Suitable rim width?

ebike11

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Hi guys..considering a fairly powerful rear hub (says its rated at 3000w) for my standard 135mm dropouts on my 26inch MTB.
Ill be pairing it with a 72V battery.
Seen a few motors on aliexpress that are narrower and can fit this standard bike dropout.
What rim width do you recommend that will allow me to put fairly wider tire on it to have more contact with the road at high speeds? I have an Alex rim DM24 on my other Mac motor. Its a bit wide..I think 2.5inch. Should I go wider than 2.5inch? Then again i can only go so wide until the tire starts rubbing etc.
Thanks!
 
The DM24 is 32mm wide on the rim which is wide enough for a 3" wide tyre. A 3" tyre is about as wide as you get.
So no you do not need wider than your Dm24
 
The DM24 is only 24mm wide inside, 32mm outside. No way in hell should you run a tire over 2.125" on it. For anything over that get the Alex DX32 or similar rim which is 32mm inside and 39mm outside. Works well with tires from 2-3" wide. The DX32 is also a much stronger rim than the DM24.
 
wesnewell said:
The DM24 is only 24mm wide inside, 32mm outside. No way in hell should you run a tire over 2.125" on it. For anything over that get the Alex DX32 or similar rim which is 32mm inside and 39mm outside. Works well with tires from 2-3" wide. The DX32 is also a much stronger rim than the DM24.


Apologies', in my head i was thinking of the dx32 mtb rim. :? I knew the 24 had a 32od , must have got mixed up. Wesnell is correct, a 3" tyre will be fine on the dx32 as long as your frame n forks will take the extra height and width of that tyre. The widest 3" mtb knobbly tyre i have come across is the vuelta usa, bit finding it in 26" may be difficult. Other than that the second widest 3" knobbly has been the Halo Contra whixh are easy to get and are a good quality tyre. Never tried a 3" road tyre, only 2.5"
 
ebike11 said:
Hi guys..considering a fairly powerful rear hub (says its rated at 3000w) for my standard 135mm dropouts on my 26inch MTB.
Ill be pairing it with a 72V battery.
Seen a few motors on aliexpress that are narrower and can fit this standard bike dropout.
What rim width do you recommend that will allow me to put fairly wider tire on it to have more contact with the road at high speeds? I have an Alex rim DM24 on my other Mac motor. Its a bit wide..I think 2.5inch. Should I go wider than 2.5inch? Then again i can only go so wide until the tire starts rubbing etc.
Thanks!

Yeah, I like to use 60mm tires, although it is a tight fit on some 26MTB frames. THe DM24 is perfect for that. Its a 24c rim (internal). Just check out an ETRO chart to see what is optimum for ya:

asimpleguideontheessentials05.jpg


Keep in mind, the amount of traction is based on weight and friction, not on tire size. And, at the same PSI, a skinny tire and a fat tire will have the same contact patch. The big advantage of larger tires is that you can use lower pressure, giving you a smoother ride, ability to conform to uneven pavement and making it hard to pinch flat.
 
You can ride lower PSI with wider rims. That is why we prefer wider rims. 47mm is the common width for trial bicycle rims, easy to find. Also pretty easy to find 60 or 65 mm rims for cruisers and choppers. DH rims are easy to find 29mm, the minimum that I like to mount a 3" tire on. On a narrower rim, a big tire is rolling laterally unless you inflate it very hard and it doesn't make a good ride.

So I do recommend a 3.0 tire to be mounted on rims 29 to 65mm wide for the street, 29 to 47 mm wide for off road. The wider the better, but not wide enough that it does compromise the reliability on the terrain that you ride.
 
Tons of MTBs use tires over 55mm on rims of about 24mm outside width (~18mm inside). There are benefits (ride quality, low rolling resistance) and drawbacks (instability at low pressure) to using a wide tire on a narrow rim. But it's normal-- don't let Wes Newell mislead you.

Don't mount a tire on a rim with an outside width wider than the tire's nominal width. And keep in mind that using a tire more than about three times as wide as the inside width of the rim obligates you to use more tire pressure than would otherwise be necessary.

In the industry, road bikes customarily use a rim about half as wide inside as the tire. MTBs customarily use a rim about a third as wide inside as the tire. Wes speaks only for himself.
 
Chalo said:
Tons of MTBs use tires over 55mm on rims of about 24mm outside width (~18mm inside). There are benefits (ride quality, low rolling resistance) and drawbacks (instability at low pressure) to using a wide tire on a narrow rim. But it's normal-- don't let Wes Newell mislead you.

Don't mount a tire on a rim with an outside width wider than the tire's nominal width. And keep in mind that using a tire more than about three times as wide as the inside width of the rim obligates you to use more tire pressure than would otherwise be necessary.

In the industry, road bikes customarily use a rim about half as wide inside as the tire. MTBs customarily use a rim about a third as wide inside as the tire. Wes speaks only for himself.

I just ordered a 42.5mm outer width and 35mm inner width. 26inch rim.
Would a maxxis hookworm be a good fit?
 
ebike11 said:
I just ordered a 42.5mm outer width and 35mm inner width. 26inch rim.
Would a maxxis hookworm be a good fit?

Yes, that's a good match. Is the rim a Weinmann DHL42? If not, then what is it?
 
Chalo said:
ebike11 said:
I just ordered a 42.5mm outer width and 35mm inner width. 26inch rim.
Would a maxxis hookworm be a good fit?

Yes, that's a good match. Is the rim a Weinmann DHL42? If not, then what is it?

Im not sure the brand..its from aliexpress so i dont expect much haha. Ill let u know when the motor and wheel arrive
 
wesnewell said:
The DM24 is only 24mm wide inside, 32mm outside. No way in hell should you run a tire over 2.125" on it. For anything over that get the Alex DX32 or similar rim which is 32mm inside and 39mm outside. Works well with tires from 2-3" wide. The DX32 is also a much stronger rim than the DM24.

Hi there again,
Would there be any danger or risk kr negative points by putting 2.5inch maxxis hookworm on a front wheel with an external width of 30mm?
 
Dangers would be more chances of pinch flats. Tire wobble/roll. Weaker less stable wheel. Smaller tire footprint to wear out middle of tire faster, etc. The wider the rim, the better it will perform. I'd consider 32mm inside a minimum for a 2.5"-3.0" tire. and wider than that won't hurt. A 30mm outside width is no more than 23mm inside. I ran 2.4" tires on rims 25mm inside and it didn't perform well. Going to 32mm inside made a world of difference.
 
ebike11 said:
Would there be any danger or risk kr negative points by putting 2.5inch maxxis hookworm on a front wheel with an external width of 30mm?

No problem there; that's pretty much industry standard for a tire that size. It will be fine if you keep tire pressure in the 25psi and up range.

Using a wider rim would allow you to use even lower pressure without causing tire instability. Drawbacks to a wider rim include poorer ride quality at any given pressure, increased rolling resistance, and reduced compatibility with narrower tires.

Please disregard wesnewell's comment about tire footprint. The size of the tire's contact patch is always a function of the tire's pressure and the amount of weight it carries. Rim width can have some effect on its shape, but not its size.

At the time 2.5" tires first became available, rims wider than 25mm were considered heavy and outdated, so most of us were mounting those tires on narrower rims. I think some of the potential advantages of big fat tires were lost that way (through using otherwise needlessly high pressure), but it worked fine even then.

For a 2.5" tire, I'd be happy with a rim anywhere between a Sun Rhyno Lite at 27.5mm, and one of the new "plus" rims up to 50mm. But if I wanted the option of using narrower, lighter tires at some other time, I'd bias towards the narrow end of that range. If I had room for 3" tires, I'd use one of the wider selections.
 
Experts would not recommend using a 2.5" tire on a 30/23mm rim. Period. Anyone that has switched to wider rims with wider tires will tell you how much better they will perform. Max recommend tire width for a 23mm rim is 50mm/ A 2.5" tire is 63.5mm. See rim chart at bottom of post. Don't listen to Chalo. He is totally wrong on this.
http://www.sheldonbrown.com/tire-sizing.html
 
I should also note that i only do street and city riding..very rarely off pavement.
I dont have an air pressure gauge but i generally put enough air in the tires where it is hard to squeeze them..i guesstimated basically. I figure the harder the tire then id get more top speed
 
On pavement, you can ride wide rims. 2/3 of tire width is safe, and let you ride lower PSI.

It is a myth that high PSI is making lower rolling resistance. Every tire has its own specific rolling resistance that is optimal at a specific rim width/PSI ratio. Small volume does require higher pressure and the larger the air volume, the lower the ideal pressure is.

Then the wider the rim, the lower the pressure, the best the puncture resistance, the best the comfort and traction BUT, the less the resistance to a hit. That is why we have to be careful using wide rims off road, or when we ride hard hitting curbs and potholes. The best hit resistance is closer to a 1/3 ratio, because higher pressure is possible then, and the the sidewalls are round enough to do the job.
 
MadRhino said:
On pavement, you can ride wide rims. 2/3 of tire width is safe, and let you ride lower PSI.

It is a myth that high PSI is making lower rolling resistance. Every tire has its own specific rolling resistance that is optimal at a specific rim width/PSI ratio. Small volume does require higher pressure and the larger the air volume, the lower the ideal pressure is.

Then the wider the rim, the lower the pressure, the best the puncture resistance, the best the comfort and traction BUT, the less the resistance to a hit. That is why we have to be careful using wide rims off road, or when we ride hard hitting curbs and potholes. The best hit resistance is closer to a 1/3 ratio, because higher pressure is possible then, and the the sidewalls are round enough to do the job.

I have to double check but the outer width is 30mm, outer edge to outer edge. I think inner width is 25mm.
This is a 26inch wheel and i bought Hookworms for front and back. The wheel with the motor is wider than the 30mm front wheel
 
Using a 25mm rim with a hookworm is OK, but I find it hard for street riding. I mean, they need to be inflated too hard on such a narrow rim. I did use Hookworms on 39mm DX32 rims for summer city commuting and they were a good ride. I tried them on 47mm and although they were riding good, they were too weak and prone to pinch flat.
 
ebike11 said:
I have to double check but the outer width is 30mm, outer edge to outer edge. I think inner width is 25mm.
This is a 26inch wheel and i bought Hookworms for front and back. The wheel with the motor is wider than the 30mm front wheel
I don't know of any rim made that only has a 5mm difference between inner and outside width. if the sides are that narrow, i wouldn't use them at all. That would make the rims ~50% weaker than normal rims
 
MadRhino said:
On pavement, you can ride wide rims. 2/3 of tire width is safe, and let you ride lower PSI.

It is a myth that high PSI is making lower rolling resistance. Every tire has its own specific rolling resistance that is optimal at a specific rim width/PSI ratio. Small volume does require higher pressure and the larger the air volume, the lower the ideal pressure is.

Then the wider the rim, the lower the pressure, the best the puncture resistance, the best the comfort and traction BUT, the less the resistance to a hit. That is why we have to be careful using wide rims off road, or when we ride hard hitting curbs and potholes. The best hit resistance is closer to a 1/3 ratio, because higher pressure is possible then, and the the sidewalls are round enough to do the job.

Ideally,... your tire should be inflated to not deform under load, with few exceptions. This maintains a stable, consistent and dependable contact patch, which affects handling and tire function INCLUDING rolling resistance and puncture resistance. Perhaps the first thing you notice when your tires are low, is that it's "soft",... not carrying the full load as it should. Then you notice the handling with that load,... that "wobble" on each pedal stroke, unsureness in a turn or unexpected deflection from road dips, bumps and imperfections, or maybe an "unsolid" stop. Perhaps you notice how hard it seems to pedal and move,... due to increased rolling resistance.

While it's true that rolling resistance is no longer reduced by increased pressure beyond the point that a tire no longer deforms, it is grossly increased by lower pressures to a point that a bike with a flat tire is downright tiresome!

The BIGGEST "myth",... is that lower pressures reduce punctures! Likely due to the reasoning that it can more easily "deform" around a puncturing object. While true, it also concentrates the puncturing energy towards the apex of that impact and deformation, and defeats the tires design and purpose. Puncture resistance is a design function of the tires carcass (TPI and material resistance) and construction (i.e. special resistant belts) that deflects and distributes puncture energy to a greater area surrounding the impact without deformation or failure,.... and obviously dependent on adequate inflation pressure. A tire that deforms dramatically under impact, also increases the likelihood of "pinch flats" and rim damage (of which tires are intended to prevent!). And of course, tire, rim and tube slippage that some will overcome with "rim locks" and such, instead of suggested inflation pressure.

"Skinny" tires have higher pressure due to the function of pneumatics, low air volume, and that contact patch. It takes greater psi to support 100lbs load on 2sq inches than on 3sq inches, without deforming. With high pressure, less air volume, and small contact area,... "road" tires can feel every nook, cranny, pebble and rolling imperfection of a road surface. The low volume, high pressure is greatly dependent on strong bead and carcass construction and proper rim design that pushes the limits of "blowout" failures.

"Fat" tires, with lower supporting pressures and large contact patch.... feel none of that. And that's the intended design function of such tires,.... stable supporting consistency with a large contact patch for traction and ride comfort on broadly variable surfaces, especially loose, rugged or soft giving surfaces, as well as streets and sidewalks.

And yes,.. there are those who run even LOWER pressures, for a bigger contact patch and greater support and traction on the softest surfaces. AND they endure all the inherent problems of low pressures as "an advantage"??? If ya need more tire,.... GET more tire!

You can put ANY tire on ANY rim you can fit it on! AND run any tire pressure you desire. Jus know that in many instances, extreme or otherwise, you may be exceeding the designed specifications of specifically engineered tires.
 
You can run pretty much any rim you want. But wider is better for the street. I ran a DM24 in the back for over 10000 miles with tires from 1.95 to 3" wide, riding hard and fast as well. I'd go with a wider rim however, cause tires will wear to a flat and it's better to have a less sharp angle on the edge of the flat when cornering... you'll know what I mean when your tire gets to that point... you start cornering and feel the rear end hop over to the side of the tire "whoops there's the rest of the tread" :mrgreen:

Hookworm is a great tire. If you want to go cheaper the CST cyclops is great as well, I have gone through probably around 10-15 of those. Currently running the beach bum 26x3.0 and I love it! half the price of the CSTs.
 
beginner01 said:
You can run pretty much any rim you want. But wider is better for the street. I ran a DM24 in the back for over 10000 miles with tires from 1.95 to 3" wide, riding hard and fast as well. I'd go with a wider rim however, cause tires will wear to a flat and it's better to have a less sharp angle on the edge of the flat when cornering... you'll know what I mean when your tire gets to that point... you start cornering and feel the rear end hop over to the side of the tire "whoops there's the rest of the tread" :mrgreen:

Hookworm is a great tire. If you want to go cheaper the CST cyclops is great as well, I have gone through probably around 10-15 of those. Currently running the beach bum 26x3.0 and I love it! half the price of the CSTs.

Actually i should note again..my rear has a wide rim coz it came with the motor laced..3000w hub.
Its the front that narrower but i put 2 identical 26 inch hookworms on both different sized rims. Not sure if its recommended..so I guess im half way covered. Motor wheel is plenty wide
 
It will do fine on warm pavement. Hookworms are dangerous to corner fast on bad conditions. They have a better grip on wider rims, but still wash out pretty quick on sandy corners or fallen leaves.
 
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