Donor bike size conundrum

[Paultr]

Hi
Am trying to decide which donor bike to buy to fit a powered rear hub onto.

Here is my dilemma - I am very weird shape !
Around 3 years ago I had a series of fractures in my back which has left my torso very much shorter. Before this all happened I was just under 6' but am now just over 5' ! This has left me with the same long legs but shorter torso.
Of course I am going to have to try quite a few bikes to find one that might suit (my old road bike just feels like it was built for a giant) but it would be good to hear from anyone who understands bike geometry that could maybe give me some pointers. Is a women's bike an idea - if so, do they make any colours other than raspberry & cream ?

Relevant info; Height 5'1" 155cm Inside leg 30.25" 77cm

Any comments welcomed

 

[Benjahmin]

Try starting with Hybrids (mountain bike/city bike cross) you can always add a stem extender to bring the bars higher, giving a more upright seating position. Try a Dutch style bike with swept back bars, very upright relaxed riding position, less reach to the bars.
There's a company called 'On One' who do some handlebars called,'Mary Bars'. They are slightly raised and swept back, a lot have said on here that they're the most comfortable they've had, mitigating back and wrist troulbes.
Given your back situation I would definitely look at an NCX seat post, mitigates some of the bumps.
Also remember that, generally speaking, the more upright the position the wider saddle is needed.
I'm 5'6", my inside leg 11/2" shorter than you. My conversion is on a Carrera crossfire 3, fitted with stem extender and a Lidl's touring saddle (best saddle I've ever had).
Good luck with your search.

 

[chris_n]

Women's bikes normally have a shorter top tube and stem than men's bikes.

 

[Woosh]

I suggest you look for a bike with a quill type stem and swept back (Dutch style) handlebars which lets you adjust the reach much better.

 

[Paultr]

For the benefit of anyone finding this thread in the future who also has a similar problem to me here is how I solved the conundrum.

I went into one of the large chain bike stores in Liverpool and went over to the women's section. Most of the bikes could be instantly dismissed due to the raspberry & cream (and similar) colour schemes. There was one bike there that looked attractive, had the features that Tony (Woosh) said I would need for conversion and was also black. It was a 'Medium' size and felt OK when I got on it. It seemed to have good equipment so I bought it.

As it turned out it was in the women's section by mistake and now having ridden it I am glad I did not get a women's size because I had forgotten than although my torso has shrunk, my arms haven't of course, so with relatively long legs and arms, this size is the best compromise imo. I am going to get a NCX seat post and the Mary bars as mentioned above.
To say I am excited to have a bike again is an understatement and next week I am ordering the hub motor When I got out of bed this morning I was as stiff as a board and wondered what was going on and then I remembered the hill climb back up to my house on the bike yesterday !
The bike is a Cannondale Quick CX3
https://www.evanscycles.com/cannondale-quick-cx-3-2018-hybrid-bike-EV280391

Tags for search engines:
Osteoporosis : vertebrae : fractures : short torso :

 

[Paultr]

Off topic - one thing I noticed is how much more energy is required to ride this bike compared to my ultra lightweight Peugeot racing bike dating back to the early 70's which has skinny road wheels.

 

[Deleted member 4366]

Off topic - one thing I noticed is how much more energy is required to ride this bike compared to my ultra lightweight Peugeot racing bike dating back to the early 70's which has skinny road wheels.

Quite a lot, but it mainly depend how fast you go. when you're climbing slowly uphill, the main difference will be the weight - probably something like 3kg difference, which would require approximately 3% more pedal effort. On the flat or into the wind, the main difference is the increased drag. At 20mph, the difference could be massive. According to this it's double the power for an mtb compared with a road bike at 20 mph:
http://users.frii.com/katana/biketext.html

 

[anotherkiwi]

Quite a lot, but it mainly depend how fast you go. when you're climbing slowly uphill, the main difference will be the weight - probably something like 3kg difference, which would require approximately 3% more pedal effort. On the flat or into the wind, the main difference is the increased drag. At 20mph, the difference could be massive. According to this it's double the power for an mtb compared with a road bike at 20 mph:
http://users.frii.com/katana/biketext.html

What a great page! You should link it to the thread on back EMF too because it explains the rpm problem with crank drives quite well.

This illustrates the problem I have on my trike: "carrying big gears is actually a waste of your time because you won't generate the power you need, in them" a 13 tooth top gear is much easier for me to pull at higher rpm than the 11 tooth at lower rpm for equal top speed.

 

[Paultr]

Quite a lot, but it mainly depend how fast you go. when you're climbing slowly uphill, the main difference will be the weight - probably something like 3kg difference, which would require approximately 3% more pedal effort. On the flat or into the wind, the main difference is the increased drag. At 20mph, the difference could be massive. According to this it's double the power for an mtb compared with a road bike at 20 mph:
http://users.frii.com/katana/biketext.html

That's very interesting - I realised that air resistance played it's part but never imagined it would be that much. I had put some down to increased weight but mainly thought it was the rolling resistance of the knobbly tyres compared to the smooth road tyres. You live and learn !

 

[anotherkiwi]

 

[grldtnr]

What a great page! You should link it to the thread on back EMF too because it explains the rpm problem with crank drives quite well.

This illustrates the problem I have on my trike: "carrying big gears is actually a waste of your time because you won't generate the power you need, in them" a 13 tooth top gear is much easier for me to pull at higher rpm than the 11 tooth at lower rpm for equal top speed.

You got that trike electrified yet ?

 

[anotherkiwi]

My washing machine needs replaced first For the moment I am enjoying hurting myself on silly steep (for me) climbs un-powered... I asked the LBS guy for a quote for lacing the Mxus into the rear wheel of Number Two and it sounds OK so things may begin to move forward soon.