# Brompton - are there any mods that don’t break your warranty?



## Mrklaw (22 Aug 2018)

thinking if I get a standard 6 speed and find I want to change later to a lower gear using official Brompton parts - is that doable while maintaining the warranty, or do any changes basically void it?

Everyone seems to talk about adjusting gearing in particular to dial in to your preferences


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## BromptonChrispy (22 Aug 2018)

Hmmm, I never thought of that but mine is four years old. How long is the warranty on a Brom? Maybe they’re worth contacting - or the dealer that supplied it to you.


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## Pale Rider (22 Aug 2018)

Using factory bits - in this case different front rings - cannot have any impact on warranty.

Using non-factory bits - such as different hub gears or double front ring conversions - could impact warranty.

Even then, it would be for the dealer/Brompton to show the non-factory modification was the cause of the failure.

In other words, if you did a non-factory gear mod and all the paint fell off the frame or a hinge failed, that would still be covered.

Also bear in mind the dealer makes the initial assessment.

Chances are if you made a claim, the dealer wouldn't even mention to Brompton the gear ring had been changed.


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## rogerzilla (20 Apr 2020)

Mine was so badly built and painted from new that I dismantled and rebuilt the wheels in the first week, then stripped it down and had the frame resprayed the following year. Warranty be damned - they wouldn't get it right a second time either!

In contrast, the Boardman Team Carbon I bought a few years later was so disappointingly perfectly assembled by Halfords that all I was able to improve was to tweak the brake toe-in a bit.


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## 12boy (20 Apr 2020)

They have warranties? Since buying my first new bike in '75 I've never used one. That bike, after being ridden hard for 15 years, and off and on after had some accordion action on the headset and buckling on the top tube, which I noticed 4 or 5 years ago. The bike was a "Witcomb Superlight". Do you think it could be repaired under warranty? Actually, I reckon I got my money's worth, and since there was a little accident that precipitated the frame failure it was probably my fault (or the dog's, who fortunately wasn't hurt) I can't complain.


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## rogerzilla (20 Apr 2020)

Funnily enough, Bromptons suffer from accordion action on the head tube at high mileages. The bottom cup becomes loose because the head tube stretches and ovalises. Lugged frames are naturally reinforced at this point and lugless steel frames should always have reinforcing rings brazed to the top and bottom of the head tube. But no-one told Brompton.

The "cure", incidentally, is the strongest gap-filling Loctite you can get your hands on. 660 worked for me.


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## Kell (29 Apr 2020)

I think 'standard' 6-spd gearing is the 50T front ring. 

You can go up or down using OEM Brompton parts, so I cannot see why changing a 50T ring to a 44T ring would have any impact on warranty as you could order it new from the factory like that - or get the work done at an official dealer.

I don't remember what the options are off-hand for the rear, but it is possible to make minor adjustments that end too. Again, using OEM parts.


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## mitchibob (30 Apr 2020)

Isn't it that different components have different warranties? I was unfortunate enough to have one with the dodgy BB, that wasn't under warranty, got replaced by non-brompton certified place that had a huge Brommie fan mechanic (because I didn't want to buy two BB tools), at reasonable price (because store where I'd bought were quoting ridiculous prices), about a month before they recalled :-(. Have I further reduced warranty by getting my local cool shop to do the repair for me?

However, when it comes to some mods, Brompton could certainly claim that if something has been modified that might have an influence on some other warrantied item failing early, or simply that it hadn't been properly serviced by a Brompton authorised repairer. Certainly, many parts, they wont supply to non-authorised repairers, preventing smaller stores from buying in parts to do certain repairs, especially around forks, headset, etc.

When it comes to gearing, changing from the standard 50T chainring on the 6-speed, to a 44T is an easy change to make that wont affect any part of your warranty, and just requires a 6mm allen key. When you're in the city, you might want to put the 54T on instead. You might want to remove a couple of chain links going from 50T to 44T, but if you're just trying it out, it's not necessary. I rode my 6-speed from London to Cardiff last year with a 54T, with a 44T as a backup in the bag. Once I got there, fitted the 44T because I knew I was going to do some sensible climbs in South Wales, but without master link pliers, could not get the link to split. In the end, just kept the chain at length for 54T, and while a little too low, it still worked fine for the next couple of days of riding 200km about about 2000m elevation. I don't recommend this long-term, but tensioner will take up the slack difference between the two chainrings. But really, use right chain length. If you shorten, and then want to put back if you want bigger chainring for city use, then two quicklinks is fine too, to add back the bit you removed.


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## roley poley (30 Apr 2020)

You might consider bolting a smaller chainwheel on the outside I use a 50/38 easy to fit and cheaper, others on this site do similar. Not Brompton spec but as said above the tensioner will cope with the slacker chain. No front derailleur I stop and move it by hand no shame its not a racing pace shift I need .If anything it eases the bike and my life without honking up hills or over spinning down them.Mind you I am beyond warranty on a 2002 made bike on the same 3 speed sachs hub it came with...PS.it also can come off very easily if you have to return it


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## 12boy (30 Apr 2020)

I went with a 58 tooth to get a higher gear, and added a 38 for lower. Originally I had the 38 on the outside, but this caused the chain to rub a bit, especially under hard pedaling, on the big chain ring. So I now have the 58 on the outer, 38 on the inner. The tensioner takes up the 20 tooth difference fine. This works just as well with a 3 speed IGH, a 1 speed, a 2 speed and thanks to BikeGang, a 3 speed . However, if you fold on the 38, the chain pops off. My BB is 118mm with a 110 BCD crank set. I added a 24 tooth chain ring for extra gnarly hills and it also worked except the bike wouldn't fold since the chain ring bolts hit the chainstays when folding. So ,my experience showed these chain tensioners are very adaptable.


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## Nibor (30 Apr 2020)

I personally changed the chainring to a -12% option using Brompton parts and have had no issues with the 2 warrenty claims I have done.


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## roley poley (30 Apr 2020)

12boy said:


> My BB is 118mm


had to shrink mine to 112mm and mount the smaller outside with spacers on the bolts for non rub on the larger, couldn't get a fold with inner fitting even with the original 119fag BB


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