Going from 700c to 26" need new forks though

The Maestro

Esteemed Pedelecer
May 15, 2008
296
0
I've decided to migrate my electric gear from my 700c 'hybrid' bike onto a 26" mainly because there are just too many pot holes around here and recently slippy roads. A mountain bike just seems to eat it up a lot easier and the lower center of gravity seems to help with the slippyness. I bought a used Schwinn Mesa mountain bike off ebay for about £50 a while ago but it has some problems - brakes (v brake) and gears (Shimana Deore) all need overhauling and the front suspension forks are shafted (falling apart).

My plan is to fit a 7 speed Nexus rim with roller brake to the back wheel and bin the old gears and rear brake. The motor will go on the front wheel along with a normal v-brake and finally fit my electric cut-off brake lever (front only). Does anyone see any problems with this set up?

as for the forks, I know nothing about swapping them - I heard that you couldn't used suspension forks with an electric motor but I've seen loads of bikes and even cheap chinese ones that have the motor on the front with suspension forks recently. Are there certain forks you can use and others not? How do you swap the forks? Do different forks take different headsets or is that independent? I think the bike at the moment has a threadless headset.

Thanks for any advice.
 

Mussels

Esteemed Pedelecer
Jun 17, 2008
3,207
8
Crowborough
I don't quite understand as there is very little difference between 26" wheels and 700c wheels, is it just the mountain bike style you are after? When you mention a lower centre of gravity this doesn't make sense either as you are most of the weight and you ride at the same height no matter what frame you are on, on a mountain bike you might even ride higher so the BB has more ground clearance.
I suspect the problem with suspension forks is that they can't be bent to accomodate a slightly wider motor, if the forks are the right width to start with then I can't see any problem.
The roller brake may be a problem as from what I remember of the ebike law every brake needs a cutoff switch, personally I wouldn't lose much sleep over it.
I'm interested in how this goes as I'm thinking of getting a normal road bike but as the roads are so poor I may not bother.
 

flecc

Member
Oct 25, 2006
52,761
30,348
The larger diameter 700c wheel is better for traversing potholes than a smaller wheel, so I suspect what might be a better solution is a much larger section tyre to absorb shocks. They are made for 700c in as large as 1.95" section.
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The Maestro

Esteemed Pedelecer
May 15, 2008
296
0
Fatter tyres is definately one reason for the better ride on the mountain bike. I didn't know that they were available for 700C but I still want to go down to 26", I tried finding 700C metal studded tyres for the snow and although I found one or two products I couldn't really find what I was looking for whereas there was a lot more choice in 26". In general there are a lot more and cheaper parts available for the 26" format I find.

I do think the centre of gravity is much higher on my 700C hybrid possibly more because of the 'sit up and beg' riding position than the wheel size. The smaller wheel size would mean the the battery and motor would be lower down too though. 26" wheels look significantly smaller than 700C when you place them side by side, I know there is only 2" in it though, still makes a difference. If I put fat tyres on a 700C then it would be even higher than it is now!

Maybe this is subjective but I do find mountain bikes better over rougher ground, I guess that's what they are designed for after all.

Anyone got any idea about replacing the forks?
 
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torrent99

Esteemed Pedelecer
Nov 14, 2008
395
36
Highgate, London
Fatter tyres is definately one reason for the better ride on the mountain bike. I didn't know that they were available for 700C but I still want to go down to 26", I tried finding 700C metal studded tyres for the snow and although I found one or two products I couldn't really find what I was looking for whereas there was a lot more choice in 26". In general there are a lot more and cheaper parts available for the 26" format I find.

I do think the centre of gravity is much higher on my 700C hybrid possibly more because of the 'sit up and beg' riding position than the wheel size. The smaller wheel size would mean the the battery and motor would be lower down too though. 26" wheels look significantly smaller than 700C when you place them side by side, I know there is only 2" in it though, still makes a difference. If I put fat tyres on a 700C then it would be even higher than it is now!

Maybe this is subjective but I do find mountain bikes better over rougher ground, I guess that's what they are designed for after all.

Anyone got any idea about replacing the forks?
If you think about the centre of gravity situation though...
I weigh 90kgs. Most of that weight will be above the waist.

My bike weighs around 20kgs.

Where is the COG?
Will 1" of wheel height make any significant difference to the placement of the COG?

Probably the most likely as you say is the postural difference between the bikes that accounts for the COG difference.