Brompton electrification

[Scottyf]

If the chain is not long enough you can add links and use a couple of split pins to join them.

 

[jerrysimon]

So to solve the problem I have to add the chain tensioner back? Not sure if the chain is long enough now lol

Easy to add or remove links. You are also going to have to drill out the tensioner fixing hole as it will be too small for the larger motor shaft.

PS and it is made to go over the smaller nut that attached to the original back wheel shaft (see above pic). The new motor nut will be larger. As with all these mods there are always little snags to over come.

PPS I see originally it also had the two speed derailleur fitted. You can remove that and associated cable, fixings and changer as you have one speed now. You will probably have to buy the single speed tensioner which is different, though it might work with the original one

Regards

Jerry

 

[cwah]

Thanks Jerry

Going to re-align the forkend first. A simple plier should be enough isn't it? going to do it now.

 

[cwah]

Actually, it seems that by tightening the bolt, the forkend realign by itself

Have to test the controller now

 

[cwah]

Actually the chain fits. I just had a double knob lol... and knobbed myself.

Now the chain is a bit loose. Need to put the chain tensioner or make the chain shorter

 

[johnc461165]

Hi cwah, good to see you are making progress with the conversion. John

 

[cwah]

Thanks John. Your work on the rear fork was really good. Thanks to you this Brompton project can move forward

It's almost there

 

[jerrysimon]

Cwah,

If you don't put the chain tensioner back on you won't be able to wing the rear triangle under without the chain falling off.

Also I think the chain tensioner is required to ensure the rear suspension can operate correctly (the triangle moves up and down when riding) again without effecting the chain position/ability to stay on the rings.

Regards

Jerry

 

[cwah]

Thanks. Will try to add the chain tensionner. Keep you posted

 

[cwah]

My rear tyre is rubbing against the rear fork:

Shall I get a hacksaw and remove a bit of the fork? Is it ok to do that?

 

[neptune]

I would only remove that bit as a last resort . You have two options in my opinion. Option one . Remove rear wheel, and if you can get in with an angle grinder, grind half of that bit away . Although that will reduce its strength, half a loaf is better than no bread . Option two,the ultimate solution would be to remove that part, and make a new part, and weld it in about one inch nearer the front of the bike. Actually there is a third option . Remove the part , and check if there is side to side flexing of the bike rear triangle under pressure with the wheel fitted . If this unduly weakens the frame, you can still have a new bit welded in to clear the tyre.

 

[cwah]

I was thinking about option 1 with a hacksaw (I don't have an angle grinder):

I was thinking about removing the area I dotted in red. Would that be ok?

I suppose I'll have to cover it with something after cutting that part?

 

[Cakey]

I would not cut it as a v shape

 

[Cakey]

I would curved file it till you get clearance

 

[neptune]

OK. Go for it, on the understanding that if it does not work out, you still have the option to have a new bit welded in . Here is how I would do it .As you are cutting at an angle, the hard bit will be getting the cut started without tha blade skidding across the metal . So first mark the metal with your blade at 90 degrees to the workpiece .Not too deep , just 3 or 4 strokes to mark the metal . Remove the blade from your hacksaw, and reassemble with the blade inside the frame, and the hacksaw frame on the outside of the bike frame . Take it easy and slow. Once you get started you can not change the angle of cut . Brush paint workpiece inside and out. Then cover with tape. Good luck.
Cakeys method is better , use a large diameter round or half-round file. Use a big bastard. [ Bastard is a type of file.]

 

[cwah]

Do you have a link to the type of tool I should use?

I have now a silverline drill:
Hammer DIY Power Drilll 500w Silverline 265897 240V 3 Years Warranty DH002 (5024763040856) | eBay

Can I convert it to an angle grinder?

 

[jerrysimon]

I don't understand that surely the joining piece is not that thick ?

I will go check the clearance on mine.

Kojak tires may give you more clearance as they are thinner, not as much puncture protection though. I have been running Kojaks on mine for 10 months and had one puncture on my daily commute.

PS Ok I have about 20-25mm clearance from that part to the tire on mine and of course widening the forks will bring the dropouts nearer to that part, as they arc backwards.

Is it actually rubbing or locked solid, as I said Kojaks would give you more clearance.

Regards

Jerry

 

[Cyclezee]

Hi CWAH,

Not sure how much metal you need to remove, if it is only a mm or two and you can actually rotate the wheel, you could try silicone carbide abrasive paper squeezed between the tyre and tube and work it to a fro by gripping tyre and rotating the wheel by hand. If it is more than a couple of mm a hand file or rotary power tool would be needed.

 

[neptune]

I would not consider buying an angle grinder[from £15] just for one job. There is a chance that you could not get it in the space available . Buy beg or borrow a large round or half round file. Some files come with a spike at the end that plugs into a wooden handle . Do not use this type without a handle . Work slow and patiently, and if you are not used to hand tool work, expect blisters. The actual type of file as regards course or fine is not critical .The bastard reference, although true, was my attempt at humour. Go for it, you can do it. You can buy a tool called a rotary rasp which fits into a power drill , but they are not cheap, and need skill to be effective .

 

[flecc]

Another approach if the metal is quite thin is to just indent it. Back the tube with a heavy hammer like a club hammer, then strike the tube with a second hammer, preferably the rounded head of a ball pene hammer, to indent it sufficiently.

The end result will be a little stronger than if you remove the metal by filing or cutting.