Convert 29er wheel to 26"

General Discussion about electric bicycles.
Post Reply
olemetry
10 W
10 W
Posts: 75
Joined: Dec 28, 2011 5:15 pm

Convert 29er wheel to 26"

Post by olemetry » Dec 21, 2017 11:19 am

Hi gang. Just getting back into e-bike after a few years. I have a 29er MAC 7T that I would like to convert to a 26" wheel.

I haven't called around yet, but I am guessing this is something a local bike shop can do? I also imagine I may need a special (heavy duty?) wheel that I need to pre-order along with the heavy duty spokes? Any recommendations? Thanks!

Voltron
100 kW
100 kW
Posts: 1440
Joined: May 02, 2013 4:53 pm
Location: Santa Barbara CA

Re: Convert 29er wheel to 26"

Post by Voltron » Dec 21, 2017 4:53 pm

With today's market you could possibly buy a complete motor wheel already laced up for less than the labor and parts of switching everything.

User avatar
Chalo
100 GW
100 GW
Posts: 6655
Joined: Apr 29, 2009 11:29 pm
Location: Austin, Texas

Re: Convert 29er wheel to 26"

Post by Chalo » Dec 21, 2017 5:11 pm

Voltron wrote:
Dec 21, 2017 4:53 pm
With today's market you could possibly buy a complete motor wheel already laced up for less than the labor and parts of switching everything.
While that's true, the wheel probably wouldn't be nearly as good as a custom built one. Most complete hub motor wheels are built out of garbage, with logs for spokes.

Yes, a local bike shop can build that for you. Some shops and shop mechanic are better than others, so getting a recommendation from a savvy local cyclist would be a good idea.

Note that the change in wheel size will drop your bottom bracket about one inch, which usually isn't a problem, but is something you should be aware of. If you ever hit your pedals on things now, you'll do it a lot more often with a smaller wheel.
This is to express my gratitude to Justin of Grin Technologies for his extraordinary measures to save this forum for the benefit of all.

User avatar
motomech
1 GW
1 GW
Posts: 3035
Joined: Sep 11, 2010 12:21 am
Location: Tucson Az.

Re: Convert 29er wheel to 26"

Post by motomech » Dec 21, 2017 6:25 pm

I went from 26" wheels to 24' and pedal strikes were a problem.
I had to change to a crank to one with the shortest crank arms I could find.
Also had to install "thin" pedals.
Motomech

'03 Rocky Mountain Edge 2WD 260 Q100H frt and Ezee V1 rear 2 Elifebike 20A & 25A 9-FET controllers 12S/20Ah Multistar Lipo rear 5Ah 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.
https://endless-sphere.com/forums/viewt ... 8#p1237928

markz
100 GW
100 GW
Posts: 5233
Joined: Jan 09, 2014 11:38 pm
Location: Alberta Canada

Re: Convert 29er wheel to 26"

Post by markz » Dec 21, 2017 10:49 pm

:lol: Who pedals anymore? 8)

Besides fake pedaling.

ScooterMan101
100 kW
100 kW
Posts: 1345
Joined: Oct 06, 2012 4:45 pm
Location: South of San Jose, California.

Re: Convert 29er wheel to 26"

Post by ScooterMan101 » Dec 23, 2017 1:32 pm

You meant to say you have a 6T ?

Yes a local bike shop . ( LBS ) can build up a wheel for you.

Where I live the cost ( just for labor not including parts ) is anywhere from $ 65 to $ 90
Typically there is only a 1 cross or 2 cross spoke pattern so no need to spend over $ 65 for the labor.
for a budget but strong rim you can get a Alex downhill rim. or for a lighter but strong rim you can buy a Mavic ( welded ) rim or even what the people who work for bike shops and in the industry use ... DT Swiss rims ( welded ) , but they can afford a DT Swiss because they get a discount since they are typically paid such a low wage.
and
for spokes get the Sapim , double butted is fine and strong enough when building a wheel by someone who know what they are doing. I think it is 13/14 guage spokes.
Part of that $ 65 should be for the LBS to tell you what size spokes to order.
If you buy from the LBS the cost will be from 2-3 times higher per spoke , so most people here order spokes online, although there is the shipping cost to consider.

olemetry wrote:
Dec 21, 2017 11:19 am
Hi gang. Just getting back into e-bike after a few years. I have a 29er MAC 7T that I would like to convert to a 26" wheel.

I haven't called around yet, but I am guessing this is something a local bike shop can do? I also imagine I may need a special (heavy duty?) wheel that I need to pre-order along with the heavy duty spokes? Any recommendations? Thanks!
My first conversion ...

https://endless-sphere.com/forums/viewt ... 1#p1077497

Oh how I wish today for no more rain
Oh how I wish to ride again
Once and for all
And all for once
Cyclist my name forevermore

ScooterMan101
100 kW
100 kW
Posts: 1345
Joined: Oct 06, 2012 4:45 pm
Location: South of San Jose, California.

Re: Convert 29er wheel to 26"

Post by ScooterMan101 » Dec 23, 2017 1:51 pm

B.T.W.
For any bottom bracket height issues , or pedal strikes , if you are using your 29er bike for off road you could/should just lace the motor into a 27.5 wheel.
There is now every kind and size of 27.5 inch tire available for any kind of riding you will be doing.
Relacing into a 26 inch wheel would be for street riding and even then for going up hills/mountains.
My first conversion ...

https://endless-sphere.com/forums/viewt ... 1#p1077497

Oh how I wish today for no more rain
Oh how I wish to ride again
Once and for all
And all for once
Cyclist my name forevermore

User avatar
amberwolf
100 GW
100 GW
Posts: 25045
Joined: Aug 17, 2009 6:43 am
Location: Phoenix, AZ, USA, Earth, Sol, Local Bubble, Orion Arm, Milky Way, Local Group
Contact:

Re: Convert 29er wheel to 26"

Post by amberwolf » Dec 23, 2017 2:52 pm

Keep in mind that the top speed will drop proportionally to the wheel size difference.

However, the torque will increase proportionally. ;)

mat h physics
100 W
100 W
Posts: 158
Joined: Dec 07, 2010 12:49 pm
Location: Ral, NC

Re: Convert 29er wheel to 26"

Post by mat h physics » Dec 24, 2017 10:21 pm

amberwolf wrote:
Dec 23, 2017 2:52 pm
Keep in mind that the top speed will drop proportionally to the wheel size difference.

However, the torque will increase proportionally. ;)
While things in 'the real world' may seem simpler, motor theory says output will be the same.
IE top speed should not suffer, the 'added torque' drops off at a higher RPM. This doesn't dismiss efficiency curves.

Then again, in the 'real world' people still believe airliners hit the twin towers.
Specialized Hardrock, still conventional.
Schwinn Avenue, still conventional.

User avatar
amberwolf
100 GW
100 GW
Posts: 25045
Joined: Aug 17, 2009 6:43 am
Location: Phoenix, AZ, USA, Earth, Sol, Local Bubble, Orion Arm, Milky Way, Local Group
Contact:

Re: Convert 29er wheel to 26"

Post by amberwolf » Dec 24, 2017 11:25 pm

mat h physics wrote:
Dec 24, 2017 10:21 pm
While things in 'the real world' may seem simpler, motor theory says output will be the same.
IE top speed should not suffer, the 'added torque' drops off at a higher RPM. This doesn't dismiss efficiency curves.
Based on experience, output of the same hubmotor is not the same in two different wheel sizes, all else the same (controller, battery, riding conditions, etc. This is a large part of the reason I use smaller wheels on the back of CrazyBike2 and SB Cruiser--to effectively "gear down" the hubmotor without taking it outside the wheel.

Take an example of this
http://www.ebikes.ca/tools/simulator.ht ... p=0&hp_b=0
which uses all the defaults except opening system b, and using a 29" wheel on that one (leaving a at 26), and using MPH vs kph, and turning off human input.

There's not *much* difference, but there is some.

If you make the wheel size difference greater (20" vs 26" in this example), you can more clearly see the difference.
http://www.ebikes.ca/tools/simulator.ht ... &wheel=20i

mat h physics
100 W
100 W
Posts: 158
Joined: Dec 07, 2010 12:49 pm
Location: Ral, NC

Re: Convert 29er wheel to 26"

Post by mat h physics » Dec 26, 2017 2:13 pm

amberwolf, you're certainly one of the best on the board. I think an agreement can be seen in the shift of eff at high RPM. Thank you for posting data to back your position.
Happy New Year
Specialized Hardrock, still conventional.
Schwinn Avenue, still conventional.

Post Reply