Decent mountain bike frame for front hub motor.

[Ash21014]

Sorry I don't mean frame, I mean bike, there doesn't seem to be any way to edit thread titles on this forum!

Now that I've got a full time job I can finally afford to start buying components for this custom build.

Don't have an exact budget in mind but I'm looking for a mountain bike that's less than £500. The bike must be able to fit disc brakes on the front and rear wheels, the more heavy duty the bike the better.

I would like to fit a 350W/500W 36v/48v hub motor kit on the front wheel for a lot of hill climbing, up to about 20% gradient, throttle is essential. I can build any battery to supply the power, from my experience of a 10 mile round trip it will need to be >500Wh. I don't intend on de-limiting the bike past any 25mph limit the controller may have programmed into it.

So any suggestions would be welcome, I know I created a similar thread to this in the past, but reading back through it started to get confusing and I'm more sure of what I need now.

 

[Deleted member 4366]

For a 500w motor on the front, it has to have steel forks. There's not many good quality bikes with steel forks, so you might have to change the forks. Look for Zoom forks, but, still, you need to check whether they're steel.

Why does it have to be a front motor, which brings more complications than a back one?

 

[Ash21014]

Well I just thought I might see some handling benefits mounting on the front with the two-wheel drive effect.

 

[Deleted member 4366]

You won't get any handling benefit with a 500w geared motor on the front. Instead, you just get a lot of wheel-spin. Also, it'll stop your suspension forks from working properly because of the extra unsprung weight. Handling will be a lot better with a rear motor and a centre battery.

 

[Ash21014]

Ok then, so let's swap out what I said in my op for rear hub.

 

[Nealh]

Ebay for used bargains H/t or Full suss. Carrera H/t good ,likes of banshee full suss can suffer breakage of rear stays after the pivot other wise they can be got cheap. Kona are nice but can be pricey, Rocky Mountain, Giant the list goes on and on. Get one with good front forks and hdb's, I managed to get one with front and rear air suss and hdb's for £300.
Also for rear hub conv you will need to make sure drop outs have enough meat on them for any modding, also a good triangle space for battery if fitting on down tube.

 

[Deleted member 4366]

You can use any bike, but the ones to avoid are:
Bikes without disc brakes
Bikes with a small main triangle in the frame
Bikes with any non-standard features
Bikes with hub-gears

In other words, you want a normal bike with a triangular frame, derailleur gears and disc brakes. Suspension will make long rides more comfortable.

When planning to build or convert a bike, it's best to consider how/where you will fit the battery first, so you need an idea of which particular battery you want to install too.. Mounting the battery on a rack is acceptable, but only if you can get it tucked up right against the seatpost. Standard racks put the battery too far back. That can still be OK if you have a front or middle motor, but not with a large hub-motor in the back wheel.

 

[Ash21014]

Thanks for the suggestions, I should be able to make a choice from those. As far as batteries go, I can build my own, or use one off the shelf, I've even got my old Sirocco CD one, claimed to be 15Ah. Incredibly slow charge rate though, and god knows what the capacity is after all this time, if I'm using a 350 or 500W at full power up hills I need to figure out what capacity I'll need anyway.

 

[D8ve]

If you find a hub geared bike then crank drive is an option.
One of the things about slow charge rate is it reduces the stress on the batteries so they last longer.

 

[Ash21014]

Crank drive is what I had before but it was not highly reliable, if there was a problem with the chain or gearing system I was dead in the water whereas a hub motor would continue to work on the throttle no problem.

 

[Ash21014]

So many to choose from http://www.evanscycles.com/categories/bikes/mountain-bikes/f/unisex#!Brake+Type=Hydraulic+Disc!price_from=300;price_to=590;on_sale=;sort=asc;

is there any particular bike that stands out here for an ebike conversion with a 350W or 500W rear motor?

I think I'd like large tyres because I feel they give me more stability when maneuvering.

 

[Deleted member 4366]

Why not get a used bike from Ebay? It'll be half the price and just as good.

 

[baldylox]

I second that view, eBay is a great place to get a real bargain bike. If you're lucky you can find a really good full suspension MTB which has been barely used for a fraction of it's retail price, I did and certainly don't regret it or miss the "new bike" feel it'll soon get a few knocks when you take it off road.

 

[Ash21014]

I'd prefer to have a new bike, not just for warranty reasons but because I know that it hasn't been put under a lot of stress and suffered metal fatigue or has hidden problems waiting to happen. For me it's a small price to pay, these bikes aren't expensive relatively.

 

[trex]

they'd void your guarantee when you convert a new bike to electric. Get a second hand from gumtree.

 

[Deleted member 4366]

I'd prefer to have a new bike, not just for warranty reasons but because I know that it hasn't been put under a lot of stress and suffered metal fatigue or has hidden problems waiting to happen. For me it's a small price to pay, these bikes aren't expensive relatively.

Normal bikes don't need any warranty. Everything can be fixed very cheaply. I've never heard of hidden problems, nor metal fatigue, except on proper off-road bikes that have been used for serious off-roading. Normal, hard-tail mountain bikes won't give you any problems.

 

[Ash21014]

Well I just prefer a new bike from a proper shop. And I've got the money for it so it's not a problem.

So to quote

In other words, you want a normal bike with a triangular frame, derailleur gears and disc brakes.

Any of those bikes from that site I linked would be fine as long as they met that criteria? With preferably a suspension.

 

[Ash21014]

What do you guys think of this model?

http://www.evanscycles.com/products/cannondale/trail-6-29er-2015-mountain-bike-ec071451

It seems to get good reviews.

 

[trex]

plenty of low end Chinese components: Suntour XCT fork, Promax brakes, Acera derailleur, square tappered bottom bracket, KMC Z chain. Not an upgrade from your previous Sirocco CD beside the seat post, headset and rims.

 

[Nealh]

It's nice to buy new but for that money you can get some quality used bikes on Fleabay with much better components.