Full Suspension converted mountain bike

[Rod Fuller]

The above has been converted with a powerful front hub motor by the previous owner.
The hub is heavy so the front suspension has no movement, can stronger springs be fitted?
The rear luggage rack is not strong enough to support the heavy battery. Is it possible to purchase a rear luggage rack which is strong enough to take the weight of the battery and allow suspension movement?

The roads and paths in around Farnborough are in a dreadful state including damage on paths by tree roots, I consider it to essential to have full working suspension.

Rod Fuller

 

[flecc]

Could you let us know the make and model of bike Rod, and if it's not a well known model, perhaps a photograph of it?

That will help members to give suitable advice.
.

 

[Rod Fuller]

Could you let us know the make and model of bike Rod, and if it's not a well known model, perhaps a photograph of it?

That will help members to give suitable advice.
.

It's a Dunlop signature series, photo enclosed

 

[RobF]

I'm guessing you don't have a photo of the front, which would be more helpful.

Dunlop bikes, sadly, are cheap and nasty.

The conversion looks to be a lash up.

All in all, a dreadful contraption which you should avoid.

 

[flecc]

Thanks Rod, I'm attaching a photo of that bike model "unclothed" to help other members. It's a difficult one to add a battery to. I've never owned a rear suspension bike so know little about the suitable rear carriers, but many other members do have that knowledge. I think few are present at the moment, probably out riding, but I'm sure they will be in later with some advice.

N.B. Crossed with Rob's post.
.

 

[Rod Fuller]

I'm guessing you don't have a photo of the front, which would be more helpful.

Dunlop bikes, sadly, are cheap and nasty.

The conversion looks to be a lash up.

All in all, a dreadful contraption which you should avoid.

Cannot avoid it, as I have it and wish to improve it!

 

[Rod Fuller]

Cannot avoid it, as I have it and wish to improve it!

(for previous unhelpful message)

 

[Rod Fuller]

Flecc, thank you. There are machines with rear suspension and luggage racks,which are allowed to move with the suspension, just that the one on my machine is not rigid or strong enough.
Regarding the front suspension, I assume that the weight of the hub motor does not allow movement. Surely this can be overcome by fitting addtional or stronger springs.

 

[RobF]

Flecc, thank you. There are machines with rear suspension and luggage racks,which are allowed to move with the suspension, just that the one on my machine is not rigid or strong enough.

The props of the luggage rack are lashed to the seat stays with hose clips.

The stays move, so the seat post fixing part of the rack is simply resting on the seat post clamp, in the hope it will move forwards and backwards with the suspension.

In no way is that anything other than a nasty bodge, so the carrier needs to come off, and one installed properly.

A point to consider is the seat stay is not designed to take a downward force.

A seat post clamp only carrier should work.

They are designed to carry up to 10kg, so you could use a large-ish battery and still have spare capacity for a flask and sandwiches.

The hub motor should not unduly effect the suspension fork.

The motor weight is on the hub, so it certainly does not compress the fork.

It's more likely the fork is faulty, cheap ones - and even some dearer ones - can seize.

 

[flecc]

I agree with Rob on the forks, the motor won't affect the way the forks work in the manner you describe. It's high unsprung weight could cause less controlled bounce when coupled with a soft fork action but won't stiffen hard acting forks.

It's likely your forks are seizing, a very common problem on bike suspension forks, especially the cheaper ones.

It's either new forks, or since I'm guessing you mainly ride on-road, a "suspension" tyre can be very effective.

The Schwalbe Big Apple tyre is very effective in this respect.

Alternatively the Schwalbe Fat Frank offers similar and comes in three colourways.

Decent seatpost rear racks can be quite expensive, sometimes outrageously so, here's a selection:

http://www.sjscycles.uk/topeak-topeak-beam-rack-ex-seatpost-mounting-rear-rack-prod16090/

.co.uk/topeak-topeak-beam-rack-ex-seatpost-mounting-rear-rack-prod16090/

http://www.sjscycles.co.uk/pletscher-orion-seat-post-fitting-rear-rack-with-mudguard-prod25435/

http://www.sjscycles.co.uk/blackburn-blackburn-central-seat-post-rear-rack-prod33051/

This next one mounts unsprung but will be very strong:

http://www.sjscycles.co.uk/thule-pack-n-pedal-tour-rack-prod31958/
.
.

 

[D C]

Be very wary of using an unsupported seat post rack. Even with an extra long seat post my aluminium frame cracked at the front top seat tube weld with just a 4 kilo battery.
It's going to be very difficult to fit your battery on a rear rack with the suspension you have though I think someone has posted last year about a rack available which attaches to just the seat stays.
I know you say you need to use that bike but I would think long and hard before riding it like that.

Dave.

 

[RobF]

I think someone has posted last year about a rack available which attaches to just the seat stays.

This Thule rack will fit on chain stays or on the front forks:

http://www.thule.com/en/gb/products/luggage-and-bags/bike-bags-and-racks/racks/thule-pack-n-pedal-sport-rack-_-pp_100015


EDIT: I see flecc included it in his list when he added to his post above.

 

[flecc]

Since a number of battery cases are only around three inches wide, depending on how high your saddle is, you could fabricate fastenings and mount a battery in the position I've marked with a blue rectangle on the below photo:

 

[Rod Fuller]

I agree with Rob on the forks, the motor won't affect the way the forks work in the manner you describe. It's high unsprung weight could cause less controlled bounce when coupled with a soft fork action but won't stiffen hard acting forks.

It's likely your forks are seizing, a very common problem on bike suspension forks, especially the cheaper ones.

It's either new forks, or since I'm guessing you mainly ride on-road, a "suspension" tyre can be very effective.

The Schwalbe Big Apple tyre is very effective in this respect.

Alternatively the Schwalbe Fat Frank offers similar and comes in three colourways.

Decent seatpost rear racks can be quite expensive, sometimes outrageously so, here's a selection:

http://www.sjscycles.uk/topeak-topeak-beam-rack-ex-seatpost-mounting-rear-rack-prod16090/

.co.uk/topeak-topeak-beam-rack-ex-seatpost-mounting-rear-rack-prod16090/

http://www.sjscycles.co.uk/pletscher-orion-seat-post-fitting-rear-rack-with-mudguard-prod25435/

http://www.sjscycles.co.uk/blackburn-blackburn-central-seat-post-rear-rack-prod33051/

This next one mounts unsprung but will be very strong:

http://www.sjscycles.co.uk/thule-pack-n-pedal-tour-rack-prod31958/
.
.

 

[Rod Fuller]

Thank you all for your advice. I have been thinking of taking the electric bits off the Dunlop and fitting them into a Powabike, strong frame, good big tyres and everything should fit into the available space in the frame which could be a waterproof as well as a lockable compartment. Result not exactly a stealth bomber, but something resembling my old James autobike back in 1958.