full suss to Hardtail = badback?

[lestershaw]

i boughtmyself a nice titanium frame mtb
put the bike together into a nice buld with great forks.
on the morning of my first ride i woke up with a slightly achy back.
i did 12 miles on the new hard tail but by the end my back was in agony.

ive had full suss bikes for years,
so is my bad back just coincidental due to the morning back pain, or something that the hard tail will always do?
i need to know as i can return the frame now, but i will not be able to in the future.

i also know a little bit about bike position and body geometry and standing when on the rough stuff and arms and legas bent etc
any advice would be welcome,
thanks

[Rolls]

Went from a 100mm full sus to a 29er hard tail - first ride I was the same. Turned out the saddle was too low, and my tyre pressure was too high. Changed both, and it made a high difference. It's not a comfy as e full sus, and your back will feel like its getting a workout, but I no longer have problems with mine hurting after a long ride!

[ewenm]

It'll be a setup/geometry change rather than anything inherent to a hardtail. Play around with saddle position and angle and stem height and angle to find a comfortable riding position.

[lestershaw]

Rolls said:

Went from a 100mm full sus to a 29er hard tail - first ride I was the same. Turned out the saddle was too low, and my tyre pressure was too high. Changed both, and it made a high difference. It's not a comfy as e full sus, and your back will feel like its getting a workout, but I no longer have problems with mine hurting after a long ride!

my tyres were soft to start with, but felt like they were rolling on the bends so i pumped them up to 35 psi, my saddle is set so balls of the feet sit on the cleats slightly bent, and i run a short stem so im not overreaching.
thing is because its an expensive frame, i will lose too much if i keep it and find out it is giving me a problem. i suppose i should send frame back and persevere with a cheaper hard tail and then buy the other frame for a second time if all is ok?

[lestershaw]

ewenm said:

It'll be a setup/geometry change rather than anything inherent to a hardtail. Play around with saddle position and angle and stem height and angle to find a comfortable riding position.

hey Ewen, ive tried to re create the same set up/ geometry from the bike i already ride.
i meaured from seat to stem, and from seat to bottom bracket and to the pedals. its more or less identical.
im trying to convince myself its ok, but it might be an expensive lesson

[ewenm]

lestershaw said:

hey Ewen, ive tried to re create the same set up/ geometry from the bike i already ride.
i meaured from seat to stem, and from seat to bottom bracket and to the pedals. its more or less identical.
im trying to convince myself its ok, but it might be an expensive lesson

Remember that the geometry of a full-sus changes a bit when you sit on it. Can you get someone else to re-measure your position while you're sat on the FS? You could invest in a bike fit session but that is more expense of course.

[d8mok]

I'd be surprised if e frame could be sent back once its been built up and ridden? Unless it has a fault obviously.

[shouldbworking]

Daft question, but are still sitting down through bumpy stuff that you would have remained seated for on the full sus?

[lestershaw]

d8mok said:

I'd be surprised if e frame could be sent back once its been built up and ridden? Unless it has a fault obviously.

im more surprised somebody would not believe me if i said that i could!
ive been offered a refund if the bike is un marked, or credit note if it is lightly marked.
there are no marks!!

[lestershaw]

shouldbworking said:

Daft question, but are still sitting down through bumpy stuff that you would have remained seated for on the full sus?

Only some of the flat sections, i am out of my seat on the climbs and on the descents, but if i have to be out of my seat on the flat sections i could get a thudbuster in stead ?
Les

[c7xlg]

Ewen,
the geometry of the 'cockpit' shouldn't change when the suspension compresses. The pedal to saddle length doesn't change as the suspension moves. BB height to the ground does (and is why my Spec Enduro is a ste bike as the BB is too low when the rear suspension compresses.The head angle will also change, but the lengths and angles from saddle to handlebars will remain static.

(assuming solid seat post and stem...).

N.

ps hello!! hope u, K and E are doing well...

[Gooby]

It isn't the saddle height, it is saddle angle, especially if it is lower back pain.

[ewenm]

c7xlg said:

Ewen,
the geometry of the 'cockpit' shouldn't change when the suspension compresses. The pedal to saddle length doesn't change as the suspension moves. BB height to the ground does (and is why my Spec Enduro is a ste bike as the BB is too low when the rear suspension compresses.The head angle will also change, but the lengths and angles from saddle to handlebars will remain static.

(assuming solid seat post and stem...).

N.

ps hello!! hope u, K and E are doing well...

True, although saddle angle and relative heights saddle to stem will change if the rear suspension compresses more than the front. Not by much of course.

All well here, hope you N and O are all good too.
E.

[lestershaw]

Gooby said:

It isn't the saddle height, it is saddle angle, especially if it is lower back pain.

i have the saddle dead level?

[WarrenG]

c7xlg said:

Ewen,
the geometry of the 'cockpit' shouldn't change when the suspension compresses. The pedal to saddle length doesn't change as the suspension moves. BB height to the ground does (and is why my Spec Enduro is a ste bike as the BB is too low when the rear suspension compresses.The head angle will also change, but the lengths and angles from saddle to handlebars will remain static.

(assuming solid seat post and stem...).

N.

ps hello!! hope u, K and E are doing well...

depends if the full suss is Unified rear triangle (usually cross-country) or swing-arm (downhill) design. both of course will still be affected by the front fork compression on the relative steerer-tube angles relative to things like KOP and trail. URT is the most difficult because the saddle height to BB keeps changing.

[Jimbo.]

You woke up with a bad back.
You went riding.
You made your back worse.

The (lack of) rear suspension had nothing to do with it.

[d8mok]

lestershaw said:

im more surprised somebody would not believe me if i said that i could!
ive been offered a refund if the bike is un marked, or credit note if it is lightly marked.
there are no marks!!

Calm down dear! I never said you couldn't for sure I just was surprised as from my experience once you've built the bike , shops can't really sell it as a new bike as strictly its not new now. I purchased a frame ages ago, and it was too big and even though I'd only fitted the bb and headset I couldn't get a refund as to anyone looking to buy it would see its been built.

I had something similiar today , I purchased a new car the other day, and this morning I woke with a Poorly toe . Drove the 12 miles to work for the first time and the toe got worse. Hoping to get a full refund on the car tomorrow as this poorly toe never was this bad with my last car.

Ps . That was complete rubbish but maybe you see my point that its very reasonable for the shop to do a full refund.

[Gren]

Jimbo. said:

You woke up with a bad back.
You went riding.
You made your back worse.

The (lack of) rear suspension had nothing to do with it.

Sounds right to me. My FS is no kinder on my back (slipped a disc a couple of years back so I watch it like a hawk) than my ht.

[lestershaw]

Gren said:

Sounds right to me. My FS is no kinder on my back (slipped a disc a couple of years back so I watch it like a hawk) than my ht.

I am hoping you and jumbo are right and I am going to keep the hard tail for a while longer I should still get a good price if I choose to sell the frame at a later date !
Thanks guys

[lestershaw]

d8mok said:

Calm down dear! I never said you couldn't for sure I just was surprised as from my experience once you've built the bike , shops can't really sell it as a new bike as strictly its not new now. I purchased a frame ages ago, and it was too big and even though I'd only fitted the bb and headset I couldn't get a refund as to anyone looking to buy it would see its been built.

I had something similiar today , I purchased a new car the other day, and this morning I woke with a Poorly toe . Drove the 12 miles to work for the first time and the toe got worse. Hoping to get a full refund on the car tomorrow as this poorly toe never was this bad with my last car.

Ps . That was complete rubbish but maybe you see my point that its very reasonable for the shop to do a full refund.

Of course I see your point but that's not how it is, I am not [e-mail] allowed to send the bike back because I have a bad back. I'm allowed to send it back as they have a 28 day return policy.
The reason why I can send it back even though it has been built is that I used their headset installation facility which means they put the headset on for me so in essence it arrived as a used bike and it would be slightly marked anyway where the headset was fitted.
Doesn't matter now as I'm keeping it :-)

Edited by lestershaw on Wednesday 14th August 22:02