Joseph Kuosac Suspension Block for Bromptons - Super Firm - Black

Customer Reviews (7)
4.9 / 5| Write your review
£19.99 Please note this product has selling restrictions to your country. was
Manufacturer : 
SJS Cycles part number : 
Manufacturer part number : 
Super firm! - harder than Bromptons Firm suspension block.

Gives a very precise and firm ride feel, great for putting the power down.
This is designed to be stiff and will not absorb shock like the Brompton Firm or Standard blocks.

Block only, does not include bolt or nut. - These can be used from existing suspension.

Weight 47g
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Product Reviews (7)
Questions & Answers (4) Q & A
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Product Reviews (7)
Overall Product Rating 4.9 / 5
Definitely firmer than the standard Brompton Block
By Matt Wood
07 Mar 2023
5 / 5
I recommend this product
If you want a more positive and less spongey ride on your Brompton then I would recommend this suspension block. Easy to install and relatively cheap when you compare with the other different designs out there.
Great upgrade
By Anonymous
15 Sep 2022
5 / 5
I recommend this product
Really good value for money and a great upgrade, much firmer than standard.

No more Brompton Bob
Bit expensive but does great job for larger Brompton riders
By Rob Cope
27 May 2022
4 / 5
I recommend this product
ConsMaybe a little pricey, but still cheaper than other similar solutions.
ProsDoes as it says on the tin (or bag)
It's just an extra firm block for the Brompton. Take the old block off, -carefully, retaining ALL parts! Reassemble, using all the parts in same order in or around the new block. In particular, make sure all washers are in right place & right way round. Put a smear of lithium grease inside the block on the bolt. Go ride, enjoy much stiffer ride and return of Brompton's proper suspension feel.

Well made, fits perfectly, looks set to last a long time.
Great Upgrade!
By Mike
07 Sep 2021
5 / 5
I recommend this product
Stops the annoying "Brompton Bob".
Should be standard
By Roger
22 Jun 2021
5 / 5
I recommend this product
ConsA bit pricey for a block of polyurethane (or whatever it is)
ProsTransforms the bike
The Brompton firm block isn't much less squishy than their standard one. This JK block is almost totally rigid and eliminates bobbing when pedalling. Expensive for what it is, but worth it for the results. My only concern would be that the total lack of movement at the rear hinge could speed up bush wear as the grease in the bush "dimples" will not be spread around during riding. I suppose grease is redistributed every time the bike is folded or parked.
Useful improvement
By Matt
06 Oct 2020
5 / 5
I recommend this product
Prossimple swap. slight improvement
Easy to install with a 10mm spanner. Difference to the current (2020) Brompton damper isn't vast, but this 80kg rider noticed a stiffer ride and more power transfer. No real difference in vibration, etc (but then I do have a TI seat post.
Fantastic Rear Damper
By Peter
12 Nov 2019
5 / 5
I recommend this product
Having tried multiple rear "shocks" for my Brompton, I was a bit dismayed that I would always have a disheartening bob during pedaling...

The Kuosac damper is the only solution I have found that actually provides a small amount of damping but prevents the annoying pedal-bob.

It's not sexy, but its not expensive and it works a treat.

For reference I weigh 70kg and would consider myself a smooth pedaler with an average cadence of 90rpm.
Questions & Answers (4)
For a heavier rider
27 Mar 2021
Would you recommend this or the Matumura Kohki Scrowave Suspension Spring block for a rider around 100kg?
This is personal preference, both would be a good upgrade, these are slightly stiffer.

How does this compare with the standard block?
01 Sep 2020
Since Brompton added a standard suspension block last year, replacing the soft/firm options, does this feel noticeably different? Is it similar to the CHPT3 block for example?
This is far stiffer than the Brompton OE block. This makes the bike feel like a fast stiff road bike.

Thanks - 01/09/20
is this better than the atumura Kohki Scrowave Suspension Spring
21 Aug 2020
What is the difference between the two please?
Thank you
This is a rubber block, the other is a spring - the Kohki will offer a slightly more active suspension. Both are very good.

Thanks - 21/08/20
Will it make a difference?
17 Aug 2020
Hi there

I have a 9 year old Brompton M3L. The original standard suspension is too soft for me - but I am not sure whether that is because of deterioration over time, or because of the standard setting. It does become very noticeably wobbly especially when pedalling at high cadence in 3rd gear.

What would be your recommendation: Should I just try installing the new Brompton standard suspension (which I understand to be firmer than the old one) or should I just go straight for this Joseph Kuosac one? I weigh 96 kilos


We would suggest this or SJS Cycles part number : 51768

Thanks - 17/08/20