Is there a 'best' electric start conversion? Looking at the viability of converting a MKIIA and was wondering what options I have besides CWN and Alton?
RGM are working on one but that's been a long time. For the MK2a you need to consider the black box airfilter which may clash with the CWN version.
Black box airfilter has been removed. running a single mikuni so hopefully no obstructions.
If the airbox is gone then the CNW is the better engineered of the 2 available, but both will work.
Correct me if I am wrong here but I think you can buy CnW parts from Holland avoiding the killer import tax from the USA.
I have used CnW parts on an 850 rebuild and have to say the quality of their parts is outstanding.
Someone asked a similar question recently in one of the forums.
Here is my opinion - truth is they are both superbly made in terms of quality. And both companies are great to work with.
Each have their benefits and drawbacks:
Colorado Norton Works
- + comes with a primary belt drive
- - you cannot use the standard air filter (cNw were looking at a building a cut down ham can which maintains a classic appearance)
- + it uses the standard alternator stator (which opens up your options for charging)
- + wound field motor means positive or negative earth compatibility
- + off the shelf (Harley style) motor with solenoid engagement
- - transmission of starter torque is solely via the alternator rotor woodruff key
- + maintains the original air filter
- - comes with it’s own alternator (which limits your choice on charging solutions)
- - permanent magnet motor means a modification (or Alton recommend they provide a different unit) to support negative earth installs
- - bespoke motor using plastic shear pins to protect against backfire
Most people’s choice is driven by cost vs geography:
- if you are in the US you buy the cNw unit
- if you are in UK or Europe you buy the Alton.
Thinking of it like this, it means the pricing is similar.
I bucked the pattern, and got the cNw kit, and am really happy with the quality of the kit - I like Matt’s stuff. It’s a project bike, and I don’t have the air filter to consider, plus I was in the market for a belt drive too.
Either way, I feel we’re blessed to have two great choices!
Two other options were available:
Old Britts - http://www.oldbritts.com/ob_3860.htm
- This was a limited run,
- Fred & Ella are sadly retiring
- I this is no longer an option.
Quiet Power Drive (QPD) - http://www.quietpowerdrive.com/QPDhtm/QPDhome.htm
- Bob ‘Ozzie’ Oswald is also in the process of retiring
- I believe he worked with Kenny Dreer on the electric start for his concept 880 - which was Kenny’s evolution of the production Commando.
- I worked with Bob on a belt drive project, and found his communication and timescales incredibly frustrating.
Both of these systems were nice as the starter drove a crown wheel attached to the clutch basket, which made the entire setup low profile and unobtrusive.
The compulsory belt drive with the CNW system is a negative if you prefer a chain drive as some people do (well I do!).
agreed, and do feel free to ignore my post, as I said it's just my opinion :-)
Holland Norton Works do indeed list the CnW kit, but they're out of stock at the moment (see https://www.hollandnortonworks.eu/en/exclusive-commando-parts).
Buying stuff from HNW will be more complex now that Brexit has happened, but possibly less so than buying from the U.S. However, they are nearer, and Constant Trossèl is a delight to deal with.
Hi Grant read with interest your post, I would like to make my own starter system for my 750 along the lines of the Old Britts one. I am trying to find out what starter Fred used, think it is a Harley Sportster? but would like to confirm before getting one. Also the ring gear, it looks to be a Harley one, if so which one or was it a special made by Fred. Would you know?
Have tried to contact Fred on email@example.com but it has bounced back presumably because Fred has retired now?
Can’t afford to buy either CNW or Alton system but could afford just a starter and ring gear as I have a belt drive and the rest of the bits I can make.
Hope you can help.
Tony, I have gone the DIY route, KLF300 starter with internal planetary gears and a GL1100 sprag unit. Problem is it won't work with a belt drive as the sprag unit needs oil.
The Old Britts ring gear is a special due to the diameter not matching the Harley but the gear profile is a standard used on a lot of starters so can be ordered from a gear cutter once you know the profile, buy the starter and then measure the gear to determine profile.
I like your comments and have the same opinion. Belt drive, only a problem if the gearbox is not fixed and blocked in the correct position. Had more than 30'000 on my first belt and only changed
before a longer trip.
Interesting John, have been looking at using similar, Honda, starter but on the timing side but worried that the crank drive gear would not be up to it. Article in Roadholder by a chap looking to do similar on a Dommie looks interesting and would like to see how he gets on.
Am favouring using the the starter to drive the clutch particularly with a belt fitted.
My clutch drum is 185mm dia, a few ring gears for Harleys look to be about a right diameter so was wondering if Old Britts used one of them and modified it, but which one?
Mine is driveside, Norton tried the timing side but something was breaking so they dropped the idea in 72 and started from scratch again to give the MK3 design. Triumph tried timing side too and chased breaking components by adding strength to each broken part until the crankcases broke themselves and went no further.
I reduce the triplex sprocket to duplex and use Merc duplex timing chain as a primary chain, use the thinnest alternator which is the 10.5A 3 phase and with some other tweaks this gives space for the GL1100 sprag unit to run on the driveside of the crank. The starter motor sits in the magneto position as per MK3 and Alton and a chain drive runs to a sprocket behind the primary and then a shaft runs inside with another sprocket that runs a chain to the GL1100 sprag unit. I used the Honda Africa Twin and Polaris 700 twin starter setups as the basis for the starter gearing ratios. It easily spins the 750, yet to try it on an 850.
The only original parts I modify are the inner and outer primary cases, easily bought 2nd hand if the changes need reversing.
A couple of thoughts on Grants excellent summary above
Alton - the woodruff key shouldn't be relied on for load transfer. The nut on the crankshaft needs to be torqued, and to my mind retorqued after the first good ride, so that all being compressed together transfers load between elements. Any relaxation of the sprocket on its taper will affect that compression hence my thought on retorquing. Just my opinion of course.
Alton - changing polarity. No too difficult for any who are handy with spanners, Alton can provide a nice clear instruction sheet, but they recommend returning to base rather than DIY.
Not sure its relevant, but I recall from when I looked at this option a couple of years it involved some significant engineering which was reflected in the cost - all up i recollect it was about £3200 at the time - not cheap compared to the alternatives.
The Harley starter is a standard Nippon Denso offset gear reduction unit which is found on many, many vehicles over the last 30 years. Usually it is 1.4kW, but there are 1kW units. As it is series wound it doesn't care about polarity. The only differences between different models are the starter dogs and the casting which bolts up to the bellhousing. Crude violent things.
I am hoping that modern electronics will allow me to control the torque and avoid the problems that Norton and Triumph struggled with. As an example I can apply gentle torque and just wait until it reaches TDC, not something that Norton could have done in the '70s.
I am only aiming for a low compression 600cc, not a high comp 750cc, and so far the development is going well. The mechanical side works satisfactorily, but I have a lot of improvements in mind.
I knew about the Bonneville, but I only learned that Norton had tried this in the last week!
Just for info, here a drawing from the Norton Villiers patent of the unfortunate starter-to-be:
Just as I suspected. Norton are stealing a lot of my ideas.