Folding Bikes - Home build Offroad Mini velo project??

Hi Guys

After searching this forum i came across a post about converting a Cannondale Mtb into a mini velo and it got me thinking:)

I`ve picked up a 15" Specialized Hardrock Pro for free (bonus of working in a bike shop)
It has a 13" high bottom bracket and was thinking it might make a sweet 406 wheeled mtb??

I`m going to use it with the original length fork 100mm suspension fork(The cannondale hooligan uses 26" wheel rigid forks)and cut down cranks,disc brakes,short arm rear mech and Maxxis Maxx Daddy 20x2.25 tyres

What do you guys think?
Will it work offroad??
Is there any problems i havent thought of???

Cheers
Adrian

P.s If anyone could do a photoshop of this before i start i would be grateful:love:

You could do this with some full suspension frames and adopt the suspension elements to compensate for the reduced bottom bracket hight. But I would guess 24" wheels are the smallest possible realistically. Hard tail frames would get too low anyway.

After the conversion the bottom bracket will be around 10"...which is too low for a MTB IMO.

Here's a thread with a photoshop Cannondale Bad Boy, and an older M800 with 20" wheels. BB height with the 406 wheels was right at 10", or about .5" below where most of the lowest BBs are nowadays... for road bikes. I was thinking of doing the same thing for a small-fat tired commuter, where BB height isn't as critical as it can be offroad.

Here's a thread with a photoshop Cannondale Bad Boy, and an older M800 with 20" wheels. BB height with the 406 wheels was right at 10", or about .5" below where most of the lowest BBs are nowadays... for road bikes. I was thinking of doing the same thing for a small-fat tired commuter, where BB height isn't as critical as it can be offroad.

Hi
It was your Cannondale that started me thinking:)

I know bb height will be an issue offroad but i`m thinking off running 152mm cranks
to help with pedal strike,

I`m going to get it built and see how well it rides,If it`s as much fun as i think it could be then i might
cut up a cro-moly RockHopper frame i have to position the bb shell higher,

Cheers
Adrian

The main problem I see is the high rolling resistance of unsuspended 20" wheels off road.

Sounds like a great idea for a road MiniVelo though. Especially a single speed, with the short cranks. I have 153s on my SS and despite a 57" gear, can spin to pretty respectable speeds.

The main problem I see is the high rolling resistance of unsuspended 20" wheels off road.

Hi
Sorry for being dumb but i`m not sure what you mean there??

Do 20" wheels have a higher rolling resistance than 26"?

Thanks
Adrian

P.s The bike will be be running 100mm Rst suspension forks

Hi Guys

After searching this forum i came across a post about converting a Cannondale Mtb into a mini velo and it got me thinking:)

P.s If anyone could do a photoshop of this before i start i would be grateful:love:

http://www.reallyserioustoys.com/images/cool-hetha-02.jpg





More HERE (http://www.reallyserioustoys.com/Featured_Product.html)

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Sorry for the dumb question, but the type of bicycle you're looking for is not a BMX ?! (high BB, long cranks, 20 inch off road wheels, off road geometry compact frame, etc...)

Hi
Sorry for being dumb but i`m not sure what you mean there??

Do 20" wheels have a higher rolling resistance than 26"?
On pavement, a good 20" tire gives up little or nothing to larger wheels. Slightly higher RR can be offset by lower aero drag. I was on my Boardwalk D7 a few weeks back, riding with a large group of Surlys and Rivendells, all running 700s. I was outcoasting everyone with my Dahon 20 x 1.5s.

Off road it's a different situation. A small wheel has to accelerate upwards more quickly going over irregularities. The energy to do this is subtracted from your forward momentum. Suspension can help here, but most off road big wheels are suspended these days too.

Small tires sink more deeply into soft soils or sand. Suspension's no help here.

Lower RR is the reason 29'ers are so popular, despite being heavier and weaker than 26".


P.s The bike will be be running 100mm Rst suspension forks
I've been away from off-roading for a while but RSTs weren't much good "back in the day".

I've been away from off-roading for a while but RSTs weren't much good "back in the day".

Hi
Yeah RST`s are still pretty bad,

But they are almost new and FREE,
Trying to spend less than £50 on the bike in total,
Because theres a good chance it wont work:cry:


Cheers
Adrian

^ The old RSTs were pretty bad, and lower-end of the new stuff would be just as bad as any other brand in that price-point. But the company has refocused and has come back with a pretty decent line up. One of the moderators at the MTB forum races downhill with a top-end RST fork so that's pretty serious application in todays standards. Check your fork model against the current line-up at the RST website... it might not be as bad as you think.

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