19" Motorcycle Wheels vs 26" Bicycle Wheels (rim and tires)

[Jamil.Siddiqi]

I am in the middle of a 26" --> 19" conversion and wanted to share some interesting findings:

- started with 26" stock MTB wheels, with 28mm Continental street tires. Max speed at 70kmh (maxed out RPM of motor). Cruising speed around 60-65km/h. Continuous pedaling is tough because of pedal RPM beyond around 45km/h (with 50T chainring)
- changed to 2.75x21" knobby tires (Shinko). Max speed at 65kmh (maxed out power of motor). Cruising speed around 55-60km/h. Battery range reduced by around 10%. Pedalling at 50kmh is still comfortable (now with 52T)
- since I get a lot of flat tires, added a Mousse tube in the rear. A bit too soft for my liking, but very comfortable. No more flats! Max sped reduced to 60km/h, cruising speed 50-55km/h. Battery range reduced by another 10% to about 33km --> now I run out of battery regularly.
- acceleration has been greatly reduced as well. I am very surprised that the softness and added weight have such an impact on acceleration.
- given the stability I will not go back to bicycle wheels anymore. I have a much better sense of safety with the MC wheels. 65kmh seemed quite fast and instable with bicycle wheels (specially with potholes, manhole covers etc), while the same speed is really comfortable with the MC wheels.

Now I have ordered an 19" wheel and tire to check impact on weight, speed and range. I will be trying out the Tubliss system instead of Mousse. I will be adding some fairings as well, to check the impact. I have also ordered a 85T (monster) chainring, so that I can pedal as much as I like.

Facts about the bike:
52V, 28AH, 1500W hubmotor, weight around 24kg with 26", close to 40kg right now. I am at 90kg including backpack.

 

[Chalo]

I have also ordered a 85T (monster) chainring, so that I can pedal as much as I like.

Pedaling at speeds over about 35mph can easily cost more energy as drag than you're contributing at the pedals. Do it if it pleases you, but you're on an improvised motorcycle now. Pedaling doesn't help.

Of course a foam tube costs speed. Everything that isn't pretty normal for a bicycle is wrong in some significant way. We've had smart people thinking about it and trying different things for over 150 years. Everything has been tried many times, and if it isn't already normal, that's probably because it sucks. (Rule 1 regarding your [anybody's] great new idea for bicycles.)

Hub motor wheels are weak and awful not because they have bicycle rims, but more because they have spoke flanges that are usually less than 40mm apart, and often asymmetrical over the axle. Fitting them with pig-heavy rims and tires doesn't fix that basic problem. I'd be willing to bet that a hub motor laced with spokes all outside the flange and crossing over to the opposite side of a highly staggered bicycle rim like a Weinmann DHL42 would have better lateral stiffness and stability than one built the usual way on a porky motorcycle rim.

If you want to go slower than necessary, for a shorter distance than you could be getting, on a bike that's bothersomely heavy, then you're doing fine.

 

[Jamil.Siddiqi]

Pedaling at speeds over about 35mph can easily cost more energy as drag than you're contributing at the pedals. Do it if it pleases you, but you're on an improvised motorcycle now. Pedaling doesn't help.

Of course a foam tube costs speed. Everything that isn't pretty normal for a bicycle is wrong in some significant way. We've had smart people thinking about it and trying different things for over 150 years. Everything has been tried many times, and if it isn't already normal, that's probably because it sucks. (Rule 1 regarding your [anybody's] great new idea for bicycles.)

Hub motor wheels are weak and awful not because they have bicycle rims, but more because they have spoke flanges that are usually less than 40mm apart, and often asymmetrical over the axle. Fitting them with pig-heavy rims and tires doesn't fix that basic problem. I'd be willing to bet that a hub motor laced with spokes all outside the flange and crossing over to the opposite side of a highly staggered bicycle rim like a Weinmann DHL42 would have better lateral stiffness and stability than one built the usual way on a porky motorcycle rim.

If you want to go slower than necessary, for a shorter distance than you could be getting, on a bike that's bothersomely heavy, then you're doing fine.

You make some very interesting points. Lateral stiffness is not really an issue (truing the wheels and keeping them true is more of an issue), but I agree with the 40mm spoke flanges being awful. Dishing them to a side becomes difficult as well. I have a 150mmx15 front hub - what a difference. My issue with the bicycle tires is the flimsiness. I ride on the shoulder of a highway, which is full of debris, potholes and other stuff. Around 70km every day (34km each way). I have tried all kinds of bicycle tires but feel more secure with the heavier MC tires. I have ordered a Japanese 19" rim, made out of 7075 (aircraft) grade aluminum. Curious if the premium for that pays off. The current Chinese 21" rims are to your point - porky.

Fairings are forbidden in all cycle & triathlon races, hence this in my opinion might have stiffled innovation in that area and might be worth a try. Just like disk brakes were forbidden for a long time. Now all of a sudden they are becoming standard.

 

[Chalo]

Please report back about that 7075 aluminum rim. I'm curious whether it's lighter than the usual stuff, or only stronger.

 

[Jamil.Siddiqi]

I did some weight analysis on some of the tires which I have at home:

1) 3 x 21" Shinko 241 and also 80/90 x 21" M/Xridgestone Exera Max are at 3670 grams
2) 2.5 x 19" Continental KKS10 is at 1650 grams (the tire has arrived, the rim not yet)

as a comparison:

3) 28mm x 26" Continental GatorSkin is at 300grams

If you hold them one after another the bicycle tire feels really flimsy. Even if there are many discussions and controversy around speed ratings, I personally would not use the bicycle tire for longer high speed (>40-50kmh) rides anymore.

 

[minde28383]

Regarding tire on front wheel.
It also depends on wheel diameter. Smaller bicycle tires (24'' - 20'' wheels) can be run up to 60km/h no problem what so ever. Some bicycle tires weighs ~1kg. I think Kenda flame bicycle balloon tire is heavy tire. It is flimsy tire but on 24'' rim and 20'' is good, actually I tried it on 26' and like it except you will need 40mm rim or slightly wider. At 80km/h I felt little bit wobbling due to unbalanced tire which is another concern. There are even stronger bicycle tires than it. It all depends on what speeds you plan to reach. You mentioned 50km/g is good for any tire be it moped or bicycle tire.
Maybe you just like more stable front which is accomplished by heavier and wider tire but if you don't reach more than 60km/h there is no necessity for moped tire.

 

[Jamil.Siddiqi]

Regarding tire on front wheel.
It also depends on wheel diameter. Smaller bicycle tires (24'' - 20'' wheels) can be run up to 60km/h no problem what so ever. Some bicycle tires weighs ~1kg. I think Kenda flame bicycle balloon tire is heavy tire. It is flimsy tire but on 24'' rim and 20'' is good, actually I tried it on 26' and like it except you will need 40mm rim or slightly wider. At 80km/h I felt little bit wobbling due to unbalanced tire which is another concern. There are even stronger bicycle tires than it. It all depends on what speeds you plan to reach. You mentioned 50km/g is good for any tire be it moped or bicycle tire.
Maybe you just like more stable front which is accomplished by heavier and wider tire but if you don't reach more than 60km/h there is no necessity for moped tire.

I do not disagree. I have ridden bicycle tires for around 30 years now (also competitively) - with the occasional puncture/burst and consequent fall & broken bone. Now that I am older and riding around 250-300 km every week in heavy traffic, I avoid the risk. I think bicycle wheels are fine, but MC wheels add some more safety.

 

[DasDouble]

Spoted the cheapest 1.85" x 19" 32H rims here:

https://www.ebay.com/itm/Moose-Racing-Rear-Aluminum-Rim-Black-1-85-x-19-32H-0210-0197/292506453200?epid=171124011&hash=item441abe44d0:g:2MMAAOSwBnZawDhx

https://www.motocross-shop.de/motocross-shop/product_info.php?products_id=19595

watch out for shipping price.

 

[Merlin]

cheap?
sm pro any wheel 100€

 

[efMX Trials Electric Freeride]

Spoted the cheapest 1.85" x 19" 32H rims here:

https://www.ebay.com/itm/Moose-Racing-Rear-Aluminum-Rim-Black-1-85-x-19-32H-0210-0197/292506453200?epid=171124011&hash=item441abe44d0:g:2MMAAOSwBnZawDhx

https://www.motocross-shop.de/motocross-shop/product_info.php?products_id=19595

watch out for shipping price.

for the rear rim you would probably want / need 36 hole to match the hub.. and 1.85 is a bit wide and heavy to use as a front rim ..

 

[Jamil.Siddiqi]

Spoted the cheapest 1.85" x 19" 32H rims here:

https://www.ebay.com/itm/Moose-Racing-Rear-Aluminum-Rim-Black-1-85-x-19-32H-0210-0197/292506453200?epid=171124011&hash=item441abe44d0:g:2MMAAOSwBnZawDhx

https://www.motocross-shop.de/motocross-shop/product_info.php?products_id=19595

watch out for shipping price.

for the rear rim you would probably want / need 36 hole to match the hub.. and 1.85 is a bit wide and heavy to use as a front rim ..

I agree with the 36 hole rear - easier to get anyway. Tubliss inserts are not available in less than 1 85, hence I went for 1.85 as well.

 

[efMX Trials Electric Freeride]

Spoted the cheapest 1.85" x 19" 32H rims here:

https://www.ebay.com/itm/Moose-Racing-Rear-Aluminum-Rim-Black-1-85-x-19-32H-0210-0197/292506453200?epid=171124011&hash=item441abe44d0:g:2MMAAOSwBnZawDhx

https://www.motocross-shop.de/motocross-shop/product_info.php?products_id=19595

watch out for shipping price.

for the rear rim you would probably want / need 36 hole to match the hub.. and 1.85 is a bit wide and heavy to use as a front rim ..

I agree with the 36 hole rear - easier to get anyway. Tubliss inserts are not available in less than 1 85, hence I went for 1.85 as well.

Tubliss are available for 21" 1.6 rim width .. some ppl are running them on motoped and surron..

 

[Rix]

Spoted the cheapest 1.85" x 19" 32H rims here:

https://www.ebay.com/itm/Moose-Racing-Rear-Aluminum-Rim-Black-1-85-x-19-32H-0210-0197/292506453200?epid=171124011&hash=item441abe44d0:g:2MMAAOSwBnZawDhx

https://www.motocross-shop.de/motocross-shop/product_info.php?products_id=19595

watch out for shipping price.

for the rear rim you would probably want / need 36 hole to match the hub.. and 1.85 is a bit wide and heavy to use as a front rim ..

Yep, whats perfect for any ebike running up to 15kw is the Prowheel racing 19x1.40 Yamaha play bike rim. has 36 hole drill and tough. http://www.prowheelracing.com/yamaha-play-bike-front-rim-1-40-x-19-black/

 

[minde28383]

Regrding rolling resistance:
I think too that rolling resistance might play biggest role between these two small, almost identical outer diameter wheels, but one wheel being slightly wider. As you said it: ''would be hardly measurable''.

Regarding Rim:
It does make noticeable difference if you weigh bare rims, but if you take into account whole hub motor wheel weight than it makes negligible difference.
If 17'' 1.6'' compared to 17'' 1.4'' sheds off only 230grams (~8oz) than you save only 8oz (230g) which makes ~1.35% of rear wheel weight. I would say no difference in handling, nor you ever will notice 8oz in rear wheel, considering your wheel is already 16kg-17kg. I would say there is no noticeable difference what rim you use out of these two 17'' 1.4'' / 17'' 1.6''. Unless you take off slightly off a rim ~230g,
use lighter tire by ~1000g,
possibly thinner spokes,
skinnier tube sheds additional - 200g

Even after all these weight savings you save only between 5% up to 10% which is ranges from 850g up to 1700g in total wheel weight. Dropping off up to two kg can start to be noticeable, but it means having skinnier wheel. I'm after making it look more moped so I rather keep 1.6''. I'm dissuading my self from getting these 3kg tires. I'm lying my eyes on Sava MC 3.25''x16'' but I suspect them to be too big balloons.

I agree with you on all accounts, however, I want to throw out one possibility just as food for thought. Yah, the 8oz or so wont be noticable as far as unsuspended mass and performance related with suspension, but that weight increase is all located away from the center of the wheel. It may give you more flywheel and gyroscopic affect. On my Bomber, I ran both 18x1.85 and 18x1.40 MC rims with the same tire on the rear. When riding on pavement at high speed, I noticed my Bomber was harder to turn and lean with the 18x1.85, in other words, it took more effort at the bars with countersteering, and would standing up easier coming out of a corner. That said, the 18x1.85 was almost 2 pounds heavier than the 18x1.40 where as you are looking at a 1/2 pound difference. That said, it may not be an issue.

"...weight increase is all located away from the center of the wheel...more flywheel and gyroscopic affect..."

That is very interesting thing to consider. Never thought about that before. Now when I saw this again, after some time, I remembered how It was hard to lean into corner with qs273 in 16'' rim with balloon tire (maye 120/90-16), especially when throttle was open.

 

[minde28383]

...considering the Heidenau K40 or M3 tires. Does anyone have experience with Heidenau? Specifically the weights and rolling resistance...

According my web source Heidenau K40 18" 2" width weighs 2kg.

 

[Jamil.Siddiqi]

...considering the Heidenau K40 or M3 tires. Does anyone have experience with Heidenau? Specifically the weights and rolling resistance...

According my web source Heidenau K40 18" 2" width weighs 2kg.

Thank you for checking! I have bought the Continental KKS10 now, since 18" seems to be less common.

 

[Jamil.Siddiqi]

ok, here some more numbers:

Chalo, I did weight the 19" rim with an interesting result:

It is 1740 grams for Japanese Excel 1.85x19 rim vs. the claimed 2100 grams for the 1.60x21" porky Chinese. I wanted to check on the claimed 2100 grams and it comes out at 1460 grams. I repeated the measurement a couple of times, but the cheap 21" comes in much lighter than the 19" rim. Of course it is a bit narrower, but I was still expecting a lower weight.

As for the tubes:
28" bicycle are coming in at 100g
26" bicycle 190g

21" MC regular 600g (heavy and extra heavy are also available)
Tubliss 19" 900g
Mousse 21" + lubrication + rimlock = approx 1600g

 

[Chalo]

Thanks for that data; it's a valuable point of reference.

 

[DasDouble]

I have had a 21" bicycle wheel, the same as the LMX bike on my Vector and switched to motorcycle 19"x1.6" (available from QS motors, shipping expensive but rim costs nothing like 30 bucks or less) as the bicycle wheel got used up too fast for my favour. Not with the motorcycle wheel. Lasted about 1 year until it got rubbed down (knobby 50% dirt 50% street tire).

It pays back to not have to change tires 2-3 times a year. I also have to mention that I used to do a lot of stoppies, may also be a reason for the fast used up material of the bicycle wheel / tire, whatever its called.

 

[Merlin]

yup...stoppies with your 60kg rear hub fat ass vector

no video = not happen ^^

 

[Merlin]

21" MC regular 600g (heavy and extra heavy are also available)
Tubliss 19" 900g
Mousse 21" + lubrication + rimlock = approx 1600g

thats alot for the tubliss 19"
they stated on all videos or advertiesments that you save weight on using tubliss.
if its 900g you put 600g on top for tubliss system.

my 3.0-19 tubes have 320g.

i had my finger on the trigger to buy it with a new 18" rear rim.

 

[Jamil.Siddiqi]

So I installed a simple fairing yesterday and tested it today. My top speed, which had been hovering around 67kmh went up to 75.8 !!! All of that with a little piece of plastic:

https://www.aliexpress.com/item/Sale-Universal-For-All-motorcycle-with-7-8-or-1-Handlebar-Brand-New-Motorcycle-Handlebar-Mount/32647810456.html?spm=a2g0s.9042311.0.0.3da24c4d3IyJbS


I am very impressed and will be making a larger one now. I hope to get the speed upto around 80 kmh and/or increase the range.

It still felt pretty stable, which was never the case with bicycle wheels, even at 70 kmh.

 

[Chalo]

I hope to get the speed upto around 80 kmh and/or increase the range.

It still felt pretty stable, which was never the case with bicycle wheels, even at 70 kmh.

I've ridden my own motorcycle at around 240 kph before. I don't own one anymore because motorcycles kinda suck compared to bicycles. Feeble little electric motorcycles combine the worst qualities of both motorcycles and bicycles, except for the stench, noise, and oil leaks. They're like using 21st century tech to get pre-WWI performance.

If you want gross performance, try a 1000cc or larger sportbike. But if you want to maximize quality of experience, stick with bicycles and their proven components and designs.

 

[DasDouble]

yup...stoppies with your 60kg rear hub fat ass vector

no video = not happen ^^

Hold my beer
Screenshot_2018-06-12-13-15-11.png

 

[Merlin]

dont know what spam shit site this is but i will not klick twice on that crap link

you can upload on youtube without such a shit who tries on all edges to install some .exe shit