Another small modification that I wanted to change on the United Trifold was the suspension block. The stock suspension block is actually very hard, almost like a solid plastic block. It is not like the stock Brompton rubber block which is a bit soft for some dampening effect. Therefore, when riding over bumpy areas, there is basically no suspension feel at all.
From the point of view of pedaling efficiency, a harder suspension block is better as there is no pedal bob during pedaling, which will happen if the rear suspension is too soft. This happened on the Flamingo London folding bike, which I rode almost 10 years ago.
A soft suspension is good for comfort but not suitable for pedaling hard, while a hard suspension is good for pedaling efficiency but not for comfort. The ideal case is to choose a suitable suspension hardness that matches your body weight and bike usage.
Stock suspension block. Looks like a soft rubber block, but it is actually just a solid plastic block!
The United Trifold cannot use Brompton suspension blocks, as the mounting design is different. This has been tested by others. Therefore, a special suspension block designed for the United Trifold is needed.
I came across a suspension block that is specially designed for the United Trifold on Shopee, and it is from Indonesia. This is not surprising as United is a large Indonesian bike OEM that assembles many many bikes.
Aluminium caps at both ends of the coil spring, plus the attachment at the end for matching the rear triangle locking mechanism.
Looks to be compatible!
Side by side comparison. Steel coil spring vs solid plastic block...
The stock suspension block is oval in shape, and has a protrusion which locks into a hole on the frame to prevent it from rotating. Not necessary though.
Stock suspension block is 49 grams.
New suspension block is heavier at 70 grams, due to the metal coil spring.
New suspension is compatible with the United Trifold frame.
No issue with the rear suspension latch. Looks good!
This coil spring suspension works well, as it can absorb bumps quite effectively, as tested on the unpaved section of the Green Corridor. Way better than the stock plastic block. During hard pedaling (>150 watts), I can feel a slight bobbing effect, but it is still acceptable, considering that it adds quite a bit of comfort on bumpy ground. The spring is stiff enough that casual pedaling (<150 watts) does not cause any noticeable pedal bob.
I am happy with this suspension upgrade, as there is a noticeable improvement in riding comfort. As a casual bike, comfort is more important than absolute pedaling efficiency. Added bonus is that it looks good on the bike.
Hello, it’s me again. Upon impact it will cost the spring to compress, the screw shaft will protrude out on the nut side exposing the thread? It’ll make some sound?
ReplyDeleteIt's designed to compress, same as Brompton design. Should be OK, I don't hear any sound.
ReplyDeletehi Steve, I bought the same suspension from shopee (indonesian seller).
ReplyDeleteBut I can't install it as the new suspension is slightly longer than the stock.
do you need to compress the new spring when installing the new spring?
I had no issue, just need to use the bolt and nut to fix it.
DeleteHi Steve, nice post and thanks for sharing. Can you send me a link for me to buy this suspension block from the Shopee Indonesia seller?
ReplyDeleteUnfortunately the product is no longer available so I can't share the link.
Delete