Brompton with 3 speed derailleur instead of hub?

philepo

Über Member
Hello all.
I have a 5 speed hub Brompton that i am about to sell on ebay as prices for Bromptons are sky high at the moment. I will then order a new one when the demand falls back post covid. My question is should i buy 2 speed derailleur in order to convert to a 3 speed derailleur (i am in a slightly hilly area) or a 3 speed hub. I dont want the clumsy 6 speed and i am thinking a 3 speed derailleur would be prety light. Has anyone used the conversion kit from Bikegang? It seems v good value at 40 quid or so, but if its a bit iffy then i might stick to a hub any thoughts much appreaciated! Here's the kit: https://www.bikegang.co.uk/bikegang...fter-Kit-MiniMODs-x-Sturmey-Archer-p115439619
 
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philepo

philepo

Über Member
https://www.sjscycles.co.uk/sprockets/minimods-brompton-3-cog-upgrade-kit-12-14-17t/

This is it from SJS... looks like a no brainer compared to a 3 speed hub, what you reckon???
 
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philepo

philepo

Über Member
Clumsy 6 speed hub. I have got one and it works fine. I dont do clumsy.
Personally, when i hired a demonstrator i didn't like it. Imho using 2 shifters is clumsy because if I forget whether I'm in e.g. gear 4 or 5 then changing the next gear suddenly becomes clumsy. Plus it combines the disadvantage of derailleur with the weight of a hub. Just seems a really poor design to me, but each to their own, if it suits you fair enough but i like the simplicity of full hub gears or efficiency of full derailleur gears.

If it was a normal shifting hub I'd like it.

Anyway, any knowledge of the 3 speed derailleur conversion?
 
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philepo

philepo

Über Member
So i think i have managed to find my own answer so I'll leave it here for, err, posterity...

My favoured gear inches at speed is around 65-75 gi on my upright commuter bike with multi gears on the flat... yes, I'm not into speed, i don't like getting to work sweaty. And i sometimes drop to 54 gi on short inclines. I only use 1st (38 gi) on a short steep slope, any more than that and I'll walk! I test rode a standard 6 speed and liked the gears 3 and 4 as changes were on the derailleur and easy (52/64 gi). But the change up to 5th (and down 2nd) involves 2 handlebar levers and i suppose if you use your bike every day this becomes second nature but i just found that in the middle of traffic and needing to make a quick decision to change gear i had to think which way to prod the double levers, and found that irritating... the 2x3 system has zero advantages over the 5 speed hub it replaced and several drawbacks. So, this leaves me with 2 speed derailleur vs 3 speed hub. If i was just buying the bike to travel by train i think 0.5 kg weight saving would swing it, but i mainly use it for taking in the car going for breaks etc, so the bail out low gear would be handy as i might be in eg cornwall or scotland. What i thought was i could convert the 2 speed derailleur to a 3 speed derailleur... and you can, but it simply makes the jumps between gears smaller not wider, a good thing but not an alternative to a 3 speed hub. My only nagging doubt now is i liked the closer ratios of the 6 speed hub but loathed the clumsy shifting.... hmmm

I will probably go with either -7% 2 speed at 52, 69 gi or the -18% 3sp hub at 39, 52, 69 gi... obviously the 69 gi on the 2 speed is direct drive so a little more efficient.

I wonder if 2 speed but with a double front chain ring would be compromise as then if in hilly area could flip to lower ratio... bit fiddly tho, which is what i was trying to avoid!

Hmmm, still can't decide, maybe I'll just keep my old 5 speed!
 
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