Brompton - ground clearance/stability when rolling in folded state

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Bugsbunny
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Brompton - ground clearance/stability when rolling in folded state

Postby Bugsbunny » 10 Aug 2018, 7:58am

Edited to make it more clear - thanks Graham. I'm finding it hard to express visually what's in my head into words :-)

Hi guys

I have just added the rear rack (original equipment) to my Brompton.

I want to make my Brompton easier to roll in its folded state as I find the original easy wheels to lack ground clearance. Any Brompton owners here have advice on how to:

- Give it more ground clearance.
- Give it a "wider" base to make it less prone to tipping over. This seems to happen with the Brompton C-bag on the front block (in the folded state).

Is it a simple case of buying bigger easy wheels to get those few extra millimeters of ground clearance?
Do "flat" bottom easy wheels offer more stability than "rounded" wheels?
Can I get a longer screw and add a few millimeters of washers to widen the base where the easy wheels sit to give it more stability?

Any tips from fellow Bromptoneers appreciated.

Bugs
Last edited by Bugsbunny on 10 Aug 2018, 8:53am, edited 2 times in total.

fatboy
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Re: Brompton - ground clearance/stability when rolling

Postby fatboy » 10 Aug 2018, 8:48am

I originally used to wheel my B around using the mini wheels. I quickly worked out that the best approach is to unfold and roll a proper bike and then fold up again when needed; since the fold is so quick this works well for me.
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rfryer
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Re: Brompton - ground clearance/stability when rolling in folded state

Postby rfryer » 10 Aug 2018, 8:58am

I agree with Fatboy. The main time that I wheel mine folded is indoors, where I pull it using the front bag. On carpet the front wheel has a tendency to catch; I compensate by tipping the bike slightly towards myself, but it then rolls in a long arc which I have to keep correcting.

I also experience the tippy problem, dealt with by leaving the bike where it would tip into a wall, or simply removing the bag.

Outdoors, I generally prefer to roll the bike, or carry it with luggage attached and the saddle hooked over my shoulder.

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Graham
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Re: Brompton - ground clearance/stability when rolling in folded state

Postby Graham » 10 Aug 2018, 9:17am

I only leave the C-bag ON if the bike remains unfolded. The C-bag cames OFF for any state of folding.

Although sometimes I will leave the C-bag on and let the back wheel fold under. I consider this inherently unstable and would prop it against a wall or equivalent.

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[XAP]Bob
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Re: Brompton - ground clearance/stability when rolling in folded state

Postby [XAP]Bob » 10 Aug 2018, 10:04am

Bugsbunny wrote:Edited to make it more clear - thanks Graham. I'm finding it hard to express visually what's in my head into words :-)

Hi guys

I have just added the rear rack (original equipment) to my Brompton.

I want to make my Brompton easier to roll in its folded state as I find the original easy wheels to lack ground clearance. Any Brompton owners here have advice on how to:

- Give it more ground clearance.
- Give it a "wider" base to make it less prone to tipping over. This seems to happen with the Brompton C-bag on the front block (in the folded state).

Is it a simple case of buying bigger easy wheels to get those few extra millimeters of ground clearance?
Do "flat" bottom easy wheels offer more stability than "rounded" wheels?
Can I get a longer screw and add a few millimeters of washers to widen the base where the easy wheels sit to give it more stability?

Any tips from fellow Bromptoneers appreciated.

Bugs


Pretty sure one of the bromptons I've used had in line skate wheels instead of the Brompton tiny wheels.
There is some limit in terms of width wrt clearance for heels etc...
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RickH
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Re: Brompton - ground clearance/stability when rolling in folded state

Postby RickH » 10 Aug 2018, 10:17am

It looks like it should be fairly straightforward to swap the supplied wheels for 80mm skate wheels - link.

ambodach
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Re: Brompton - ground clearance/stability when rolling in folded state

Postby ambodach » 10 Aug 2018, 1:37pm

I agree with Graham. Do not leave the bag on when folded. I had a couple of 4 inch diameter wheels lying around so fitted them with slightly longer bolts. Works ok for me for short distances. Still rattle a bit but I will get round to sorting that sometime. A couple of months ago I left a full bag on the bike and folded it into the park position. Turned round to lock the van door and the thing fell over and the pedal gouged the back of my leg. Foolishly thought it would be ok but a week later I had a fortnight of a massive dose of antibiotic to fix the infection. So do not leave the bag on and particularly do not turn your back on it if you do.

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Cunobelin
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Re: Brompton - ground clearance/stability when rolling in folded state

Postby Cunobelin » 10 Aug 2018, 3:39pm

[XAP]Bob wrote:
Bugsbunny wrote:Edited to make it more clear - thanks Graham. I'm finding it hard to express visually what's in my head into words :-)

Hi guys

I have just added the rear rack (original equipment) to my Brompton.

I want to make my Brompton easier to roll in its folded state as I find the original easy wheels to lack ground clearance. Any Brompton owners here have advice on how to:

- Give it more ground clearance.
- Give it a "wider" base to make it less prone to tipping over. This seems to happen with the Brompton C-bag on the front block (in the folded state).

Is it a simple case of buying bigger easy wheels to get those few extra millimeters of ground clearance?
Do "flat" bottom easy wheels offer more stability than "rounded" wheels?
Can I get a longer screw and add a few millimeters of washers to widen the base where the easy wheels sit to give it more stability?

Any tips from fellow Bromptoneers appreciated.

Bugs


Pretty sure one of the bromptons I've used had in line skate wheels instead of the Brompton tiny wheels.
There is some limit in terms of width wrt clearance for heels etc...



Prior totte introduction of the “Easy Wheels” this was a standard modification despite the clearance issues

Barks
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Re: Brompton - ground clearance/stability when rolling in folded state

Postby Barks » 10 Aug 2018, 4:53pm

You will probably find that one of the rearmost easy wheels is located on the ‘inside’ of the rack rail, this is done to minimise the folded width. I moved mine to the outside of the rack like the one opposite - it diesn’t make a massive difference to the stability but can only help as it widens the base width. As mentioned further up, I only ever wheel the bike folded when I really have too - one other help I have is the telescopic seatpost which allows the saddle to raised much higher so that I can walk normally with my hand naturally on the saddle (it also helps to turn the nose of the saddle towards your leg which improves the hang angle of the folded bike when you need to lift it up so that you have a little more clearance between your leg and the bike). I also fold the bungee cords ‘under’ the rack rails (‘under’ when bike unfolded) so that they do not scrape on stones or muck on the pavement surface.

SA_SA_SA
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Re: Brompton - ground clearance/stability when rolling in folded state

Postby SA_SA_SA » 10 Aug 2018, 9:46pm

On ebay there are some modifications that allow one 'easzi' wheel to slide out further to compensate for the offset nature of the standard fitting ie folded brompton wants to fall over on folded front wheel side.
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rmurphy195
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Re: Brompton - ground clearance/stability when rolling in folded state

Postby rmurphy195 » 11 Aug 2018, 12:56pm

Barks wrote:You will probably find that one of the rearmost easy wheels is located on the ‘inside’ of the rack rail, this is done to minimise the folded width. I moved mine to the outside of the rack like the one opposite - it diesn’t make a massive difference to the stability but can only help as it widens the base width. As mentioned further up, I only ever wheel the bike folded when I really have too - one other help I have is the telescopic seatpost which allows the saddle to raised much higher so that I can walk normally with my hand naturally on the saddle (it also helps to turn the nose of the saddle towards your leg which improves the hang angle of the folded bike when you need to lift it up so that you have a little more clearance between your leg and the bike). I also fold the bungee cords ‘under’ the rack rails (‘under’ when bike unfolded) so that they do not scrape on stones or muck on the pavement surface.


+1in On rough ground or concrete I unfold or simply carry it if its only a few yards. Haven't tried the easy wheels yet though, still use the standard ones.
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Bugsbunny
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Re: Brompton - ground clearance/stability when rolling in folded state

Postby Bugsbunny » 13 Aug 2018, 1:41am

Thank you all for your inputs.

Got a cheapy quickfix for now to try out.

I've found one pair of second hand roller wheels (branded Nov) which are slightly larger than the original Brompton easy wheels. I've mounted them onto the rack on the side closest to the seat post. I haven't measured them, but they're probably around 6-8mm larger in diameter. First impressions are that the larger size means that when I wheelie the opposing sided easy wheels to "steer it" - the suspension block has a bit more angular clearance to prevent it from scraping pointy end on the ground. So that helps a little on the clearance front - not so much on stability.

Bugs

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Graham
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Re: Brompton - ground clearance/stability when rolling in folded state

Postby Graham » 13 Aug 2018, 10:33am

OT : I appear to have removed the rattling wheels and have cut a rubber suspension block in half, placing each half in place of a wheel ( no rack ).

That fixed the rattle :D

I don't think that I found the rolling-whilst-folded of much use, even with the original wheels. ( Obviously, ) It doesn't roll with the rubber bumpers in place of wheels.