much of a market for the rims we need, and perhaps the biggest advantage of the DT Swiss U663 is the high strength without being as heavy?

,.. Both the 30mm and 39mm rim overlap in tire useage.

With a narrower rim, a large tire starts to get donut shaped and the tire is wider than the rim.

Then the tire can "roll" on the rim, and tires can break their bead and pop right off the rim.

The tire is more bouncy too because of the rounded sidewalls.

A bouncy tire can act like suspension and make the ride smoother, but if you're ebike is full suspension, you don't need that, and a bouncy, squishy tire affects control and stability.

 

[PCeBiker]

Both the 30mm and 39mm rim overlap in tire useage.

I didn't measure the internal rim width of my original rim because I didn't want to bother taking the tire off.


I just realized that my ~40 mm rim may have a 30 mm inner diameter?

I did find a couple rims that may be what I've got,..

I just found this on AliExpress:
Sunringle sun MTX39 27.5/26Inch 650B Mountain Welding Am/Fr/Dh 32H 36Holes Hoops E-bike MTB Bicycle Rims

https://a.aliexpress.com/_mMfIMu3

I just found this on AliExpress:
26/27.5/29inch MTX MTB Double Aluminium Alloy High Strength 36H Rims for Electric Bike

https://a.aliexpress.com/_mMBfVEF

The J-hooks are 5mm thick.


This 28 spoke MTB rim has a larger inner diameter, but a smaller outer diameter.

Perfect for making Tacos !!

Just fill your innertube (or tubeless tire) with your favorite ingredients.

 

[PCeBiker]

This pic makes the closer tire appear larger.
View attachment 211349

I noticed in your picture that your 26 x4 tire has more of a street tread than I was figuring.

This is the CST Big Boat tire that came with my first ebike.
I specifically bought the ebike because of the street tread.

These are my Super Moto-X tire, my (unmounted) Kenda Havok tire that came with my second ebike, and my Schwalbe 29" x 2" Hurricane.

I only took the Havok tires for a 20 minute test ride when I got the ebike, then swapped the tires, and I haven't even tried the Hurricane yet.

So I don't really know how the different tires feel and behave, and my only goal is to have the fastest rolling tires I could get to increase my range.

I thought it would be smart to inflate my first Super Moto-X tires to the maximum (42 psi) thinking it would have less rolling resistance, but I ended up swelling the tire, and the rubber delaminated.

I did get 7,000 km on the tire and the tread looked almost new, but it was no longer connected to the tire.

 

[Marcela]

Information about the Velocity Dually:

The ERD on a 27.5 Dually is 566.

We do not consider the Dually to have asymmetric or offset spoke holes; only the A23 OC in our line up does.

Also, keep in mind all our rims are drilled for a 14g nipple. We tend to use Sapim E-Strong spokes with the reduction nipples. 12g at the elbow bend and 13g at the nipple end. The reduction nipples have a 13g thread but the OD is the same as a 12g nipple. Also, we recommend getting tension close to 120kgf.

This all make sense? And what is 120 kgf converted to in lbs?

 

[PCeBiker]

This all make sense?

Yeah, that all makes sense to me.
They seem to know all about connecting a fat motor to a semi-fat rim.

And what is 120 kgf converted to in lbs?

That doesn't make sense to me? That's not a torque spec.

120 kgf is 264 pounds.
264 foot pounds doesn't make any sense to me?

EDIT: They probably mean pulling force?
How the hell are are you supposed to measure that??

I'd just wing and go by feel and sound.
Like you said, it's not brain science or rocket surgery.
I just gotta get the right parts.

Well,.. The Dually rim is what I want.

I didn't want to spend $268 for it though.
And that doesn't include the spokes, and I think that's USD as well?

I'm still considering it.
I did spend $290 on inverted air forks that didn't fit.

 

[Marcela]

I think the 120 kgf converts to 104 in lbs. I asked them how they do that. My 600 lb motorcycle I laced specs 52 in lbs with bigger spokes and stronger rim. He came back and explained how they lace their wheels, on the table then in a truing stand, never referenced the tq figure, said they check with a tension gauge which I am guessing the really good stringers just ping the spokes. Again, I would say consistent tension would be important. If you are lacing by feel and everything is lubed pretty good, after a while they just won't turn any more. Get your torque wrench out and find out what 36 or 48 or whatever inch pounds feels like, then the difference between that and a higher number. The nipple doesn't turn very much if at all, there is not much difference, leastways there wasn't on the motorcycle. Just get an idea of what your goal feels like.

I saw that above. Some of those websites looked really fishy with really good deals. I ordered a couple rims from pro wheel builder dot com. $170 a wack but looked all over, the cheaper ones are 32h and everybody has them. Another place had them with free shipping but they cost more so it was same amount. $35 to ship mine. If you are in GA you could pick them up.

I was real close to ordering a couple weinnman rims on the cheap at $40, think that is what grin carries. The thought of a rim failure on a downhill concrete 8 ft. wide path may be the true cost.