Quick question on rim size preference

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markz   100 GW

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Quick question on rim size preference

Post by markz » Jan 27 2015 10:55pm

I bought a 20" Alex rim from ebay, I realize now its to small.
I should have bought a 24" rim, now I am thinking maybe just stay with the 26" rim for my mxus 3000w v2 motor.

http://www.alexrims.com/product_detail. ... =21&pid=73
I can buy this rim from a local national retailer, Alex Ace‑18 Rim 26" 36 Hole CSW for $32. Double wall, made for XC and mountain riding.
Sheldon Browns website says I can put a 2.3" tire on a 559x17 clincher rim.

I am probably just over analyzing this
All I think I know is - That larger diameter = more speed/less torque, smaller diameter = less speed/more torque.

I kind of want the more torque/less speed, but also after doing a bit of reading I realize that I also loose some footprint on the ground for the 24", also it puts my stock pedal arms closer to the ground. Also I have read that holes, bumps are not good for smaller rims. I might just stay at 26" rim afterall.

So is there that much of a difference in torque between the 24" and the 26" rims, and with that how much extra diameter does a knobby tire add?

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MadRhino   100 GW

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Re: Quick question on rim size preference

Post by MadRhino » Jan 27 2015 11:31pm

The issue is heat. We all know that a larger wheel rides better. I accepted the compromise to ride on 24 X 3.0, for the ride quality is close to a 26, with better reliability. 20 is good only on smooth surface, but the safest when it comes to motor heat. I still have a bike that rides on 26 (28.5 OD with a 3.0 tire) for the very bad trails, but it has a heavy slow motor (X 5404) to limit the heat.

The faster the motor, the more advantage it has to be in a smaller wheel.
Make it fool-proof, and I will make a better fool.
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motomech   1 GW

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Re: Quick question on rim size preference

Post by motomech » Jan 28 2015 12:07am

markz wrote:I bought a 20" Alex rim from ebay, I realize now its to small.
I should have bought a 24" rim, now I am thinking maybe just stay with the 26" rim for my mxus 3000w v2 motor.

http://www.alexrims.com/product_detail. ... =21&pid=73
I can buy this rim from a local national retailer, Alex Ace‑18 Rim 26" 36 Hole CSW for $32. Double wall, made for XC and mountain riding.
Sheldon Browns website says I can put a 2.3" tire on a 559x17 clincher rim.

I am probably just over analyzing this
All I think I know is - That larger diameter = more speed/less torque, smaller diameter = less speed/more torque.

I kind of want the more torque/less speed, but also after doing a bit of reading I realize that I also loose some footprint on the ground for the 24", also it puts my stock pedal arms closer to the ground. Also I have read that holes, bumps are not good for smaller rims. I might just stay at 26" rim afterall.

So is there that much of a difference in torque between the 24" and the 26" rims, and with that how much extra diameter does a knobby tire add?
Why would you go to the trouble to replace a rim and use a pizza-cutter. Sure, I can lever a 2.4 tire on a 22 rim, but they work much better on a 32. I don't think Sheldon Brown did much trail riding.
If you can "flat-foot" your bike with the 26 incher's stay with them. If you go with 24's, start looking for a new crank-set with shorter crank-arms.
Also, there is a much better selection with 26" tires.
Motomech

'03 Rocky Mountain Edge 2WD 260 Q100H frt and Ezee V1 rear 2 Elifebike 20A & 25A 9-FET controllers 12S/10Ah Multistar Lipo rear 4Ah Turnigy frt Luna Cyclops Extra lite Alex 24DM rims, Crazy Bobs run ghetto tubeless. 25 mph. Mean Well HLG-320H-54A
https://endless-sphere.com/forums/viewt ... =3&t=83430
'07 GT Idive 4 4.0, Q100C 201 14S LiPoly elifebike 9-FET 20A controller. 23 MPH.
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wesnewell   100 GW

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Re: Quick question on rim size preference

Post by wesnewell » Jan 28 2015 2:01am

Get the DX32 if you are going to use1.95 or wider tires.
http://www.alexrims.com/product_detail. ... =22&pid=82
Need Advice? https://endless-sphere.com/forums/viewt ... =3&t=66302
Mongoose 26" Ledge 2.1 mtb bike $99, yescomusa.com 48V 1000W rear hub kit $200, Hua Tong 72V 40A controller $35, 10ah 24s lipo $217=~43mph, range=45 miles @ 20mph. 25K miles and still going strong.
Huffy Fortress 3.0 with MXUS 3000 4T motor, 24s lipo, 96V 60A controller. Total cost with extras <$700. Top speed ~50mph
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