Rose Bikes Jumbo Jimbo Tandem MK1
November 11th, 2016
By Andrew Dodd in Bikes,Tech
Rose Bikes Jumbo Jimbo Tandem MK1 Prototype
Most the mountain bikers we know that have been involved in the sport since the beginning are far from normal – and Finlay Paton of Rose Bikes UK is one of those folk.
Fin’s work shop. Crammed with lots of things most would find useless – but to a tinkerer it’s the perfect place to assemble crazy bikes. For the record, he stores all his bikes and kit in a secure lock up elsewhere.
Having worked in many aspects of the bike scene from the beginning, and been a major car tinkerer (check out his VW T25 Transporter conversion with a Suburu Imprezza engine right here – it’s bonkers), Fin’s also a dab hand with a brazing torch.
So when left with two paint damaged Uncle Jimbo frames and another transit damaged frame, there was only one thing he could do with them – make a full suspension tandem that he calls the Rose Bikes Jumbo Jimbo!
Re-Cycling
With the help from expert welder Ben Hampton of Mr H Fabrications (who makes the coolest beer keg BBQ/Fire pits ever) Fin got to work cutting and shutting!
Bikes like the Rose Bikes Jumbo Jimbo are supposed to be made by mad tinkerers like Fin. Long live home made projects!
The three frames Fin used to butcher and make the Rose Bikes Jumbo Jimbo are current models of Rose Uncle Jimbo; but with defects. Two were heavily scratched from life as demo bikes, and the other had a damaged rear end from transit – and all three were different sizes!
The back end of the Rose Bikes Jumbo Jimbo is a medium frame; the front end a size large and the downtube sections in the middle from the damaged size XL. Now that’s proper re-cycling!
The Rose Bikes Jumbo Jimbo Mark 1. Straight out the workshop before it’s maiden voyage. A project like this needs to be refined as it was using existing frame parts – though the shape looks pretty good to us (except for the scary looking camel hump top tube out back)
The end result is this beast – front top tube is 585mm; rear is 705mm but measured from bar position works out about 565mm. It has a 66degree head angle; 1850mm wheelbase and a 43lb total weight with pedals.
When it came to speccing the bike, Fin pulled the fork, shock and wheels off his current bike but raided his spares boxes to get the rest of the kit together. Gearing needs to be tweaked, and he might fit a BMX/single speed chain to get rid of some of the stretch that can be felt when pedalling.
The BB shells on the Rose Bikes Jumbo Jimbo allow for eccentric bottom brackets. Currently the front BB is eccentric though it might end up moving to the rear.
Yep, XTR transmission. Two sets of cranks; a rear mech and shifter and Hope jockey wheels. All from the spares box..!
OK, so it might not be the prettiest thing on the scene, but it’s a home made work of art!
Rose Bikes Jumbo Jimbo Progression
Now that Fin has the bike up and running, it’s time to iron out niggles and get the thing performing properly. The rear BB is a little low currently – and the Fox rear shock as stock can’t cope. Fin is looking at coil options, revising the shock position out back and will be raising the BB and fitting 170mm cranks and low profile pedals for the stoker.
It’s an exciting project – and we reckon might start a craze of people making DIY bikes at home.
If you have anything planned – let us know! We’d love to see what you have tucked up your sleeve…
Oh, here’s a clip from the first ride – Fin took it out for a night ride!
The Rose Bikes Jumbo Jimbo pre-Thursday night ride. It still lives – and so do the pilots!
What do you think of the Rose Bikes Jumbo Jimbo?
Let us know in the comments below!
