Brompton - upgrade or buy new?

[Skids]

Hi,

I am thinking of upgrading my Brompton to extend the surface types that I am happy to ride it over and I am wondering about converting it with kits from Kinetics to allow me to fit wider tyres and gain more gears. I'm thinking of the eighteen inch wheels with 50mm tyres.

Or should I be looking at the G-Line?

I'm interested in any user experiences as well as any other helpful comments.

S

[pjclinch]

Hi,

I am thinking of upgrading my Brompton to extend the surface types that I am happy to ride it over and I am wondering about converting it with kits from Kinetics to allow me to fit wider tyres and gain more gears. I'm thinking of the eighteen inch wheels with 50mm tyres.

Or should I be looking at the G-Line?

I'm interested in any user experiences as well as any other helpful comments.

I've not personally used a Kinetics Brom conversion, but I've been a customer of Ben's for over 20 years and trust him to do a good build.

Part of the choice here will be how specifically do you want stuff? If it's 18" wheels you really want then an off-the-shelf G has 20", so that plays to a Kinetics conversion, but if it's just "bigger than usual with wider tyres" the G has you covered.
Other things you might want that nod towards a Kinetics conversion are more gears (e.g., an Alfine 11) or alternatives to Brompton's supplied brakes. Belt drive is also an option with Kinetics, though that does add quite a bit to the price. You can also have (within reason, or at least the RAL chart) any colour you like.

(Or you can get Kinetics upgrades on a G...)

Part of the equation will be what state the existing bike is in. The better it is the better the resale value will be to put towards a G, where if it's a bit tatty but basically sound you can factor a clean and repaint into part of the upgrade.

(Faced with a similar choice coming up in a couple of years I'll probably go for a belt/Alfine 8/discs conversion, but keep the 16" wheels for the smaller fold.)

Pete.

[fatmac]

Back in the 80's, I used to ride my M3L on day rides (70~90 miles) & some offroad bits, including some of the South Downs Way, it coped well enough, but I had replaced those 'U' shaped bars with straights, which made it much less twitchy.

If it is an old model, I suggest considering the G-Line.

[sizbut]

I've just bought a G Line and sold my C Line. I liked a lot about the C. But I never got confident enough with it's twitchy handling to do basics like look over my shoulder whilst also indicating. And as a heavier rider I was always worrying about the slightest rumble from below might be a flat.

The G by comparison is stability heaven but without being sluggish when you want it to steer. The linear 8-speed gears are lovely. Not much different than the 6-speed C in terms of range but much easier to get the gear you want in operation. I might go to a smaller chainring but we'll give it more time and rides for that decision.

The tyres look ridiculously OTT but once you've ridden them you'll forgive that. All the worries about anything other than smooth tarmac have gone.

Yes it's bigger and it's heavier. If I were a daily on/off other public transport commuter I can see that would be a serious issue and staying with a more standard Brompton would still make sense - fortunately I'm not and if I do take the G on a train or bus it's still smaller than a full bike.

Gripes - naturally. What's with the ultra wide heavily tapering rack that makes it incompatible with either of my existing rack bags? You can't lower the seat post all the way so that the bung on the bottom acts as a anti-roll brake - WARNING: Folded G Line bikes with a rack will roll on the slightest slope. And if that suspension bloke is doing anything it's undetectable even when I put my full weight on it (fortunately the OTT tyres and long seatpost make that not critical, just a would be nice). And I appear too weak to easily remove the pedal when folding but hope that will improve with some wear and usage.

[Brucey]

......(Faced with a similar choice coming up in a couple of years I'll probably go for a belt/Alfine 8/discs conversion......

what goes on with the belt and the fold?

[rareposter]

what goes on with the belt and the fold?

https://www.cyclingabout.com/belt-drive ... ing-bikes/

He uses a dremel! And some welding gear!
Right up your street.

Tern have had a folding belt-drive bike for a while now. Kind of specialist but certainly not unique.

[pjclinch]

......(Faced with a similar choice coming up in a couple of years I'll probably go for a belt/Alfine 8/discs conversion......

what goes on with the belt and the fold?

Very much the same as a chain, but with a suitably reworked tensioner.

The Brompton isn't very chain guard friendly and they use a lot of salt in Dundee in winter, it's fairly common that I change the chain as past worth trying to revive about March, hence the interest in the belt.

Pete.

[Skids]

what goes on with the belt and the fold?

The chain tensioner is replaced with a custom belt tensioner

Part of the equation will be what state the existing bike is in.

Its a 2004 Mk 3, so the shorter frame which may be more prone to cracking than the redesigned Mk 4.

(Faced with a similar choice coming up in a couple of years I'll probably go for a belt/Alfine 8/discs conversion, but keep the 16" wheels for the smaller fold.)

If I understand correctly the 18 inch is a 355 tyre so is just 6mm greater diameter than the standard 349 Brompton meaning that the Bike folds ok and is just a little bit wider when folded.

day rides (70~90 miles) & some offroad bits

Respect!

The linear 8-speed gears are lovely. Not much different than the 6-speed C in terms of range but much easier to get the gear you want in operation.

The only mod I have made so far to my Mk3 is to fit a 18/12 rear cluster (?) to the SRAM 3 speed which gives me a 280% range - I fitted it for riding in Cornwall.

I think I may be tending towards the G-Line which would mean that I would have two folders to choose from. Certainly the influencers like it but they would wouldn't they?

Mind you my judgement is impaired at present by a reasonable red wine - hic !

[Brucey]

I only ask because, typically, one of the many things that will wreck a belt is any form of fold or crease. T his kind of damage is made more likely whenever the belt lacks tension (ie especially when the bike is folded). Normally this kind of belt damage only happens during transit or when the belt is handled (eg when being fitted), but on a folding bike, the belt seems more vulnerable to such damage, because it could happen in service, too.

FWIW I suspect that you would really have to hate chains before the £395 cost would be palatable. Saving time? Maybe, if nothing goes wrong (which is not that uncommon with conversions). If you are just attracted by the cleanliness aspect, note the following;

1) if your clothes make contact with an oily chain, they are very likely to get dirty. However, a similar contact with a nice clean belt might tear them to shreds instead.

2) Any chain can be rendered almost perfectly clean by cleaning it (once) and thenceforth lubricating via molten wax. This is considerably less expensive than a belt, but almost as effective at keeping your togs clean.

[pjclinch]

FWIW I suspect that you would really have to hate chains before the £395 cost would be palatable. Saving time? Maybe, if nothing goes wrong (which is not that uncommon with conversions). If you are just attracted by the cleanliness aspect, note the following;

1) if your clothes make contact with an oily chain, they are very likely to get dirty. However, a similar contact with a nice clean belt might tear them to shreds instead.

The fold-to-the-inside on the Brom makes contact with the chain pretty much limited to deliberate (e.g., cleaning it, putting it back on).

2) Any chain can be rendered almost perfectly clean by cleaning it (once) and thenceforth lubricating via molten wax. This is considerably less expensive than a belt, but almost as effective at keeping your togs clean.

And frequent lubrication with molten wax (and with the amount of salt that gets used November through to March here it needs to be frequent) doesn't take any time or faff at all...

Yes, £400 is a lot of money, but it'll be out of a pension lump sum with which I want to treat myself a bit, and not resuscitating a chain that's stopped going round bends again thanks to the local salt use for the remainder of the bike's working life strikes me as palatable.

I get that you think belts are a solution to a problem that doesn't exist, but quite a few of us are very happy with belts despite considerable experience with chains because we actually have that problem you don't!

Pete.

[Cyclothesist]

There's Silca Synergetic lube. I use that on all my bikes now. I used to commute through the winter to work in Scotland like you. (Now retired - yippee!). I can empathise with the salt and grimey state of the roads. Synergetic though expensive for a lube has kept my drivetrain running clean and smooth. Chains do last 1.5 to twice as long c.f. Finish Line wet and the dry lube. So the price is worth it.
I do wipe the chain after every ride and parsimoniously relube if it's sounding/feeling a bit dry.
That works for me (just one city away from you). I don't have a belt drive but they look interesting too. On the hills I might begrudge the inefficiency c.f. a clean chain though.

[Skids]

Synergetic though expensive for a lube has kept my drivetrain running clean and smooth.

Is this the stuff : https://road.cc/content/review/silca-sy ... ube-286041 ?

S

[Skids]

Thank for all your thoughts. Having read a number of reviews and thought back to some of the rides I have used my Brompton on, such as off road through the Forest of Dean, I have decided to stick with my present machine for the time being.

The key advantage of the classic Brompton is its compact fold and while the G-Line still folds well it results in a larger package. It is also in competition with many other twenty inch folders some which cost a fifth of the price, yet are well thought of e.g. Halfords Intercity 9.

S

[Cyclothesist]

Synergetic though expensive for a lube has kept my drivetrain running clean and smooth.

Is this the stuff : https://road.cc/content/review/silca-sy ... ube-286041 ?

S

Yes. That's it!

[plancashire]

I have a Brompton M3L I bought in 2004. It's still going strong - rode it today. I used to ride on a gravel track on my way to work on the summer. Sand is also used a lot to bed the blocks many bike tracks are made from here - it finds its way out between the blocks, encouraged by ants. To protect the chain more I modified the bike in two ways very early on:

Add a much longer mudflap at the front.

Add a piece of clear semi-rigid plastic taped to the rear mudguard next to the chain to prevent spray and dust from the rear wheel that emerges from the side of the mudguard getting onto the chain. Fitting the plastic closely is a process of trial and error with a paper template.

Brompton should have done this themselves. They should also have added a partial chainguard, although the folding mechanism makes this tricky.

The chain seems to survive OK. I still have the original chain ring, so it can't be that bad.