Brompton lower-pressure tyre

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rmurphy195
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Joined: 20 May 2011, 11:23am
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Brompton lower-pressure tyre

Postby rmurphy195 » 9 Oct 2014, 7:53pm

My fairly new brommie is fitted with Schwalbe Marathon tyres.

I use the bike mainly on trails/towpaths such as the Tissington/High Peak trails, family trails in the forest of dean etc. the surfaces of which can be a bit rough in parts.

With the tyres pumped up to 100psi the ride at the rear is uncomfortable over some of the less-than smooth surfaces, dropping the pressure a tad makes the bike much more comfortable, but it seems very hard work!

Is there a tyre I can put on this bike that will run a bit better at these lower pressures?

(PS I've considerable reduced discomfort by fitting a softer suspension block, and a well-fitted B17 saddle, it's just the rougher surfaces that set up a bit of an uncomfortable vibration)

Thanks for your advice - Richard.
Brompton, Condor Heritage, creaky joints and thinning white (formerly grey) hair
""You know you're getting old when it's easier to ride a bike than to get on and off it" - quote from observant jogger !

sreten
Posts: 347
Joined: 29 Sep 2013, 10:59pm

Re: Brompton lower-pressure tyre

Postby sreten » 12 Oct 2014, 12:25am

Hi,

A bike with 16" wheels is never going to be good on the rough stuff, ever.
Still if you never use it on the road fitting fatter tyres might help.
http://www.sjscycles.co.uk/tyres-16-(305)-dept339_pg1/#page=1&page=1&order=PRICE ASCENDING

Run the front significantly lower pressure than the rear.

rgds, sreten.

AM7
Posts: 297
Joined: 18 Jul 2014, 10:24pm
Location: North West Essex

Re: Brompton lower-pressure tyre

Postby AM7 » 12 Oct 2014, 8:28am

sreten wrote:Hi,

A bike with 16" wheels is never going to be good on the rough stuff, ever.
Still if you never use it on the road fitting fatter tyres might help.
http://www.sjscycles.co.uk/tyres-16-(305)-dept339_pg1/#page=1&page=1&order=PRICE ASCENDING

Run the front significantly lower pressure than the rear.

rgds, sreten.

Unfortunately none of the tyres on that page will fit a Brompton as they're ETRO 305 rather than ETRO 349.

There's not a huge selection of tyres available in the 349 size. I think the widest tyre you can get in this size is the Greenspeed Scorcher at 40mm wide. I've read some reports which say the Brompton rear triangle doesn't have enough clearance for these, while other people appear to have squeezed them in. At £30 a pop, it could be an expensive mistake...

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al_yrpal
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Re: Brompton lower-pressure tyre

Postby al_yrpal » 12 Oct 2014, 9:04am

Wrong sort of bike for those surfaces. If it must be a folder one with large wheels that take MTB tyres would be my choice.

Al
Touring on a bicycle is a great way to explore and appreciate the countryside and towns you pass through. Make a difference...

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MLJ
Posts: 536
Joined: 15 Jan 2007, 11:48am
Location: Rugby

Re: Brompton lower-pressure tyre

Postby MLJ » 12 Oct 2014, 9:13am

Those are the maximum pressures! I use my Brompton on trails like you, and run the tyres on pressures appropriate to my weight, at about 3.25 bar (45) front and 4.25 bar (60) rear, with a bit more when fully laden. Recently I rode along the Camel Trail with the camping gear loaded with no problem, currently on Brompton tyres, although I have also used Marathons on the rear, at similar pressures.

mr_mark_sid
Posts: 78
Joined: 8 Mar 2011, 4:13pm

Re: Brompton lower-pressure tyre

Postby mr_mark_sid » 12 Oct 2014, 6:18pm

the first thing I wold try is a softer suspension bung. They come in three levels of hardness: soft, hard and medium. That will make more difference to the ride of a brompton than the tyre. Tyre squidge is a bigger issue on small wheel tyres so they need to be run at higher pressure to reduce rolling resistance.

rmurphy195
Posts: 1754
Joined: 20 May 2011, 11:23am
Location: South Birmingham

Re: Brompton lower-pressure tyre

Postby rmurphy195 » 13 Oct 2014, 6:51pm

MLJ wrote:Those are the maximum pressures! I use my Brompton on trails like you, and run the tyres on pressures appropriate to my weight, at about 3.25 bar (45) front and 4.25 bar (60) rear, with a bit more when fully laden. Recently I rode along the Camel Trail with the camping gear loaded with no problem, currently on Brompton tyres, although I have also used Marathons on the rear, at similar pressures.


Thanks MLJ, looks as if I already have the right compromise, just need to experiment a tad more with measured pressures to reach an optimum, which might vary from trail to trail.
Brompton, Condor Heritage, creaky joints and thinning white (formerly grey) hair
""You know you're getting old when it's easier to ride a bike than to get on and off it" - quote from observant jogger !

Merry_Wanderer
Posts: 1002
Joined: 31 Aug 2012, 9:33am
Location: North Leicestershire

Re: Brompton lower-pressure tyre

Postby Merry_Wanderer » 14 Oct 2014, 8:20am

I have Marathon tyres in my Brompton and the max pressure stated on the sidewalk is 85psi. The max for the Brompton tyres is 100 or 110 psi from memory. I have used my Brompton on trails in UK and abroad and tend to have tyres at 60 psi or above