Winter Tyres

[Mussels]

I reached the limit of the TopContact's ability yesterday, sheet ice with rainwater running over the top is too much. They were the conditions that made me fall off with the studded tyres last winter, this time I decided not to make the same mistake and when the grip felt too bad I got off.
These tyres are probably not as good as full on winter spikes but they are a very good compromise.

 

[Tourangang]

any chance of puttting a image of your heavily moded e bike

merry christmas

John

 

[jkirkebo]

any chance of puttting a image of your heavily moded e bike

John

Sure, no problem.

Since my bike is my only means of transport to/from the railway station (I take the train to work), I needed an e-bike that could be depended on year round regardless of weather conditions. Since no such e-bike seems to exist I started with a US model Ezee Forza (with the 350W motor) and changed what I deemed neccessary.

Picture comments

Forza-1
The Forza was delivered with a "comfort" gel seat, short suspension seat post and swept-back riser bars. I can't stand that seating position or type of seat, so I changed the seatpost to a 400mm one (still 20mm too short, so I have a 500mm titanium one on order), the seat to a proper narrow MTB seat and the bars to straight ones.

For the winter the tyres are Nokian WXC300's. Summer tyres are Hutchinson Pythons.

Forza-2
Real estate on the handle bars is in short supply
From the top left:
- Gear shifter is changed to a SRAM X.9, this works better in winter than the standard Deore triggers. The twist shifter is much easier to operate with thick mitts on, and the 1:1 actuation ratio works better against frozen wires.
- Brakes have been changed to Avid Code 5 hydraulics.These have superior braking force and modulation compared to the original mechanical disc brakes. Also there's no wires to freeze.
- Twin Niterider HID lamps, one spot and one flood.
- Cycle Analyst mounted on the stem.
- The CA uses the same plug as the handlerbar led/switch assembly. Since the LEDs are of no use when you have a CA, the assembly is removed and replaced by a handlebar mounted light switch for the standard LED lights.
- The bell has been replaced by a better one.
- The throttle has been replaced by a left side half throttle.

Lower image:
Under the rear rack a custom battery for the NR HID lights are mounted. A 22cm long 50mm PVC pipe contains 12 (3s4p) 18650 Li-ion cells removed from otherwise defective laptop batteries, and a protection module. Runtime approx. 3 hours.

Forza-3
4 piston calipers and 185mm discs stop the heavy bike scary fast. Somewhere around 20 feet from 30mph.

Forza-4
The seat bag contains a 7.2V (6s) 12Ah NiMh booster pack, made of 6 D-cells (Titanium brand). The controller has been swapped for a customized Ezee controller from ebikes.ca that can take the extra voltage. Cruising speed approx. 23 mph, top speed a bit over 25. Peak power ~800W and cruising power ~400W.

Forza-5
The rear derailleur have been swapped for a SRAM X.7 (because of the 1:1 actuation ratio needed) and the gear wires to Avid Flak Jackets to stop water intrusion and freezing.

Also a pedelec sensor have been fitted, the US model doesn't have one standard.

 

[Northern Irelander]

nice machine jkirk, but I still think you'd have better control with that 800w beast on the back wheel

The nokian knobblies and spikes are whats keeping you upright.

Is that a single chain ring? It looks quite high geared, in order for the bike to be '2wd'
Im guessing you are pedalling at a fair lick, otherwise it's predominantly fwd

 

[Northern Irelander]

I reached the limit of the TopContact's ability yesterday, sheet ice with rainwater running over the top is too much. They were the conditions that made me fall off with the studded tyres last winter, this time I decided not to make the same mistake and when the grip felt too bad I got off.
These tyres are probably not as good as full on winter spikes but they are a very good compromise.

How disappointing, useful info, I was just about to order a set.

So they don't work on water over ice or slush over snow,

Does the broad centre bead aquaplane under certain conditions?

Needs a few grooves cut into it??

Looks like I'll be going for Schwalbe marathon winters then

 

[flecc]

Im guessing you are pedalling at a fair lick, otherwise it's predominantly fwd

I think the Deore 9 set has a top sprocket of 11 teeth and that chainring is 52 tooth, so with it's 26" tyres the top gear would be about 122" and the pedal cadences would be about 63 at 23 mph and 68 at 25 mph.

These are both moderate, the generally accepted cycle sport cadence for best efficiency is about 90.

That's a nicely set-up bike you have there jkirkebo.
.

 

[jkirkebo]

nice machine jkirk, but I still think you'd have better control with that 800w beast on the back wheel

No go, I have such a machine too. It's a 2004 Giant NRS 2 full suspension bike with a 400W Ezee kit on the rear wheel. I could not chance to mount a motor hub to the expensive, lightweight front fork (Manitou Scarab Platinum).

The battery is a triangle shaped 48.1V nominal (13s8p LiMn w/Konion cells from Bosch Fatpacks) 8.8Ah one, mounted in a frame bag. The controller is an Infineon 48V 20A. Peak power about 1300 watts, top speed around 30mph.

In the winter, I have Nokian Extreme 294 tyres on it. Most days it works okay (and is great fun!), but when conditions are bad (a lot of "mushy" brown snow on unplowed roads) I can't control it in any way. The front wheel slides everywhere and there's just no grip. The FWD Forza excels in these conditions as the FWD pulls the front wheel through the stuff, keeping it straight.

But on steep single-track in the woods in summer, the RWD is much better since a FWD would loose traction too often.

 

[jkirkebo]

I think the Deore 9 set has a top sprocket of 11 teeth and that chainring is 52 tooth, so with it's 26" tyres the top gear would be about 122" and the pedal cadences would be about 63 at 23 mph and 68 at 25 mph.

These are both moderate, the generally accepted cycle sport cadence for best efficiency is about 90.

You are correct about the rear cassette, which is a 11-32. The front however is 48T. This is big enough that I seldom use the 11T rear. At cruising speed (typically 22-23mph) I usually prefer the 12T rear. My pedaling typically adds about 2mph to the speed, more on hills.

My NRS needs a bigger front ring though, I'm going to order a 52T for it for the 30mph top speed.

 

[Mussels]

How disappointing, useful info, I was just about to order a set.

So they don't work on water over ice or slush over snow,

Does the broad centre bead aquaplane under certain conditions?

Needs a few grooves cut into it??

Looks like I'll be going for Schwalbe marathon winters then

The contis don't aquaplane and in the same slush only big knobblies like the Nokians or snow stud tyres would work. When the ice was too slippery the snow stud tyres would have failed as they only have two rows of studs, the Marathon winters should be better then as they have more studs. I'm not at all disappointed with the Contis as they have been a good compromise with a much better ride on normal roads.
I don't know what I'll go for next year, it will probably be the Marathon Winters because I haven't tried them yet.

 

[stevebee]

I've used Schwalbe Ice Spikers on my Thorn Raven this cold spell. Last year I tried Marathon Snow but found the rear still slid. The Ice Spikers though were a different kettle of fish. No sliding on ice or snow - even tried throwing it about on our frozen car park at work but it stayed upright all the time. Noisy on Tarmac but pumped up to 65psi they are fine - at least I don't need a bell!!
I went for these as I thought I will only use them when conditions are bad enough and will switch back when ok. Considered Nokian but more difficult to find and I like Schwalbe tyres. Never tried on my electric but they are really grippy so I would always go overspec to avoid a fall