28mm tyres with DA9000 brakes
Mr.Mouse
Posts: 68
so, i know the callipers are rated to 25mm clearance, and, i know there is plenty clearance on the frame i am using for 28mm tyres.
i bought some vittoria corsa 28mm tyres for my Reynolds Assault wheels 'before' it occurred to me to check if the callipers were designed to handle that size. Shimano says they aren't ( as i now know, qualified above in my opener ). whilst i obviously won't be using these wheels day in, day out over the summer, i do like taking them out on longer rides, weekends away, special days etc.
now, with the tyres pumped to about 100, i reckon overall clearance through the calliper is about 4mm, with the pivot bolts obviously smaller, can still wiggle a matchstick without any contact, so, 2/3 mm or so..
i guess the two factors are debris, and flex on the wheels that might cause issues ( and why the callipers aren't rated for this type of tyre even though they clearly fit without any sign of obstruction ) oh and i guess low pressure tyre malformation also. Believe it or not, from what you all have probably heard, it is a lie that i am the 'Cav of Sussex' and i am not going to be mashing the rims, especially on this bike..
does this scenario sound fine, or are there any considerations i am not taking into account?
many thanks
i bought some vittoria corsa 28mm tyres for my Reynolds Assault wheels 'before' it occurred to me to check if the callipers were designed to handle that size. Shimano says they aren't ( as i now know, qualified above in my opener ). whilst i obviously won't be using these wheels day in, day out over the summer, i do like taking them out on longer rides, weekends away, special days etc.
now, with the tyres pumped to about 100, i reckon overall clearance through the calliper is about 4mm, with the pivot bolts obviously smaller, can still wiggle a matchstick without any contact, so, 2/3 mm or so..
i guess the two factors are debris, and flex on the wheels that might cause issues ( and why the callipers aren't rated for this type of tyre even though they clearly fit without any sign of obstruction ) oh and i guess low pressure tyre malformation also. Believe it or not, from what you all have probably heard, it is a lie that i am the 'Cav of Sussex' and i am not going to be mashing the rims, especially on this bike..
does this scenario sound fine, or are there any considerations i am not taking into account?
many thanks
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Comments
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On a quick internet search, it seems 3mm clearance is the minimum quoted for safety so it looks like you are borderline. I’ve got approx 5mm clearance under my front brake and wouldn’t want to go lower. I’ve had issues with gravel getting wedged in the gap on newly tarred roads. Only a matchstick clearance could mean a risk of your front wheel locking up.0
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Thank you, for taking time to read my post and respond to me, i really appreciate it.
and i agree, its borderline, and i guess just thinking the bigger the tyre, the more it will deform, due to lower pressures, and whilst it looks fine on the bike stand it might be a different scenario when out on the road... they are nice wheels though, and the tyres are nice also. first world problems!
a new set of DA 9100 callipers aren't cheap though. and i'm a skinflint, so i guess i just wanted someone to tell me it would all be hunky dory!0 -
sorry, just to be clear, front was pretty much 5mm, it was the back i was concerned about.
ta0 -
You’re going to die. But the unintentional tyre lock up followed by tyre explosion will be awesome to watch.0
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thanks for that. i thought you would pipe up with something unhelpful and mildly insulting, as per usual. Walt.0
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Mr.Mouse wrote:thanks for that. i thought you would pipe up with something unhelpful and mildly insulting, as per usual. Walt.
Thats the risk you are taking though. But probably quite not the death bit.I'm sorry you don't believe in miracles0 -
100psi in 28mm tyres?0
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Ultegra R8000 (or even 105 R7000) callipers will give better braking than your DA9000 ones and fit the tyres better. You just need to get over the slight weight gain and logo mismatch.
You'd get your money back and likely even make a small profit by selling on the DA9000 brakes.
Function >> style......FFS! Harden up and grow a pair
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Regardless of what happens down at the contact patch with the road, unless damaged, the tyres aren't going to be deforming as they pass through the caliper.
Road debris is more likely to be carried up on the tread of the tyre than the sidewall, but having said that I got some nasty scrapes on the insides of the chainstays of my CR1 when I tried a 25mm Pro4 SC, so it can happen. And I had more than 3mm clearance... (Now run a 25 front / 23 rear)
Do you really need 100psi in a 28mm tyre?0 -
SloppySchleckonds wrote:Mr.Mouse wrote:thanks for that. i thought you would pipe up with something unhelpful and mildly insulting, as per usual. Walt.
Thats the risk you are taking though. But probably quite not the death bit.
Theres always hope.0 -
9000 brakes that I use work really well with 25mm tyres from the following manufacturers.
Pirelli
Vittoria (corsa G+ and the old pave's)
Conti (23 and 25 work fine
I tried 28s by conti and they wouldn't work at 70 PSI. was getting rub.
not tried any other brands.
as for 9000's braking ability, they are pretty much some of the best brakes you can get on a road bike (in terms of calipers), if set up correctly.0 -
philbar72 wrote:as for 9000's braking ability, they are pretty much some of the best brakes you can get on a road bike (in terms of calipers), if set up correctly.
I'd have agreed with this until my latest 2 bikes - one with DA 9100, the other U 8000. The re-design to accommodate larger tyres in the latest series components also beefed up the arms and the resulting increase in stiffness has given them more bite and feel.FFS! Harden up and grow a pair0 -
Svetty wrote:philbar72 wrote:as for 9000's braking ability, they are pretty much some of the best brakes you can get on a road bike (in terms of calipers), if set up correctly.
I'd have agreed with this until my latest 2 bikes - one with DA 9100, the other U 8000. The re-design to accommodate larger tyres in the latest series components also beefed up the arms and the resulting increase in stiffness has given them more bite and feel.
Well the DA9000 brakes are awesome, if the u8000 are somehow better then I really don’t see the need for disc brakes on a road bike. There is hope yet
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only pumped them to 100 just to get a good idea of the clearance against the calipers. wouldn't run them that high, that's why i mentioned it, sorry of i was a bit woolly on that.
i think its a bit risky, so i will change out the brakes, i did think about going ultegra for cost but have found some 9100's on the bay for an acceptable price, so its now a moot point. the 9000's can go on the BMX!!
i think primarily my concern was just around what is a 'safe' clearance, and i think it probably wasn't.
Sorry for calling you a Walt Alejandro, but you are going to wind people up if you post that type of trash. i'm sure it was in jest and not intentionally rude. all good...0 -
although i guess at lower pressure would have given a better idea of how they would work with the callipers. anyhoo, my bad.0
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Alejandrosdog wrote:SloppySchleckonds wrote:Mr.Mouse wrote:thanks for that. i thought you would pipe up with something unhelpful and mildly insulting, as per usual. Walt.
Thats the risk you are taking though. But probably quite not the death bit.
Theres always hope.
really? 'sigh'... and there's me saying you might actually be alright. my bad. again0 -
Svetty wrote:philbar72 wrote:as for 9000's braking ability, they are pretty much some of the best brakes you can get on a road bike (in terms of calipers), if set up correctly.
I'd have agreed with this until my latest 2 bikes - one with DA 9100, the other U 8000. The re-design to accommodate larger tyres in the latest series components also beefed up the arms and the resulting increase in stiffness has given them more bite and feel.
got 9100 direct mount on the nice bike. I see what you are saying, they are very very good. as opposed to just really very good on 9000s. either way they get the job done!0 -
Mr.Mouse wrote:Alejandrosdog wrote:SloppySchleckonds wrote:Mr.Mouse wrote:thanks for that. i thought you would pipe up with something unhelpful and mildly insulting, as per usual. Walt.
Thats the risk you are taking though. But probably quite not the death bit.
Theres always hope.
really? 'sigh'... and there's me saying you might actually be alright. my bad. again
Listen in, youve asked for advice, it's been given with a bit of hunmour that you dont get. Thats no need for the faux mincing im so clever responses youre giving. I couldn't care less wether you think I'm alright or not. That you think i might is testament to your own completely distorted view of your own value.
Use them if youre comfortable dont if youre not. It really makes no odds to anyone else and if you really do need the comfort and support of strangers on the internet o decide if youre comfortable then your problems run deeper than tyre size.0 -
Alejandrosdog wrote:Mr.Mouse wrote:Alejandrosdog wrote:SloppySchleckonds wrote:Mr.Mouse wrote:thanks for that. i thought you would pipe up with something unhelpful and mildly insulting, as per usual. Walt.
Thats the risk you are taking though. But probably quite not the death bit.
Theres always hope.
really? 'sigh'... and there's me saying you might actually be alright. my bad. again
Listen in, youve asked for advice, it's been given with a bit of hunmour that you dont get. Thats no need for the faux mincing im so clever responses youre giving. I couldn't care less wether you think I'm alright or not. That you think i might is testament to your own completely distorted view of your own value.
Use them if youre comfortable dont if youre not. It really makes no odds to anyone else and if you really do need the comfort and support of strangers on the internet o decide if youre comfortable then your problems run deeper than tyre size.
You are a grade A tw*t. Just sayin' like0 -
wow. saying it would be hilarious if i had an accident is both advice, and humour? yes, i asked for advice, thanks for not giving any of value.
and i'm sure you don't really care if people thing you are alright or not, you'd have probably done something about it if you did, by now.
I was actually asking a genuine question, i was unsure as to whether it would be safe or not, thats why i asked it. surely thats the point of this part of the forum, to ask questions? if 'the comfort and support' of strangers ( not what i was asking for ) is an alien concept when asking for some advice from strangers then what exactly is the point of having a forum? apart from unhelpful tools trying to be funny.
thanks for anyone that was actually trying to be helpful, doubt i'll bother again though.. happy trails0 -
and, in the spirit of derailing a thread, i completely forgot to say that i installed the 9100 callipers, only with my CERO AR30's running with GP4k 25mm at this point, and i totally get what Svetty has mentioned early in the thread, the new generation Shimano callipers feel a lot different, and somehow more 'authoritative', and definitely more grip ( i know that probably sounds like nonsense )
superlatives aside, and regardless of the need to run larger tyres, which was my initial concern, they do actually feel like a legitimate upgrade anyway.0 -
johnnymcg259 wrote:
You are a grade A tw*t. Just sayin' like
Yes sometimes I am. Your second faux throwaway confirms you probably don’t have the backbone or strength of personality to be anything other than colourless and banal. But don’t worry, on average people are average and you’re in good company.0 -
Alejandrosdog wrote:johnnymcg259 wrote:
You are a grade A tw*t. Just sayin' like
Yes sometimes I am. Your second faux throwaway confirms you probably don’t have the backbone or strength of personality to be anything other than colourless and banal. But don’t worry, on average people are average and you’re in good company.
Oh God....please ....please just shut up.0 -
well block me and stop being histrionic.johnnymcg259 wrote:Alejandrosdog wrote:johnnymcg259 wrote:
You are a grade A tw*t. Just sayin' like
Yes sometimes I am. Your second faux throwaway confirms you probably don’t have the backbone or strength of personality to be anything other than colourless and banal. But don’t worry, on average people are average and you’re in good company.
Oh God....please ....please just shut up.0
