dawes discovery 401 conversion
 

Hi
i have the above bike and was going to consider a 500w electric bike upgrade, my only worry is that the wheels are 700 x 32c in size.
They are very narrow tyres and would this cause a problem if i put a rear hub conversion kit on the bike? in terms of weight along with a 13 stone guy sat on the bike!!

many thanks

you using a rear hub motor or what (mid drive, front??)

Wiht a rear, you probably won't get the 9 speed cassette to fit. They are designed for 7 speeds. I wouldn't put a front motor on a non steel fork (steel will bend, anything else will break and cause a sudden crash).

Yeah, tires are kinda small for ya. I'll bet you could put 38mm tires on there. I put 47mm tires on my Bianchi hybrid. There is usually a lot of room for wider rims (especially if you don't need fenders).

32mm will carry the load (at the right pressure), just like any tire. Fatter tires will give you a smoother ride, more protection against pinch flats, and probably make you a lot happier.

i was thinking of a rear kit, so reading what you have put maybe selling my 401 and going for a bike that suits a rear kit mat be the way to go. can you suggest any mid price bikes that would be suitable? im in the UK and speed is restricted to 15mph but the kit im getting can be switched to (off-road) mode 28mph. which is what i will use.

thank you

Personally I use 1990 steel mountain bikes with 8 speed rear cassette. I end up using a 7 speed cassette as they use the same chain and derailer (although I suppose if I shifted into 1st gear it would shift the chain off the cassette.

Advice: anything with an 8 speed cassette will work. You can get a 7 speed cassette with your hub motor or squeeze an 8 speed on there (with some washers/spacers). Either way will work.

Steel is the best for a conversion, as it has some flexibility to bend (rather than break) when stressed, and is some what repairable. This makes it optimum for higher powered kits (1000w or more). Aluminum is OK too with lighter power (250w to 500w).

(FYI, I have steel and aluminum 350 watt builds based off of 8 speed mountain bikes, hybrids, and a road single speed).

Choose a steel (or aluminum) mountain bike or hybrid that has an 8 speed cassette.

I converted my steel touring bike with a BionX rear hub. I run 700c 28mm tires. No problems at all. I'm 230 lbs (16+ stone?), the converted bike is about 50 lbs and I carry about 20 lbs of gear... so it's a 300 lb (21+ stone?) load. "Tires" aren't an issue. You need to be confident that your frame is strong enough to handle the torque exerted and the extra weight (the BionX system adds about 16 lbs.) You need to be confident that your wheels can handle the extra weight and the extra torque. I'd recommend double walled rims and 36 spokes.

Thank you all for your input, below is the spec for my bike and wondered if you could take a quick look to see if i could possible get a convertible kit for it.
As you can see im a complete novice so any input would be fantastic. I already have a green zebra folding electric bike but with only 6 gears my legs look like road runner when i up the pace.

Discovery 401 - Dawes Cycles Touring Tandem and Sportif bikes

And this is the kit i was thinking of purchasing because its in the UK and comes with a warrnty


500w Rear Wheel Lithium-Ion Battery Conversion Kit

Many thanks for all your help

Yep, I read those bike specs. You should ask them if the kit will work on your bike. They are the one’s taking your money. ;-) Typically due to the width of the motor, you can only put a 7 speed cassette on the motor and get it to fit a standard drop out (which is why they give you the cassette with the motor). That would make it difficult or impossible to use your 9 speed chain and shifters. But, maybe you could spread the rear drop out a little and get it to fit; you would have to know the dimensions. Generally spreading aluminum frames is frowned upon.
Other than that, it looks like a great bike for a conversion.

There is not a lot of detail on the conversion kit, but the battery is the most important part, and a 36v13ah Samsung pack is likely a good battery.
You could always check with this forum for purchase advice and installation advice:
Pedelecs - Electric Bike Community
or
Endless-sphere.com ? Index page

Others will disagree, but FOR ME, an aluminum road frame and fork isn't a good platform for an ebike - I prefer steel. However, you could get by with a rear hub system and good (or double) torque arm(s).

You'll have to get the specs on the dropouts and ask the electric motor manufacturer if it will fit. It looks like the kit is a front wheel kit... you'll need a torque arm to reinforce that fork.

The kit referenced in post #6 is a rear wheel kit. Many of these kits have a rear wheel spacing of 135mm which is appropriate for MTB's. However, your Dawes PROBABLY has 130mm spacing (you can measure) I wouldn't (many would) spread the rear dropouts that much on an aluminum frame.

I look at the picture and description on referenced kit... it has a cassette on it... seem rear wheel. However, when you click on the "options" drop down... it asks only for front wheel size - rather confusing. I have seen electric cargo bikes where the rear wheel is smaller than the front wheel.

Splendid Cycles | EdgeRunner Primo BionX S350 Specs